Doubly linked freelist fix #44585
Merged
Doubly linked freelist fix #44585
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Details: In gc_heap::allocate_uoh_object. we set the background mark bit if the new object is in a range that has mark bits committed. However, if the object is in a segment that is allocated during background_sweep, we won't actually sweep the segment, and so the background mark bits stays on, causing confusion in the next background GC - the object itself will survive, but we won't keep the objects that it points at, so we'll have heap corruption.
|
Tagging subscribers to this area: @dotnet/gc Issue meta data
|
jkotas
reviewed
Nov 12, 2020
mangod9
approved these changes
Nov 12, 2020
ghost
locked as resolved and limited conversation to collaborators
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
In gc_heap::allocate_uoh_object. we set the background mark bit if the new object is in a range that has the corresponding portions of the background mark_array committed.
However, if the object is in a segment that is allocated during background_sweep, we won't actually sweep the segment, and so the background mark bit stays on, causing confusion in the next background GC - the object itself will survive, but we won't keep the objects that it points at, so we'll have heap corruption.