From 3a14afa51320e5583712a81e148896583065ed7b Mon Sep 17 00:00:00 2001 From: Kuba Mracek Date: Wed, 11 Jan 2017 00:54:26 +0000 Subject: [tsan] Implement a 'ignore_noninstrumented_modules' flag to better suppress false positive races On Darwin, we currently use 'ignore_interceptors_accesses', which is a heavy-weight solution that simply turns of race detection in all interceptors. This was done to suppress false positives coming from system libraries (non-instrumented code), but it also silences a lot of real races. This patch implements an alternative approach that should allow us to enable interceptors and report races coming from them, but only if they are called directly from instrumented code. The patch matches the caller PC in each interceptors. For non-instrumented code, we call ThreadIgnoreBegin. The assumption here is that the number of instrumented modules is low. Most likely there's only one (the instrumented main executable) and all the other modules are system libraries (non-instrumented). Differential Revision: https://reviews.llvm.org/D28264 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@291631 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/tsan/Darwin/ignore-noninstrumented.mm | 53 ++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 test/tsan/Darwin/ignore-noninstrumented.mm (limited to 'test/tsan') diff --git a/test/tsan/Darwin/ignore-noninstrumented.mm b/test/tsan/Darwin/ignore-noninstrumented.mm new file mode 100644 index 000000000..5e4453102 --- /dev/null +++ b/test/tsan/Darwin/ignore-noninstrumented.mm @@ -0,0 +1,53 @@ +// Check that ignore_noninstrumented_modules=1 supresses races from system libraries on OS X. + +// RUN: %clang_tsan %s -o %t -framework Foundation + +// Check that without the flag, there are false positives. +// RUN: %deflake %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-RACE + +// With ignore_noninstrumented_modules=1, no races are reported. +// RUN: %env_tsan_opts=ignore_noninstrumented_modules=1 %run %t 2>&1 | FileCheck %s + +// With ignore_noninstrumented_modules=1, races in user's code are still reported. +// RUN: %env_tsan_opts=ignore_noninstrumented_modules=1 %deflake %run %t race 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-RACE + +#import + +#import "../test.h" + +char global_buf[64]; + +void *Thread1(void *x) { + barrier_wait(&barrier); + strcpy(global_buf, "hello world"); + return NULL; +} + +void *Thread2(void *x) { + strcpy(global_buf, "world hello"); + barrier_wait(&barrier); + return NULL; +} + +int main(int argc, char *argv[]) { + fprintf(stderr, "Hello world.\n"); + + // NSUserDefaults uses XPC which triggers the false positive. + NSDictionary *d = [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]; + fprintf(stderr, "d = %p\n", d); + + if (argc > 1 && strcmp(argv[1], "race") == 0) { + barrier_init(&barrier, 2); + pthread_t t[2]; + pthread_create(&t[0], NULL, Thread1, NULL); + pthread_create(&t[1], NULL, Thread2, NULL); + pthread_join(t[0], NULL); + pthread_join(t[1], NULL); + } + + fprintf(stderr, "Done.\n"); +} + +// CHECK: Hello world. +// CHECK-RACE: SUMMARY: ThreadSanitizer: data race +// CHECK: Done. -- cgit v1.2.3