diff options
| -rw-r--r-- | compiler-rt/lib/tsan/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | compiler-rt/lib/tsan/rtl/tsan_interceptors.cc | 11 | ||||
| -rw-r--r-- | compiler-rt/lib/tsan/rtl/tsan_interceptors.h | 12 | ||||
| -rw-r--r-- | compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc | 72 | ||||
| -rw-r--r-- | compiler-rt/test/tsan/Darwin/gcd-once.mm | 55 |
5 files changed, 140 insertions, 11 deletions
diff --git a/compiler-rt/lib/tsan/CMakeLists.txt b/compiler-rt/lib/tsan/CMakeLists.txt index de0fb439eaf..66ba30c031c 100644 --- a/compiler-rt/lib/tsan/CMakeLists.txt +++ b/compiler-rt/lib/tsan/CMakeLists.txt @@ -47,6 +47,7 @@ set(TSAN_CXX_SOURCES if(APPLE) list(APPEND TSAN_SOURCES + rtl/tsan_libdispatch_mac.cc rtl/tsan_platform_mac.cc rtl/tsan_platform_posix.cc) elseif(UNIX) diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc index 7aaa4c304bc..f389d6596e1 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc +++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc @@ -264,17 +264,6 @@ ScopedInterceptor::~ScopedInterceptor() { } } -#define SCOPED_TSAN_INTERCEPTOR(func, ...) \ - SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__); \ - if (REAL(func) == 0) { \ - Report("FATAL: ThreadSanitizer: failed to intercept %s\n", #func); \ - Die(); \ - } \ - if (thr->ignore_interceptors || thr->in_ignored_lib) \ - return REAL(func)(__VA_ARGS__); \ -/**/ - -#define TSAN_INTERCEPTOR(ret, func, ...) INTERCEPTOR(ret, func, __VA_ARGS__) #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func) #if SANITIZER_FREEBSD # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func) diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.h b/compiler-rt/lib/tsan/rtl/tsan_interceptors.h index 49b79a7c5f9..451e8645fc8 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.h +++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.h @@ -26,6 +26,18 @@ class ScopedInterceptor { (void)pc; \ /**/ +#define SCOPED_TSAN_INTERCEPTOR(func, ...) \ + SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__); \ + if (REAL(func) == 0) { \ + Report("FATAL: ThreadSanitizer: failed to intercept %s\n", #func); \ + Die(); \ + } \ + if (thr->ignore_interceptors || thr->in_ignored_lib) \ + return REAL(func)(__VA_ARGS__); \ +/**/ + +#define TSAN_INTERCEPTOR(ret, func, ...) INTERCEPTOR(ret, func, __VA_ARGS__) + #if SANITIZER_FREEBSD #define __libc_free __free #define __libc_malloc __malloc diff --git a/compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc b/compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc new file mode 100644 index 00000000000..7f80a470288 --- /dev/null +++ b/compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc @@ -0,0 +1,72 @@ +//===-- tsan_libdispatch_mac.cc -------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of ThreadSanitizer (TSan), a race detector. +// +// Mac-specific libdispatch (GCD) support. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_platform.h" +#if SANITIZER_MAC + +#include "sanitizer_common/sanitizer_common.h" +#include "interception/interception.h" +#include "tsan_interceptors.h" +#include "tsan_platform.h" +#include "tsan_rtl.h" + +#include <dispatch/dispatch.h> +#include <pthread.h> + +namespace __tsan { + +// GCD's dispatch_once implementation has a fast path that contains a racy read +// and it's inlined into user's code. Furthermore, this fast path doesn't +// establish a proper happens-before relations between the initialization and +// code following the call to dispatch_once. We could deal with this in +// instrumented code, but there's not much we can do about it in system +// libraries. Let's disable the fast path (by never storing the value ~0 to +// predicate), so the interceptor is always called, and let's add proper release +// and acquire semantics. Since TSan does not see its own atomic stores, the +// race on predicate won't be reported - the only accesses to it that TSan sees +// are the loads on the fast path. Loads don't race. Secondly, dispatch_once is +// both a macro and a real function, we want to intercept the function, so we +// need to undefine the macro. +#undef dispatch_once +TSAN_INTERCEPTOR(void, dispatch_once, dispatch_once_t *predicate, + dispatch_block_t block) { + SCOPED_TSAN_INTERCEPTOR(dispatch_once, predicate, block); + atomic_uint32_t *a = reinterpret_cast<atomic_uint32_t *>(predicate); + u32 v = atomic_load(a, memory_order_acquire); + if (v == 0 && + atomic_compare_exchange_strong(a, &v, 1, memory_order_relaxed)) { + block(); + Release(thr, pc, (uptr)a); + atomic_store(a, 2, memory_order_release); + } else { + while (v != 2) { + internal_sched_yield(); + v = atomic_load(a, memory_order_acquire); + } + Acquire(thr, pc, (uptr)a); + } +} + +#undef dispatch_once_f +TSAN_INTERCEPTOR(void, dispatch_once_f, dispatch_once_t *predicate, + void *context, dispatch_function_t function) { + SCOPED_TSAN_INTERCEPTOR(dispatch_once_f, predicate, context, function); + WRAP(dispatch_once)(predicate, ^(void) { + function(context); + }); +} + +} // namespace __tsan + +#endif // SANITIZER_MAC diff --git a/compiler-rt/test/tsan/Darwin/gcd-once.mm b/compiler-rt/test/tsan/Darwin/gcd-once.mm new file mode 100644 index 00000000000..17757d20375 --- /dev/null +++ b/compiler-rt/test/tsan/Darwin/gcd-once.mm @@ -0,0 +1,55 @@ +// RUN: %clang_tsan %s -o %t -framework Foundation +// RUN: %run %t 2>&1 + +#import <Foundation/Foundation.h> + +#import "../test.h" + +static const long kNumThreads = 4; + +long global; +long global2; + +static dispatch_once_t once_token; +static dispatch_once_t once_token2; + +void f(void *) { + global2 = 42; + usleep(100000); +} + +void *Thread(void *a) { + barrier_wait(&barrier); + + dispatch_once(&once_token, ^{ + global = 42; + usleep(100000); + }); + long x = global; + + dispatch_once_f(&once_token2, NULL, f); + long x2 = global2; + + fprintf(stderr, "global = %ld\n", x); + fprintf(stderr, "global2 = %ld\n", x2); + return 0; +} + +int main() { + fprintf(stderr, "Hello world.\n"); + barrier_init(&barrier, kNumThreads); + + pthread_t t[kNumThreads]; + for (int i = 0; i < kNumThreads; i++) { + pthread_create(&t[i], 0, Thread, 0); + } + for (int i = 0; i < kNumThreads; i++) { + pthread_join(t[i], 0); + } + + fprintf(stderr, "Done.\n"); +} + +// CHECK: Hello world. +// CHECK: Done. +// CHECK-NOT: WARNING: ThreadSanitizer |
