[msan] Block signals during MsanThread::TSDDtor #98405
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
MSan may segfault inside a signal handler, if MSan instrumentation is trying to access thread-local storage that has already been destroyed. This fixes the issue by blocking asychronous signals inside MsanThread::Destroy, as suggested by Paul Pluzhnikov. Note: ed8565c changed *BlockSignals to only block asynchronous signals, despite the name.
llvmbot
added
compiler-rt
compiler-rt:msan
|
@llvm/pr-subscribers-compiler-rt-sanitizer Author: Thurston Dang (thurstond) ChangesFull diff: https://github.com/llvm/llvm-project/pull/98405.diff 1 Files Affected:
diff --git a/compiler-rt/lib/msan/msan_thread.cpp b/compiler-rt/lib/msan/msan_thread.cpp
index ff9b90bb81f0c..cc4dfe601ead6 100644
--- a/compiler-rt/lib/msan/msan_thread.cpp
+++ b/compiler-rt/lib/msan/msan_thread.cpp
@@ -3,6 +3,7 @@
#include "msan_thread.h"
#include "msan_interface_internal.h"
+#include "sanitizer_common/sanitizer_linux.h"
#include "sanitizer_common/sanitizer_tls_get_addr.h"
namespace __msan {
@@ -56,6 +57,9 @@ void MsanThread::TSDDtor(void *tsd) {
}
void MsanThread::Destroy() {
+#if SANITIZER_LINUX
+ ScopedBlockSignals block(nullptr);
+#endif
malloc_storage().CommitBack();
// We also clear the shadow on thread destruction because
// some code may still be executing in later TSD destructors
|
thurstond
changed the title
|
✅ With the latest revision this PR passed the C/C++ code formatter. |
vitalybuka
approved these changes
Jul 10, 2024
vitalybuka
approved these changes
Jul 10, 2024
|
I suggest to move blocker just before msan_current_thread = nullptr in MsanTSDDtor |
per Vitaly's feedback
thurstond
changed the title
vitalybuka
approved these changes
Jul 11, 2024
aaryanshukla
pushed a commit
to aaryanshukla/llvm-project
that referenced
this pull request
Jul 14, 2024
MSan may segfault inside a signal handler, if MSan instrumentation is
trying to access thread-local storage that has already been destroyed.
This fixes the issue by blocking asychronous signals inside
MsanThread::TSDDtor. This is based on an idea suggested by Paul
Pluzhnikov (block async signals in MsanThread::Destroy()) and refined by
Vitaly Buka.
Note: ed8565c changed *BlockSignals to
only block asynchronous signals, despite the name.
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.
MSan may segfault inside a signal handler, if MSan instrumentation is trying to access thread-local storage that has already been destroyed. This fixes the issue by blocking asychronous signals inside MsanThread::TSDDtor. This is based on an idea suggested by Paul Pluzhnikov (block async signals in MsanThread::Destroy()) and refined by Vitaly Buka.
Note: ed8565c changed *BlockSignals to only block asynchronous signals, despite the name.