Make exegesis annotator work with mappings that aren't page aligned #33
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
This patch makes the exegesis annotator work with mappings that are not page aligned. Currently if a segfault occurs at an address that isn't page aligned, Exegesis will try and map an address at that address and then the mmap call will silently fail as there is no error handling wired up for that and it will segfault again, thus creating a loop within the annotator.
Should there be one wired up then? |
mtrofin
reviewed
Feb 3, 2024
mtrofin
approved these changes
Feb 3, 2024
Yes. It's been on my todo list for a while. It's not trivial to add though as the mmap calls that potentially fail are in the assembled benchmark snippet which is manually created assembly using the LLVM APIs. So it's possible to do a conditional jump if This is also less of an issue if assertions are enabled as llvm/llvm-project#75554 adds an assertion that triggers when this case occurs (which I did hit after bumping the LLVM version). |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
This patch makes the exegesis annotator work with mappings that are not page aligned. Currently if a segfault occurs at an address that isn't page aligned, Exegesis will try and map an address at that address and then the mmap call will silently fail as there is no error handling wired up for that and it will segfault again, thus creating a loop within the annotator.