[tsan] Use pthread_sigmask instead of sigprocmask to block signals in a thread on Darwin
On Darwin, sigprocmask changes the signal mask for the entire process. This has some unwanted consequences, because e.g. internal_start_thread wants to disable signals only in the current thread (to make the new thread inherit the signal mask), which is currently broken on Darwin. This patch switches to pthread_sigmask.
Differential Revision: https://reviews.llvm.org/D35016
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@307212 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index b4f8ab5..4fcef60 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -189,7 +189,8 @@
uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
__sanitizer_sigset_t *oldset) {
- return sigprocmask(how, set, oldset);
+ // Don't use sigprocmask here, because it affects all threads.
+ return pthread_sigmask(how, set, oldset);
}
// Doesn't call pthread_atfork() handlers.
diff --git a/test/tsan/Darwin/signals-blocked.cc b/test/tsan/Darwin/signals-blocked.cc
new file mode 100644
index 0000000..209dc22
--- /dev/null
+++ b/test/tsan/Darwin/signals-blocked.cc
@@ -0,0 +1,75 @@
+// RUN: %clangxx_tsan %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <errno.h>
+
+volatile bool signal_delivered;
+
+static void handler(int sig) {
+ if (sig == SIGALRM)
+ signal_delivered = true;
+}
+
+static void* thr(void *p) {
+ sigset_t sigset;
+ sigemptyset(&sigset);
+ sigaddset(&sigset, SIGALRM);
+ int ret = pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
+ if (ret) abort();
+
+ struct sigaction act = {};
+ act.sa_handler = &handler;
+ if (sigaction(SIGALRM, &act, 0)) {
+ perror("sigaction");
+ exit(1);
+ }
+
+ itimerval t;
+ t.it_value.tv_sec = 0;
+ t.it_value.tv_usec = 10000;
+ t.it_interval = t.it_value;
+ if (setitimer(ITIMER_REAL, &t, 0)) {
+ perror("setitimer");
+ exit(1);
+ }
+
+ while (!signal_delivered) {
+ usleep(1000);
+ }
+
+ t.it_value.tv_usec = 0;
+ if (setitimer(ITIMER_REAL, &t, 0)) {
+ perror("setitimer");
+ exit(1);
+ }
+
+ fprintf(stderr, "SIGNAL DELIVERED\n");
+
+ return 0;
+}
+
+int main() {
+ sigset_t sigset;
+ sigemptyset(&sigset);
+ sigaddset(&sigset, SIGALRM);
+ int ret = pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+ if (ret) abort();
+
+ pthread_t th;
+ pthread_create(&th, 0, thr, 0);
+ pthread_join(th, 0);
+
+ fprintf(stderr, "DONE\n");
+ return 0;
+}
+
+// CHECK-NOT: WARNING: ThreadSanitizer:
+// CHECK: SIGNAL DELIVERED
+// CHECK: DONE
+// CHECK-NOT: WARNING: ThreadSanitizer:
