[ASan] Disable InstallAtForkHandler on Linux/sparc64#108542
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When SPARC Asan testing is enabled by PR llvm#107405, many Linux/sparc64 tests just hang like ``` #0 0xf7ae8e90 in syscall () from /usr/lib32/libc.so.6 #1 0x701065e8 in __sanitizer::FutexWait(__sanitizer::atomic_uint32_t*, unsigned int) () at compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp:766 llvm#2 0x70107c90 in Wait () at compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp:35 llvm#3 0x700f7cac in Lock () at compiler-rt/lib/asan/../sanitizer_common/sanitizer_mutex.h:196 llvm#4 Lock () at compiler-rt/lib/asan/../sanitizer_common/sanitizer_thread_registry.h:98 llvm#5 LockThreads () at compiler-rt/lib/asan/asan_thread.cpp:489 llvm#6 0x700e9c8c in __asan::BeforeFork() () at compiler-rt/lib/asan/asan_posix.cpp:157 llvm#7 0xf7ac83f4 in ?? () from /usr/lib32/libc.so.6 Backtrace stopped: previous frame identical to this frame (corrupt stack?) ``` It turns out that this happens in tests using `internal_fork` (e.g. invoking `llvm-symbolizer`): unlike most other Linux targets, which use `clone`, Linux/sparc64 has to use `__fork` instead. While `clone` doesn't trigger `pthread_atfork` handlers, `__fork` obviously does, causing the hang. To avoid this, this patch disables `InstallAtForkHandler` and lets the ASan tests run to completion. Tested on `sparc64-unknown-linux-gnu`.
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@llvm/pr-subscribers-compiler-rt-sanitizer Author: Rainer Orth (rorth) ChangesWhen SPARC Asan testing is enabled by PR #107405, many Linux/sparc64 tests just hang like It turns out that this happens in tests using To avoid this, this patch disables Tested on Full diff: https://github.com/llvm/llvm-project/pull/108542.diff 1 Files Affected:
diff --git a/compiler-rt/lib/asan/asan_posix.cpp b/compiler-rt/lib/asan/asan_posix.cpp
index 76564538bd5d77..c42c0472592b78 100644
--- a/compiler-rt/lib/asan/asan_posix.cpp
+++ b/compiler-rt/lib/asan/asan_posix.cpp
@@ -171,7 +171,11 @@ static void AfterFork(bool fork_child) {
}
void InstallAtForkHandler() {
-# if SANITIZER_SOLARIS || SANITIZER_NETBSD || SANITIZER_APPLE
+# if SANITIZER_SOLARIS || SANITIZER_NETBSD || SANITIZER_APPLE || \
+ (SANITIZER_LINUX && SANITIZER_SPARC)
+ // While other Linux targets use clone in internal_fork which doesn't
+ // trigger pthread_atfork handlers, Linux/sparc64 uses __fork, causing a
+ // hang.
return; // FIXME: Implement FutexWait.
# endif
pthread_atfork(
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vitalybuka
approved these changes
Sep 14, 2024
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When SPARC Asan testing is enabled by PR #107405, many Linux/sparc64 tests just hang like
It turns out that this happens in tests using
internal_fork(e.g. invokingllvm-symbolizer): unlike most other Linux targets, which useclone, Linux/sparc64 has to use__forkinstead. Whileclonedoesn't triggerpthread_atforkhandlers,__forkobviously does, causing the hang.To avoid this, this patch disables
InstallAtForkHandlerand lets the ASan tests run to completion.Tested on
sparc64-unknown-linux-gnu.