From 9b237b4013e86741cf7d4fcd95a7bc70772d2286 Mon Sep 17 00:00:00 2001 From: Rainer Orth Date: Mon, 16 Sep 2024 09:44:07 +0200 Subject: [PATCH] [ASan] Disable InstallAtForkHandler on Linux/sparc64 (#108542) When SPARC Asan testing is enabled by PR #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 #2 0x70107c90 in Wait () at compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp:35 #3 0x700f7cac in Lock () at compiler-rt/lib/asan/../sanitizer_common/sanitizer_mutex.h:196 #4 Lock () at compiler-rt/lib/asan/../sanitizer_common/sanitizer_thread_registry.h:98 #5 LockThreads () at compiler-rt/lib/asan/asan_thread.cpp:489 #6 0x700e9c8c in __asan::BeforeFork() () at compiler-rt/lib/asan/asan_posix.cpp:157 #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`. --- compiler-rt/lib/asan/asan_posix.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/compiler-rt/lib/asan/asan_posix.cpp b/compiler-rt/lib/asan/asan_posix.cpp index 76564538bd5d7..c42c0472592b7 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(