Don't hoist potentially invalid byrefs#124833
Closed
EgorBo wants to merge 4 commits intodotnet:mainfrom
Closed
Conversation
github-actions
bot
added
the
area-CodeGen-coreclr
Contributor
|
Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
Contributor
There was a problem hiding this comment.
Pull request overview
This pull request fixes a critical GC crash issue where if-conversion was speculatively hoisting potentially invalid managed references (byrefs). The issue occurred when if-conversion transformed ternary operations involving null references (like Unsafe.NullRef<byte>()) into unconditionally evaluated code, leading to GC crashes.
Changes:
- Added
gtTreeMayHaveInvalidByrefsmethod to detect trees with potentially invalid byrefs - Integrated the check into if-conversion logic to skip conversion when invalid byrefs are detected
- The fix prevents speculative hoisting of GC-typed nodes that could be invalid
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| src/coreclr/jit/ifconversion.cpp | Added check to skip if-conversion when potentially invalid byrefs are detected in then or else branches |
| src/coreclr/jit/gentree.cpp | Implemented gtTreeMayHaveInvalidByrefs method with tree visitor to detect potentially invalid GC-typed nodes |
| src/coreclr/jit/compiler.h | Added declaration for the new static method gtTreeMayHaveInvalidByrefs |
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
3 tasks
Member
Author
|
Too ad-hoc fix since we have more code paths where we might produce these (#124807 (comment)) |
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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.
Fixes #124807