Common: Don't use MAP_FIXED on Linux #11282
Merged
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
MAP_FIXED will clobber any existing memory mapping, and is not safe to use in a multi-threaded environment. Whether we like it or not, we are a multi-threaded environment, because Qt initializes before we get to main(), so it's already too late to safely use MAP_FIXED by the time we get there. Use MAP_FIXED_NOREPLACE instead. This is how MAP_FIXED should have behaved from the beginning. Obviously this means you'll need Linux 4.17+ and a semi-recent libc to use PCSX2 now. But if you're running a 6 year old unsupported kernel, you have bigger problems. Fixes "random" startup crashes.
stenzek
force-pushed
the
linux-MAP_FIXED-is-dumb
branch
from
f6d12d4
to
e47bcf8
Compare
|
Actions doesn't want to pick up the change, maybe it doesn't like my branch name.... But I've tested this locally, and it does appear to resolve the issue. |
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Outdated suggestions cannot be applied.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.
Description of Changes
MAP_FIXED will clobber any existing memory mapping, and is not safe to use in a multi-threaded environment. Whether we like it or not, we are a multi-threaded environment, because Qt initializes before we get to main(), so it's already too late to safely use MAP_FIXED by the time we get there.
Use MAP_FIXED_NOREPLACE instead. This is how MAP_FIXED should have behaved from the beginning.
Obviously this means you'll need Linux 4.17+ and a semi-recent libc to use PCSX2 now. But if you're running a 6 year old unsupported kernel, you have bigger problems.
Rationale behind Changes
Fixes "random" startup crashes on Meme Linux.
Suggested Testing Steps
Try to crash PCSX2 by repeatedly shutting down+restarting the application.