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diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -1976,7 +1976,8 @@
// because in async signal processing case (when handler is called directly
// from rtl_generic_sighandler) we have not yet received the reraised
// signal; and it looks too fragile to intercept all ways to reraise a signal.
- if (flags()->report_bugs && !sync && sig != SIGTERM && errno != 99) {
+ if (ShouldReport(thr, ReportTypeErrnoInSignal) && !sync && sig != SIGTERM &&
+ errno != 99) {
VarSizeStackTrace stack;
// StackTrace::GetNestInstructionPc(pc) is used because return address is
// expected, OutputReport() will undo this.
diff --git a/compiler-rt/lib/tsan/rtl/tsan_mman.cpp b/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
@@ -145,7 +145,7 @@
static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
- !flags()->report_signal_unsafe)
+ !ShouldReport(thr, ReportTypeSignalUnsafe))
return;
VarSizeStackTrace stack;
ObtainCurrentStack(thr, pc, &stack);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -624,6 +624,7 @@
ScopedErrorReportLock lock_;
};
+bool ShouldReport(ThreadState *thr, ReportType typ);
ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack);
void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
MutexSet *mset, uptr *tag = nullptr);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
@@ -519,23 +519,22 @@
void ForkBefore(ThreadState *thr, uptr pc) {
ctx->thread_registry->Lock();
ctx->report_mtx.Lock();
- // Ignore memory accesses in the pthread_atfork callbacks.
- // If any of them triggers a data race we will deadlock
- // on the report_mtx.
+ // Suppress all reports in the pthread_atfork callbacks.
+ // Reports will deadlock on the report_mtx.
// We could ignore interceptors and sync operations as well,
// but so far it's unclear if it will do more good or harm.
// Unnecessarily ignoring things can lead to false positives later.
- ThreadIgnoreBegin(thr, pc);
+ thr->suppress_reports++;
}
void ForkParentAfter(ThreadState *thr, uptr pc) {
- ThreadIgnoreEnd(thr, pc); // Begin is in ForkBefore.
+ thr->suppress_reports--; // Enabled in ForkBefore.
ctx->report_mtx.Unlock();
ctx->thread_registry->Unlock();
}
void ForkChildAfter(ThreadState *thr, uptr pc) {
- ThreadIgnoreEnd(thr, pc); // Begin is in ForkBefore.
+ thr->suppress_reports--; // Enabled in ForkBefore.
ctx->report_mtx.Unlock();
ctx->thread_registry->Unlock();
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
@@ -51,6 +51,8 @@
// or false positives (e.g. unlock in a different thread).
if (SANITIZER_GO)
return;
+ if (!ShouldReport(thr, typ))
+ return;
ThreadRegistryLock l(ctx->thread_registry);
ScopedReport rep(typ);
rep.AddMutex(mid);
@@ -107,7 +109,7 @@
if (!unlock_locked)
s->Reset(thr->proc()); // must not reset it before the report is printed
s->mtx.Unlock();
- if (unlock_locked) {
+ if (unlock_locked && ShouldReport(thr, ReportTypeMutexDestroyLocked)) {
ThreadRegistryLock l(ctx->thread_registry);
ScopedReport rep(ReportTypeMutexDestroyLocked);
rep.AddMutex(mid);
@@ -534,7 +536,7 @@
}
void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
- if (r == 0)
+ if (r == 0 || !ShouldReport(thr, ReportTypeDeadlock))
return;
ThreadRegistryLock l(ctx->thread_registry);
ScopedReport rep(ReportTypeDeadlock);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -142,6 +142,27 @@
return stack;
}
+bool ShouldReport(ThreadState *thr, ReportType typ) {
+ // We set thr->suppress_reports in the fork context.
+ // Taking any locking in the fork context can lead to deadlocks.
+ // If any locks are already taken, it's too late to do this check.
+ CheckNoLocks(thr);
+ if (SANITIZER_DEBUG)
+ ThreadRegistryLock l(ctx->thread_registry);
+ if (!flags()->report_bugs || thr->suppress_reports)
+ return false;
+ switch (typ) {
+ case ReportTypeSignalUnsafe:
+ return flags()->report_signal_unsafe;
+ case ReportTypeThreadLeak:
+ return flags()->report_thread_leaks;
+ case ReportTypeMutexDestroyLocked:
+ return flags()->report_destroy_locked;
+ default:
+ return true;
+ }
+}
+
ScopedReportBase::ScopedReportBase(ReportType typ, uptr tag) {
ctx->thread_registry->CheckLocked();
void *mem = internal_alloc(MBlockReport, sizeof(ReportDesc));
@@ -497,8 +518,10 @@
}
bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
- if (!flags()->report_bugs || thr->suppress_reports)
- return false;
+ // These should have been checked in ShouldReport.
+ // It's too late to check them here, we have already taken locks.
+ CHECK(flags()->report_bugs);
+ CHECK(!thr->suppress_reports);
atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
const ReportDesc *rep = srep.GetReport();
CHECK_EQ(thr->current_report, nullptr);
@@ -589,7 +612,7 @@
// at best it will cause deadlocks on internal mutexes.
ScopedIgnoreInterceptors ignore;
- if (!flags()->report_bugs)
+ if (!ShouldReport(thr, ReportTypeRace))
return;
if (!flags()->report_atomic_races && !RaceBetweenAtomicAndFree(thr))
return;
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
@@ -210,7 +210,7 @@
void ThreadFinalize(ThreadState *thr) {
ThreadCheckIgnore(thr);
#if !SANITIZER_GO
- if (!flags()->report_thread_leaks)
+ if (!ShouldReport(thr, ReportTypeThreadLeak))
return;
ThreadRegistryLock l(ctx->thread_registry);
Vector<ThreadLeak> leaks;
diff --git a/compiler-rt/test/tsan/pthread_atfork_deadlock3.c b/compiler-rt/test/tsan/pthread_atfork_deadlock3.c
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/tsan/pthread_atfork_deadlock3.c
@@ -0,0 +1,71 @@
+// RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// Regression test for
+// https://groups.google.com/g/thread-sanitizer/c/TQrr4-9PRYo/m/HFR4FMi6AQAJ
+#include "test.h"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+#include <signal.h>
+
+long glob = 0;
+
+void *worker(void *main) {
+ glob++;
+ barrier_wait(&barrier);
+ barrier_wait(&barrier);
+ pthread_kill((pthread_t)main, SIGPROF);
+ barrier_wait(&barrier);
+ return NULL;
+}
+
+void atfork() {
+ barrier_wait(&barrier);
+ barrier_wait(&barrier);
+ write(2, "in atfork\n", strlen("in atfork\n"));
+ static volatile long a;
+ __atomic_fetch_add(&a, 1, __ATOMIC_RELEASE);
+}
+
+void handler(int sig) {
+ write(2, "in handler\n", strlen("in handler\n"));
+ glob++;
+}
+
+int main() {
+ barrier_init(&barrier, 2);
+ struct sigaction act = {};
+ act.sa_handler = &handler;
+ if (sigaction(SIGPROF, &act, 0)) {
+ perror("sigaction");
+ exit(1);
+ }
+ pthread_atfork(atfork, NULL, NULL);
+ pthread_t t;
+ pthread_create(&t, NULL, worker, (void*)pthread_self());
+ barrier_wait(&barrier);
+ pid_t pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "fork failed: %d\n", errno);
+ return 1;
+ }
+ if (pid == 0) {
+ fprintf(stderr, "CHILD\n");
+ return 0;
+ }
+ if (pid != waitpid(pid, NULL, 0)) {
+ fprintf(stderr, "waitpid failed: %d\n", errno);
+ return 1;
+ }
+ pthread_join(t, NULL);
+ fprintf(stderr, "PARENT\n");
+ return 0;
+}
+
+// CHECK: in atfork
+// CHECK: in handler
+// Note: There is a race, but we won't report it
+// to not deadlock.
+// CHECK-NOT: ThreadSanitizer: data race
+// CHECK: CHILD
+// CHECK: PARENT
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