Cleanup submit bh patchv4 #1

riteshharjani · 2022-08-17T09:55:59Z

No description provided.

submit_bh always returns 0. This patch cleans up 2 of it's caller in jbd2 to drop submit_bh's useless return value. Once all submit_bh callers are cleaned up, we can make it's return type as void. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

…or_read submit_bh always returns 0. This patch drops the useless return value of submit_bh from ntfs_submit_bh_for_read(). Once all of submit_bh callers are cleaned up, we can make it's return type as void. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Ritesh Harjani <ritesh.list@gmail.com>

submit_bh always returns 0. This patch drops the useless return value of submit_bh from __sync_dirty_buffer(). Once all of submit_bh callers are cleaned up, we can make it's return type as void. Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

submit_bh/submit_bh_wbc are non-blocking functions which just submit the bio and return. The caller of submit_bh/submit_bh_wbc needs to wait on buffer till I/O completion and then check buffer head's b_state field to know if there was any I/O error. Hence there is no need for these functions to have any return type. Even now they always returns 0. Hence drop the return value and make their return type as void to avoid any confusion. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

Fix possible NULL pointer dereference, due to freeing of adapter->vf_res in iavf_init_get_resources. Previous commit introduced a regression, where receiving IAVF_ERR_ADMIN_QUEUE_NO_WORK from iavf_get_vf_config would free adapter->vf_res. However, netdev is still registered, so ethtool_ops can be called. Calling iavf_get_link_ksettings with no vf_res, will result with: [ 9385.242676] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 9385.242683] #PF: supervisor read access in kernel mode [ 9385.242686] #PF: error_code(0x0000) - not-present page [ 9385.242690] PGD 0 P4D 0 [ 9385.242696] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [ 9385.242701] CPU: 6 PID: 3217 Comm: pmdalinux Kdump: loaded Tainted: G S E 5.18.0-04958-ga54ce3703613-dirty #1 [ 9385.242708] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.11.0 11/02/2019 [ 9385.242710] RIP: 0010:iavf_get_link_ksettings+0x29/0xd0 [iavf] [ 9385.242745] Code: 00 0f 1f 44 00 00 b8 01 ef ff ff 48 c7 46 30 00 00 00 00 48 c7 46 38 00 00 00 00 c6 46 0b 00 66 89 46 08 48 8b 87 68 0e 00 00 <f6> 40 08 80 75 50 8b 87 5c 0e 00 00 83 f8 08 74 7a 76 1d 83 f8 20 [ 9385.242749] RSP: 0018:ffffc0560ec7fbd0 EFLAGS: 00010246 [ 9385.242755] RAX: 0000000000000000 RBX: ffffc0560ec7fc08 RCX: 0000000000000000 [ 9385.242759] RDX: ffffffffc0ad4550 RSI: ffffc0560ec7fc08 RDI: ffffa0fc66674000 [ 9385.242762] RBP: 00007ffd1fb2bf50 R08: b6a2d54b892363ee R09: ffffa101dc14fb00 [ 9385.242765] R10: 0000000000000000 R11: 0000000000000004 R12: ffffa0fc66674000 [ 9385.242768] R13: 0000000000000000 R14: ffffa0fc66674000 R15: 00000000ffffffa1 [ 9385.242771] FS: 00007f93711a2980(0000) GS:ffffa0fad72c0000(0000) knlGS:0000000000000000 [ 9385.242775] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9385.242778] CR2: 0000000000000008 CR3: 0000000a8e61c003 CR4: 00000000003706e0 [ 9385.242781] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 9385.242784] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 9385.242787] Call Trace: [ 9385.242791] <TASK> [ 9385.242793] ethtool_get_settings+0x71/0x1a0 [ 9385.242814] __dev_ethtool+0x426/0x2f40 [ 9385.242823] ? slab_post_alloc_hook+0x4f/0x280 [ 9385.242836] ? kmem_cache_alloc_trace+0x15d/0x2f0 [ 9385.242841] ? dev_ethtool+0x59/0x170 [ 9385.242848] dev_ethtool+0xa7/0x170 [ 9385.242856] dev_ioctl+0xc3/0x520 [ 9385.242866] sock_do_ioctl+0xa0/0xe0 [ 9385.242877] sock_ioctl+0x22f/0x320 [ 9385.242885] __x64_sys_ioctl+0x84/0xc0 [ 9385.242896] do_syscall_64+0x3a/0x80 [ 9385.242904] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 9385.242918] RIP: 0033:0x7f93702396db [ 9385.242923] Code: 73 01 c3 48 8b 0d ad 57 38 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7d 57 38 00 f7 d8 64 89 01 48 [ 9385.242927] RSP: 002b:00007ffd1fb2bf18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 9385.242932] RAX: ffffffffffffffda RBX: 000055671b1d2fe0 RCX: 00007f93702396db [ 9385.242935] RDX: 00007ffd1fb2bf20 RSI: 0000000000008946 RDI: 0000000000000007 [ 9385.242937] RBP: 00007ffd1fb2bf20 R08: 0000000000000003 R09: 0030763066307330 [ 9385.242940] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd1fb2bf80 [ 9385.242942] R13: 0000000000000007 R14: 0000556719f6de90 R15: 00007ffd1fb2c1b0 [ 9385.242948] </TASK> [ 9385.242949] Modules linked in: iavf(E) xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_compat nf_nat_tftp nft_objref nf_conntrack_tftp bridge stp llc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables rfkill nfnetlink vfat fat irdma ib_uverbs ib_core intel_rapl_msr intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support ice irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel rapl i40e pcspkr intel_cstate joydev mei_me intel_uncore mxm_wmi mei ipmi_ssif lpc_ich ipmi_si acpi_power_meter xfs libcrc32c mgag200 i2c_algo_bit drm_shmem_helper drm_kms_helper sd_mod t10_pi crc64_rocksoft crc64 syscopyarea sg sysfillrect sysimgblt fb_sys_fops drm ixgbe ahci libahci libata crc32c_intel mdio dca wmi dm_mirror dm_region_hash dm_log dm_mod ipmi_devintf ipmi_msghandler fuse [ 9385.243065] [last unloaded: iavf] Dereference happens in if (ADV_LINK_SUPPORT(adapter)) statement Fixes: 209f2f9 ("iavf: Add support for VIRTCHNL_VF_OFFLOAD_VLAN_V2 negotiation") Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com> Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com> Tested-by: Marek Szlosek <marek.szlosek@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Do not call iavf_close in iavf_reset_task error handling. Doing so can lead to double call of napi_disable, which can lead to deadlock there. Removing VF would lead to iavf_remove task being stuck, because it requires crit_lock, which is held by iavf_close. Call iavf_disable_vf if reset fail, so that driver will clean up remaining invalid resources. During rapid VF resets, HW can fail to setup VF mailbox. Wrong error handling can lead to iavf_remove being stuck with: [ 5218.999087] iavf 0000:82:01.0: Failed to init adminq: -53 ... [ 5267.189211] INFO: task repro.sh:11219 blocked for more than 30 seconds. [ 5267.189520] Tainted: G S E 5.18.0-04958-ga54ce3703613-dirty #1 [ 5267.189764] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 5267.190062] task:repro.sh state:D stack: 0 pid:11219 ppid: 8162 flags:0x00000000 [ 5267.190347] Call Trace: [ 5267.190647] <TASK> [ 5267.190927] __schedule+0x460/0x9f0 [ 5267.191264] schedule+0x44/0xb0 [ 5267.191563] schedule_preempt_disabled+0x14/0x20 [ 5267.191890] __mutex_lock.isra.12+0x6e3/0xac0 [ 5267.192237] ? iavf_remove+0xf9/0x6c0 [iavf] [ 5267.192565] iavf_remove+0x12a/0x6c0 [iavf] [ 5267.192911] ? _raw_spin_unlock_irqrestore+0x1e/0x40 [ 5267.193285] pci_device_remove+0x36/0xb0 [ 5267.193619] device_release_driver_internal+0xc1/0x150 [ 5267.193974] pci_stop_bus_device+0x69/0x90 [ 5267.194361] pci_stop_and_remove_bus_device+0xe/0x20 [ 5267.194735] pci_iov_remove_virtfn+0xba/0x120 [ 5267.195130] sriov_disable+0x2f/0xe0 [ 5267.195506] ice_free_vfs+0x7d/0x2f0 [ice] [ 5267.196056] ? pci_get_device+0x4f/0x70 [ 5267.196496] ice_sriov_configure+0x78/0x1a0 [ice] [ 5267.196995] sriov_numvfs_store+0xfe/0x140 [ 5267.197466] kernfs_fop_write_iter+0x12e/0x1c0 [ 5267.197918] new_sync_write+0x10c/0x190 [ 5267.198404] vfs_write+0x24e/0x2d0 [ 5267.198886] ksys_write+0x5c/0xd0 [ 5267.199367] do_syscall_64+0x3a/0x80 [ 5267.199827] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 5267.200317] RIP: 0033:0x7f5b381205c8 [ 5267.200814] RSP: 002b:00007fff8c7e8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 5267.201981] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f5b381205c8 [ 5267.202620] RDX: 0000000000000002 RSI: 00005569420ee900 RDI: 0000000000000001 [ 5267.203426] RBP: 00005569420ee900 R08: 000000000000000a R09: 00007f5b38180820 [ 5267.204327] R10: 000000000000000a R11: 0000000000000246 R12: 00007f5b383c06e0 [ 5267.205193] R13: 0000000000000002 R14: 00007f5b383bb880 R15: 0000000000000002 [ 5267.206041] </TASK> [ 5267.206970] Kernel panic - not syncing: hung_task: blocked tasks [ 5267.207809] CPU: 48 PID: 551 Comm: khungtaskd Kdump: loaded Tainted: G S E 5.18.0-04958-ga54ce3703613-dirty #1 [ 5267.208726] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.11.0 11/02/2019 [ 5267.209623] Call Trace: [ 5267.210569] <TASK> [ 5267.211480] dump_stack_lvl+0x33/0x42 [ 5267.212472] panic+0x107/0x294 [ 5267.213467] watchdog.cold.8+0xc/0xbb [ 5267.214413] ? proc_dohung_task_timeout_secs+0x30/0x30 [ 5267.215511] kthread+0xf4/0x120 [ 5267.216459] ? kthread_complete_and_exit+0x20/0x20 [ 5267.217505] ret_from_fork+0x22/0x30 [ 5267.218459] </TASK> Fixes: f0db789 ("i40evf: use netdev variable in reset task") Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com> Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com> Tested-by: Marek Szlosek <marek.szlosek@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

bpf_sk_reuseport_detach() calls __rcu_dereference_sk_user_data_with_flags() to obtain the value of sk->sk_user_data, but that function is only usable if the RCU read lock is held, and neither that function nor any of its callers hold it. Fix this by adding a new helper, __locked_read_sk_user_data_with_flags() that checks to see if sk->sk_callback_lock() is held and use that here instead. Alternatively, making __rcu_dereference_sk_user_data_with_flags() use rcu_dereference_checked() might suffice. Without this, the following warning can be occasionally observed: ============================= WARNING: suspicious RCU usage 6.0.0-rc1-build2+ #563 Not tainted ----------------------------- include/net/sock.h:592 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 5 locks held by locktest/29873: #0: ffff88812734b550 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release+0x77/0x121 #1: ffff88812f5621b0 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_close+0x1c/0x70 #2: ffff88810312f5c8 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_unhash+0x76/0x1c0 #3: ffffffff83768bb8 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x18/0xdd #4: ffff88812f562438 (clock-AF_INET){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x24/0xa4 stack backtrace: CPU: 1 PID: 29873 Comm: locktest Not tainted 6.0.0-rc1-build2+ #563 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <TASK> dump_stack_lvl+0x4c/0x5f bpf_sk_reuseport_detach+0x6d/0xa4 reuseport_detach_sock+0x75/0xdd inet_unhash+0xa5/0x1c0 tcp_set_state+0x169/0x20f ? lockdep_sock_is_held+0x3a/0x3a ? __lock_release.isra.0+0x13e/0x220 ? reacquire_held_locks+0x1bb/0x1bb ? hlock_class+0x31/0x96 ? mark_lock+0x9e/0x1af __tcp_close+0x50/0x4b6 tcp_close+0x28/0x70 inet_release+0x8e/0xa7 __sock_release+0x95/0x121 sock_close+0x14/0x17 __fput+0x20f/0x36a task_work_run+0xa3/0xcc exit_to_user_mode_prepare+0x9c/0x14d syscall_exit_to_user_mode+0x18/0x44 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: cf8c1e9 ("net: refactor bpf_sk_reuseport_detach()") Signed-off-by: David Howells <dhowells@redhat.com> cc: Hawkins Jiawei <yin31149@gmail.com> Link: https://lore.kernel.org/r/166064248071.3502205.10036394558814861778.stgit@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>

cec_unregister_adapter() assumes that the underlying adapter ops are callable. For example, if the CEC adapter currently has a valid physical address, then the unregistration procedure will invalidate the physical address by setting it to f.f.f.f. Whence the following kernel oops observed after removing the adv7511 module: Unable to handle kernel execution of user memory at virtual address 0000000000000000 Internal error: Oops: 86000004 [#1] PREEMPT_RT SMP Call trace: 0x0 adv7511_cec_adap_log_addr+0x1ac/0x1c8 [adv7511] cec_adap_unconfigure+0x44/0x90 [cec] __cec_s_phys_addr.part.0+0x68/0x230 [cec] __cec_s_phys_addr+0x40/0x50 [cec] cec_unregister_adapter+0xb4/0x118 [cec] adv7511_remove+0x60/0x90 [adv7511] i2c_device_remove+0x34/0xe0 device_release_driver_internal+0x114/0x1f0 driver_detach+0x54/0xe0 bus_remove_driver+0x60/0xd8 driver_unregister+0x34/0x60 i2c_del_driver+0x2c/0x68 adv7511_exit+0x1c/0x67c [adv7511] __arm64_sys_delete_module+0x154/0x288 invoke_syscall+0x48/0x100 el0_svc_common.constprop.0+0x48/0xe8 do_el0_svc+0x28/0x88 el0_svc+0x1c/0x50 el0t_64_sync_handler+0xa8/0xb0 el0t_64_sync+0x15c/0x160 Code: bad PC value ---[ end trace 0000000000000000 ]--- Protect against this scenario by unregistering i2c_cec after unregistering the CEC adapter. Duly disable the CEC clock afterwards too. Fixes: 3b1b975 ("drm: adv7511/33: add HDMI CEC support") Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk> Reviewed-by: Robert Foss <robert.foss@linaro.org> Signed-off-by: Robert Foss <robert.foss@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220612144854.2223873-3-alvin@pqrs.dk

There are some struct drm_driver fields that are required by drivers since drm_copy_field() attempts to copy them to user-space via DRM_IOCTL_VERSION. But it can be possible that a driver has a bug and did not set some of the fields, which leads to drm_copy_field() attempting to copy a NULL pointer: [ +10.395966] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000 [ +0.010955] Mem abort info: [ +0.002835] ESR = 0x0000000096000004 [ +0.003872] EC = 0x25: DABT (current EL), IL = 32 bits [ +0.005395] SET = 0, FnV = 0 [ +0.003113] EA = 0, S1PTW = 0 [ +0.003182] FSC = 0x04: level 0 translation fault [ +0.004964] Data abort info: [ +0.002919] ISV = 0, ISS = 0x00000004 [ +0.003886] CM = 0, WnR = 0 [ +0.003040] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000115dad000 [ +0.006536] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ +0.006925] Internal error: Oops: 96000004 [#1] SMP ... [ +0.011113] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ +0.007061] pc : __pi_strlen+0x14/0x150 [ +0.003895] lr : drm_copy_field+0x30/0x1a4 [ +0.004156] sp : ffff8000094b3a50 [ +0.003355] x29: ffff8000094b3a50 x28: ffff8000094b3b70 x27: 0000000000000040 [ +0.007242] x26: ffff443743c2ba00 x25: 0000000000000000 x24: 0000000000000040 [ +0.007243] x23: ffff443743c2ba00 x22: ffff8000094b3b70 x21: 0000000000000000 [ +0.007241] x20: 0000000000000000 x19: ffff8000094b3b90 x18: 0000000000000000 [ +0.007241] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaab14b9af40 [ +0.007241] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ +0.007239] x11: 0000000000000000 x10: 0000000000000000 x9 : ffffa524ad67d4d8 [ +0.007242] x8 : 0101010101010101 x7 : 7f7f7f7f7f7f7f7f x6 : 6c6e6263606e7141 [ +0.007239] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 [ +0.007241] x2 : 0000000000000000 x1 : ffff8000094b3b90 x0 : 0000000000000000 [ +0.007240] Call trace: [ +0.002475] __pi_strlen+0x14/0x150 [ +0.003537] drm_version+0x84/0xac [ +0.003448] drm_ioctl_kernel+0xa8/0x16c [ +0.003975] drm_ioctl+0x270/0x580 [ +0.003448] __arm64_sys_ioctl+0xb8/0xfc [ +0.003978] invoke_syscall+0x78/0x100 [ +0.003799] el0_svc_common.constprop.0+0x4c/0xf4 [ +0.004767] do_el0_svc+0x38/0x4c [ +0.003357] el0_svc+0x34/0x100 [ +0.003185] el0t_64_sync_handler+0x11c/0x150 [ +0.004418] el0t_64_sync+0x190/0x194 [ +0.003716] Code: 92402c04 b200c3e8 f13fc09f 5400088c (a9400c02) [ +0.006180] ---[ end trace 0000000000000000 ]--- Reported-by: Peter Robinson <pbrobinson@gmail.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220705100215.572498-3-javierm@redhat.com

Kurt Kanzenbach says: ==================== Hi, add a BPF-helper for accessing CLOCK_TAI. Use cases for such a BPF helper include functionalities such as Tx launch time (e.g. ETF and TAPRIO Qdiscs), timestamping and policing. Patch #1 - Introduce BPF helper Patch #2 - Add test case (skb based) Changes since v1: * Update changelog (Alexei Starovoitov) * Add test case (Alexei Starovoitov, Andrii Nakryiko) * Add missing function prototype (netdev ci) Previous versions: * v1: https://lore.kernel.org/r/20220606103734.92423-1-kurt@linutronix.de/ Jesper Dangaard Brouer (1): bpf: Add BPF-helper for accessing CLOCK_TAI ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>

We have been hitting the following lockdep splat with btrfs/187 recently WARNING: possible circular locking dependency detected 5.19.0-rc8+ #775 Not tainted ------------------------------------------------------ btrfs/752500 is trying to acquire lock: ffff97e1875a97b8 (btrfs-treloc-02#2){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 but task is already holding lock: ffff97e1875a9278 (btrfs-tree-01/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-tree-01/1){+.+.}-{3:3}: down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_init_new_buffer+0x7d/0x2c0 btrfs_alloc_tree_block+0x120/0x3b0 __btrfs_cow_block+0x136/0x600 btrfs_cow_block+0x10b/0x230 btrfs_search_slot+0x53b/0xb70 btrfs_lookup_inode+0x2a/0xa0 __btrfs_update_delayed_inode+0x5f/0x280 btrfs_async_run_delayed_root+0x24c/0x290 btrfs_work_helper+0xf2/0x3e0 process_one_work+0x271/0x590 worker_thread+0x52/0x3b0 kthread+0xf0/0x120 ret_from_fork+0x1f/0x30 -> #1 (btrfs-tree-01){++++}-{3:3}: down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_search_slot+0x3c3/0xb70 do_relocation+0x10c/0x6b0 relocate_tree_blocks+0x317/0x6d0 relocate_block_group+0x1f1/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (btrfs-treloc-02#2){+.+.}-{3:3}: __lock_acquire+0x1122/0x1e10 lock_acquire+0xc2/0x2d0 down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_lock_root_node+0x31/0x50 btrfs_search_slot+0x1cb/0xb70 replace_path+0x541/0x9f0 merge_reloc_root+0x1d6/0x610 merge_reloc_roots+0xe2/0x260 relocate_block_group+0x2c8/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: btrfs-treloc-02#2 --> btrfs-tree-01 --> btrfs-tree-01/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-01/1); lock(btrfs-tree-01); lock(btrfs-tree-01/1); lock(btrfs-treloc-02#2); *** DEADLOCK *** 7 locks held by btrfs/752500: #0: ffff97e292fdf460 (sb_writers#12){.+.+}-{0:0}, at: btrfs_ioctl+0x208/0x2c90 #1: ffff97e284c02050 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0x55f/0xe40 #2: ffff97e284c00878 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x236/0x400 #3: ffff97e292fdf650 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xef/0x610 #4: ffff97e284c02378 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x1a8/0x5a0 #5: ffff97e284c023a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x1a8/0x5a0 #6: ffff97e1875a9278 (btrfs-tree-01/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 stack backtrace: CPU: 1 PID: 752500 Comm: btrfs Not tainted 5.19.0-rc8+ #775 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x56/0x73 check_noncircular+0xd6/0x100 ? lock_is_held_type+0xe2/0x140 __lock_acquire+0x1122/0x1e10 lock_acquire+0xc2/0x2d0 ? __btrfs_tree_lock+0x24/0x110 down_write_nested+0x41/0x80 ? __btrfs_tree_lock+0x24/0x110 __btrfs_tree_lock+0x24/0x110 btrfs_lock_root_node+0x31/0x50 btrfs_search_slot+0x1cb/0xb70 ? lock_release+0x137/0x2d0 ? _raw_spin_unlock+0x29/0x50 ? release_extent_buffer+0x128/0x180 replace_path+0x541/0x9f0 merge_reloc_root+0x1d6/0x610 merge_reloc_roots+0xe2/0x260 relocate_block_group+0x2c8/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 ? lock_is_held_type+0xe2/0x140 ? lock_is_held_type+0xe2/0x140 ? __x64_sys_ioctl+0x88/0xc0 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd This isn't necessarily new, it's just tricky to hit in practice. There are two competing things going on here. With relocation we create a snapshot of every fs tree with a reloc tree. Any extent buffers that get initialized here are initialized with the reloc root lockdep key. However since it is a snapshot, any blocks that are currently in cache that originally belonged to the fs tree will have the normal tree lockdep key set. This creates the lock dependency of reloc tree -> normal tree for the extent buffer locking during the first phase of the relocation as we walk down the reloc root to relocate blocks. However this is problematic because the final phase of the relocation is merging the reloc root into the original fs root. This involves searching down to any keys that exist in the original fs root and then swapping the relocated block and the original fs root block. We have to search down to the fs root first, and then go search the reloc root for the block we need to replace. This creates the dependency of normal tree -> reloc tree which is why lockdep complains. Additionally even if we were to fix this particular mismatch with a different nesting for the merge case, we're still slotting in a block that has a owner of the reloc root objectid into a normal tree, so that block will have its lockdep key set to the tree reloc root, and create a lockdep splat later on when we wander into that block from the fs root. Unfortunately the only solution here is to make sure we do not set the lockdep key to the reloc tree lockdep key normally, and then reset any blocks we wander into from the reloc root when we're doing the merged. This solves the problem of having mixed tree reloc keys intermixed with normal tree keys, and then allows us to make sure in the merge case we maintain the lock order of normal tree -> reloc tree We handle this by setting a bit on the reloc root when we do the search for the block we want to relocate, and any block we search into or COW at that point gets set to the reloc tree key. This works correctly because we only ever COW down to the parent node, so we aren't resetting the key for the block we're linking into the fs root. With this patch we no longer have the lockdep splat in btrfs/187. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

Commit c89191c ("x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS") missed one use case of SWAPGS in entry_INT80_compat(). Removing of the SWAPGS macro led to asm just using "swapgs", as it is accepting instructions in capital letters, too. This in turn leads to splats in Xen PV guests like: [ 36.145223] general protection fault, maybe for address 0x2d: 0000 [#1] PREEMPT SMP NOPTI [ 36.145794] CPU: 2 PID: 1847 Comm: ld-linux.so.2 Not tainted 5.19.1-1-default #1 \ openSUSE Tumbleweed f3b44bfb672cdb9f235aff53b57724eba8b9411b [ 36.146608] Hardware name: HP ProLiant ML350p Gen8, BIOS P72 11/14/2013 [ 36.148126] RIP: e030:entry_INT80_compat+0x3/0xa3 Fix that by open coding this single instance of the SWAPGS macro. Fixes: c89191c ("x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jan Beulich <jbeulich@suse.com> Cc: <stable@vger.kernel.org> # 5.19 Link: https://lore.kernel.org/r/20220816071137.4893-1-jgross@suse.com

If amdgpu_cs_vm_handling returns r != 0, then it will unlock the bo_list_mutex inside the function amdgpu_cs_vm_handling and again on amdgpu_cs_parser_fini. This problem results in the following use-after-free problem: [ 220.280990] ------------[ cut here ]------------ [ 220.281000] refcount_t: underflow; use-after-free. [ 220.281019] WARNING: CPU: 1 PID: 3746 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ 220.281029] ------------[ cut here ]------------ [ 220.281415] CPU: 1 PID: 3746 Comm: chrome:cs0 Tainted: G W L ------- --- 5.20.0-0.rc0.20220812git7ebfc85e2cd7.10.fc38.x86_64 #1 [ 220.281421] Hardware name: System manufacturer System Product Name/ROG STRIX X570-I GAMING, BIOS 4403 04/27/2022 [ 220.281426] RIP: 0010:refcount_warn_saturate+0xba/0x110 [ 220.281431] Code: 01 01 e8 79 4a 6f 00 0f 0b e9 42 47 a5 00 80 3d de 7e be 01 00 75 85 48 c7 c7 f8 98 8e 98 c6 05 ce 7e be 01 01 e8 56 4a 6f 00 <0f> 0b e9 1f 47 a5 00 80 3d b9 7e be 01 00 0f 85 5e ff ff ff 48 c7 [ 220.281437] RSP: 0018:ffffb4b0d18d7a80 EFLAGS: 00010282 [ 220.281443] RAX: 0000000000000026 RBX: 0000000000000003 RCX: 0000000000000000 [ 220.281448] RDX: 0000000000000001 RSI: ffffffff988d06dc RDI: 00000000ffffffff [ 220.281452] RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffb4b0d18d7930 [ 220.281457] R10: 0000000000000003 R11: ffffa0672e2fffe8 R12: ffffa058ca360400 [ 220.281461] R13: ffffa05846c50a18 R14: 00000000fffffe00 R15: 0000000000000003 [ 220.281465] FS: 00007f82683e06c0(0000) GS:ffffa066e2e00000(0000) knlGS:0000000000000000 [ 220.281470] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 220.281475] CR2: 00003590005cc000 CR3: 00000001fca46000 CR4: 0000000000350ee0 [ 220.281480] Call Trace: [ 220.281485] <TASK> [ 220.281490] amdgpu_cs_ioctl+0x4e2/0x2070 [amdgpu] [ 220.281806] ? amdgpu_cs_find_mapping+0xe0/0xe0 [amdgpu] [ 220.282028] drm_ioctl_kernel+0xa4/0x150 [ 220.282043] drm_ioctl+0x21f/0x420 [ 220.282053] ? amdgpu_cs_find_mapping+0xe0/0xe0 [amdgpu] [ 220.282275] ? lock_release+0x14f/0x460 [ 220.282282] ? _raw_spin_unlock_irqrestore+0x30/0x60 [ 220.282290] ? _raw_spin_unlock_irqrestore+0x30/0x60 [ 220.282297] ? lockdep_hardirqs_on+0x7d/0x100 [ 220.282305] ? _raw_spin_unlock_irqrestore+0x40/0x60 [ 220.282317] amdgpu_drm_ioctl+0x4a/0x80 [amdgpu] [ 220.282534] __x64_sys_ioctl+0x90/0xd0 [ 220.282545] do_syscall_64+0x5b/0x80 [ 220.282551] ? futex_wake+0x6c/0x150 [ 220.282568] ? lock_is_held_type+0xe8/0x140 [ 220.282580] ? do_syscall_64+0x67/0x80 [ 220.282585] ? lockdep_hardirqs_on+0x7d/0x100 [ 220.282592] ? do_syscall_64+0x67/0x80 [ 220.282597] ? do_syscall_64+0x67/0x80 [ 220.282602] ? lockdep_hardirqs_on+0x7d/0x100 [ 220.282609] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 220.282616] RIP: 0033:0x7f8282a4f8bf [ 220.282639] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00 00 [ 220.282644] RSP: 002b:00007f82683df410 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 220.282651] RAX: ffffffffffffffda RBX: 00007f82683df588 RCX: 00007f8282a4f8bf [ 220.282655] RDX: 00007f82683df4d0 RSI: 00000000c0186444 RDI: 0000000000000018 [ 220.282659] RBP: 00007f82683df4d0 R08: 00007f82683df5e0 R09: 00007f82683df4b0 [ 220.282663] R10: 00001d04000a0600 R11: 0000000000000246 R12: 00000000c0186444 [ 220.282667] R13: 0000000000000018 R14: 00007f82683df588 R15: 0000000000000003 [ 220.282689] </TASK> [ 220.282693] irq event stamp: 6232311 [ 220.282697] hardirqs last enabled at (6232319): [<ffffffff9718cd7e>] __up_console_sem+0x5e/0x70 [ 220.282704] hardirqs last disabled at (6232326): [<ffffffff9718cd63>] __up_console_sem+0x43/0x70 [ 220.282709] softirqs last enabled at (6232072): [<ffffffff970ff669>] __irq_exit_rcu+0xf9/0x170 [ 220.282716] softirqs last disabled at (6232061): [<ffffffff970ff669>] __irq_exit_rcu+0xf9/0x170 [ 220.282722] ---[ end trace 0000000000000000 ]--- Therefore, remove the mutex_unlock from the amdgpu_cs_vm_handling function, so that amdgpu_cs_submit and amdgpu_cs_parser_fini can handle the unlock. Fixes: 90af0ca ("drm/amdgpu: Protect the amdgpu_bo_list list with a mutex v2") Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Melissa Wen <mwen@igalia.com> Signed-off-by: Maíra Canal <mairacanal@riseup.net> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

When we try to transmit an skb with metadata_dst attached (i.e. dst->dev == NULL) through xfrm interface we can hit a null pointer dereference[1] in xfrmi_xmit2() -> xfrm_lookup_with_ifid() due to the check for a loopback skb device when there's no policy which dereferences dst->dev unconditionally. Not having dst->dev can be interepreted as it not being a loopback device, so just add a check for a null dst_orig->dev. With this fix xfrm interface's Tx error counters go up as usual. [1] net-next calltrace captured via netconsole: BUG: kernel NULL pointer dereference, address: 00000000000000c0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 7231 Comm: ping Kdump: loaded Not tainted 5.19.0+ #24 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014 RIP: 0010:xfrm_lookup_with_ifid+0x5eb/0xa60 Code: 8d 74 24 38 e8 26 a4 37 00 48 89 c1 e9 12 fc ff ff 49 63 ed 41 83 fd be 0f 85 be 01 00 00 41 be ff ff ff ff 45 31 ed 48 8b 03 <f6> 80 c0 00 00 00 08 75 0f 41 80 bc 24 19 0d 00 00 01 0f 84 1e 02 RSP: 0018:ffffb0db82c679f0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffd0db7fcad430 RCX: ffffb0db82c67a10 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffb0db82c67a80 RBP: ffffb0db82c67a80 R08: ffffb0db82c67a14 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8fa449667dc8 R12: ffffffff966db880 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007ff35c83f000(0000) GS:ffff8fa478480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c0 CR3: 000000001ebb7000 CR4: 0000000000350ee0 Call Trace: <TASK> xfrmi_xmit+0xde/0x460 ? tcf_bpf_act+0x13d/0x2a0 dev_hard_start_xmit+0x72/0x1e0 __dev_queue_xmit+0x251/0xd30 ip_finish_output2+0x140/0x550 ip_push_pending_frames+0x56/0x80 raw_sendmsg+0x663/0x10a0 ? try_charge_memcg+0x3fd/0x7a0 ? __mod_memcg_lruvec_state+0x93/0x110 ? sock_sendmsg+0x30/0x40 sock_sendmsg+0x30/0x40 __sys_sendto+0xeb/0x130 ? handle_mm_fault+0xae/0x280 ? do_user_addr_fault+0x1e7/0x680 ? kvm_read_and_reset_apf_flags+0x3b/0x50 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7ff35cac1366 Code: eb 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 72 c3 90 55 48 83 ec 30 44 89 4c 24 2c 4c 89 RSP: 002b:00007fff738e4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fff738e57b0 RCX: 00007ff35cac1366 RDX: 0000000000000040 RSI: 0000557164e4b450 RDI: 0000000000000003 RBP: 0000557164e4b450 R08: 00007fff738e7a2c R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040 R13: 00007fff738e5770 R14: 00007fff738e4030 R15: 0000001d00000001 </TASK> Modules linked in: netconsole veth br_netfilter bridge bonding virtio_net [last unloaded: netconsole] CR2: 00000000000000c0 CC: Steffen Klassert <steffen.klassert@secunet.com> CC: Daniel Borkmann <daniel@iogearbox.net> Fixes: 2d151d3 ("xfrm: Add possibility to set the default to block if we have no policy") Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

The thermal zone is freed after being unregistered. The release method devm_thermal_zone_device_register() calls -> thermal_of_zone_device_unregister() This one calls thermal_zone_device_unregister() which frees the thermal zone. However, thermal_of_zone_device_unregister() does access this freed pointer to free different resources allocated by the thermal_of framework which is invalid. It results in a kernel panic: [ 1.915140] thermal_sys: Failed to find thermal zone for tmu id=2 [ 1.921279] qoriq_thermal 1f80000.tmu: Failed to register sensors [ 1.927395] qoriq_thermal: probe of 1f80000.tmu failed with error -22 [ 1.934189] Unable to handle kernel paging request at virtual address 01adadadadadad88 [ 1.942146] Mem abort info: [ 1.944948] ESR = 0x0000000096000004 [ 1.948708] EC = 0x25: DABT (current EL), IL = 32 bits [ 1.954042] SET = 0, FnV = 0 [ 1.957107] EA = 0, S1PTW = 0 [ 1.960253] FSC = 0x04: level 0 translation fault [ 1.965147] Data abort info: [ 1.968030] ISV = 0, ISS = 0x00000004 [ 1.971878] CM = 0, WnR = 0 [ 1.974852] [01adadadadadad88] address between user and kernel address ranges [ 1.982016] Internal error: Oops: 96000004 [#1] SMP [ 1.986907] Modules linked in: [ 1.989969] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-next-20220808-00080-g1c46f44502e0 #1697 [ 1.999135] Hardware name: Kontron KBox A-230-LS (DT) [ 2.004199] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 2.011185] pc : kfree+0x5c/0x3c0 [ 2.014516] lr : devm_thermal_of_zone_release+0x38/0x60 [ 2.019761] sp : ffff80000a22bad0 [ 2.023081] x29: ffff80000a22bad0 x28: 0000000000000000 x27: ffff800009960464 [ 2.030245] x26: ffff800009a16960 x25: 0000000000000006 x24: ffff800009f09a40 [ 2.037407] x23: ffff800009ab9008 x22: ffff800008d0eea8 x21: 01adadadadadad80 [ 2.044569] x20: 6b6b6b6b6b6b6b6b x19: ffff00200232b800 x18: 00000000fffffffb [ 2.051731] x17: ffff800008d0eea0 x16: ffff800008d07d44 x15: ffff800008d0d154 [ 2.056647] usb 1-1: new high-speed USB device number 2 using xhci-hcd [ 2.058893] x14: ffff800008d0cddc x13: ffff8000088d1c2c x12: ffff8000088d5034 [ 2.072597] x11: ffff8000088d46d4 x10: 0000000000000000 x9 : ffff800008d0eea8 [ 2.079759] x8 : ffff002000b1a158 x7 : bbbbbbbbbbbbbbbb x6 : ffff80000a0f53b8 [ 2.086921] x5 : ffff80000a22b960 x4 : 0000000000000000 x3 : 0000000000000000 [ 2.094082] x2 : fffffc0000000000 x1 : ffff002000838040 x0 : 01adb1adadadad80 [ 2.101244] Call trace: [ 2.103692] kfree+0x5c/0x3c0 [ 2.106666] devm_thermal_of_zone_release+0x38/0x60 [ 2.111561] release_nodes+0x64/0xd0 [ 2.115146] devres_release_all+0xbc/0x350 [ 2.119253] device_unbind_cleanup+0x20/0x70 [ 2.123536] really_probe+0x1a0/0x2e4 [ 2.127208] __driver_probe_device+0x80/0xec [ 2.131490] driver_probe_device+0x44/0x130 [ 2.135685] __driver_attach+0x104/0x1b4 [ 2.139619] bus_for_each_dev+0x7c/0xe0 [ 2.143465] driver_attach+0x30/0x40 [ 2.147048] bus_add_driver+0x160/0x210 [ 2.150894] driver_register+0x84/0x140 [ 2.154741] __platform_driver_register+0x34/0x40 [ 2.159461] qoriq_tmu_init+0x28/0x34 [ 2.163133] do_one_initcall+0x50/0x250 [ 2.166979] kernel_init_freeable+0x278/0x31c [ 2.171349] kernel_init+0x30/0x140 [ 2.174847] ret_from_fork+0x10/0x20 [ 2.178433] Code: b25657e2 d34cfc00 d37ae400 8b020015 (f94006a1) [ 2.184546] ---[ end trace 0000000000000000 ]--- Store the allocated resource pointers before the thermal zone is free and use them to release the resource after unregistering the thermal zone. Fixes: 3bd52ac ("thermal/of: Rework the thermal device tree initialization") Reported-by: Michael Walle <michael@walle.cc> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Tested-by: Michael Walle <michael@walle.cc> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20220809085629.509116-4-daniel.lezcano@linaro.org

We have been hitting the following lockdep splat with btrfs/187 recently WARNING: possible circular locking dependency detected 5.19.0-rc8+ #775 Not tainted ------------------------------------------------------ btrfs/752500 is trying to acquire lock: ffff97e1875a97b8 (btrfs-treloc-02#2){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 but task is already holding lock: ffff97e1875a9278 (btrfs-tree-01/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-tree-01/1){+.+.}-{3:3}: down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_init_new_buffer+0x7d/0x2c0 btrfs_alloc_tree_block+0x120/0x3b0 __btrfs_cow_block+0x136/0x600 btrfs_cow_block+0x10b/0x230 btrfs_search_slot+0x53b/0xb70 btrfs_lookup_inode+0x2a/0xa0 __btrfs_update_delayed_inode+0x5f/0x280 btrfs_async_run_delayed_root+0x24c/0x290 btrfs_work_helper+0xf2/0x3e0 process_one_work+0x271/0x590 worker_thread+0x52/0x3b0 kthread+0xf0/0x120 ret_from_fork+0x1f/0x30 -> #1 (btrfs-tree-01){++++}-{3:3}: down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_search_slot+0x3c3/0xb70 do_relocation+0x10c/0x6b0 relocate_tree_blocks+0x317/0x6d0 relocate_block_group+0x1f1/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (btrfs-treloc-02#2){+.+.}-{3:3}: __lock_acquire+0x1122/0x1e10 lock_acquire+0xc2/0x2d0 down_write_nested+0x41/0x80 __btrfs_tree_lock+0x24/0x110 btrfs_lock_root_node+0x31/0x50 btrfs_search_slot+0x1cb/0xb70 replace_path+0x541/0x9f0 merge_reloc_root+0x1d6/0x610 merge_reloc_roots+0xe2/0x260 relocate_block_group+0x2c8/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: btrfs-treloc-02#2 --> btrfs-tree-01 --> btrfs-tree-01/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-01/1); lock(btrfs-tree-01); lock(btrfs-tree-01/1); lock(btrfs-treloc-02#2); *** DEADLOCK *** 7 locks held by btrfs/752500: #0: ffff97e292fdf460 (sb_writers#12){.+.+}-{0:0}, at: btrfs_ioctl+0x208/0x2c90 #1: ffff97e284c02050 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0x55f/0xe40 #2: ffff97e284c00878 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x236/0x400 #3: ffff97e292fdf650 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xef/0x610 #4: ffff97e284c02378 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x1a8/0x5a0 #5: ffff97e284c023a0 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x1a8/0x5a0 #6: ffff97e1875a9278 (btrfs-tree-01/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x24/0x110 stack backtrace: CPU: 1 PID: 752500 Comm: btrfs Not tainted 5.19.0-rc8+ #775 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x56/0x73 check_noncircular+0xd6/0x100 ? lock_is_held_type+0xe2/0x140 __lock_acquire+0x1122/0x1e10 lock_acquire+0xc2/0x2d0 ? __btrfs_tree_lock+0x24/0x110 down_write_nested+0x41/0x80 ? __btrfs_tree_lock+0x24/0x110 __btrfs_tree_lock+0x24/0x110 btrfs_lock_root_node+0x31/0x50 btrfs_search_slot+0x1cb/0xb70 ? lock_release+0x137/0x2d0 ? _raw_spin_unlock+0x29/0x50 ? release_extent_buffer+0x128/0x180 replace_path+0x541/0x9f0 merge_reloc_root+0x1d6/0x610 merge_reloc_roots+0xe2/0x260 relocate_block_group+0x2c8/0x560 btrfs_relocate_block_group+0x23e/0x400 btrfs_relocate_chunk+0x4c/0x140 btrfs_balance+0x755/0xe40 btrfs_ioctl+0x1ea2/0x2c90 ? lock_is_held_type+0xe2/0x140 ? lock_is_held_type+0xe2/0x140 ? __x64_sys_ioctl+0x88/0xc0 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd This isn't necessarily new, it's just tricky to hit in practice. There are two competing things going on here. With relocation we create a snapshot of every fs tree with a reloc tree. Any extent buffers that get initialized here are initialized with the reloc root lockdep key. However since it is a snapshot, any blocks that are currently in cache that originally belonged to the fs tree will have the normal tree lockdep key set. This creates the lock dependency of reloc tree -> normal tree for the extent buffer locking during the first phase of the relocation as we walk down the reloc root to relocate blocks. However this is problematic because the final phase of the relocation is merging the reloc root into the original fs root. This involves searching down to any keys that exist in the original fs root and then swapping the relocated block and the original fs root block. We have to search down to the fs root first, and then go search the reloc root for the block we need to replace. This creates the dependency of normal tree -> reloc tree which is why lockdep complains. Additionally even if we were to fix this particular mismatch with a different nesting for the merge case, we're still slotting in a block that has a owner of the reloc root objectid into a normal tree, so that block will have its lockdep key set to the tree reloc root, and create a lockdep splat later on when we wander into that block from the fs root. Unfortunately the only solution here is to make sure we do not set the lockdep key to the reloc tree lockdep key normally, and then reset any blocks we wander into from the reloc root when we're doing the merged. This solves the problem of having mixed tree reloc keys intermixed with normal tree keys, and then allows us to make sure in the merge case we maintain the lock order of normal tree -> reloc tree We handle this by setting a bit on the reloc root when we do the search for the block we want to relocate, and any block we search into or COW at that point gets set to the reloc tree key. This works correctly because we only ever COW down to the parent node, so we aren't resetting the key for the block we're linking into the fs root. With this patch we no longer have the lockdep splat in btrfs/187. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

Syzkaller reported BUG_ON as follows: ------------[ cut here ]------------ kernel BUG at fs/ntfs/dir.c:86! invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 3 PID: 758 Comm: a.out Not tainted 5.19.0-next-20220808 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:ntfs_lookup_inode_by_name+0xd11/0x2d10 Code: ff e9 b9 01 00 00 e8 1e fe d6 fe 48 8b 7d 98 49 8d 5d 07 e8 91 85 29 ff 48 c7 45 98 00 00 00 00 e9 5a fb ff ff e8 ff fd d6 fe <0f> 0b e8 f8 fd d6 fe 0f 0b e8 f1 fd d6 fe 48 8b b5 50 ff ff ff 4c RSP: 0018:ffff888079607978 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000008000 RCX: 0000000000000000 RDX: ffff88807cf10000 RSI: ffffffff82a4a081 RDI: 0000000000000003 RBP: ffff888079607a70 R08: 0000000000000001 R09: ffff88807a6d01d7 R10: ffffed100f4da03a R11: 0000000000000000 R12: ffff88800f0fb110 R13: ffff88800f0ee000 R14: ffff88800f0fb000 R15: 0000000000000001 FS: 00007f33b63c7540(0000) GS:ffff888108580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f33b635c090 CR3: 000000000f39e005 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> load_system_files+0x1f7f/0x3620 ntfs_fill_super+0xa01/0x1be0 mount_bdev+0x36a/0x440 ntfs_mount+0x3a/0x50 legacy_get_tree+0xfb/0x210 vfs_get_tree+0x8f/0x2f0 do_new_mount+0x30a/0x760 path_mount+0x4de/0x1880 __x64_sys_mount+0x2b3/0x340 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f33b62ff9ea Code: 48 8b 0d a9 f4 0b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 76 f4 0b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd0c471aa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f33b62ff9ea RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd0c471be0 RBP: 00007ffd0c471c60 R08: 00007ffd0c471ae0 R09: 00007ffd0c471c24 R10: 0000000000000000 R11: 0000000000000202 R12: 000055bac5afc160 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fix this by adding sanity check on extended system files' directory inode to ensure that it is directory, just like ntfs_extend_init() when mounting ntfs3. Link: https://lkml.kernel.org/r/20220809064730.2316892-1-chenxiaosong2@huawei.com Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

An argument list like "arg=val arg2 \"" can trigger a page fault if the page pointed by 'args[0xffffffff]' is not mapped and potential memory corruption otherwise (unlikely but possible if the bogus address is mapped and contents happen to match the ascii value of the quote character). The fix is to ensure that we load 'args[i-1]' only when (i > 0). Prior to this commit the following command would trigger an unhandled page fault in the kernel: root@(none):/linus/fs/fat# insmod ./fat.ko "foo=bar \"" [ 33.870507] BUG: unable to handle page fault for address: ffff888204252608 [ 33.872180] #PF: supervisor read access in kernel mode [ 33.873414] #PF: error_code(0x0000) - not-present page [ 33.874650] PGD 4401067 P4D 4401067 PUD 0 [ 33.875321] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [ 33.876113] CPU: 16 PID: 399 Comm: insmod Not tainted 5.19.0-dbg-DEV #4 [ 33.877193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 33.878739] RIP: 0010:next_arg+0xd1/0x110 [ 33.879399] Code: 22 75 1d 41 c6 04 01 00 41 80 f8 22 74 18 eb 35 4c 89 0e 45 31 d2 4c 89 cf 48 c7 02 00 00 00 00 41 80 f8 22 75 1f 41 8d 42 ff <41> 80 3c 01 22 75 14 41 c6 04 01 00 eb 0d 48 c7 02 00 00 00 00 41 [ 33.882338] RSP: 0018:ffffc90001253d08 EFLAGS: 00010246 [ 33.883174] RAX: 00000000ffffffff RBX: ffff888104252608 RCX: 0fc317bba1c1dd00 [ 33.884311] RDX: ffffc90001253d40 RSI: ffffc90001253d48 RDI: ffff888104252609 [ 33.885450] RBP: ffffc90001253d10 R08: 0000000000000022 R09: ffff888104252609 [ 33.886595] R10: 0000000000000000 R11: ffffffff82c7ff20 R12: 0000000000000282 [ 33.887748] R13: 00000000ffff8000 R14: 0000000000000000 R15: 0000000000007fff [ 33.888887] FS: 00007f04ec7432c0(0000) GS:ffff88813d300000(0000) knlGS:0000000000000000 [ 33.890183] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.891111] CR2: ffff888204252608 CR3: 0000000100f36005 CR4: 0000000000170ee0 [ 33.892241] Call Trace: [ 33.892641] <TASK> [ 33.892989] parse_args+0x8f/0x220 [ 33.893538] load_module+0x138b/0x15a0 [ 33.894149] ? prepare_coming_module+0x50/0x50 [ 33.894879] ? kernel_read_file_from_fd+0x5f/0x90 [ 33.895639] __se_sys_finit_module+0xce/0x130 [ 33.896342] __x64_sys_finit_module+0x1d/0x20 [ 33.897042] do_syscall_64+0x44/0xa0 [ 33.897622] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 33.898434] RIP: 0033:0x7f04ec85ef79 [ 33.899009] Code: 48 8d 3d da db 0d 00 0f 05 eb a5 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c7 9e 0d 00 f7 d8 64 89 01 48 [ 33.901912] RSP: 002b:00007fffae81bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 33.903081] RAX: ffffffffffffffda RBX: 0000559c5f1d2640 RCX: 00007f04ec85ef79 [ 33.904191] RDX: 0000000000000000 RSI: 0000559c5f1d12a0 RDI: 0000000000000003 [ 33.905304] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 33.906421] R10: 0000000000000003 R11: 0000000000000246 R12: 0000559c5f1d12a0 [ 33.907526] R13: 0000000000000000 R14: 0000559c5f1d25f0 R15: 0000559c5f1d12a0 [ 33.908631] </TASK> [ 33.908986] Modules linked in: fat(+) [last unloaded: fat] [ 33.909843] CR2: ffff888204252608 [ 33.910375] ---[ end trace 0000000000000000 ]--- [ 33.911172] RIP: 0010:next_arg+0xd1/0x110 [ 33.911796] Code: 22 75 1d 41 c6 04 01 00 41 80 f8 22 74 18 eb 35 4c 89 0e 45 31 d2 4c 89 cf 48 c7 02 00 00 00 00 41 80 f8 22 75 1f 41 8d 42 ff <41> 80 3c 01 22 75 14 41 c6 04 01 00 eb 0d 48 c7 02 00 00 00 00 41 [ 33.914643] RSP: 0018:ffffc90001253d08 EFLAGS: 00010246 [ 33.915446] RAX: 00000000ffffffff RBX: ffff888104252608 RCX: 0fc317bba1c1dd00 [ 33.916544] RDX: ffffc90001253d40 RSI: ffffc90001253d48 RDI: ffff888104252609 [ 33.917636] RBP: ffffc90001253d10 R08: 0000000000000022 R09: ffff888104252609 [ 33.918727] R10: 0000000000000000 R11: ffffffff82c7ff20 R12: 0000000000000282 [ 33.919821] R13: 00000000ffff8000 R14: 0000000000000000 R15: 0000000000007fff [ 33.920908] FS: 00007f04ec7432c0(0000) GS:ffff88813d300000(0000) knlGS:0000000000000000 [ 33.922125] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.923017] CR2: ffff888204252608 CR3: 0000000100f36005 CR4: 0000000000170ee0 [ 33.924098] Kernel panic - not syncing: Fatal exception [ 33.925776] Kernel Offset: disabled [ 33.926347] Rebooting in 10 seconds.. Link: https://lkml.kernel.org/r/20220728232434.1666488-1-neelnatu@google.com Signed-off-by: Neel Natu <neelnatu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "Dump command line of faulting process to syslog", v3. This patch series dumps the command line (including the program parameters) of a faulting process to the syslog. The motivation for this patch is that it's sometimes quite hard to find out and annoying to not know which program *exactly* faulted when looking at the syslog. For example, a dump on parisc shows: do_page_fault() command='cc1' type=15 address=0x00000000 in libc-2.33.so[f6abb000+184000] -> We see the "cc1" compiler crashed, but it would be useful to know which file was compiled. With this patch you will see that cc1 crashed while compiling some haskell code: cc1[13472] cmdline: /usr/lib/gcc/hppa-linux-gnu/12/cc1 -quiet @/tmp/ccRkFSfY -imultilib . -imultiarch hppa-linux-gnu -D USE_MINIINTERPRETER -D NO_REGS -D _HPUX_SOURCE -D NOSMP -D THREADED_RTS -include /build/ghc/ghc-9.0.2/includes/dist-install/build/ghcversion.h -iquote compiler/GHC/Iface -quiet -dumpdir /tmp/ghc13413_0/ -dumpbase ghc_5.hc -dumpbase-ext .hc -O -Wimplicit -fno-PIC -fwrapv -fno-builtin -fno-strict-aliasing -o /tmp/ghc13413_0/ghc_5.s Another example are the glibc testcases which always segfault in "ld.so.1" with no other info: do_page_fault() command='ld.so.1' type=15 address=0x565921d8 in libc.so[f7339000+1bb000] -> With the patch you can see it was the "tst-safe-linking-malloc-hugetlb1" testcase: ld.so.1[1151] cmdline: /home/gnu/glibc/objdir/elf/ld.so.1 --library-path /home/gnu/glibc/objdir:/home/gnu/glibc/objdir/math:/home/gnu/ /home/gnu/glibc/objdir/malloc/tst-safe-linking-malloc-hugetlb1 An example of a typical x86 fault shows up as: crash[2326]: segfault at 0 ip 0000561a7969c12e sp 00007ffe97a05630 error 6 in crash[561a7969c000+1000] Code: 68 ff ff ff c6 05 19 2f 00 00 01 5d c3 0f 1f 80 00 00 00 00 c3 0f 1f 80 00 00 ... -> with this patch you now see the whole command line: crash[2326] cmdline: ./crash test_write_to_page_0 The patches are relatively small, and reuse functions which are used to create the output for the /proc/<pid>/cmdline files. The relevant changes are in patches #1 and #2. Patch #3 adds the cmdline dump on x86. Patch #4 drops code from arc which now becomes unnecessary as this is done by generic code. This patch (of 4): Add a new function get_task_cmdline_kernel() which reads the command line of a process into a kernel buffer. This command line can then be dumped by arch code to give additional debug info via the parameters with which a faulting process was started. The new function reuses the existing code which provides the cmdline for the procfs. For that the existing functions were modified so that the buffer page is allocated outside of get_mm_proctitle() and get_mm_cmdline() and instead provided as parameter. Link: https://lkml.kernel.org/r/20220808130917.30760-1-deller@gmx.de Link: https://lkml.kernel.org/r/20220808130917.30760-2-deller@gmx.de Signed-off-by: Helge Deller <deller@gmx.de> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Syzkaller reported a triggered kernel BUG as follows: ------------[ cut here ]------------ kernel BUG at kernel/bpf/cgroup.c:925! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 194 Comm: detach Not tainted 5.19.0-14184-g69dac8e431af #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__cgroup_bpf_detach+0x1f2/0x2a0 Code: 00 e8 92 60 30 00 84 c0 75 d8 4c 89 e0 31 f6 85 f6 74 19 42 f6 84 28 48 05 00 00 02 75 0e 48 8b 80 c0 00 00 00 48 85 c0 75 e5 <0f> 0b 48 8b 0c5 RSP: 0018:ffffc9000055bdb0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888100ec0800 RCX: ffffc900000f1000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888100ec4578 RBP: 0000000000000000 R08: ffff888100ec0800 R09: 0000000000000040 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888100ec4000 R13: 000000000000000d R14: ffffc90000199000 R15: ffff888100effb00 FS: 00007f68213d2b80(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f74a0e5850 CR3: 0000000102836000 CR4: 00000000000006e0 Call Trace: <TASK> cgroup_bpf_prog_detach+0xcc/0x100 __sys_bpf+0x2273/0x2a00 __x64_sys_bpf+0x17/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f68214dbcb9 Code: 08 44 89 e0 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff8 RSP: 002b:00007ffeb487db68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f68214dbcb9 RDX: 0000000000000090 RSI: 00007ffeb487db70 RDI: 0000000000000009 RBP: 0000000000000003 R08: 0000000000000012 R09: 0000000b00000003 R10: 00007ffeb487db70 R11: 0000000000000246 R12: 00007ffeb487dc20 R13: 0000000000000004 R14: 0000000000000001 R15: 000055f74a1011b0 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Repetition steps: For the following cgroup tree, root | cg1 | cg2 1. attach prog2 to cg2, and then attach prog1 to cg1, both bpf progs attach type is NONE or OVERRIDE. 2. write 1 to /proc/thread-self/fail-nth for failslab. 3. detach prog1 for cg1, and then kernel BUG occur. Failslab injection will cause kmalloc fail and fall back to purge_effective_progs. The problem is that cg2 have attached another prog, so when go through cg2 layer, iteration will add pos to 1, and subsequent operations will be skipped by the following condition, and cg will meet NULL in the end. `if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI))` The NULL cg means no link or prog match, this is as expected, and it's not a bug. So here just skip the no match situation. Fixes: 4c46091 ("bpf: Fix KASAN use-after-free Read in compute_effective_progs") Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220813134030.1972696-1-pulehui@huawei.com

If ntfs_fill_super() wasn't called then sbi->sb will be equal to NULL. Code should check this ptr before dereferencing. Syzbot hit this issue via passing wrong mount param as can be seen from log below Fail log: ntfs3: Unknown parameter 'iochvrset' general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 1 PID: 3589 Comm: syz-executor210 Not tainted 5.18.0-rc3-syzkaller-00016-gb253435746d9 #0 ... Call Trace: <TASK> put_ntfs+0x1ed/0x2a0 fs/ntfs3/super.c:463 ntfs_fs_free+0x6a/0xe0 fs/ntfs3/super.c:1363 put_fs_context+0x119/0x7a0 fs/fs_context.c:469 do_new_mount+0x2b4/0xad0 fs/namespace.c:3044 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] Fixes: 82cae26 ("fs/ntfs3: Add initialization of super block") Reported-and-tested-by: syzbot+c95173762127ad76a824@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP warning on some systems: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 1 lock held by swapper/1: #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220 Preemption disabled at: [<00000000>] 0x0 CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1 Call Trace: [d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable) [d101dcb0] [c0093b70] __might_resched+0x258/0x2a8 [d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec [d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4 [d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220 [d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784 [d101de50] [c140852c] discover_phbs+0x30/0x4c [d101de60] [c0007fd4] do_one_initcall+0x94/0x344 [d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c [d101df10] [c00086e0] kernel_init+0x34/0x160 [d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64 This is because pcibios_alloc_controller() holds hose_spinlock but of_alias_get_id() takes of_mutex which can sleep. The hose_spinlock protects the phb_bitmap, and also the hose_list, but it doesn't need to be held while get_phb_number() calls the OF routines, because those are only looking up information in the device tree. So fix it by having get_phb_number() take the hose_spinlock itself, only where required, and then dropping the lock before returning. pcibios_alloc_controller() then needs to take the lock again before the list_add() but that's safe, the order of the list is not important. Fixes: 0fe1e96 ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220815065550.1303620-1-mpe@ellerman.id.au

Petr Machata says: ==================== mlxsw: Fixes for PTP support This set fixes several issues in mlxsw PTP code. - Patch #1 fixes compilation warnings. - Patch #2 adjusts the order of operation during cleanup, thereby closing the window after PTP state was already cleaned in the ASIC for the given port, but before the port is removed, when the user could still in theory make changes to the configuration. - Patch #3 protects the PTP configuration with a custom mutex, instead of relying on RTNL, which is not held in all access paths. - Patch #4 forbids enablement of PTP only in RX or only in TX. The driver implicitly assumed this would be the case, but neglected to sanitize the configuration. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

The following BUG was reported: traps: Missing ENDBR: andw_ax_dx+0x0/0x10 [kvm] ------------[ cut here ]------------ kernel BUG at arch/x86/kernel/traps.c:253! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI <TASK> asm_exc_control_protection+0x2b/0x30 RIP: 0010:andw_ax_dx+0x0/0x10 [kvm] Code: c3 cc cc cc cc 0f 1f 44 00 00 66 0f 1f 00 48 19 d0 c3 cc cc cc cc 0f 1f 40 00 f3 0f 1e fa 20 d0 c3 cc cc cc cc 0f 1f 44 00 00 <66> 0f 1f 00 66 21 d0 c3 cc cc cc cc 0f 1f 40 00 66 0f 1f 00 21 d0 ? andb_al_dl+0x10/0x10 [kvm] ? fastop+0x5d/0xa0 [kvm] x86_emulate_insn+0x822/0x1060 [kvm] x86_emulate_instruction+0x46f/0x750 [kvm] complete_emulated_mmio+0x216/0x2c0 [kvm] kvm_arch_vcpu_ioctl_run+0x604/0x650 [kvm] kvm_vcpu_ioctl+0x2f4/0x6b0 [kvm] ? wake_up_q+0xa0/0xa0 The BUG occurred because the ENDBR in the andw_ax_dx() fastop function had been incorrectly "sealed" (converted to a NOP) by apply_ibt_endbr(). Objtool marked it to be sealed because KVM has no compile-time references to the function. Instead KVM calculates its address at runtime. Prevent objtool from annotating fastop functions as sealable by creating throwaway dummy compile-time references to the functions. Fixes: 6649fa8 ("x86/ibt,kvm: Add ENDBR to fastops") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Debugged-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Message-Id: <0d4116f90e9d0c1b754bb90c585e6f0415a1c508.1660837839.git.jpoimboe@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

…kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.0, take #1 - Fix unexpected sign extension of KVM_ARM_DEVICE_ID_MASK - Tidy-up handling of AArch32 on asymmetric systems

Check the bo->resource value before accessing the resource mem_type. v2: Fix commit description unwrapped warning <log snip> [ 40.191227][ T184] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI [ 40.192995][ T184] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 40.194411][ T184] CPU: 1 PID: 184 Comm: systemd-udevd Not tainted 5.19.0-rc4-00721-gb297c22b7070 #1 [ 40.196063][ T184] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 40.199605][ T184] RIP: 0010:ttm_bo_validate+0x1b3/0x240 [ttm] [ 40.200754][ T184] Code: e8 72 c5 ff ff 83 f8 b8 74 d4 85 c0 75 54 49 8b 9e 58 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 10 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 44 8b 53 10 31 c0 85 d2 0f 85 58 [ 40.203685][ T184] RSP: 0018:ffffc900006df0c8 EFLAGS: 00010202 [ 40.204630][ T184] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1102f4bb71b [ 40.205864][ T184] RDX: 0000000000000002 RSI: ffffc900006df208 RDI: 0000000000000010 [ 40.207102][ T184] RBP: 1ffff920000dbe1a R08: ffffc900006df208 R09: 0000000000000000 [ 40.208394][ T184] R10: ffff88817a5f0000 R11: 0000000000000001 R12: ffffc900006df110 [ 40.209692][ T184] R13: ffffc900006df0f0 R14: ffff88817a5db800 R15: ffffc900006df208 [ 40.210862][ T184] FS: 00007f6b1d16e8c0(0000) GS:ffff88839d700000(0000) knlGS:0000000000000000 [ 40.212250][ T184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 40.213275][ T184] CR2: 000055a1001d4ff0 CR3: 00000001700f4000 CR4: 00000000000006e0 [ 40.214469][ T184] Call Trace: [ 40.214974][ T184] <TASK> [ 40.215438][ T184] ? ttm_bo_bounce_temp_buffer+0x140/0x140 [ttm] [ 40.216572][ T184] ? mutex_spin_on_owner+0x240/0x240 [ 40.217456][ T184] ? drm_vma_offset_add+0xaa/0x100 [drm] [ 40.218457][ T184] ttm_bo_init_reserved+0x3d6/0x540 [ttm] [ 40.219410][ T184] ? shmem_get_inode+0x744/0x980 [ 40.220231][ T184] ttm_bo_init_validate+0xb1/0x200 [ttm] [ 40.221172][ T184] ? bo_driver_evict_flags+0x340/0x340 [drm_vram_helper] [ 40.222530][ T184] ? ttm_bo_init_reserved+0x540/0x540 [ttm] [ 40.223643][ T184] ? __do_sys_finit_module+0x11a/0x1c0 [ 40.224654][ T184] ? __shmem_file_setup+0x102/0x280 [ 40.234764][ T184] drm_gem_vram_create+0x305/0x480 [drm_vram_helper] [ 40.235766][ T184] ? bo_driver_evict_flags+0x340/0x340 [drm_vram_helper] [ 40.236846][ T184] ? __kasan_slab_free+0x108/0x180 [ 40.237650][ T184] drm_gem_vram_fill_create_dumb+0x134/0x340 [drm_vram_helper] [ 40.238864][ T184] ? local_pci_probe+0xdf/0x180 [ 40.239674][ T184] ? drmm_vram_helper_init+0x400/0x400 [drm_vram_helper] [ 40.240826][ T184] drm_client_framebuffer_create+0x19c/0x400 [drm] [ 40.241955][ T184] ? drm_client_buffer_delete+0x200/0x200 [drm] [ 40.243001][ T184] ? drm_client_pick_crtcs+0x554/0xb80 [drm] [ 40.244030][ T184] drm_fb_helper_generic_probe+0x23f/0x940 [drm_kms_helper] [ 40.245226][ T184] ? __cond_resched+0x1c/0xc0 [ 40.245987][ T184] ? drm_fb_helper_memory_range_to_clip+0x180/0x180 [drm_kms_helper] [ 40.247316][ T184] ? mutex_unlock+0x80/0x100 [ 40.248005][ T184] ? __mutex_unlock_slowpath+0x2c0/0x2c0 [ 40.249083][ T184] drm_fb_helper_single_fb_probe+0x907/0xf00 [drm_kms_helper] [ 40.250314][ T184] ? drm_fb_helper_check_var+0x1180/0x1180 [drm_kms_helper] [ 40.251540][ T184] ? __cond_resched+0x1c/0xc0 [ 40.252321][ T184] ? mutex_lock+0x9f/0x100 [ 40.253062][ T184] __drm_fb_helper_initial_config_and_unlock+0xb9/0x2c0 [drm_kms_helper] [ 40.254394][ T184] drm_fbdev_client_hotplug+0x56f/0x840 [drm_kms_helper] [ 40.255477][ T184] drm_fbdev_generic_setup+0x165/0x3c0 [drm_kms_helper] [ 40.256607][ T184] bochs_pci_probe+0x6b7/0x900 [bochs] [ 40.257515][ T184] ? _raw_spin_lock_irqsave+0x87/0x100 [ 40.258312][ T184] ? bochs_hw_init+0x480/0x480 [bochs] [ 40.259244][ T184] ? bochs_hw_init+0x480/0x480 [bochs] [ 40.260186][ T184] local_pci_probe+0xdf/0x180 [ 40.260928][ T184] pci_call_probe+0x15f/0x500 [ 40.265798][ T184] ? _raw_spin_lock+0x81/0x100 [ 40.266508][ T184] ? pci_pm_suspend_noirq+0x980/0x980 [ 40.267322][ T184] ? pci_assign_irq+0x81/0x280 [ 40.268096][ T184] ? pci_match_device+0x351/0x6c0 [ 40.268883][ T184] ? kernfs_put+0x18/0x40 [ 40.269611][ T184] pci_device_probe+0xee/0x240 [ 40.270352][ T184] really_probe+0x435/0xa80 [ 40.271021][ T184] __driver_probe_device+0x2ab/0x480 [ 40.271828][ T184] driver_probe_device+0x49/0x140 [ 40.272627][ T184] __driver_attach+0x1bd/0x4c0 [ 40.273372][ T184] ? __device_attach_driver+0x240/0x240 [ 40.274273][ T184] bus_for_each_dev+0x11e/0x1c0 [ 40.275080][ T184] ? subsys_dev_iter_exit+0x40/0x40 [ 40.275951][ T184] ? klist_add_tail+0x132/0x280 [ 40.276767][ T184] bus_add_driver+0x39b/0x580 [ 40.277574][ T184] driver_register+0x20f/0x3c0 [ 40.278281][ T184] ? 0xffffffffc04a2000 [ 40.278894][ T184] do_one_initcall+0x8a/0x300 [ 40.279642][ T184] ? trace_event_raw_event_initcall_level+0x1c0/0x1c0 [ 40.280707][ T184] ? kasan_unpoison+0x23/0x80 [ 40.281479][ T184] ? kasan_unpoison+0x23/0x80 [ 40.282197][ T184] do_init_module+0x190/0x640 [ 40.282926][ T184] load_module+0x221b/0x2780 [ 40.283611][ T184] ? layout_and_allocate+0x5c0/0x5c0 [ 40.284401][ T184] ? kernel_read_file+0x286/0x6c0 [ 40.285216][ T184] ? __x64_sys_fspick+0x2c0/0x2c0 [ 40.286043][ T184] ? mmap_region+0x4e7/0x1300 [ 40.286832][ T184] ? __do_sys_finit_module+0x11a/0x1c0 [ 40.287743][ T184] __do_sys_finit_module+0x11a/0x1c0 [ 40.288636][ T184] ? __ia32_sys_init_module+0xc0/0xc0 [ 40.289557][ T184] ? __seccomp_filter+0x15e/0xc80 [ 40.290341][ T184] ? vm_mmap_pgoff+0x185/0x240 [ 40.291060][ T184] do_syscall_64+0x3b/0xc0 [ 40.291763][ T184] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 40.292678][ T184] RIP: 0033:0x7f6b1d6279b9 [ 40.293438][ T184] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a7 54 0c 00 f7 d8 64 89 01 48 [ 40.296302][ T184] RSP: 002b:00007ffe7f51b798 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 40.297633][ T184] RAX: ffffffffffffffda RBX: 00005642dcca2880 RCX: 00007f6b1d6279b9 [ 40.298890][ T184] RDX: 0000000000000000 RSI: 00007f6b1d7b2e2d RDI: 0000000000000016 [ 40.300199][ T184] RBP: 0000000000020000 R08: 0000000000000000 R09: 00005642dccd5530 [ 40.301547][ T184] R10: 0000000000000016 R11: 0000000000000246 R12: 00007f6b1d7b2e2d [ 40.302698][ T184] R13: 0000000000000000 R14: 00005642dcca4230 R15: 00005642dcca2880 Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com> Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220726162205.2778-1-Arunpravin.PaneerSelvam@amd.com Link: https://patchwork.freedesktop.org/patch/msgid/20220809095623.3569-1-Arunpravin.PaneerSelvam@amd.com Signed-off-by: Christian König <christian.koenig@amd.com> CC: stable@vger.kernel.org

…ace is dead ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // return here, __unregister_ftrace_function is not executed, // as a result, ops is still in the ftrace_ops_list __unregister_ftrace_function ... If ops is dynamically allocated, it will be free later, in this case, is_ftrace_trampoline accesses NULL pointer: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL! Syzkaller reports as follows: [ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b [ 1203.508039] #PF: supervisor read access in kernel mode [ 1203.508798] #PF: error_code(0x0000) - not-present page [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8 [ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Therefore, when ftrace_startup_enable fails, we need to rollback registration process and remove ops from ftrace_ops_list. Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

While playing with event probes (eprobes), I tried to see what would happen if I attempted to retrieve the instruction pointer (%rip) knowing that event probes do not use pt_regs. The result was: BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:get_event_field.isra.0+0x0/0x50 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8 50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24 8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff916c9ea40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0 Call Trace: <TASK> get_eprobe_size+0xb4/0x640 ? __mod_node_page_state+0x72/0xc0 __eprobe_trace_func+0x59/0x1a0 ? __mod_lruvec_page_state+0xaa/0x1b0 ? page_remove_file_rmap+0x14/0x230 ? page_remove_rmap+0xda/0x170 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x18f/0x240 trace_event_raw_event_sched_wakeup_template+0x7a/0xb0 try_to_wake_up+0x260/0x4c0 __wake_up_common+0x80/0x180 __wake_up_common_lock+0x7c/0xc0 do_notify_parent+0x1c9/0x2a0 exit_notify+0x1a9/0x220 do_exit+0x2ba/0x450 do_group_exit+0x2d/0x90 __x64_sys_exit_group+0x14/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Obviously this is not the desired result. Move the testing for TPARG_FL_TPOINT which is only used for event probes to the top of the "$" variable check, as all the other variables are not used for event probes. Also add a check in the register parsing "%" to fail if an event probe is used. Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

…odel' Petr Machata says: ==================== selftests: mlxsw: Add ordering tests for unified bridge model Amit Cohen writes: Commit 798661c ("Merge branch 'mlxsw-unified-bridge-conversion-part-6'") converted mlxsw driver to use unified bridge model. In the legacy model, when a RIF was created / destroyed, it was firmware's responsibility to update it in the relevant FID classification records. In the unified bridge model, this responsibility moved to software. This set adds tests to check the order of configuration for the following classifications: 1. {Port, VID} -> FID 2. VID -> FID 3. VNI -> FID (after decapsulation) In addition, in the legacy model, software is responsible to update a table which is used to determine the packet's egress VID. Add a test to check that the order of configuration does not impact switch behavior. See more details in the commit messages. Note that the tests supposed to pass also using the legacy model, they are added now as with the new model they test the driver and not the firmware. Patch set overview: Patch #1 adds test for {Port, VID} -> FID Patch #2 adds test for VID -> FID Patch #3 adds test for VNI -> FID Patch #4 adds test for egress VID classification ==================== Link: https://lore.kernel.org/r/cover.1660747162.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Patch series "mm: fixes for device-exclusive entries (hmm)", v2. Discussing the PageTail() call in make_device_exclusive_range() with Willy, I recently discovered [1] that device-exclusive handling does not properly work with THP, making the hmm-tests selftests fail if THPs are enabled on the system. Looking into more details, I found that hugetlb is not properly fenced, and I realized that something that was bugging me for longer -- how device-exclusive entries interact with mapcounts -- completely breaks migration/swapout/split/hwpoison handling of these folios while they have device-exclusive PTEs. The program below can be used to allocate 1 GiB worth of pages and making them device-exclusive on a kernel with CONFIG_TEST_HMM. Once they are device-exclusive, these folios cannot get swapped out (proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much one forces memory reclaim), and when having a memory block onlined to ZONE_MOVABLE, trying to offline it will loop forever and complain about failed migration of a page that should be movable. # echo offline > /sys/devices/system/memory/memory136/state # echo online_movable > /sys/devices/system/memory/memory136/state # ./hmm-swap & ... wait until everything is device-exclusive # echo offline > /sys/devices/system/memory/memory136/state [ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x7f20671f7 pfn:0x442b6a [ 285.196618][T14882] memcg:ffff888179298000 [ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate| dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff) [ 285.201734][T14882] raw: ... [ 285.204464][T14882] raw: ... [ 285.207196][T14882] page dumped because: migration failure [ 285.209072][T14882] page_owner tracks the page as allocated [ 285.210915][T14882] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774 [ 285.216765][T14882] post_alloc_hook+0x197/0x1b0 [ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280 [ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740 [ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540 [ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340 [ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0 [ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0 [ 285.230822][T14882] handle_mm_fault+0x368/0x9f0 ... This series fixes all issues I found so far. There is no easy way to fix without a bigger rework/cleanup. I have a bunch of cleanups on top (some previous sent, some the result of the discussion in v1) that I will send out separately once this landed and I get to it. I wish we could just use some special present PROT_NONE PTEs instead of these (non-present, non-none) fake-swap entries; but that just results in the same problem we keep having (lack of spare PTE bits), and staring at other similar fake-swap entries, that ship has sailed. With this series, make_device_exclusive() doesn't actually belong into mm/rmap.c anymore, but I'll leave moving that for another day. I only tested this series with the hmm-tests selftests due to lack of HW, so I'd appreciate some testing, especially if the interaction between two GPUs wanting a device-exclusive entry works as expected. <program> #include <stdio.h> #include <fcntl.h> #include <stdint.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/ioctl.h> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) struct hmm_dmirror_cmd { __u64 addr; __u64 ptr; __u64 npages; __u64 cpages; __u64 faults; }; const size_t size = 1 * 1024 * 1024 * 1024ul; const size_t chunk_size = 2 * 1024 * 1024ul; int main(void) { struct hmm_dmirror_cmd cmd; size_t cur_size; int fd, ret; char *addr, *mirror; fd = open("/dev/hmm_dmirror1", O_RDWR, 0); if (fd < 0) { perror("open failed\n"); exit(1); } addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (addr == MAP_FAILED) { perror("mmap failed\n"); exit(1); } madvise(addr, size, MADV_NOHUGEPAGE); memset(addr, 1, size); mirror = malloc(chunk_size); for (cur_size = 0; cur_size < size; cur_size += chunk_size) { cmd.addr = (uintptr_t)addr + cur_size; cmd.ptr = (uintptr_t)mirror; cmd.npages = chunk_size / getpagesize(); ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd); if (ret) { perror("ioctl failed\n"); exit(1); } } pause(); return 0; } </program> [1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com This patch (of 17): We only have two FOLL_SPLIT_PMD users. While uprobe refuses hugetlb early, make_device_exclusive_range() can end up getting called on hugetlb VMAs. Right now, this means that with a PMD-sized hugetlb page, we can end up calling split_huge_pmd(), because pmd_trans_huge() also succeeds with hugetlb PMDs. For example, using a modified hmm-test selftest one can trigger: [ 207.017134][T14945] ------------[ cut here ]------------ [ 207.018614][T14945] kernel BUG at mm/page_table_check.c:87! [ 207.019716][T14945] Oops: invalid opcode: 0000 [linuxppc#1] PREEMPT SMP KASAN NOPTI [ 207.021072][T14945] CPU: 3 UID: 0 PID: ... [ 207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510 [ 207.026128][T14945] Code: ... [ 207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293 [ 207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd [ 207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80 [ 207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000 [ 207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001 [ 207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000 [ 207.038711][T14945] FS: 00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000 [ 207.040407][T14945] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0 [ 207.043196][T14945] PKRU: 55555554 [ 207.043880][T14945] Call Trace: [ 207.044506][T14945] <TASK> [ 207.045086][T14945] ? __die+0x51/0x92 [ 207.045864][T14945] ? die+0x29/0x50 [ 207.046596][T14945] ? do_trap+0x250/0x320 [ 207.047430][T14945] ? do_error_trap+0xe7/0x220 [ 207.048346][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.049535][T14945] ? handle_invalid_op+0x34/0x40 [ 207.050494][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.051681][T14945] ? exc_invalid_op+0x2e/0x50 [ 207.052589][T14945] ? asm_exc_invalid_op+0x1a/0x20 [ 207.053596][T14945] ? page_table_check_clear.part.0+0x1fd/0x510 [ 207.054790][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.055993][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.057195][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.058384][T14945] __page_table_check_pmd_clear+0x34b/0x5a0 [ 207.059524][T14945] ? __pfx___page_table_check_pmd_clear+0x10/0x10 [ 207.060775][T14945] ? __pfx___mutex_unlock_slowpath+0x10/0x10 [ 207.061940][T14945] ? __pfx___lock_acquire+0x10/0x10 [ 207.062967][T14945] pmdp_huge_clear_flush+0x279/0x360 [ 207.064024][T14945] split_huge_pmd_locked+0x82b/0x3750 ... Before commit 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code"), we would have ignored the flag; instead, let's simply refuse the combination completely in check_vma_flags(): the caller is likely not prepared to handle any hugetlb folios. We'll teach make_device_exclusive_range() separately to ignore any hugetlb folios as a future-proof safety net. Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com Fixes: 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Barry Song <v-songbaohua@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

We have recently seen reports of lockdep circular lock dependency warnings when loading the iAVF driver: [ 1504.790308] ====================================================== [ 1504.790309] WARNING: possible circular locking dependency detected [ 1504.790310] 6.13.0 #net_next_rt.c2933b2befe2.el9 Not tainted [ 1504.790311] ------------------------------------------------------ [ 1504.790312] kworker/u128:0/13566 is trying to acquire lock: [ 1504.790313] ffff97d0e4738f18 (&dev->lock){+.+.}-{4:4}, at: register_netdevice+0x52c/0x710 [ 1504.790320] [ 1504.790320] but task is already holding lock: [ 1504.790321] ffff97d0e47392e8 (&adapter->crit_lock){+.+.}-{4:4}, at: iavf_finish_config+0x37/0x240 [iavf] [ 1504.790330] [ 1504.790330] which lock already depends on the new lock. [ 1504.790330] [ 1504.790330] [ 1504.790330] the existing dependency chain (in reverse order) is: [ 1504.790331] [ 1504.790331] -> linuxppc#1 (&adapter->crit_lock){+.+.}-{4:4}: [ 1504.790333] __lock_acquire+0x52d/0xbb0 [ 1504.790337] lock_acquire+0xd9/0x330 [ 1504.790338] mutex_lock_nested+0x4b/0xb0 [ 1504.790341] iavf_finish_config+0x37/0x240 [iavf] [ 1504.790347] process_one_work+0x248/0x6d0 [ 1504.790350] worker_thread+0x18d/0x330 [ 1504.790352] kthread+0x10e/0x250 [ 1504.790354] ret_from_fork+0x30/0x50 [ 1504.790357] ret_from_fork_asm+0x1a/0x30 [ 1504.790361] [ 1504.790361] -> #0 (&dev->lock){+.+.}-{4:4}: [ 1504.790364] check_prev_add+0xf1/0xce0 [ 1504.790366] validate_chain+0x46a/0x570 [ 1504.790368] __lock_acquire+0x52d/0xbb0 [ 1504.790370] lock_acquire+0xd9/0x330 [ 1504.790371] mutex_lock_nested+0x4b/0xb0 [ 1504.790372] register_netdevice+0x52c/0x710 [ 1504.790374] iavf_finish_config+0xfa/0x240 [iavf] [ 1504.790379] process_one_work+0x248/0x6d0 [ 1504.790381] worker_thread+0x18d/0x330 [ 1504.790383] kthread+0x10e/0x250 [ 1504.790385] ret_from_fork+0x30/0x50 [ 1504.790387] ret_from_fork_asm+0x1a/0x30 [ 1504.790389] [ 1504.790389] other info that might help us debug this: [ 1504.790389] [ 1504.790389] Possible unsafe locking scenario: [ 1504.790389] [ 1504.790390] CPU0 CPU1 [ 1504.790391] ---- ---- [ 1504.790391] lock(&adapter->crit_lock); [ 1504.790393] lock(&dev->lock); [ 1504.790394] lock(&adapter->crit_lock); [ 1504.790395] lock(&dev->lock); [ 1504.790397] [ 1504.790397] *** DEADLOCK *** This appears to be caused by the change in commit 5fda3f3 ("net: make netdev_lock() protect netdev->reg_state"), which added a netdev_lock() in register_netdevice. The iAVF driver calls register_netdevice() from iavf_finish_config(), as a final stage of its state machine post-probe. It currently takes the RTNL lock, then the netdev lock, and then the device critical lock. This pattern is used throughout the driver. Thus there is a strong dependency that the crit_lock should not be acquired before the net device lock. The change to register_netdevice creates an ABBA lock order violation because the iAVF driver is holding the crit_lock while calling register_netdevice, which then takes the netdev_lock. It seems likely that future refactors could result in netdev APIs which hold the netdev_lock while calling into the driver. This means that we should not re-order the locks so that netdev_lock is acquired after the device private crit_lock. Instead, notice that we already release the netdev_lock prior to calling the register_netdevice. This flow only happens during the early driver initialization as we transition through the __IAVF_STARTUP, __IAVF_INIT_VERSION_CHECK, __IAVF_INIT_GET_RESOURCES, etc. Analyzing the places where we take crit_lock in the driver there are two sources: a) several of the work queue tasks including adminq_task, watchdog_task, reset_task, and the finish_config task. b) various callbacks which ultimately stem back to .ndo operations or ethtool operations. The latter cannot be triggered until after the netdevice registration is completed successfully. The iAVF driver uses alloc_ordered_workqueue, which is an unbound workqueue that has a max limit of 1, and thus guarantees that only a single work item on the queue is executing at any given time, so none of the other work threads could be executing due to the ordered workqueue guarantees. The iavf_finish_config() function also does not do anything else after register_netdevice, unless it fails. It seems unlikely that the driver private crit_lock is protecting anything that register_netdevice() itself touches. Thus, to fix this ABBA lock violation, lets simply release the adapter->crit_lock as well as netdev_lock prior to calling register_netdevice(). We do still keep holding the RTNL lock as required by the function. If we do fail to register the netdevice, then we re-acquire the adapter critical lock to finish the transition back to __IAVF_INIT_CONFIG_ADAPTER. This ensures every call where both netdev_lock and the adapter->crit_lock are acquired under the same ordering. Fixes: afc6649 ("eth: iavf: extend the netdev_lock usage") Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Tested-by: Rafal Romanowski <rafal.romanowski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Link: https://patch.msgid.link/20250224190647.3601930-5-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Commit b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined) add page poison checks in do_migrate_range in order to make offline hwpoisoned page possible by introducing isolate_lru_page and try_to_unmap for hwpoisoned page. However folio lock must be held before calling try_to_unmap. Add it to fix this problem. Warning will be produced if folio is not locked during unmap: ------------[ cut here ]------------ kernel BUG at ./include/linux/swapops.h:400! Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP Modules linked in: CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41 Tainted: [W]=WARN Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : try_to_unmap_one+0xb08/0xd3c lr : try_to_unmap_one+0x3dc/0xd3c Call trace: try_to_unmap_one+0xb08/0xd3c (P) try_to_unmap_one+0x3dc/0xd3c (L) rmap_walk_anon+0xdc/0x1f8 rmap_walk+0x3c/0x58 try_to_unmap+0x88/0x90 unmap_poisoned_folio+0x30/0xa8 do_migrate_range+0x4a0/0x568 offline_pages+0x5a4/0x670 memory_block_action+0x17c/0x374 memory_subsys_offline+0x3c/0x78 device_offline+0xa4/0xd0 state_store+0x8c/0xf0 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x118/0x1a8 vfs_write+0x3a8/0x4bc ksys_write+0x6c/0xf8 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xd0 el0t_64_sync_handler+0xc8/0xcc el0t_64_sync+0x198/0x19c Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000) ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20250217014329.3610326-4-mawupeng1@huawei.com Fixes: b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Address an Oops issues when performing test of loading XE GPU driver module after applying the GPU SVM and Xe SVM patch series[1] and the Dept patch series[2]. The issue occurs when loading the xe driver via modprobe [3], which adds a struct page for device memory via devm_memremap_pages(). When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This patch translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. [1] https://lore.kernel.org/dri-devel/20250213021112.1228481-1-matthew.brost@intel.com/ [2] https://lore.kernel.org/lkml/20240508094726.35754-1-byungchul@sk.com/ [3] [ 49.103630] xe 0000:00:04.0: [drm] Available VRAM: 0x0000000800000000, 0x00000002fb800000 [ 49.116710] BUG: unable to handle page fault for address: ffffeb3ff1200000 [ 49.117175] #PF: supervisor write access in kernel mode [ 49.117511] #PF: error_code(0x0002) - not-present page [ 49.117835] PGD 0 P4D 0 [ 49.118015] Oops: Oops: 0002 [linuxppc#1] PREEMPT SMP NOPTI [ 49.118366] CPU: 3 UID: 0 PID: 302 Comm: modprobe Tainted: G W 6.13.0-drm-tip-test+ #62 [ 49.118976] Tainted: [W]=WARN [ 49.119179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 49.119710] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.120011] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.121158] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.121502] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.121966] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.122499] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.123032] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.123566] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.124096] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.124698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.125129] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.125662] PKRU: 55555554 [ 49.125880] Call Trace: [ 49.126078] <TASK> [ 49.126252] ? __die_body.cold+0x19/0x26 [ 49.126509] ? page_fault_oops+0xa2/0x240 [ 49.126736] ? preempt_count_add+0x47/0xa0 [ 49.126968] ? search_module_extables+0x4a/0x80 [ 49.127224] ? exc_page_fault+0x206/0x230 [ 49.127454] ? asm_exc_page_fault+0x22/0x30 [ 49.127691] ? vmemmap_set_pmd+0xff/0x230 [ 49.127919] vmemmap_populate_hugepages+0x176/0x180 [ 49.128194] vmemmap_populate+0x34/0x80 [ 49.128416] __populate_section_memmap+0x41/0x90 [ 49.128676] sparse_add_section+0x121/0x3e0 [ 49.128914] __add_pages+0xba/0x150 [ 49.129116] add_pages+0x1d/0x70 [ 49.129305] memremap_pages+0x3dc/0x810 [ 49.129529] devm_memremap_pages+0x1c/0x60 [ 49.129762] xe_devm_add+0x8b/0x100 [xe] [ 49.130072] xe_tile_init_noalloc+0x6a/0x70 [xe] [ 49.130408] xe_device_probe+0x48c/0x740 [xe] [ 49.130714] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.130982] ? __drmm_add_action+0x85/0xd0 [ 49.131208] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.131478] xe_pci_probe+0x7ef/0xd90 [xe] [ 49.131777] ? _raw_spin_unlock_irqrestore+0x66/0x90 [ 49.132049] ? lockdep_hardirqs_on+0xba/0x140 [ 49.132290] pci_device_probe+0x99/0x110 [ 49.132510] really_probe+0xdb/0x340 [ 49.132710] ? pm_runtime_barrier+0x50/0x90 [ 49.132941] ? __pfx___driver_attach+0x10/0x10 [ 49.133190] __driver_probe_device+0x78/0x110 [ 49.133433] driver_probe_device+0x1f/0xa0 [ 49.133661] __driver_attach+0xba/0x1c0 [ 49.133874] bus_for_each_dev+0x7a/0xd0 [ 49.134089] bus_add_driver+0x114/0x200 [ 49.134302] driver_register+0x6e/0xc0 [ 49.134515] xe_init+0x1e/0x50 [xe] [ 49.134827] ? __pfx_xe_init+0x10/0x10 [xe] [ 49.134926] xe 0000:00:04.0: [drm:process_one_work] GT1: GuC CT safe-mode canceled [ 49.135112] do_one_initcall+0x5b/0x2b0 [ 49.135734] ? rcu_is_watching+0xd/0x40 [ 49.135995] ? __kmalloc_cache_noprof+0x231/0x310 [ 49.136315] do_init_module+0x60/0x210 [ 49.136572] init_module_from_file+0x86/0xc0 [ 49.136863] idempotent_init_module+0x12b/0x340 [ 49.137156] __x64_sys_finit_module+0x61/0xc0 [ 49.137437] do_syscall_64+0x69/0x140 [ 49.137681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 49.137953] RIP: 0033:0x7f53ae1261fd [ 49.138153] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 fa 0c 00 f7 d8 64 89 01 48 [ 49.139117] RSP: 002b:00007ffd0e9021e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 49.139525] RAX: ffffffffffffffda RBX: 000055c02951ee50 RCX: 00007f53ae1261fd [ 49.139905] RDX: 0000000000000000 RSI: 000055bfff125478 RDI: 0000000000000010 [ 49.140282] RBP: 000055bfff125478 R08: 00007f53ae1f6b20 R09: 00007ffd0e902230 [ 49.140663] R10: 000055c029522000 R11: 0000000000000246 R12: 0000000000040000 [ 49.141040] R13: 000055c02951ef80 R14: 0000000000000000 R15: 000055c029521fc0 [ 49.141424] </TASK> [ 49.141552] Modules linked in: xe(+) drm_ttm_helper gpu_sched drm_suballoc_helper drm_gpuvm drm_exec drm_gpusvm i2c_algo_bit drm_buddy video wmi ttm drm_display_helper drm_kms_helper crct10dif_pclmul crc32_pclmul i2c_piix4 e1000 ghash_clmulni_intel i2c_smbus fuse [ 49.142824] CR2: ffffeb3ff1200000 [ 49.143010] ---[ end trace 0000000000000000 ]--- [ 49.143268] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.143523] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.144489] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.144775] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.145154] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.145536] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.145914] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.146292] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.146671] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.147097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.147407] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.147786] PKRU: 55555554 [ 49.147941] note: modprobe[302] exited with irqs disabled When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. Link: https://lkml.kernel.org/r/20250217114133.400063-2-gwan-gyeong.mun@intel.com Fixes: faf1c00 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs") Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add a NULL check on the return value of swp_swap_info in __swap_duplicate to prevent crashes caused by NULL pointer dereference. The reason why swp_swap_info() returns NULL is unclear; it may be due to CPU cache issues or DDR bit flips. The probability of this issue is very small - it has been observed to occur approximately 1 in 500,000 times per week. The stack info we encountered is as follows: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [RB/E]rb_sreason_str_set: sreason_str set null_pointer Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=00000008a80e5000 [0000000000000058] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 0000000096000005 [linuxppc#1] PREEMPT SMP Skip md ftrace buffer dump for: 0x1609e0 ... pc : swap_duplicate+0x44/0x164 lr : copy_page_range+0x508/0x1e78 sp : ffffffc0f2a699e0 x29: ffffffc0f2a699e0 x28: ffffff8a5b28d388 x27: ffffff8b06603388 x26: ffffffdf7291fe70 x25: 0000000000000006 x24: 0000000000100073 x23: 00000000002d2d2f x22: 0000000000000008 x21: 0000000000000000 x20: 00000000002d2d2f x19: 18000000002d2d2f x18: ffffffdf726faec0 x17: 0000000000000000 x16: 0010000000000001 x15: 0040000000000001 x14: 0400000000000001 x13: ff7ffffffffffb7f x12: ffeffffffffffbff x11: ffffff8a5c7e1898 x10: 0000000000000018 x9 : 0000000000000006 x8 : 1800000000000000 x7 : 0000000000000000 x6 : ffffff8057c01f10 x5 : 000000000000a318 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000006daf200000 x1 : 0000000000000001 x0 : 18000000002d2d2f Call trace: swap_duplicate+0x44/0x164 copy_page_range+0x508/0x1e78 copy_process+0x1278/0x21cc kernel_clone+0x90/0x438 __arm64_sys_clone+0x5c/0x8c invoke_syscall+0x58/0x110 do_el0_svc+0x8c/0xe0 el0_svc+0x38/0x9c el0t_64_sync_handler+0x44/0xec el0t_64_sync+0x1a8/0x1ac Code: 9139c35a 71006f3f 54000568 f8797b55 (f9402ea8) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception SMP: stopping secondary CPUs The patch seems to only provide a workaround, but there are no more effective software solutions to handle the bit flips problem. This path will change the issue from a system crash to a process exception, thereby reducing the impact on the entire machine. Signed-off-by: gao xu <gaoxu2@honor.com> Link: https://lkml.kernel.org/r/e223b0e6ba2f4924984b1917cc717bd5@honor.com Reviewed-by: Barry Song <baohua@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

userfaultfd_move() checks whether the PTE entry is present or a swap entry. - If the PTE entry is present, move_present_pte() handles folio migration by setting: src_folio->index = linear_page_index(dst_vma, dst_addr); - If the PTE entry is a swap entry, move_swap_pte() simply copies the PTE to the new dst_addr. This approach is incorrect because, even if the PTE is a swap entry, it can still reference a folio that remains in the swap cache. This creates a race window between steps 2 and 4. 1. add_to_swap: The folio is added to the swapcache. 2. try_to_unmap: PTEs are converted to swap entries. 3. pageout: The folio is written back. 4. Swapcache is cleared. If userfaultfd_move() occurs in the window between steps 2 and 4, after the swap PTE has been moved to the destination, accessing the destination triggers do_swap_page(), which may locate the folio in the swapcache. However, since the folio's index has not been updated to match the destination VMA, do_swap_page() will detect a mismatch. This can result in two critical issues depending on the system configuration. If KSM is disabled, both small and large folios can trigger a BUG during the add_rmap operation due to: page_pgoff(folio, page) != linear_page_index(vma, address) [ 13.336953] page: refcount:6 mapcount:1 mapping:00000000f43db19c index:0xffffaf150 pfn:0x4667c [ 13.337520] head: order:2 mapcount:1 entire_mapcount:0 nr_pages_mapped:1 pincount:0 [ 13.337716] memcg:ffff00000405f000 [ 13.337849] anon flags: 0x3fffc0000020459(locked|uptodate|dirty|owner_priv_1|head|swapbacked|node=0|zone=0|lastcpupid=0xffff) [ 13.338630] raw: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.338831] raw: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339031] head: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.339204] head: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339375] head: 03fffc0000000202 fffffdffc0199f01 ffffffff00000000 0000000000000001 [ 13.339546] head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 [ 13.339736] page dumped because: VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address)) [ 13.340190] ------------[ cut here ]------------ [ 13.340316] kernel BUG at mm/rmap.c:1380! [ 13.340683] Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP [ 13.340969] Modules linked in: [ 13.341257] CPU: 1 UID: 0 PID: 107 Comm: a.out Not tainted 6.14.0-rc3-gcf42737e247a-dirty #299 [ 13.341470] Hardware name: linux,dummy-virt (DT) [ 13.341671] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 13.341815] pc : __page_check_anon_rmap+0xa0/0xb0 [ 13.341920] lr : __page_check_anon_rmap+0xa0/0xb0 [ 13.342018] sp : ffff80008752bb20 [ 13.342093] x29: ffff80008752bb20 x28: fffffdffc0199f00 x27: 0000000000000001 [ 13.342404] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000001 [ 13.342575] x23: 0000ffffaf0d0000 x22: 0000ffffaf0d0000 x21: fffffdffc0199f00 [ 13.342731] x20: fffffdffc0199f00 x19: ffff000006210700 x18: 00000000ffffffff [ 13.342881] x17: 6c203d2120296567 x16: 6170202c6f696c6f x15: 662866666f67705f [ 13.343033] x14: 6567617028454741 x13: 2929737365726464 x12: ffff800083728ab0 [ 13.343183] x11: ffff800082996bf8 x10: 0000000000000fd7 x9 : ffff80008011bc40 [ 13.343351] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000829eebf8 [ 13.343498] x5 : c0000000fffff000 x4 : 0000000000000000 x3 : 0000000000000000 [ 13.343645] x2 : 0000000000000000 x1 : ffff0000062db980 x0 : 000000000000005f [ 13.343876] Call trace: [ 13.344045] __page_check_anon_rmap+0xa0/0xb0 (P) [ 13.344234] folio_add_anon_rmap_ptes+0x22c/0x320 [ 13.344333] do_swap_page+0x1060/0x1400 [ 13.344417] __handle_mm_fault+0x61c/0xbc8 [ 13.344504] handle_mm_fault+0xd8/0x2e8 [ 13.344586] do_page_fault+0x20c/0x770 [ 13.344673] do_translation_fault+0xb4/0xf0 [ 13.344759] do_mem_abort+0x48/0xa0 [ 13.344842] el0_da+0x58/0x130 [ 13.344914] el0t_64_sync_handler+0xc4/0x138 [ 13.345002] el0t_64_sync+0x1ac/0x1b0 [ 13.345208] Code: aa1503e0 f000f801 910f6021 97ff5779 (d4210000) [ 13.345504] ---[ end trace 0000000000000000 ]--- [ 13.345715] note: a.out[107] exited with irqs disabled [ 13.345954] note: a.out[107] exited with preempt_count 2 If KSM is enabled, Peter Xu also discovered that do_swap_page() may trigger an unexpected CoW operation for small folios because ksm_might_need_to_copy() allocates a new folio when the folio index does not match linear_page_index(vma, addr). This patch also checks the swapcache when handling swap entries. If a match is found in the swapcache, it processes it similarly to a present PTE. However, there are some differences. For example, the folio is no longer exclusive because folio_try_share_anon_rmap_pte() is performed during unmapping. Furthermore, in the case of swapcache, the folio has already been unmapped, eliminating the risk of concurrent rmap walks and removing the need to acquire src_folio's anon_vma or lock. Note that for large folios, in the swapcache handling path, we directly return -EBUSY since split_folio() will return -EBUSY regardless if the folio is under writeback or unmapped. This is not an urgent issue, so a follow-up patch may address it separately. Link: https://lkml.kernel.org/r/20250226001400.9129-1-21cnbao@gmail.com Fixes: adef440 ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

I found a NULL pointer dereference as followed: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [linuxppc#1] SMP PTI CPU: 5 UID: 0 PID: 5964 Comm: sh Kdump: loaded Not tainted 6.13.0-dirty #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1. RIP: 0010:has_unmovable_pages+0x184/0x360 ... Call Trace: <TASK> set_migratetype_isolate+0xd1/0x180 start_isolate_page_range+0xd2/0x170 alloc_contig_range_noprof+0x101/0x660 alloc_contig_pages_noprof+0x238/0x290 alloc_gigantic_folio.isra.0+0xb6/0x1f0 only_alloc_fresh_hugetlb_folio.isra.0+0xf/0x60 alloc_pool_huge_folio+0x80/0xf0 set_max_huge_pages+0x211/0x490 __nr_hugepages_store_common+0x5f/0xe0 nr_hugepages_store+0x77/0x80 kernfs_fop_write_iter+0x118/0x200 vfs_write+0x23c/0x3f0 ksys_write+0x62/0xe0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e As has_unmovable_pages() call folio_hstate() without hugetlb_lock, there is a race to free the HugeTLB page between PageHuge() and folio_hstate(). There is no need to add hugetlb_lock here as the HugeTLB page can be freed in lot of places. So it's enough to unfold folio_hstate() and add a check to avoid NULL pointer dereference for hugepage_migration_supported(). Link: https://lkml.kernel.org/r/20250122061151.578768-1-liushixin2@huawei.com Fixes: 464c7ff ("mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm: fixes for device-exclusive entries (hmm)", v2. Discussing the PageTail() call in make_device_exclusive_range() with Willy, I recently discovered [1] that device-exclusive handling does not properly work with THP, making the hmm-tests selftests fail if THPs are enabled on the system. Looking into more details, I found that hugetlb is not properly fenced, and I realized that something that was bugging me for longer -- how device-exclusive entries interact with mapcounts -- completely breaks migration/swapout/split/hwpoison handling of these folios while they have device-exclusive PTEs. The program below can be used to allocate 1 GiB worth of pages and making them device-exclusive on a kernel with CONFIG_TEST_HMM. Once they are device-exclusive, these folios cannot get swapped out (proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much one forces memory reclaim), and when having a memory block onlined to ZONE_MOVABLE, trying to offline it will loop forever and complain about failed migration of a page that should be movable. # echo offline > /sys/devices/system/memory/memory136/state # echo online_movable > /sys/devices/system/memory/memory136/state # ./hmm-swap & ... wait until everything is device-exclusive # echo offline > /sys/devices/system/memory/memory136/state [ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x7f20671f7 pfn:0x442b6a [ 285.196618][T14882] memcg:ffff888179298000 [ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate| dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff) [ 285.201734][T14882] raw: ... [ 285.204464][T14882] raw: ... [ 285.207196][T14882] page dumped because: migration failure [ 285.209072][T14882] page_owner tracks the page as allocated [ 285.210915][T14882] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774 [ 285.216765][T14882] post_alloc_hook+0x197/0x1b0 [ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280 [ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740 [ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540 [ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340 [ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0 [ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0 [ 285.230822][T14882] handle_mm_fault+0x368/0x9f0 ... This series fixes all issues I found so far. There is no easy way to fix without a bigger rework/cleanup. I have a bunch of cleanups on top (some previous sent, some the result of the discussion in v1) that I will send out separately once this landed and I get to it. I wish we could just use some special present PROT_NONE PTEs instead of these (non-present, non-none) fake-swap entries; but that just results in the same problem we keep having (lack of spare PTE bits), and staring at other similar fake-swap entries, that ship has sailed. With this series, make_device_exclusive() doesn't actually belong into mm/rmap.c anymore, but I'll leave moving that for another day. I only tested this series with the hmm-tests selftests due to lack of HW, so I'd appreciate some testing, especially if the interaction between two GPUs wanting a device-exclusive entry works as expected. <program> #include <stdio.h> #include <fcntl.h> #include <stdint.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/ioctl.h> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) struct hmm_dmirror_cmd { __u64 addr; __u64 ptr; __u64 npages; __u64 cpages; __u64 faults; }; const size_t size = 1 * 1024 * 1024 * 1024ul; const size_t chunk_size = 2 * 1024 * 1024ul; int main(void) { struct hmm_dmirror_cmd cmd; size_t cur_size; int fd, ret; char *addr, *mirror; fd = open("/dev/hmm_dmirror1", O_RDWR, 0); if (fd < 0) { perror("open failed\n"); exit(1); } addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (addr == MAP_FAILED) { perror("mmap failed\n"); exit(1); } madvise(addr, size, MADV_NOHUGEPAGE); memset(addr, 1, size); mirror = malloc(chunk_size); for (cur_size = 0; cur_size < size; cur_size += chunk_size) { cmd.addr = (uintptr_t)addr + cur_size; cmd.ptr = (uintptr_t)mirror; cmd.npages = chunk_size / getpagesize(); ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd); if (ret) { perror("ioctl failed\n"); exit(1); } } pause(); return 0; } </program> [1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com This patch (of 17): We only have two FOLL_SPLIT_PMD users. While uprobe refuses hugetlb early, make_device_exclusive_range() can end up getting called on hugetlb VMAs. Right now, this means that with a PMD-sized hugetlb page, we can end up calling split_huge_pmd(), because pmd_trans_huge() also succeeds with hugetlb PMDs. For example, using a modified hmm-test selftest one can trigger: [ 207.017134][T14945] ------------[ cut here ]------------ [ 207.018614][T14945] kernel BUG at mm/page_table_check.c:87! [ 207.019716][T14945] Oops: invalid opcode: 0000 [linuxppc#1] PREEMPT SMP KASAN NOPTI [ 207.021072][T14945] CPU: 3 UID: 0 PID: ... [ 207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510 [ 207.026128][T14945] Code: ... [ 207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293 [ 207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd [ 207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80 [ 207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000 [ 207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001 [ 207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000 [ 207.038711][T14945] FS: 00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000 [ 207.040407][T14945] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0 [ 207.043196][T14945] PKRU: 55555554 [ 207.043880][T14945] Call Trace: [ 207.044506][T14945] <TASK> [ 207.045086][T14945] ? __die+0x51/0x92 [ 207.045864][T14945] ? die+0x29/0x50 [ 207.046596][T14945] ? do_trap+0x250/0x320 [ 207.047430][T14945] ? do_error_trap+0xe7/0x220 [ 207.048346][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.049535][T14945] ? handle_invalid_op+0x34/0x40 [ 207.050494][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.051681][T14945] ? exc_invalid_op+0x2e/0x50 [ 207.052589][T14945] ? asm_exc_invalid_op+0x1a/0x20 [ 207.053596][T14945] ? page_table_check_clear.part.0+0x1fd/0x510 [ 207.054790][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.055993][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.057195][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.058384][T14945] __page_table_check_pmd_clear+0x34b/0x5a0 [ 207.059524][T14945] ? __pfx___page_table_check_pmd_clear+0x10/0x10 [ 207.060775][T14945] ? __pfx___mutex_unlock_slowpath+0x10/0x10 [ 207.061940][T14945] ? __pfx___lock_acquire+0x10/0x10 [ 207.062967][T14945] pmdp_huge_clear_flush+0x279/0x360 [ 207.064024][T14945] split_huge_pmd_locked+0x82b/0x3750 ... Before commit 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code"), we would have ignored the flag; instead, let's simply refuse the combination completely in check_vma_flags(): the caller is likely not prepared to handle any hugetlb folios. We'll teach make_device_exclusive_range() separately to ignore any hugetlb folios as a future-proof safety net. Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com Fixes: 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Barry Song <v-songbaohua@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The customer reports that there is a soft lockup issue related to the i2c driver. After checking, the i2c module was doing a tx transfer and the bmc machine reboots in the middle of the i2c transaction, the i2c module keeps the status without being reset. Due to such an i2c module status, the i2c irq handler keeps getting triggered since the i2c irq handler is registered in the kernel booting process after the bmc machine is doing a warm rebooting. The continuous triggering is stopped by the soft lockup watchdog timer. Disable the interrupt enable bit in the i2c module before calling devm_request_irq to fix this issue since the i2c relative status bit is read-only. Here is the soft lockup log. [ 28.176395] watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [swapper/0:1] [ 28.183351] Modules linked in: [ 28.186407] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.120-yocto-s-dirty-bbebc78 linuxppc#1 [ 28.201174] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 28.208128] pc : __do_softirq+0xb0/0x368 [ 28.212055] lr : __do_softirq+0x70/0x368 [ 28.215972] sp : ffffff8035ebca00 [ 28.219278] x29: ffffff8035ebca00 x28: 0000000000000002 x27: ffffff80071a3780 [ 28.226412] x26: ffffffc008bdc000 x25: ffffffc008bcc640 x24: ffffffc008be50c0 [ 28.233546] x23: ffffffc00800200c x22: 0000000000000000 x21: 000000000000001b [ 28.240679] x20: 0000000000000000 x19: ffffff80001c3200 x18: ffffffffffffffff [ 28.247812] x17: ffffffc02d2e0000 x16: ffffff8035eb8b40 x15: 00001e8480000000 [ 28.254945] x14: 02c3647e37dbfcb6 x13: 02c364f2ab14200c x12: 0000000002c364f2 [ 28.262078] x11: 00000000fa83b2da x10: 000000000000b67e x9 : ffffffc008010250 [ 28.269211] x8 : 000000009d983d00 x7 : 7fffffffffffffff x6 : 0000036d74732434 [ 28.276344] x5 : 00ffffffffffffff x4 : 0000000000000015 x3 : 0000000000000198 [ 28.283476] x2 : ffffffc02d2e0000 x1 : 00000000000000e0 x0 : ffffffc008bdcb40 [ 28.290611] Call trace: [ 28.293052] __do_softirq+0xb0/0x368 [ 28.296625] __irq_exit_rcu+0xe0/0x100 [ 28.300374] irq_exit+0x14/0x20 [ 28.303513] handle_domain_irq+0x68/0x90 [ 28.307440] gic_handle_irq+0x78/0xb0 [ 28.311098] call_on_irq_stack+0x20/0x38 [ 28.315019] do_interrupt_handler+0x54/0x5c [ 28.319199] el1_interrupt+0x2c/0x4c [ 28.322777] el1h_64_irq_handler+0x14/0x20 [ 28.326872] el1h_64_irq+0x74/0x78 [ 28.330269] __setup_irq+0x454/0x780 [ 28.333841] request_threaded_irq+0xd0/0x1b4 [ 28.338107] devm_request_threaded_irq+0x84/0x100 [ 28.342809] npcm_i2c_probe_bus+0x188/0x3d0 [ 28.346990] platform_probe+0x6c/0xc4 [ 28.350653] really_probe+0xcc/0x45c [ 28.354227] __driver_probe_device+0x8c/0x160 [ 28.358578] driver_probe_device+0x44/0xe0 [ 28.362670] __driver_attach+0x124/0x1d0 [ 28.366589] bus_for_each_dev+0x7c/0xe0 [ 28.370426] driver_attach+0x28/0x30 [ 28.373997] bus_add_driver+0x124/0x240 [ 28.377830] driver_register+0x7c/0x124 [ 28.381662] __platform_driver_register+0x2c/0x34 [ 28.386362] npcm_i2c_init+0x3c/0x5c [ 28.389937] do_one_initcall+0x74/0x230 [ 28.393768] kernel_init_freeable+0x24c/0x2b4 [ 28.398126] kernel_init+0x28/0x130 [ 28.401614] ret_from_fork+0x10/0x20 [ 28.405189] Kernel panic - not syncing: softlockup: hung tasks [ 28.411011] SMP: stopping secondary CPUs [ 28.414933] Kernel Offset: disabled [ 28.418412] CPU features: 0x00000000,00000802 [ 28.427644] Rebooting in 20 seconds.. Fixes: 56a1485 ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver") Signed-off-by: Tyrone Ting <kfting@nuvoton.com> Cc: <stable@vger.kernel.org> # v5.8+ Reviewed-by: Tali Perry <tali.perry1@gmail.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org> Link: https://lore.kernel.org/r/20250220040029.27596-2-kfting@nuvoton.com

syzbot reported a deadlock in lock_system_sleep() (see below). The write operation to "/sys/module/hibernate/parameters/compressor" conflicts with the registration of ieee80211 device, resulting in a deadlock when attempting to acquire system_transition_mutex under param_lock. To avoid this deadlock, change hibernate_compressor_param_set() to use mutex_trylock() for attempting to acquire system_transition_mutex and return -EBUSY when it fails. Task flags need not be saved or adjusted before calling mutex_trylock(&system_transition_mutex) because the caller is not going to end up waiting for this mutex and if it runs concurrently with system suspend in progress, it will be frozen properly when it returns to user space. syzbot report: syz-executor895/5833 is trying to acquire lock: ffffffff8e0828c8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 but task is already holding lock: ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: kernel_param_lock kernel/params.c:607 [inline] ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: param_attr_store+0xe6/0x300 kernel/params.c:586 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (param_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ieee80211_rate_control_ops_get net/mac80211/rate.c:220 [inline] rate_control_alloc net/mac80211/rate.c:266 [inline] ieee80211_init_rate_ctrl_alg+0x18d/0x6b0 net/mac80211/rate.c:1015 ieee80211_register_hw+0x20cd/0x4060 net/mac80211/main.c:1531 mac80211_hwsim_new_radio+0x304e/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558 init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910 do_one_initcall+0x128/0x700 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1568 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> linuxppc#2 (rtnl_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 wg_pm_notification drivers/net/wireguard/device.c:80 [inline] wg_pm_notification+0x49/0x180 drivers/net/wireguard/device.c:64 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> linuxppc#1 ((pm_chain_head).rwsem){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (system_transition_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 hibernate_compressor_param_set+0x1c/0x210 kernel/power/hibernate.c:1452 param_attr_store+0x18f/0x300 kernel/params.c:588 module_attr_store+0x55/0x80 kernel/params.c:924 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: system_transition_mutex --> rtnl_mutex --> param_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(param_lock); lock(rtnl_mutex); lock(param_lock); lock(system_transition_mutex); *** DEADLOCK *** Reported-by: syzbot+ace60642828c074eb913@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=ace60642828c074eb913 Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Link: https://patch.msgid.link/20250224013139.3994500-1-lizhi.xu@windriver.com [ rjw: New subject matching the code changes, changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined) add page poison checks in do_migrate_range in order to make offline hwpoisoned page possible by introducing isolate_lru_page and try_to_unmap for hwpoisoned page. However folio lock must be held before calling try_to_unmap. Add it to fix this problem. Warning will be produced if folio is not locked during unmap: ------------[ cut here ]------------ kernel BUG at ./include/linux/swapops.h:400! Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP Modules linked in: CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41 Tainted: [W]=WARN Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : try_to_unmap_one+0xb08/0xd3c lr : try_to_unmap_one+0x3dc/0xd3c Call trace: try_to_unmap_one+0xb08/0xd3c (P) try_to_unmap_one+0x3dc/0xd3c (L) rmap_walk_anon+0xdc/0x1f8 rmap_walk+0x3c/0x58 try_to_unmap+0x88/0x90 unmap_poisoned_folio+0x30/0xa8 do_migrate_range+0x4a0/0x568 offline_pages+0x5a4/0x670 memory_block_action+0x17c/0x374 memory_subsys_offline+0x3c/0x78 device_offline+0xa4/0xd0 state_store+0x8c/0xf0 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x118/0x1a8 vfs_write+0x3a8/0x4bc ksys_write+0x6c/0xf8 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xd0 el0t_64_sync_handler+0xc8/0xcc el0t_64_sync+0x198/0x19c Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000) ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20250217014329.3610326-4-mawupeng1@huawei.com Fixes: b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Address an Oops issues when performing test of loading XE GPU driver module after applying the GPU SVM and Xe SVM patch series[1] and the Dept patch series[2]. The issue occurs when loading the xe driver via modprobe [3], which adds a struct page for device memory via devm_memremap_pages(). When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This patch translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. [1] https://lore.kernel.org/dri-devel/20250213021112.1228481-1-matthew.brost@intel.com/ [2] https://lore.kernel.org/lkml/20240508094726.35754-1-byungchul@sk.com/ [3] [ 49.103630] xe 0000:00:04.0: [drm] Available VRAM: 0x0000000800000000, 0x00000002fb800000 [ 49.116710] BUG: unable to handle page fault for address: ffffeb3ff1200000 [ 49.117175] #PF: supervisor write access in kernel mode [ 49.117511] #PF: error_code(0x0002) - not-present page [ 49.117835] PGD 0 P4D 0 [ 49.118015] Oops: Oops: 0002 [linuxppc#1] PREEMPT SMP NOPTI [ 49.118366] CPU: 3 UID: 0 PID: 302 Comm: modprobe Tainted: G W 6.13.0-drm-tip-test+ #62 [ 49.118976] Tainted: [W]=WARN [ 49.119179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 49.119710] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.120011] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.121158] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.121502] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.121966] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.122499] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.123032] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.123566] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.124096] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.124698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.125129] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.125662] PKRU: 55555554 [ 49.125880] Call Trace: [ 49.126078] <TASK> [ 49.126252] ? __die_body.cold+0x19/0x26 [ 49.126509] ? page_fault_oops+0xa2/0x240 [ 49.126736] ? preempt_count_add+0x47/0xa0 [ 49.126968] ? search_module_extables+0x4a/0x80 [ 49.127224] ? exc_page_fault+0x206/0x230 [ 49.127454] ? asm_exc_page_fault+0x22/0x30 [ 49.127691] ? vmemmap_set_pmd+0xff/0x230 [ 49.127919] vmemmap_populate_hugepages+0x176/0x180 [ 49.128194] vmemmap_populate+0x34/0x80 [ 49.128416] __populate_section_memmap+0x41/0x90 [ 49.128676] sparse_add_section+0x121/0x3e0 [ 49.128914] __add_pages+0xba/0x150 [ 49.129116] add_pages+0x1d/0x70 [ 49.129305] memremap_pages+0x3dc/0x810 [ 49.129529] devm_memremap_pages+0x1c/0x60 [ 49.129762] xe_devm_add+0x8b/0x100 [xe] [ 49.130072] xe_tile_init_noalloc+0x6a/0x70 [xe] [ 49.130408] xe_device_probe+0x48c/0x740 [xe] [ 49.130714] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.130982] ? __drmm_add_action+0x85/0xd0 [ 49.131208] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.131478] xe_pci_probe+0x7ef/0xd90 [xe] [ 49.131777] ? _raw_spin_unlock_irqrestore+0x66/0x90 [ 49.132049] ? lockdep_hardirqs_on+0xba/0x140 [ 49.132290] pci_device_probe+0x99/0x110 [ 49.132510] really_probe+0xdb/0x340 [ 49.132710] ? pm_runtime_barrier+0x50/0x90 [ 49.132941] ? __pfx___driver_attach+0x10/0x10 [ 49.133190] __driver_probe_device+0x78/0x110 [ 49.133433] driver_probe_device+0x1f/0xa0 [ 49.133661] __driver_attach+0xba/0x1c0 [ 49.133874] bus_for_each_dev+0x7a/0xd0 [ 49.134089] bus_add_driver+0x114/0x200 [ 49.134302] driver_register+0x6e/0xc0 [ 49.134515] xe_init+0x1e/0x50 [xe] [ 49.134827] ? __pfx_xe_init+0x10/0x10 [xe] [ 49.134926] xe 0000:00:04.0: [drm:process_one_work] GT1: GuC CT safe-mode canceled [ 49.135112] do_one_initcall+0x5b/0x2b0 [ 49.135734] ? rcu_is_watching+0xd/0x40 [ 49.135995] ? __kmalloc_cache_noprof+0x231/0x310 [ 49.136315] do_init_module+0x60/0x210 [ 49.136572] init_module_from_file+0x86/0xc0 [ 49.136863] idempotent_init_module+0x12b/0x340 [ 49.137156] __x64_sys_finit_module+0x61/0xc0 [ 49.137437] do_syscall_64+0x69/0x140 [ 49.137681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 49.137953] RIP: 0033:0x7f53ae1261fd [ 49.138153] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 fa 0c 00 f7 d8 64 89 01 48 [ 49.139117] RSP: 002b:00007ffd0e9021e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 49.139525] RAX: ffffffffffffffda RBX: 000055c02951ee50 RCX: 00007f53ae1261fd [ 49.139905] RDX: 0000000000000000 RSI: 000055bfff125478 RDI: 0000000000000010 [ 49.140282] RBP: 000055bfff125478 R08: 00007f53ae1f6b20 R09: 00007ffd0e902230 [ 49.140663] R10: 000055c029522000 R11: 0000000000000246 R12: 0000000000040000 [ 49.141040] R13: 000055c02951ef80 R14: 0000000000000000 R15: 000055c029521fc0 [ 49.141424] </TASK> [ 49.141552] Modules linked in: xe(+) drm_ttm_helper gpu_sched drm_suballoc_helper drm_gpuvm drm_exec drm_gpusvm i2c_algo_bit drm_buddy video wmi ttm drm_display_helper drm_kms_helper crct10dif_pclmul crc32_pclmul i2c_piix4 e1000 ghash_clmulni_intel i2c_smbus fuse [ 49.142824] CR2: ffffeb3ff1200000 [ 49.143010] ---[ end trace 0000000000000000 ]--- [ 49.143268] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.143523] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.144489] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.144775] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.145154] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.145536] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.145914] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.146292] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.146671] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.147097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.147407] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.147786] PKRU: 55555554 [ 49.147941] note: modprobe[302] exited with irqs disabled When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. Link: https://lkml.kernel.org/r/20250217114133.400063-2-gwan-gyeong.mun@intel.com Fixes: faf1c00 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs") Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add a NULL check on the return value of swp_swap_info in __swap_duplicate to prevent crashes caused by NULL pointer dereference. The reason why swp_swap_info() returns NULL is unclear; it may be due to CPU cache issues or DDR bit flips. The probability of this issue is very small - it has been observed to occur approximately 1 in 500,000 times per week. The stack info we encountered is as follows: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [RB/E]rb_sreason_str_set: sreason_str set null_pointer Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=00000008a80e5000 [0000000000000058] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 0000000096000005 [linuxppc#1] PREEMPT SMP Skip md ftrace buffer dump for: 0x1609e0 ... pc : swap_duplicate+0x44/0x164 lr : copy_page_range+0x508/0x1e78 sp : ffffffc0f2a699e0 x29: ffffffc0f2a699e0 x28: ffffff8a5b28d388 x27: ffffff8b06603388 x26: ffffffdf7291fe70 x25: 0000000000000006 x24: 0000000000100073 x23: 00000000002d2d2f x22: 0000000000000008 x21: 0000000000000000 x20: 00000000002d2d2f x19: 18000000002d2d2f x18: ffffffdf726faec0 x17: 0000000000000000 x16: 0010000000000001 x15: 0040000000000001 x14: 0400000000000001 x13: ff7ffffffffffb7f x12: ffeffffffffffbff x11: ffffff8a5c7e1898 x10: 0000000000000018 x9 : 0000000000000006 x8 : 1800000000000000 x7 : 0000000000000000 x6 : ffffff8057c01f10 x5 : 000000000000a318 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000006daf200000 x1 : 0000000000000001 x0 : 18000000002d2d2f Call trace: swap_duplicate+0x44/0x164 copy_page_range+0x508/0x1e78 copy_process+0x1278/0x21cc kernel_clone+0x90/0x438 __arm64_sys_clone+0x5c/0x8c invoke_syscall+0x58/0x110 do_el0_svc+0x8c/0xe0 el0_svc+0x38/0x9c el0t_64_sync_handler+0x44/0xec el0t_64_sync+0x1a8/0x1ac Code: 9139c35a 71006f3f 54000568 f8797b55 (f9402ea8) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception SMP: stopping secondary CPUs The patch seems to only provide a workaround, but there are no more effective software solutions to handle the bit flips problem. This path will change the issue from a system crash to a process exception, thereby reducing the impact on the entire machine. Signed-off-by: gao xu <gaoxu2@honor.com> Link: https://lkml.kernel.org/r/e223b0e6ba2f4924984b1917cc717bd5@honor.com Reviewed-by: Barry Song <baohua@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

userfaultfd_move() checks whether the PTE entry is present or a swap entry. - If the PTE entry is present, move_present_pte() handles folio migration by setting: src_folio->index = linear_page_index(dst_vma, dst_addr); - If the PTE entry is a swap entry, move_swap_pte() simply copies the PTE to the new dst_addr. This approach is incorrect because, even if the PTE is a swap entry, it can still reference a folio that remains in the swap cache. This creates a race window between steps 2 and 4. 1. add_to_swap: The folio is added to the swapcache. 2. try_to_unmap: PTEs are converted to swap entries. 3. pageout: The folio is written back. 4. Swapcache is cleared. If userfaultfd_move() occurs in the window between steps 2 and 4, after the swap PTE has been moved to the destination, accessing the destination triggers do_swap_page(), which may locate the folio in the swapcache. However, since the folio's index has not been updated to match the destination VMA, do_swap_page() will detect a mismatch. This can result in two critical issues depending on the system configuration. If KSM is disabled, both small and large folios can trigger a BUG during the add_rmap operation due to: page_pgoff(folio, page) != linear_page_index(vma, address) [ 13.336953] page: refcount:6 mapcount:1 mapping:00000000f43db19c index:0xffffaf150 pfn:0x4667c [ 13.337520] head: order:2 mapcount:1 entire_mapcount:0 nr_pages_mapped:1 pincount:0 [ 13.337716] memcg:ffff00000405f000 [ 13.337849] anon flags: 0x3fffc0000020459(locked|uptodate|dirty|owner_priv_1|head|swapbacked|node=0|zone=0|lastcpupid=0xffff) [ 13.338630] raw: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.338831] raw: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339031] head: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.339204] head: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339375] head: 03fffc0000000202 fffffdffc0199f01 ffffffff00000000 0000000000000001 [ 13.339546] head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 [ 13.339736] page dumped because: VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address)) [ 13.340190] ------------[ cut here ]------------ [ 13.340316] kernel BUG at mm/rmap.c:1380! [ 13.340683] Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP [ 13.340969] Modules linked in: [ 13.341257] CPU: 1 UID: 0 PID: 107 Comm: a.out Not tainted 6.14.0-rc3-gcf42737e247a-dirty #299 [ 13.341470] Hardware name: linux,dummy-virt (DT) [ 13.341671] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 13.341815] pc : __page_check_anon_rmap+0xa0/0xb0 [ 13.341920] lr : __page_check_anon_rmap+0xa0/0xb0 [ 13.342018] sp : ffff80008752bb20 [ 13.342093] x29: ffff80008752bb20 x28: fffffdffc0199f00 x27: 0000000000000001 [ 13.342404] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000001 [ 13.342575] x23: 0000ffffaf0d0000 x22: 0000ffffaf0d0000 x21: fffffdffc0199f00 [ 13.342731] x20: fffffdffc0199f00 x19: ffff000006210700 x18: 00000000ffffffff [ 13.342881] x17: 6c203d2120296567 x16: 6170202c6f696c6f x15: 662866666f67705f [ 13.343033] x14: 6567617028454741 x13: 2929737365726464 x12: ffff800083728ab0 [ 13.343183] x11: ffff800082996bf8 x10: 0000000000000fd7 x9 : ffff80008011bc40 [ 13.343351] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000829eebf8 [ 13.343498] x5 : c0000000fffff000 x4 : 0000000000000000 x3 : 0000000000000000 [ 13.343645] x2 : 0000000000000000 x1 : ffff0000062db980 x0 : 000000000000005f [ 13.343876] Call trace: [ 13.344045] __page_check_anon_rmap+0xa0/0xb0 (P) [ 13.344234] folio_add_anon_rmap_ptes+0x22c/0x320 [ 13.344333] do_swap_page+0x1060/0x1400 [ 13.344417] __handle_mm_fault+0x61c/0xbc8 [ 13.344504] handle_mm_fault+0xd8/0x2e8 [ 13.344586] do_page_fault+0x20c/0x770 [ 13.344673] do_translation_fault+0xb4/0xf0 [ 13.344759] do_mem_abort+0x48/0xa0 [ 13.344842] el0_da+0x58/0x130 [ 13.344914] el0t_64_sync_handler+0xc4/0x138 [ 13.345002] el0t_64_sync+0x1ac/0x1b0 [ 13.345208] Code: aa1503e0 f000f801 910f6021 97ff5779 (d4210000) [ 13.345504] ---[ end trace 0000000000000000 ]--- [ 13.345715] note: a.out[107] exited with irqs disabled [ 13.345954] note: a.out[107] exited with preempt_count 2 If KSM is enabled, Peter Xu also discovered that do_swap_page() may trigger an unexpected CoW operation for small folios because ksm_might_need_to_copy() allocates a new folio when the folio index does not match linear_page_index(vma, addr). This patch also checks the swapcache when handling swap entries. If a match is found in the swapcache, it processes it similarly to a present PTE. However, there are some differences. For example, the folio is no longer exclusive because folio_try_share_anon_rmap_pte() is performed during unmapping. Furthermore, in the case of swapcache, the folio has already been unmapped, eliminating the risk of concurrent rmap walks and removing the need to acquire src_folio's anon_vma or lock. Note that for large folios, in the swapcache handling path, we directly return -EBUSY since split_folio() will return -EBUSY regardless if the folio is under writeback or unmapped. This is not an urgent issue, so a follow-up patch may address it separately. Link: https://lkml.kernel.org/r/20250226001400.9129-1-21cnbao@gmail.com Fixes: adef440 ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

I found a NULL pointer dereference as followed: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [linuxppc#1] SMP PTI CPU: 5 UID: 0 PID: 5964 Comm: sh Kdump: loaded Not tainted 6.13.0-dirty #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1. RIP: 0010:has_unmovable_pages+0x184/0x360 ... Call Trace: <TASK> set_migratetype_isolate+0xd1/0x180 start_isolate_page_range+0xd2/0x170 alloc_contig_range_noprof+0x101/0x660 alloc_contig_pages_noprof+0x238/0x290 alloc_gigantic_folio.isra.0+0xb6/0x1f0 only_alloc_fresh_hugetlb_folio.isra.0+0xf/0x60 alloc_pool_huge_folio+0x80/0xf0 set_max_huge_pages+0x211/0x490 __nr_hugepages_store_common+0x5f/0xe0 nr_hugepages_store+0x77/0x80 kernfs_fop_write_iter+0x118/0x200 vfs_write+0x23c/0x3f0 ksys_write+0x62/0xe0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e As has_unmovable_pages() call folio_hstate() without hugetlb_lock, there is a race to free the HugeTLB page between PageHuge() and folio_hstate(). There is no need to add hugetlb_lock here as the HugeTLB page can be freed in lot of places. So it's enough to unfold folio_hstate() and add a check to avoid NULL pointer dereference for hugepage_migration_supported(). Link: https://lkml.kernel.org/r/20250122061151.578768-1-liushixin2@huawei.com Fixes: 464c7ff ("mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm: fixes for device-exclusive entries (hmm)", v2. Discussing the PageTail() call in make_device_exclusive_range() with Willy, I recently discovered [1] that device-exclusive handling does not properly work with THP, making the hmm-tests selftests fail if THPs are enabled on the system. Looking into more details, I found that hugetlb is not properly fenced, and I realized that something that was bugging me for longer -- how device-exclusive entries interact with mapcounts -- completely breaks migration/swapout/split/hwpoison handling of these folios while they have device-exclusive PTEs. The program below can be used to allocate 1 GiB worth of pages and making them device-exclusive on a kernel with CONFIG_TEST_HMM. Once they are device-exclusive, these folios cannot get swapped out (proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much one forces memory reclaim), and when having a memory block onlined to ZONE_MOVABLE, trying to offline it will loop forever and complain about failed migration of a page that should be movable. # echo offline > /sys/devices/system/memory/memory136/state # echo online_movable > /sys/devices/system/memory/memory136/state # ./hmm-swap & ... wait until everything is device-exclusive # echo offline > /sys/devices/system/memory/memory136/state [ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x7f20671f7 pfn:0x442b6a [ 285.196618][T14882] memcg:ffff888179298000 [ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate| dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff) [ 285.201734][T14882] raw: ... [ 285.204464][T14882] raw: ... [ 285.207196][T14882] page dumped because: migration failure [ 285.209072][T14882] page_owner tracks the page as allocated [ 285.210915][T14882] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774 [ 285.216765][T14882] post_alloc_hook+0x197/0x1b0 [ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280 [ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740 [ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540 [ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340 [ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0 [ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0 [ 285.230822][T14882] handle_mm_fault+0x368/0x9f0 ... This series fixes all issues I found so far. There is no easy way to fix without a bigger rework/cleanup. I have a bunch of cleanups on top (some previous sent, some the result of the discussion in v1) that I will send out separately once this landed and I get to it. I wish we could just use some special present PROT_NONE PTEs instead of these (non-present, non-none) fake-swap entries; but that just results in the same problem we keep having (lack of spare PTE bits), and staring at other similar fake-swap entries, that ship has sailed. With this series, make_device_exclusive() doesn't actually belong into mm/rmap.c anymore, but I'll leave moving that for another day. I only tested this series with the hmm-tests selftests due to lack of HW, so I'd appreciate some testing, especially if the interaction between two GPUs wanting a device-exclusive entry works as expected. <program> #include <stdio.h> #include <fcntl.h> #include <stdint.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/ioctl.h> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) struct hmm_dmirror_cmd { __u64 addr; __u64 ptr; __u64 npages; __u64 cpages; __u64 faults; }; const size_t size = 1 * 1024 * 1024 * 1024ul; const size_t chunk_size = 2 * 1024 * 1024ul; int main(void) { struct hmm_dmirror_cmd cmd; size_t cur_size; int fd, ret; char *addr, *mirror; fd = open("/dev/hmm_dmirror1", O_RDWR, 0); if (fd < 0) { perror("open failed\n"); exit(1); } addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (addr == MAP_FAILED) { perror("mmap failed\n"); exit(1); } madvise(addr, size, MADV_NOHUGEPAGE); memset(addr, 1, size); mirror = malloc(chunk_size); for (cur_size = 0; cur_size < size; cur_size += chunk_size) { cmd.addr = (uintptr_t)addr + cur_size; cmd.ptr = (uintptr_t)mirror; cmd.npages = chunk_size / getpagesize(); ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd); if (ret) { perror("ioctl failed\n"); exit(1); } } pause(); return 0; } </program> [1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com This patch (of 17): We only have two FOLL_SPLIT_PMD users. While uprobe refuses hugetlb early, make_device_exclusive_range() can end up getting called on hugetlb VMAs. Right now, this means that with a PMD-sized hugetlb page, we can end up calling split_huge_pmd(), because pmd_trans_huge() also succeeds with hugetlb PMDs. For example, using a modified hmm-test selftest one can trigger: [ 207.017134][T14945] ------------[ cut here ]------------ [ 207.018614][T14945] kernel BUG at mm/page_table_check.c:87! [ 207.019716][T14945] Oops: invalid opcode: 0000 [linuxppc#1] PREEMPT SMP KASAN NOPTI [ 207.021072][T14945] CPU: 3 UID: 0 PID: ... [ 207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510 [ 207.026128][T14945] Code: ... [ 207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293 [ 207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd [ 207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80 [ 207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000 [ 207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001 [ 207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000 [ 207.038711][T14945] FS: 00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000 [ 207.040407][T14945] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0 [ 207.043196][T14945] PKRU: 55555554 [ 207.043880][T14945] Call Trace: [ 207.044506][T14945] <TASK> [ 207.045086][T14945] ? __die+0x51/0x92 [ 207.045864][T14945] ? die+0x29/0x50 [ 207.046596][T14945] ? do_trap+0x250/0x320 [ 207.047430][T14945] ? do_error_trap+0xe7/0x220 [ 207.048346][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.049535][T14945] ? handle_invalid_op+0x34/0x40 [ 207.050494][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.051681][T14945] ? exc_invalid_op+0x2e/0x50 [ 207.052589][T14945] ? asm_exc_invalid_op+0x1a/0x20 [ 207.053596][T14945] ? page_table_check_clear.part.0+0x1fd/0x510 [ 207.054790][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.055993][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.057195][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.058384][T14945] __page_table_check_pmd_clear+0x34b/0x5a0 [ 207.059524][T14945] ? __pfx___page_table_check_pmd_clear+0x10/0x10 [ 207.060775][T14945] ? __pfx___mutex_unlock_slowpath+0x10/0x10 [ 207.061940][T14945] ? __pfx___lock_acquire+0x10/0x10 [ 207.062967][T14945] pmdp_huge_clear_flush+0x279/0x360 [ 207.064024][T14945] split_huge_pmd_locked+0x82b/0x3750 ... Before commit 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code"), we would have ignored the flag; instead, let's simply refuse the combination completely in check_vma_flags(): the caller is likely not prepared to handle any hugetlb folios. We'll teach make_device_exclusive_range() separately to ignore any hugetlb folios as a future-proof safety net. Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com Fixes: 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Barry Song <v-songbaohua@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…ate_pagetables' This commit addresses a circular locking dependency in the svm_range_cpu_invalidate_pagetables function. The function previously held a lock while determining whether to perform an unmap or eviction operation, which could lead to deadlocks. Fixes the below: [ 223.418794] ====================================================== [ 223.418820] WARNING: possible circular locking dependency detected [ 223.418845] 6.12.0-amdstaging-drm-next-lol-050225 #14 Tainted: G U OE [ 223.418869] ------------------------------------------------------ [ 223.418889] kfdtest/3939 is trying to acquire lock: [ 223.418906] ffff8957552eae38 (&dqm->lock_hidden){+.+.}-{3:3}, at: evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.419302] but task is already holding lock: [ 223.419303] ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu] [ 223.419447] Console: switching to colour dummy device 80x25 [ 223.419477] [IGT] amd_basic: executing [ 223.419599] which lock already depends on the new lock. [ 223.419611] the existing dependency chain (in reverse order) is: [ 223.419621] -> linuxppc#2 (&prange->lock){+.+.}-{3:3}: [ 223.419636] __mutex_lock+0x85/0xe20 [ 223.419647] mutex_lock_nested+0x1b/0x30 [ 223.419656] svm_range_validate_and_map+0x2f1/0x15b0 [amdgpu] [ 223.419954] svm_range_set_attr+0xe8c/0x1710 [amdgpu] [ 223.420236] svm_ioctl+0x46/0x50 [amdgpu] [ 223.420503] kfd_ioctl_svm+0x50/0x90 [amdgpu] [ 223.420763] kfd_ioctl+0x409/0x6d0 [amdgpu] [ 223.421024] __x64_sys_ioctl+0x95/0xd0 [ 223.421036] x64_sys_call+0x1205/0x20d0 [ 223.421047] do_syscall_64+0x87/0x140 [ 223.421056] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.421068] -> linuxppc#1 (reservation_ww_class_mutex){+.+.}-{3:3}: [ 223.421084] __ww_mutex_lock.constprop.0+0xab/0x1560 [ 223.421095] ww_mutex_lock+0x2b/0x90 [ 223.421103] amdgpu_amdkfd_alloc_gtt_mem+0xcc/0x2b0 [amdgpu] [ 223.421361] add_queue_mes+0x3bc/0x440 [amdgpu] [ 223.421623] unhalt_cpsch+0x1ae/0x240 [amdgpu] [ 223.421888] kgd2kfd_start_sched+0x5e/0xd0 [amdgpu] [ 223.422148] amdgpu_amdkfd_start_sched+0x3d/0x50 [amdgpu] [ 223.422414] amdgpu_gfx_enforce_isolation_handler+0x132/0x270 [amdgpu] [ 223.422662] process_one_work+0x21e/0x680 [ 223.422673] worker_thread+0x190/0x330 [ 223.422682] kthread+0xe7/0x120 [ 223.422690] ret_from_fork+0x3c/0x60 [ 223.422699] ret_from_fork_asm+0x1a/0x30 [ 223.422708] -> #0 (&dqm->lock_hidden){+.+.}-{3:3}: [ 223.422723] __lock_acquire+0x16f4/0x2810 [ 223.422734] lock_acquire+0xd1/0x300 [ 223.422742] __mutex_lock+0x85/0xe20 [ 223.422751] mutex_lock_nested+0x1b/0x30 [ 223.422760] evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.423025] kfd_process_evict_queues+0x8a/0x1d0 [amdgpu] [ 223.423285] kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu] [ 223.423540] svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu] [ 223.423807] __mmu_notifier_invalidate_range_start+0x1f5/0x250 [ 223.423819] copy_page_range+0x1e94/0x1ea0 [ 223.423829] copy_process+0x172f/0x2ad0 [ 223.423839] kernel_clone+0x9c/0x3f0 [ 223.423847] __do_sys_clone+0x66/0x90 [ 223.423856] __x64_sys_clone+0x25/0x30 [ 223.423864] x64_sys_call+0x1d7c/0x20d0 [ 223.423872] do_syscall_64+0x87/0x140 [ 223.423880] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.423891] other info that might help us debug this: [ 223.423903] Chain exists of: &dqm->lock_hidden --> reservation_ww_class_mutex --> &prange->lock [ 223.423926] Possible unsafe locking scenario: [ 223.423935] CPU0 CPU1 [ 223.423942] ---- ---- [ 223.423949] lock(&prange->lock); [ 223.423958] lock(reservation_ww_class_mutex); [ 223.423970] lock(&prange->lock); [ 223.423981] lock(&dqm->lock_hidden); [ 223.423990] *** DEADLOCK *** [ 223.423999] 5 locks held by kfdtest/3939: [ 223.424006] #0: ffffffffb82b4fc0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x1387/0x2ad0 [ 223.424026] linuxppc#1: ffff89575eda81b0 (&mm->mmap_lock){++++}-{3:3}, at: copy_process+0x13a8/0x2ad0 [ 223.424046] linuxppc#2: ffff89575edaf3b0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_process+0x13e4/0x2ad0 [ 223.424066] #3: ffffffffb82e76e0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: copy_page_range+0x1cea/0x1ea0 [ 223.424088] #4: ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu] [ 223.424365] stack backtrace: [ 223.424374] CPU: 0 UID: 0 PID: 3939 Comm: kfdtest Tainted: G U OE 6.12.0-amdstaging-drm-next-lol-050225 #14 [ 223.424392] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 223.424401] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO WIFI/X570 AORUS PRO WIFI, BIOS F36a 02/16/2022 [ 223.424416] Call Trace: [ 223.424423] <TASK> [ 223.424430] dump_stack_lvl+0x9b/0xf0 [ 223.424441] dump_stack+0x10/0x20 [ 223.424449] print_circular_bug+0x275/0x350 [ 223.424460] check_noncircular+0x157/0x170 [ 223.424469] ? __bfs+0xfd/0x2c0 [ 223.424481] __lock_acquire+0x16f4/0x2810 [ 223.424490] ? srso_return_thunk+0x5/0x5f [ 223.424505] lock_acquire+0xd1/0x300 [ 223.424514] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.424783] __mutex_lock+0x85/0xe20 [ 223.424792] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425058] ? srso_return_thunk+0x5/0x5f [ 223.425067] ? mark_held_locks+0x54/0x90 [ 223.425076] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425339] ? srso_return_thunk+0x5/0x5f [ 223.425350] mutex_lock_nested+0x1b/0x30 [ 223.425358] ? mutex_lock_nested+0x1b/0x30 [ 223.425367] evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425631] kfd_process_evict_queues+0x8a/0x1d0 [amdgpu] [ 223.425893] kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu] [ 223.426156] svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu] [ 223.426423] ? srso_return_thunk+0x5/0x5f [ 223.426436] __mmu_notifier_invalidate_range_start+0x1f5/0x250 [ 223.426450] copy_page_range+0x1e94/0x1ea0 [ 223.426461] ? srso_return_thunk+0x5/0x5f [ 223.426474] ? srso_return_thunk+0x5/0x5f [ 223.426484] ? lock_acquire+0xd1/0x300 [ 223.426494] ? copy_process+0x1718/0x2ad0 [ 223.426502] ? srso_return_thunk+0x5/0x5f [ 223.426510] ? sched_clock_noinstr+0x9/0x10 [ 223.426519] ? local_clock_noinstr+0xe/0xc0 [ 223.426528] ? copy_process+0x1718/0x2ad0 [ 223.426537] ? srso_return_thunk+0x5/0x5f [ 223.426550] copy_process+0x172f/0x2ad0 [ 223.426569] kernel_clone+0x9c/0x3f0 [ 223.426577] ? __schedule+0x4c9/0x1b00 [ 223.426586] ? srso_return_thunk+0x5/0x5f [ 223.426594] ? sched_clock_noinstr+0x9/0x10 [ 223.426602] ? srso_return_thunk+0x5/0x5f [ 223.426610] ? local_clock_noinstr+0xe/0xc0 [ 223.426619] ? schedule+0x107/0x1a0 [ 223.426629] __do_sys_clone+0x66/0x90 [ 223.426643] __x64_sys_clone+0x25/0x30 [ 223.426652] x64_sys_call+0x1d7c/0x20d0 [ 223.426661] do_syscall_64+0x87/0x140 [ 223.426671] ? srso_return_thunk+0x5/0x5f [ 223.426679] ? common_nsleep+0x44/0x50 [ 223.426690] ? srso_return_thunk+0x5/0x5f [ 223.426698] ? trace_hardirqs_off+0x52/0xd0 [ 223.426709] ? srso_return_thunk+0x5/0x5f [ 223.426717] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426727] ? srso_return_thunk+0x5/0x5f [ 223.426736] ? do_syscall_64+0x93/0x140 [ 223.426748] ? srso_return_thunk+0x5/0x5f [ 223.426756] ? up_write+0x1c/0x1e0 [ 223.426765] ? srso_return_thunk+0x5/0x5f [ 223.426775] ? srso_return_thunk+0x5/0x5f [ 223.426783] ? trace_hardirqs_off+0x52/0xd0 [ 223.426792] ? srso_return_thunk+0x5/0x5f [ 223.426800] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426810] ? srso_return_thunk+0x5/0x5f [ 223.426818] ? do_syscall_64+0x93/0x140 [ 223.426826] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426836] ? srso_return_thunk+0x5/0x5f [ 223.426844] ? do_syscall_64+0x93/0x140 [ 223.426853] ? srso_return_thunk+0x5/0x5f [ 223.426861] ? irqentry_exit+0x6b/0x90 [ 223.426869] ? srso_return_thunk+0x5/0x5f [ 223.426877] ? exc_page_fault+0xa7/0x2c0 [ 223.426888] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.426898] RIP: 0033:0x7f46758eab57 [ 223.426906] Code: ba 04 00 f3 0f 1e fa 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 41 89 c0 85 c0 75 2c 64 48 8b 04 25 10 00 [ 223.426930] RSP: 002b:00007fff5c3e5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 [ 223.426943] RAX: ffffffffffffffda RBX: 00007f4675f8c040 RCX: 00007f46758eab57 [ 223.426954] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 [ 223.426965] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 223.426975] R10: 00007f4675e81a50 R11: 0000000000000246 R12: 0000000000000001 [ 223.426986] R13: 00007fff5c3e5470 R14: 00007fff5c3e53e0 R15: 00007fff5c3e5410 [ 223.427004] </TASK> v2: To resolve this issue, the allocation of the process context buffer (`proc_ctx_bo`) has been moved from the `add_queue_mes` function to the `pqm_create_queue` function. This change ensures that the buffer is allocated only when the first queue for a process is created and only if the Micro Engine Scheduler (MES) is enabled. (Felix) v3: Fix typo s/Memory Execution Scheduler (MES)/Micro Engine Scheduler in commit message. (Lijo) Fixes: 438b39a ("drm/amdkfd: pause autosuspend when creating pdd") Cc: Jesse Zhang <jesse.zhang@amd.com> Cc: Yunxiang Li <Yunxiang.Li@amd.com> Cc: Philip Yang <Philip.Yang@amd.com> Cc: Alex Sierra <alex.sierra@amd.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Christian König <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

If waiting for gpu reset done in KFD release_work, thers is WARNING: possible circular locking dependency detected linuxppc#2 kfd_create_process kfd_process_mutex flush kfd release work linuxppc#1 kfd release work wait for amdgpu reset work #0 amdgpu_device_gpu_reset kgd2kfd_pre_reset kfd_process_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&p->release_work)); lock((wq_completion)kfd_process_wq); lock((work_completion)(&p->release_work)); lock((wq_completion)amdgpu-reset-dev); To fix this, KFD create process move flush release work outside kfd_process_mutex. Signed-off-by: Philip Yang <Philip.Yang@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Commit b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined) add page poison checks in do_migrate_range in order to make offline hwpoisoned page possible by introducing isolate_lru_page and try_to_unmap for hwpoisoned page. However folio lock must be held before calling try_to_unmap. Add it to fix this problem. Warning will be produced if folio is not locked during unmap: ------------[ cut here ]------------ kernel BUG at ./include/linux/swapops.h:400! Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP Modules linked in: CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41 Tainted: [W]=WARN Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : try_to_unmap_one+0xb08/0xd3c lr : try_to_unmap_one+0x3dc/0xd3c Call trace: try_to_unmap_one+0xb08/0xd3c (P) try_to_unmap_one+0x3dc/0xd3c (L) rmap_walk_anon+0xdc/0x1f8 rmap_walk+0x3c/0x58 try_to_unmap+0x88/0x90 unmap_poisoned_folio+0x30/0xa8 do_migrate_range+0x4a0/0x568 offline_pages+0x5a4/0x670 memory_block_action+0x17c/0x374 memory_subsys_offline+0x3c/0x78 device_offline+0xa4/0xd0 state_store+0x8c/0xf0 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x118/0x1a8 vfs_write+0x3a8/0x4bc ksys_write+0x6c/0xf8 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xd0 el0t_64_sync_handler+0xc8/0xcc el0t_64_sync+0x198/0x19c Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000) ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20250217014329.3610326-4-mawupeng1@huawei.com Fixes: b15c872 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Address an Oops issues when performing test of loading XE GPU driver module after applying the GPU SVM and Xe SVM patch series[1] and the Dept patch series[2]. The issue occurs when loading the xe driver via modprobe [3], which adds a struct page for device memory via devm_memremap_pages(). When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This patch translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. [1] https://lore.kernel.org/dri-devel/20250213021112.1228481-1-matthew.brost@intel.com/ [2] https://lore.kernel.org/lkml/20240508094726.35754-1-byungchul@sk.com/ [3] [ 49.103630] xe 0000:00:04.0: [drm] Available VRAM: 0x0000000800000000, 0x00000002fb800000 [ 49.116710] BUG: unable to handle page fault for address: ffffeb3ff1200000 [ 49.117175] #PF: supervisor write access in kernel mode [ 49.117511] #PF: error_code(0x0002) - not-present page [ 49.117835] PGD 0 P4D 0 [ 49.118015] Oops: Oops: 0002 [linuxppc#1] PREEMPT SMP NOPTI [ 49.118366] CPU: 3 UID: 0 PID: 302 Comm: modprobe Tainted: G W 6.13.0-drm-tip-test+ #62 [ 49.118976] Tainted: [W]=WARN [ 49.119179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 49.119710] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.120011] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.121158] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.121502] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.121966] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.122499] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.123032] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.123566] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.124096] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.124698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.125129] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.125662] PKRU: 55555554 [ 49.125880] Call Trace: [ 49.126078] <TASK> [ 49.126252] ? __die_body.cold+0x19/0x26 [ 49.126509] ? page_fault_oops+0xa2/0x240 [ 49.126736] ? preempt_count_add+0x47/0xa0 [ 49.126968] ? search_module_extables+0x4a/0x80 [ 49.127224] ? exc_page_fault+0x206/0x230 [ 49.127454] ? asm_exc_page_fault+0x22/0x30 [ 49.127691] ? vmemmap_set_pmd+0xff/0x230 [ 49.127919] vmemmap_populate_hugepages+0x176/0x180 [ 49.128194] vmemmap_populate+0x34/0x80 [ 49.128416] __populate_section_memmap+0x41/0x90 [ 49.128676] sparse_add_section+0x121/0x3e0 [ 49.128914] __add_pages+0xba/0x150 [ 49.129116] add_pages+0x1d/0x70 [ 49.129305] memremap_pages+0x3dc/0x810 [ 49.129529] devm_memremap_pages+0x1c/0x60 [ 49.129762] xe_devm_add+0x8b/0x100 [xe] [ 49.130072] xe_tile_init_noalloc+0x6a/0x70 [xe] [ 49.130408] xe_device_probe+0x48c/0x740 [xe] [ 49.130714] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.130982] ? __drmm_add_action+0x85/0xd0 [ 49.131208] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.131478] xe_pci_probe+0x7ef/0xd90 [xe] [ 49.131777] ? _raw_spin_unlock_irqrestore+0x66/0x90 [ 49.132049] ? lockdep_hardirqs_on+0xba/0x140 [ 49.132290] pci_device_probe+0x99/0x110 [ 49.132510] really_probe+0xdb/0x340 [ 49.132710] ? pm_runtime_barrier+0x50/0x90 [ 49.132941] ? __pfx___driver_attach+0x10/0x10 [ 49.133190] __driver_probe_device+0x78/0x110 [ 49.133433] driver_probe_device+0x1f/0xa0 [ 49.133661] __driver_attach+0xba/0x1c0 [ 49.133874] bus_for_each_dev+0x7a/0xd0 [ 49.134089] bus_add_driver+0x114/0x200 [ 49.134302] driver_register+0x6e/0xc0 [ 49.134515] xe_init+0x1e/0x50 [xe] [ 49.134827] ? __pfx_xe_init+0x10/0x10 [xe] [ 49.134926] xe 0000:00:04.0: [drm:process_one_work] GT1: GuC CT safe-mode canceled [ 49.135112] do_one_initcall+0x5b/0x2b0 [ 49.135734] ? rcu_is_watching+0xd/0x40 [ 49.135995] ? __kmalloc_cache_noprof+0x231/0x310 [ 49.136315] do_init_module+0x60/0x210 [ 49.136572] init_module_from_file+0x86/0xc0 [ 49.136863] idempotent_init_module+0x12b/0x340 [ 49.137156] __x64_sys_finit_module+0x61/0xc0 [ 49.137437] do_syscall_64+0x69/0x140 [ 49.137681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 49.137953] RIP: 0033:0x7f53ae1261fd [ 49.138153] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 fa 0c 00 f7 d8 64 89 01 48 [ 49.139117] RSP: 002b:00007ffd0e9021e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 49.139525] RAX: ffffffffffffffda RBX: 000055c02951ee50 RCX: 00007f53ae1261fd [ 49.139905] RDX: 0000000000000000 RSI: 000055bfff125478 RDI: 0000000000000010 [ 49.140282] RBP: 000055bfff125478 R08: 00007f53ae1f6b20 R09: 00007ffd0e902230 [ 49.140663] R10: 000055c029522000 R11: 0000000000000246 R12: 0000000000040000 [ 49.141040] R13: 000055c02951ef80 R14: 0000000000000000 R15: 000055c029521fc0 [ 49.141424] </TASK> [ 49.141552] Modules linked in: xe(+) drm_ttm_helper gpu_sched drm_suballoc_helper drm_gpuvm drm_exec drm_gpusvm i2c_algo_bit drm_buddy video wmi ttm drm_display_helper drm_kms_helper crct10dif_pclmul crc32_pclmul i2c_piix4 e1000 ghash_clmulni_intel i2c_smbus fuse [ 49.142824] CR2: ffffeb3ff1200000 [ 49.143010] ---[ end trace 0000000000000000 ]--- [ 49.143268] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.143523] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.144489] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.144775] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.145154] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.145536] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.145914] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.146292] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.146671] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.147097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.147407] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.147786] PKRU: 55555554 [ 49.147941] note: modprobe[302] exited with irqs disabled When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. Link: https://lkml.kernel.org/r/20250217114133.400063-2-gwan-gyeong.mun@intel.com Fixes: faf1c00 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs") Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add a NULL check on the return value of swp_swap_info in __swap_duplicate to prevent crashes caused by NULL pointer dereference. The reason why swp_swap_info() returns NULL is unclear; it may be due to CPU cache issues or DDR bit flips. The probability of this issue is very small - it has been observed to occur approximately 1 in 500,000 times per week. The stack info we encountered is as follows: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [RB/E]rb_sreason_str_set: sreason_str set null_pointer Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=00000008a80e5000 [0000000000000058] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 0000000096000005 [linuxppc#1] PREEMPT SMP Skip md ftrace buffer dump for: 0x1609e0 ... pc : swap_duplicate+0x44/0x164 lr : copy_page_range+0x508/0x1e78 sp : ffffffc0f2a699e0 x29: ffffffc0f2a699e0 x28: ffffff8a5b28d388 x27: ffffff8b06603388 x26: ffffffdf7291fe70 x25: 0000000000000006 x24: 0000000000100073 x23: 00000000002d2d2f x22: 0000000000000008 x21: 0000000000000000 x20: 00000000002d2d2f x19: 18000000002d2d2f x18: ffffffdf726faec0 x17: 0000000000000000 x16: 0010000000000001 x15: 0040000000000001 x14: 0400000000000001 x13: ff7ffffffffffb7f x12: ffeffffffffffbff x11: ffffff8a5c7e1898 x10: 0000000000000018 x9 : 0000000000000006 x8 : 1800000000000000 x7 : 0000000000000000 x6 : ffffff8057c01f10 x5 : 000000000000a318 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000006daf200000 x1 : 0000000000000001 x0 : 18000000002d2d2f Call trace: swap_duplicate+0x44/0x164 copy_page_range+0x508/0x1e78 copy_process+0x1278/0x21cc kernel_clone+0x90/0x438 __arm64_sys_clone+0x5c/0x8c invoke_syscall+0x58/0x110 do_el0_svc+0x8c/0xe0 el0_svc+0x38/0x9c el0t_64_sync_handler+0x44/0xec el0t_64_sync+0x1a8/0x1ac Code: 9139c35a 71006f3f 54000568 f8797b55 (f9402ea8) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception SMP: stopping secondary CPUs The patch seems to only provide a workaround, but there are no more effective software solutions to handle the bit flips problem. This path will change the issue from a system crash to a process exception, thereby reducing the impact on the entire machine. Signed-off-by: gao xu <gaoxu2@honor.com> Link: https://lkml.kernel.org/r/e223b0e6ba2f4924984b1917cc717bd5@honor.com Reviewed-by: Barry Song <baohua@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

userfaultfd_move() checks whether the PTE entry is present or a swap entry. - If the PTE entry is present, move_present_pte() handles folio migration by setting: src_folio->index = linear_page_index(dst_vma, dst_addr); - If the PTE entry is a swap entry, move_swap_pte() simply copies the PTE to the new dst_addr. This approach is incorrect because, even if the PTE is a swap entry, it can still reference a folio that remains in the swap cache. This creates a race window between steps 2 and 4. 1. add_to_swap: The folio is added to the swapcache. 2. try_to_unmap: PTEs are converted to swap entries. 3. pageout: The folio is written back. 4. Swapcache is cleared. If userfaultfd_move() occurs in the window between steps 2 and 4, after the swap PTE has been moved to the destination, accessing the destination triggers do_swap_page(), which may locate the folio in the swapcache. However, since the folio's index has not been updated to match the destination VMA, do_swap_page() will detect a mismatch. This can result in two critical issues depending on the system configuration. If KSM is disabled, both small and large folios can trigger a BUG during the add_rmap operation due to: page_pgoff(folio, page) != linear_page_index(vma, address) [ 13.336953] page: refcount:6 mapcount:1 mapping:00000000f43db19c index:0xffffaf150 pfn:0x4667c [ 13.337520] head: order:2 mapcount:1 entire_mapcount:0 nr_pages_mapped:1 pincount:0 [ 13.337716] memcg:ffff00000405f000 [ 13.337849] anon flags: 0x3fffc0000020459(locked|uptodate|dirty|owner_priv_1|head|swapbacked|node=0|zone=0|lastcpupid=0xffff) [ 13.338630] raw: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.338831] raw: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339031] head: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361 [ 13.339204] head: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000 [ 13.339375] head: 03fffc0000000202 fffffdffc0199f01 ffffffff00000000 0000000000000001 [ 13.339546] head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 [ 13.339736] page dumped because: VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address)) [ 13.340190] ------------[ cut here ]------------ [ 13.340316] kernel BUG at mm/rmap.c:1380! [ 13.340683] Internal error: Oops - BUG: 00000000f2000800 [linuxppc#1] PREEMPT SMP [ 13.340969] Modules linked in: [ 13.341257] CPU: 1 UID: 0 PID: 107 Comm: a.out Not tainted 6.14.0-rc3-gcf42737e247a-dirty #299 [ 13.341470] Hardware name: linux,dummy-virt (DT) [ 13.341671] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 13.341815] pc : __page_check_anon_rmap+0xa0/0xb0 [ 13.341920] lr : __page_check_anon_rmap+0xa0/0xb0 [ 13.342018] sp : ffff80008752bb20 [ 13.342093] x29: ffff80008752bb20 x28: fffffdffc0199f00 x27: 0000000000000001 [ 13.342404] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000001 [ 13.342575] x23: 0000ffffaf0d0000 x22: 0000ffffaf0d0000 x21: fffffdffc0199f00 [ 13.342731] x20: fffffdffc0199f00 x19: ffff000006210700 x18: 00000000ffffffff [ 13.342881] x17: 6c203d2120296567 x16: 6170202c6f696c6f x15: 662866666f67705f [ 13.343033] x14: 6567617028454741 x13: 2929737365726464 x12: ffff800083728ab0 [ 13.343183] x11: ffff800082996bf8 x10: 0000000000000fd7 x9 : ffff80008011bc40 [ 13.343351] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000829eebf8 [ 13.343498] x5 : c0000000fffff000 x4 : 0000000000000000 x3 : 0000000000000000 [ 13.343645] x2 : 0000000000000000 x1 : ffff0000062db980 x0 : 000000000000005f [ 13.343876] Call trace: [ 13.344045] __page_check_anon_rmap+0xa0/0xb0 (P) [ 13.344234] folio_add_anon_rmap_ptes+0x22c/0x320 [ 13.344333] do_swap_page+0x1060/0x1400 [ 13.344417] __handle_mm_fault+0x61c/0xbc8 [ 13.344504] handle_mm_fault+0xd8/0x2e8 [ 13.344586] do_page_fault+0x20c/0x770 [ 13.344673] do_translation_fault+0xb4/0xf0 [ 13.344759] do_mem_abort+0x48/0xa0 [ 13.344842] el0_da+0x58/0x130 [ 13.344914] el0t_64_sync_handler+0xc4/0x138 [ 13.345002] el0t_64_sync+0x1ac/0x1b0 [ 13.345208] Code: aa1503e0 f000f801 910f6021 97ff5779 (d4210000) [ 13.345504] ---[ end trace 0000000000000000 ]--- [ 13.345715] note: a.out[107] exited with irqs disabled [ 13.345954] note: a.out[107] exited with preempt_count 2 If KSM is enabled, Peter Xu also discovered that do_swap_page() may trigger an unexpected CoW operation for small folios because ksm_might_need_to_copy() allocates a new folio when the folio index does not match linear_page_index(vma, addr). This patch also checks the swapcache when handling swap entries. If a match is found in the swapcache, it processes it similarly to a present PTE. However, there are some differences. For example, the folio is no longer exclusive because folio_try_share_anon_rmap_pte() is performed during unmapping. Furthermore, in the case of swapcache, the folio has already been unmapped, eliminating the risk of concurrent rmap walks and removing the need to acquire src_folio's anon_vma or lock. Note that for large folios, in the swapcache handling path, we directly return -EBUSY since split_folio() will return -EBUSY regardless if the folio is under writeback or unmapped. This is not an urgent issue, so a follow-up patch may address it separately. Link: https://lkml.kernel.org/r/20250226001400.9129-1-21cnbao@gmail.com Fixes: adef440 ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

I found a NULL pointer dereference as followed: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [linuxppc#1] SMP PTI CPU: 5 UID: 0 PID: 5964 Comm: sh Kdump: loaded Not tainted 6.13.0-dirty #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1. RIP: 0010:has_unmovable_pages+0x184/0x360 ... Call Trace: <TASK> set_migratetype_isolate+0xd1/0x180 start_isolate_page_range+0xd2/0x170 alloc_contig_range_noprof+0x101/0x660 alloc_contig_pages_noprof+0x238/0x290 alloc_gigantic_folio.isra.0+0xb6/0x1f0 only_alloc_fresh_hugetlb_folio.isra.0+0xf/0x60 alloc_pool_huge_folio+0x80/0xf0 set_max_huge_pages+0x211/0x490 __nr_hugepages_store_common+0x5f/0xe0 nr_hugepages_store+0x77/0x80 kernfs_fop_write_iter+0x118/0x200 vfs_write+0x23c/0x3f0 ksys_write+0x62/0xe0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e As has_unmovable_pages() call folio_hstate() without hugetlb_lock, there is a race to free the HugeTLB page between PageHuge() and folio_hstate(). There is no need to add hugetlb_lock here as the HugeTLB page can be freed in lot of places. So it's enough to unfold folio_hstate() and add a check to avoid NULL pointer dereference for hugepage_migration_supported(). Link: https://lkml.kernel.org/r/20250122061151.578768-1-liushixin2@huawei.com Fixes: 464c7ff ("mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm: fixes for device-exclusive entries (hmm)", v2. Discussing the PageTail() call in make_device_exclusive_range() with Willy, I recently discovered [1] that device-exclusive handling does not properly work with THP, making the hmm-tests selftests fail if THPs are enabled on the system. Looking into more details, I found that hugetlb is not properly fenced, and I realized that something that was bugging me for longer -- how device-exclusive entries interact with mapcounts -- completely breaks migration/swapout/split/hwpoison handling of these folios while they have device-exclusive PTEs. The program below can be used to allocate 1 GiB worth of pages and making them device-exclusive on a kernel with CONFIG_TEST_HMM. Once they are device-exclusive, these folios cannot get swapped out (proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much one forces memory reclaim), and when having a memory block onlined to ZONE_MOVABLE, trying to offline it will loop forever and complain about failed migration of a page that should be movable. # echo offline > /sys/devices/system/memory/memory136/state # echo online_movable > /sys/devices/system/memory/memory136/state # ./hmm-swap & ... wait until everything is device-exclusive # echo offline > /sys/devices/system/memory/memory136/state [ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x7f20671f7 pfn:0x442b6a [ 285.196618][T14882] memcg:ffff888179298000 [ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate| dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff) [ 285.201734][T14882] raw: ... [ 285.204464][T14882] raw: ... [ 285.207196][T14882] page dumped because: migration failure [ 285.209072][T14882] page_owner tracks the page as allocated [ 285.210915][T14882] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774 [ 285.216765][T14882] post_alloc_hook+0x197/0x1b0 [ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280 [ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740 [ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540 [ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340 [ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0 [ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0 [ 285.230822][T14882] handle_mm_fault+0x368/0x9f0 ... This series fixes all issues I found so far. There is no easy way to fix without a bigger rework/cleanup. I have a bunch of cleanups on top (some previous sent, some the result of the discussion in v1) that I will send out separately once this landed and I get to it. I wish we could just use some special present PROT_NONE PTEs instead of these (non-present, non-none) fake-swap entries; but that just results in the same problem we keep having (lack of spare PTE bits), and staring at other similar fake-swap entries, that ship has sailed. With this series, make_device_exclusive() doesn't actually belong into mm/rmap.c anymore, but I'll leave moving that for another day. I only tested this series with the hmm-tests selftests due to lack of HW, so I'd appreciate some testing, especially if the interaction between two GPUs wanting a device-exclusive entry works as expected. <program> #include <stdio.h> #include <fcntl.h> #include <stdint.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/ioctl.h> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) struct hmm_dmirror_cmd { __u64 addr; __u64 ptr; __u64 npages; __u64 cpages; __u64 faults; }; const size_t size = 1 * 1024 * 1024 * 1024ul; const size_t chunk_size = 2 * 1024 * 1024ul; int main(void) { struct hmm_dmirror_cmd cmd; size_t cur_size; int fd, ret; char *addr, *mirror; fd = open("/dev/hmm_dmirror1", O_RDWR, 0); if (fd < 0) { perror("open failed\n"); exit(1); } addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (addr == MAP_FAILED) { perror("mmap failed\n"); exit(1); } madvise(addr, size, MADV_NOHUGEPAGE); memset(addr, 1, size); mirror = malloc(chunk_size); for (cur_size = 0; cur_size < size; cur_size += chunk_size) { cmd.addr = (uintptr_t)addr + cur_size; cmd.ptr = (uintptr_t)mirror; cmd.npages = chunk_size / getpagesize(); ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd); if (ret) { perror("ioctl failed\n"); exit(1); } } pause(); return 0; } </program> [1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com This patch (of 17): We only have two FOLL_SPLIT_PMD users. While uprobe refuses hugetlb early, make_device_exclusive_range() can end up getting called on hugetlb VMAs. Right now, this means that with a PMD-sized hugetlb page, we can end up calling split_huge_pmd(), because pmd_trans_huge() also succeeds with hugetlb PMDs. For example, using a modified hmm-test selftest one can trigger: [ 207.017134][T14945] ------------[ cut here ]------------ [ 207.018614][T14945] kernel BUG at mm/page_table_check.c:87! [ 207.019716][T14945] Oops: invalid opcode: 0000 [linuxppc#1] PREEMPT SMP KASAN NOPTI [ 207.021072][T14945] CPU: 3 UID: 0 PID: ... [ 207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510 [ 207.026128][T14945] Code: ... [ 207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293 [ 207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd [ 207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80 [ 207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000 [ 207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001 [ 207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000 [ 207.038711][T14945] FS: 00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000 [ 207.040407][T14945] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0 [ 207.043196][T14945] PKRU: 55555554 [ 207.043880][T14945] Call Trace: [ 207.044506][T14945] <TASK> [ 207.045086][T14945] ? __die+0x51/0x92 [ 207.045864][T14945] ? die+0x29/0x50 [ 207.046596][T14945] ? do_trap+0x250/0x320 [ 207.047430][T14945] ? do_error_trap+0xe7/0x220 [ 207.048346][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.049535][T14945] ? handle_invalid_op+0x34/0x40 [ 207.050494][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.051681][T14945] ? exc_invalid_op+0x2e/0x50 [ 207.052589][T14945] ? asm_exc_invalid_op+0x1a/0x20 [ 207.053596][T14945] ? page_table_check_clear.part.0+0x1fd/0x510 [ 207.054790][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.055993][T14945] ? page_table_check_clear.part.0+0x488/0x510 [ 207.057195][T14945] ? page_table_check_clear.part.0+0x487/0x510 [ 207.058384][T14945] __page_table_check_pmd_clear+0x34b/0x5a0 [ 207.059524][T14945] ? __pfx___page_table_check_pmd_clear+0x10/0x10 [ 207.060775][T14945] ? __pfx___mutex_unlock_slowpath+0x10/0x10 [ 207.061940][T14945] ? __pfx___lock_acquire+0x10/0x10 [ 207.062967][T14945] pmdp_huge_clear_flush+0x279/0x360 [ 207.064024][T14945] split_huge_pmd_locked+0x82b/0x3750 ... Before commit 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code"), we would have ignored the flag; instead, let's simply refuse the combination completely in check_vma_flags(): the caller is likely not prepared to handle any hugetlb folios. We'll teach make_device_exclusive_range() separately to ignore any hugetlb folios as a future-proof safety net. Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com Fixes: 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Barry Song <v-songbaohua@oppo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Final responsibility of ceph_writepages_start() is to submit write requests for processed dirty folios/pages. The ceph_submit_write() summarize all this logic in one method. The generic/421 fails to finish because of the issue: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.894678] INFO: task kworker/u48:0:11 blocked for more than 122 seconds. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895403] Not tainted 6.13.0-rc5+ linuxppc#1 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895867] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896633] task:kworker/u48:0 state:D stack:0 pid:11 tgid:11 ppid:2 flags:0x00004000 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896641] Workqueue: writeback wb_workfn (flush-ceph-24) Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897614] Call Trace: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897620] <TASK> Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897629] __schedule+0x443/0x16b0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897637] schedule+0x2b/0x140 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897640] io_schedule+0x4c/0x80 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897643] folio_wait_bit_common+0x11b/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897646] ? _raw_spin_unlock_irq+0xe/0x50 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897652] ? __pfx_wake_page_function+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897655] __folio_lock+0x17/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897658] ceph_writepages_start+0xca9/0x1fb0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897663] ? fsnotify_remove_queued_event+0x2f/0x40 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897668] do_writepages+0xd2/0x240 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897672] __writeback_single_inode+0x44/0x350 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897675] writeback_sb_inodes+0x25c/0x550 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897680] wb_writeback+0x89/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897683] ? finish_task_switch.isra.0+0x97/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897687] wb_workfn+0xb5/0x410 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897689] process_one_work+0x188/0x3d0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897692] worker_thread+0x2b5/0x3c0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897694] ? __pfx_worker_thread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897696] kthread+0xe1/0x120 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897699] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897701] ret_from_fork+0x43/0x70 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897705] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897707] ret_from_fork_asm+0x1a/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897711] </TASK> There are two problems here: if (!ceph_inc_osd_stopping_blocker(fsc->mdsc)) { rc = -EIO; goto release_folios; } (1) ceph_kill_sb() doesn't wait ending of flushing all dirty folios/pages because of racy nature of mdsc->stopping_blockers. As a result, mdsc->stopping becomes CEPH_MDSC_STOPPING_FLUSHED too early. (2) The ceph_inc_osd_stopping_blocker(fsc->mdsc) fails to increment mdsc->stopping_blockers. Finally, already locked folios/pages are never been unlocked and the logic tries to lock the same page second time. This patch implements refactoring of ceph_submit_write() and also it solves the second issue. Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Link: https://lore.kernel.org/r/20250205000249.123054-4-slava@dubeyko.com Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>

The generic/421 fails to finish because of the issue: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.894678] INFO: task kworker/u48:0:11 blocked for more than 122 seconds. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895403] Not tainted 6.13.0-rc5+ linuxppc#1 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895867] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896633] task:kworker/u48:0 state:D stack:0 pid:11 tgid:11 ppid:2 flags:0x00004000 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896641] Workqueue: writeback wb_workfn (flush-ceph-24) Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897614] Call Trace: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897620] <TASK> Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897629] __schedule+0x443/0x16b0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897637] schedule+0x2b/0x140 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897640] io_schedule+0x4c/0x80 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897643] folio_wait_bit_common+0x11b/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897646] ? _raw_spin_unlock_irq+0xe/0x50 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897652] ? __pfx_wake_page_function+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897655] __folio_lock+0x17/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897658] ceph_writepages_start+0xca9/0x1fb0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897663] ? fsnotify_remove_queued_event+0x2f/0x40 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897668] do_writepages+0xd2/0x240 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897672] __writeback_single_inode+0x44/0x350 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897675] writeback_sb_inodes+0x25c/0x550 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897680] wb_writeback+0x89/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897683] ? finish_task_switch.isra.0+0x97/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897687] wb_workfn+0xb5/0x410 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897689] process_one_work+0x188/0x3d0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897692] worker_thread+0x2b5/0x3c0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897694] ? __pfx_worker_thread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897696] kthread+0xe1/0x120 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897699] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897701] ret_from_fork+0x43/0x70 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897705] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897707] ret_from_fork_asm+0x1a/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897711] </TASK> There are several issues here: (1) ceph_kill_sb() doesn't wait ending of flushing all dirty folios/pages because of racy nature of mdsc->stopping_blockers. As a result, mdsc->stopping becomes CEPH_MDSC_STOPPING_FLUSHED too early. (2) The ceph_inc_osd_stopping_blocker(fsc->mdsc) fails to increment mdsc->stopping_blockers. Finally, already locked folios/pages are never been unlocked and the logic tries to lock the same page second time. (3) The folio_batch with found dirty pages by filemap_get_folios_tag() is not processed properly. And this is why some number of dirty pages simply never processed and we have dirty folios/pages after unmount anyway. This patch fixes the issues by means of: (1) introducing dirty_folios counter and flush_end_wq waiting queue in struct ceph_mds_client; (2) ceph_dirty_folio() increments the dirty_folios counter; (3) writepages_finish() decrements the dirty_folios counter and wake up all waiters on the queue if dirty_folios counter is equal or lesser than zero; (4) adding in ceph_kill_sb() method the logic of checking the value of dirty_folios counter and waiting if it is bigger than zero; (5) adding ceph_inc_osd_stopping_blocker() call in the beginning of the ceph_writepages_start() and ceph_dec_osd_stopping_blocker() at the end of the ceph_writepages_start() with the goal to resolve the racy nature of mdsc->stopping_blockers. sudo ./check generic/421 FSTYP -- ceph PLATFORM -- Linux/x86_64 ceph-testing-0001 6.13.0+ #137 SMP PREEMPT_DYNAMIC Mon Feb 3 20:30:08 UTC 2025 MKFS_OPTIONS -- 127.0.0.1:40551:/scratch MOUNT_OPTIONS -- -o name=fs,secret=<secret>,ms_mode=crc,nowsync,copyfrom 127.0.0.1:40551:/scratch /mnt/scratch generic/421 7s ... 4s Ran: generic/421 Passed all 1 tests Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Link: https://lore.kernel.org/r/20250205000249.123054-5-slava@dubeyko.com Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>

Viacheslav Dubeyko <slava@dubeyko.com> says: From: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> The generic/421 fails to finish because of the issue: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.894678] INFO: task kworker/u48:0:11 blocked for more than 122 seconds. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895403] Not tainted 6.13.0-rc5+ linuxppc#1 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.895867] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896633] task:kworker/u48:0 state:D stack:0 pid:11 tgid:11 ppid:2 flags:0x00004000 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.896641] Workqueue: writeback wb_workfn (flush-ceph-24) Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897614] Call Trace: Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897620] <TASK> Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897629] __schedule+0x443/0x16b0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897637] schedule+0x2b/0x140 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897640] io_schedule+0x4c/0x80 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897643] folio_wait_bit_common+0x11b/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897646] ? _raw_spin_unlock_irq+0xe/0x50 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897652] ? __pfx_wake_page_function+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897655] __folio_lock+0x17/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897658] ceph_writepages_start+0xca9/0x1fb0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897663] ? fsnotify_remove_queued_event+0x2f/0x40 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897668] do_writepages+0xd2/0x240 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897672] __writeback_single_inode+0x44/0x350 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897675] writeback_sb_inodes+0x25c/0x550 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897680] wb_writeback+0x89/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897683] ? finish_task_switch.isra.0+0x97/0x310 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897687] wb_workfn+0xb5/0x410 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897689] process_one_work+0x188/0x3d0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897692] worker_thread+0x2b5/0x3c0 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897694] ? __pfx_worker_thread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897696] kthread+0xe1/0x120 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897699] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897701] ret_from_fork+0x43/0x70 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897705] ? __pfx_kthread+0x10/0x10 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897707] ret_from_fork_asm+0x1a/0x30 Jan 3 14:25:27 ceph-testing-0001 kernel: [ 369.897711] </TASK> There are several issues here: (1) ceph_kill_sb() doesn't wait ending of flushing all dirty folios/pages because of racy nature of mdsc->stopping_blockers. As a result, mdsc->stopping becomes CEPH_MDSC_STOPPING_FLUSHED too early. (2) The ceph_inc_osd_stopping_blocker(fsc->mdsc) fails to increment mdsc->stopping_blockers. Finally, already locked folios/pages are never been unlocked and the logic tries to lock the same page second time. (3) The folio_batch with found dirty pages by filemap_get_folios_tag() is not processed properly. And this is why some number of dirty pages simply never processed and we have dirty folios/pages after unmount anyway. This patchset is refactoring the ceph_writepages_start() method and it fixes the issues by means of: (1) introducing dirty_folios counter and flush_end_wq waiting queue in struct ceph_mds_client; (2) ceph_dirty_folio() increments the dirty_folios counter; (3) writepages_finish() decrements the dirty_folios counter and wake up all waiters on the queue if dirty_folios counter is equal or lesser than zero; (4) adding in ceph_kill_sb() method the logic of checking the value of dirty_folios counter and waiting if it is bigger than zero; (5) adding ceph_inc_osd_stopping_blocker() call in the beginning of the ceph_writepages_start() and ceph_dec_osd_stopping_blocker() at the end of the ceph_writepages_start() with the goal to resolve the racy nature of mdsc->stopping_blockers. sudo ./check generic/421 FSTYP -- ceph PLATFORM -- Linux/x86_64 ceph-testing-0001 6.13.0+ #137 SMP PREEMPT_DYNAMIC Mon Feb 3 20:30:08 UTC 2025 MKFS_OPTIONS -- 127.0.0.1:40551:/scratch MOUNT_OPTIONS -- -o name=fs,secret=<secret>,ms_mode=crc,nowsync,copyfrom 127.0.0.1:40551:/scratch /mnt/scratch generic/421 7s ... 4s Ran: generic/421 Passed all 1 tests * patches from https://lore.kernel.org/r/20250205000249.123054-1-slava@dubeyko.com: ceph: fix generic/421 test failure ceph: introduce ceph_submit_write() method ceph: introduce ceph_process_folio_batch() method ceph: extend ceph_writeback_ctl for ceph_writepages_start() refactoring Link: https://lore.kernel.org/r/20250205000249.123054-1-slava@dubeyko.com Signed-off-by: Christian Brauner <brauner@kernel.org>

Commit <d74169ceb0d2> ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 linuxppc#1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55 Call Trace: <TASK> dump_stack_lvl+0xb7/0xd0 lockdep_rcu_suspicious+0x159/0x1f0 ? __pfx_enable_drhd_fault_handling+0x10/0x10 enable_drhd_fault_handling+0x151/0x180 cpuhp_invoke_callback+0x1df/0x990 cpuhp_thread_fun+0x1ea/0x2c0 smpboot_thread_fn+0x1f5/0x2e0 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x12a/0x2d0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x4a/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat about a possible deadlock between dmar_global_lock and cpu_hotplug_lock. This is avoided by not holding dmar_global_lock when calling iommu_device_register(), which initiates the device probe process. Fixes: d74169c ("iommu/vt-d: Allocate DMAR fault interrupts locally") Reported-and-tested-by: Ido Schimmel <idosch@nvidia.com> Closes: https://lore.kernel.org/linux-iommu/Zx9OwdLIc_VoQ0-a@shredder.mtl.com/ Tested-by: Breno Leitao <leitao@debian.org> Cc: stable@vger.kernel.org Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20250218022422.2315082-1-baolu.lu@linux.intel.com Tested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>

Currently kvfree_rcu() APIs use a system workqueue which is "system_unbound_wq" to driver RCU machinery to reclaim a memory. Recently, it has been noted that the following kernel warning can be observed: <snip> workqueue: WQ_MEM_RECLAIM nvme-wq:nvme_scan_work is flushing !WQ_MEM_RECLAIM events_unbound:kfree_rcu_work WARNING: CPU: 21 PID: 330 at kernel/workqueue.c:3719 check_flush_dependency+0x112/0x120 Modules linked in: intel_uncore_frequency(E) intel_uncore_frequency_common(E) skx_edac(E) ... CPU: 21 UID: 0 PID: 330 Comm: kworker/u144:6 Tainted: G E 6.13.2-0_g925d379822da linuxppc#1 Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM20 02/01/2023 Workqueue: nvme-wq nvme_scan_work RIP: 0010:check_flush_dependency+0x112/0x120 Code: 05 9a 40 14 02 01 48 81 c6 c0 00 00 00 48 8b 50 18 48 81 c7 c0 00 00 00 48 89 f9 48 ... RSP: 0018:ffffc90000df7bd8 EFLAGS: 00010082 RAX: 000000000000006a RBX: ffffffff81622390 RCX: 0000000000000027 RDX: 00000000fffeffff RSI: 000000000057ffa8 RDI: ffff88907f960c88 RBP: 0000000000000000 R08: ffffffff83068e50 R09: 000000000002fffd R10: 0000000000000004 R11: 0000000000000000 R12: ffff8881001a4400 R13: 0000000000000000 R14: ffff88907f420fb8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88907f940000(0000) knlGS:0000000000000000 CR2: 00007f60c3001000 CR3: 000000107d010005 CR4: 00000000007726f0 PKRU: 55555554 Call Trace: <TASK> ? __warn+0xa4/0x140 ? check_flush_dependency+0x112/0x120 ? report_bug+0xe1/0x140 ? check_flush_dependency+0x112/0x120 ? handle_bug+0x5e/0x90 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? timer_recalc_next_expiry+0x190/0x190 ? check_flush_dependency+0x112/0x120 ? check_flush_dependency+0x112/0x120 __flush_work.llvm.1643880146586177030+0x174/0x2c0 flush_rcu_work+0x28/0x30 kvfree_rcu_barrier+0x12f/0x160 kmem_cache_destroy+0x18/0x120 bioset_exit+0x10c/0x150 disk_release.llvm.6740012984264378178+0x61/0xd0 device_release+0x4f/0x90 kobject_put+0x95/0x180 nvme_put_ns+0x23/0xc0 nvme_remove_invalid_namespaces+0xb3/0xd0 nvme_scan_work+0x342/0x490 process_scheduled_works+0x1a2/0x370 worker_thread+0x2ff/0x390 ? pwq_release_workfn+0x1e0/0x1e0 kthread+0xb1/0xe0 ? __kthread_parkme+0x70/0x70 ret_from_fork+0x30/0x40 ? __kthread_parkme+0x70/0x70 ret_from_fork_asm+0x11/0x20 </TASK> ---[ end trace 0000000000000000 ]--- <snip> To address this switch to use of independent WQ_MEM_RECLAIM workqueue, so the rules are not violated from workqueue framework point of view. Apart of that, since kvfree_rcu() does reclaim memory it is worth to go with WQ_MEM_RECLAIM type of wq because it is designed for this purpose. Fixes: 6c6c47b ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), Reported-by: Keith Busch <kbusch@kernel.org> Closes: https://lore.kernel.org/all/Z7iqJtCjHKfo8Kho@kbusch-mbp/ Cc: stable@vger.kernel.org Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

A cache device failing to resume due to mapping errors should not be retried, as the failure leaves a partially initialized policy object. Repeating the resume operation risks triggering BUG_ON when reloading cache mappings into the incomplete policy object. Reproduce steps: 1. create a cache metadata consisting of 512 or more cache blocks, with some mappings stored in the first array block of the mapping array. Here we use cache_restore v1.0 to build the metadata. cat <<EOF >> cmeta.xml <superblock uuid="" block_size="128" nr_cache_blocks="512" \ policy="smq" hint_width="4"> <mappings> <mapping cache_block="0" origin_block="0" dirty="false"/> </mappings> </superblock> EOF dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2 dmsetup remove cmeta 2. wipe the second array block of the mapping array to simulate data degradations. mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \ 2>/dev/null | hexdump -e '1/8 "%u\n"') ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \ 2>/dev/null | hexdump -e '1/8 "%u\n"') dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock 3. try bringing up the cache device. The resume is expected to fail due to the broken array block. dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dmsetup create cache --notable dmsetup load cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" dmsetup resume cache 4. try resuming the cache again. An unexpected BUG_ON is triggered while loading cache mappings. dmsetup resume cache Kernel logs: (snip) ------------[ cut here ]------------ kernel BUG at drivers/md/dm-cache-policy-smq.c:752! Oops: invalid opcode: 0000 [linuxppc#1] PREEMPT SMP KASAN NOPTI CPU: 0 UID: 0 PID: 332 Comm: dmsetup Not tainted 6.13.4 #3 RIP: 0010:smq_load_mapping+0x3e5/0x570 Fix by disallowing resume operations for devices that failed the initial attempt. Signed-off-by: Ming-Hung Tsai <mtsai@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

riteshharjani added 4 commits August 17, 2022 04:40

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Cleanup submit bh patchv4 #1

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Cleanup submit bh patchv4 #1

Cleanup submit bh patchv4 #1

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riteshharjani commented Aug 17, 2022