[compiler-rt] Also consider SIGPROF as a synchronous signal

Blocking that signal causes inter-blocking for profilers that monitor
threads through that signal.

Update tests accordingly to use an uncaught signal.

This is a recommit of 6f3f659 with the
tests fixed.

Fix #83844 and #83561

Author: serge-sans-paille

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

@@ -126,6 +126,7 @@ const int SIGFPE = 8;
 const int SIGSEGV = 11;
 const int SIGPIPE = 13;
 const int SIGTERM = 15;
+const int SIGPROF = 27;
 #if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_APPLE || SANITIZER_NETBSD
 const int SIGBUS = 10;
 const int SIGSYS = 12;
@@ -2168,7 +2169,8 @@ 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 == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS ||
+         sig == SIGPROF;
 }
 
 void sighandler(int sig, __sanitizer_siginfo *info, void *ctx) {

compiler-rt/test/tsan/signal_errno.cpp

@@ -18,7 +18,7 @@ static void MyHandler(int, siginfo_t *s, void *c) {
 
 static void* sendsignal(void *p) {
   barrier_wait(&barrier);
-  pthread_kill(mainth, SIGPROF);
+  pthread_kill(mainth, SIGALRM);
   return 0;
 }
 
@@ -37,7 +37,7 @@ int main() {
   mainth = pthread_self();
   struct sigaction act = {};
   act.sa_sigaction = &MyHandler;
-  sigaction(SIGPROF, &act, 0);
+  sigaction(SIGALRM, &act, 0);
   pthread_t th;
   pthread_create(&th, 0, sendsignal, 0);
   loop();
@@ -46,7 +46,7 @@ int main() {
 }
 
 // CHECK: WARNING: ThreadSanitizer: signal handler spoils errno
-// CHECK:   Signal 27 handler invoked at:
+// CHECK:   Signal 14 handler invoked at:
 // CHECK:     #0 MyHandler(int, {{(__)?}}siginfo{{(_t)?}}*, void*) {{.*}}signal_errno.cpp
 // CHECK:     main
 // CHECK: SUMMARY: ThreadSanitizer: signal handler spoils errno{{.*}}MyHandler

compiler-rt/test/tsan/signal_sync.cpp

@@ -30,7 +30,7 @@ int main() {
 
   struct sigaction act = {};
   act.sa_handler = &handler;
-  if (sigaction(SIGPROF, &act, 0)) {
+  if (sigaction(SIGALRM, &act, 0)) {
     perror("sigaction");
     exit(1);
   }
@@ -39,7 +39,7 @@ int main() {
   t.it_value.tv_sec = 0;
   t.it_value.tv_usec = 10;
   t.it_interval = t.it_value;
-  if (setitimer(ITIMER_PROF, &t, 0)) {
+  if (setitimer(ITIMER_REAL, &t, 0)) {
     perror("setitimer");
     exit(1);
   }

compiler-rt/test/tsan/signal_thread.cpp

@@ -24,7 +24,7 @@ static void* thr(void *p) {
 int main() {
   struct sigaction act = {};
   act.sa_handler = &handler;
-  if (sigaction(SIGPROF, &act, 0)) {
+  if (sigaction(SIGALRM, &act, 0)) {
     perror("sigaction");
     exit(1);
   }
@@ -33,7 +33,7 @@ int main() {
   t.it_value.tv_sec = 0;
   t.it_value.tv_usec = 10;
   t.it_interval = t.it_value;
-  if (setitimer(ITIMER_PROF, &t, 0)) {
+  if (setitimer(ITIMER_REAL, &t, 0)) {
     perror("setitimer");
     exit(1);
   }

compiler-rt/test/tsan/signal_thread2.cpp

@@ -40,7 +40,7 @@ static void *thr(void *p) {
 int main() {
   struct sigaction act = {};
   act.sa_handler = &handler;
-  if (sigaction(SIGPROF, &act, 0)) {
+  if (sigaction(SIGALRM, &act, 0)) {
     perror("sigaction");
     exit(1);
   }
@@ -49,7 +49,7 @@ int main() {
   t.it_value.tv_sec = 0;
   t.it_value.tv_usec = 10;
   t.it_interval = t.it_value;
-  if (setitimer(ITIMER_PROF, &t, 0)) {
+  if (setitimer(ITIMER_REAL, &t, 0)) {
     perror("setitimer");
     exit(1);
   }