tsan: fix crash during thread exit
Use of gethostent provokes caching of some resources inside of libc.
They are freed in __libc_thread_freeres very late in thread lifetime,
after our ThreadFinish. __libc_thread_freeres calls free which
previously crashed in malloc hooks.
Fix it by setting ignore_interceptors for finished threads,
which in turn prevents malloc hooks.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D113989
GitOrigin-RevId: c7081b5b4cb57f27e6a075e1b5a63b7951cd8a7a
diff --git a/lib/tsan/rtl/tsan_rtl_thread.cpp b/lib/tsan/rtl/tsan_rtl_thread.cpp
index 8532f5d..dfead43 100644
--- a/lib/tsan/rtl/tsan_rtl_thread.cpp
+++ b/lib/tsan/rtl/tsan_rtl_thread.cpp
@@ -228,6 +228,9 @@
DontNeedShadowFor(thr->tls_addr, thr->tls_size);
thr->is_dead = true;
thr->is_inited = false;
+#if !SANITIZER_GO
+ thr->ignore_interceptors++;
+#endif
ctx->thread_registry.FinishThread(thr->tid);
}
diff --git a/test/tsan/Linux/sethostent.cpp b/test/tsan/Linux/sethostent.cpp
new file mode 100644
index 0000000..6cb8c29
--- /dev/null
+++ b/test/tsan/Linux/sethostent.cpp
@@ -0,0 +1,37 @@
+// RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+
+// Use of gethostent provokes caching of some resources inside of libc.
+// They are freed in __libc_thread_freeres very late in thread lifetime,
+// after our ThreadFinish. __libc_thread_freeres calls free which
+// previously crashed in malloc hooks.
+
+#include "../test.h"
+#include <netdb.h>
+
+long X;
+
+extern "C" void __sanitizer_malloc_hook(void *ptr, size_t size) {
+ __atomic_fetch_add(&X, 1, __ATOMIC_RELAXED);
+}
+
+extern "C" void __sanitizer_free_hook(void *ptr) {
+ __atomic_fetch_sub(&X, 1, __ATOMIC_RELAXED);
+}
+
+void *Thread(void *x) {
+ sethostent(1);
+ gethostbyname("llvm.org");
+ gethostent();
+ endhostent();
+ return NULL;
+}
+
+int main() {
+ pthread_t th;
+ pthread_create(&th, NULL, Thread, NULL);
+ pthread_join(th, NULL);
+ fprintf(stderr, "DONE\n");
+ return 0;
+}
+
+// CHECK: DONE
