[tsan] Process SIGPROF as sync signal only if thread is alive

[vitalybuka]

Otherwise it may crash too early.

This is followup to #85188

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Vitaly Buka (vitalybuka)

Changes

Otherwise it may crash too early.

This is followup to #85188

---

Full diff: https://github.com/llvm/llvm-project/pull/86343.diff

1 Files Affected:

• (modified) compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp (+3-3)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index 2bebe651b994e5..810ce69663d050 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -2169,8 +2169,7 @@ static bool is_sync_signal(ThreadSignalContext *sctx, int sig,
     return false;
 #endif
   return sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || sig == SIGTRAP ||
-         sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS ||
-         sig == SIGPROF;
+         sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS;
 }
 
 void sighandler(int sig, __sanitizer_siginfo *info, void *ctx) {
@@ -2181,7 +2180,8 @@ void sighandler(int sig, __sanitizer_siginfo *info, void *ctx) {
     return;
   }
   // Don't mess with synchronous signals.
-  const bool sync = is_sync_signal(sctx, sig, info);
+  const bool sync = is_sync_signal(sctx, sig, info) ||
+                    (sig == SIGPROF && thr->is_inited && !thr->is_dead);
   if (sync ||
       // If we are in blocking function, we can safely process it now
       // (but check if we are in a recursive interceptor,

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