From 312ad250ff2c396bf5ff42fd8aaf132fda9218ce Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Tue, 27 Jan 2015 20:19:12 +0000 Subject: [PATCH] tsan: properly instrument unaligned accesses If a memory access is unaligned, emit __tsan_unaligned_read/write callbacks instead of __tsan_read/write. Required to change semantics of __tsan_unaligned_read/write to not do the user memory. But since they were unused (other than through __sanitizer_unaligned_load/store) this is fine. Fixes long standing issue 17: https://code.google.com/p/thread-sanitizer/issues/detail?id=17 llvm-svn: 227230 --- compiler-rt/lib/tsan/rtl/tsan_interface.cc | 71 ++++++++++++++-------- compiler-rt/lib/tsan/rtl/tsan_interface.h | 15 +++-- compiler-rt/test/tsan/aligned_vs_unaligned_race.cc | 17 +++--- compiler-rt/test/tsan/unaligned_norace.cc | 18 +++--- 4 files changed, 74 insertions(+), 47 deletions(-) diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface.cc b/compiler-rt/lib/tsan/rtl/tsan_interface.cc index 9de3808..9bc9a69 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_interface.cc +++ b/compiler-rt/lib/tsan/rtl/tsan_interface.cc @@ -38,56 +38,79 @@ void __tsan_write16(void *addr) { MemoryWrite(cur_thread(), CALLERPC, (uptr)addr + 8, kSizeLog8); } -u16 __tsan_unaligned_read2(const uu16 *addr) { +// __tsan_unaligned_read/write calls are emitted by compiler. + +void __tsan_unaligned_read2(const void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 2, false, false); - return *addr; } -u32 __tsan_unaligned_read4(const uu32 *addr) { +void __tsan_unaligned_read4(const void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 4, false, false); - return *addr; } -u64 __tsan_unaligned_read8(const uu64 *addr) { +void __tsan_unaligned_read8(const void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 8, false, false); - return *addr; } -void __tsan_unaligned_write2(uu16 *addr, u16 v) { +void __tsan_unaligned_read16(const void *addr) { + UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 16, false, false); +} + +void __tsan_unaligned_write2(void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 2, true, false); - *addr = v; } -void __tsan_unaligned_write4(uu32 *addr, u32 v) { +void __tsan_unaligned_write4(void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 4, true, false); - *addr = v; } -void __tsan_unaligned_write8(uu64 *addr, u64 v) { +void __tsan_unaligned_write8(void *addr) { UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 8, true, false); - *addr = v; } +void __tsan_unaligned_write16(void *addr) { + UnalignedMemoryAccess(cur_thread(), CALLERPC, (uptr)addr, 16, true, false); +} + +// __sanitizer_unaligned_load/store are for user instrumentation. + extern "C" { SANITIZER_INTERFACE_ATTRIBUTE -uint16_t __sanitizer_unaligned_load16(void *addr) - ALIAS("__tsan_unaligned_read2"); +u16 __sanitizer_unaligned_load16(const uu16 *addr) { + __tsan_unaligned_read2(addr); + return *addr; +} + SANITIZER_INTERFACE_ATTRIBUTE -uint32_t __sanitizer_unaligned_load32(void *addr) - ALIAS("__tsan_unaligned_read4"); +u32 __sanitizer_unaligned_load32(const uu32 *addr) { + __tsan_unaligned_read4(addr); + return *addr; +} + SANITIZER_INTERFACE_ATTRIBUTE -uint64_t __sanitizer_unaligned_load64(void *addr) - ALIAS("__tsan_unaligned_read8"); +u64 __sanitizer_unaligned_load64(const uu64 *addr) { + __tsan_unaligned_read8(addr); + return *addr; +} + SANITIZER_INTERFACE_ATTRIBUTE -void __sanitizer_unaligned_store16(void *addr, uint16_t v) - ALIAS("__tsan_unaligned_write2"); +void __sanitizer_unaligned_store16(uu16 *addr, u16 v) { + __tsan_unaligned_write2(addr); + *addr = v; +} + SANITIZER_INTERFACE_ATTRIBUTE -void __sanitizer_unaligned_store32(void *addr, uint32_t v) - ALIAS("__tsan_unaligned_write4"); +void __sanitizer_unaligned_store32(uu32 *addr, u32 v) { + __tsan_unaligned_write4(addr); + *addr = v; +} + SANITIZER_INTERFACE_ATTRIBUTE -void __sanitizer_unaligned_store64(void *addr, uint64_t v) - ALIAS("__tsan_unaligned_write8"); +void __sanitizer_unaligned_store64(uu64 *addr, u64 v) { + __tsan_unaligned_write8(addr); + *addr = v; } +} // extern "C" void __tsan_acquire(void *addr) { Acquire(cur_thread(), CALLERPC, (uptr)addr); diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface.h b/compiler-rt/lib/tsan/rtl/tsan_interface.h index 7045069..a05e6f0 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_interface.h +++ b/compiler-rt/lib/tsan/rtl/tsan_interface.h @@ -41,12 +41,15 @@ SANITIZER_INTERFACE_ATTRIBUTE void __tsan_write4(void *addr); SANITIZER_INTERFACE_ATTRIBUTE void __tsan_write8(void *addr); SANITIZER_INTERFACE_ATTRIBUTE void __tsan_write16(void *addr); -SANITIZER_INTERFACE_ATTRIBUTE u16 __tsan_unaligned_read2(const uu16 *addr); -SANITIZER_INTERFACE_ATTRIBUTE u32 __tsan_unaligned_read4(const uu32 *addr); -SANITIZER_INTERFACE_ATTRIBUTE u64 __tsan_unaligned_read8(const uu64 *addr); -SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write2(uu16 *addr, u16 v); -SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write4(uu32 *addr, u32 v); -SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write8(uu64 *addr, u64 v); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_read2(const void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_read4(const void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_read8(const void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_read16(const void *addr); + +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write2(void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write4(void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write8(void *addr); +SANITIZER_INTERFACE_ATTRIBUTE void __tsan_unaligned_write16(void *addr); SANITIZER_INTERFACE_ATTRIBUTE void __tsan_vptr_read(void **vptr_p); SANITIZER_INTERFACE_ATTRIBUTE diff --git a/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc b/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc index f82542e..5c1189f 100644 --- a/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc +++ b/compiler-rt/test/tsan/aligned_vs_unaligned_race.cc @@ -1,34 +1,35 @@ -// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s +// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s // Race between an aligned access and an unaligned access, which // touches the same memory region. -// This is a real race which is not detected by tsan. -// https://code.google.com/p/thread-sanitizer/issues/detail?id=17 -#include -#include +#include "test.h" #include uint64_t Global[2]; void *Thread1(void *x) { Global[1]++; + barrier_wait(&barrier); return NULL; } void *Thread2(void *x) { + barrier_wait(&barrier); char *p1 = reinterpret_cast(&Global[0]); - uint64_t *p4 = reinterpret_cast(p1 + 1); - (*p4)++; + struct __attribute__((packed, aligned(1))) u_uint64_t { uint64_t val; }; + u_uint64_t *p4 = reinterpret_cast(p1 + 1); + (*p4).val++; return NULL; } int main() { + 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); printf("Pass\n"); - // CHECK-NOT: ThreadSanitizer: data race + // CHECK: ThreadSanitizer: data race // CHECK: Pass return 0; } diff --git a/compiler-rt/test/tsan/unaligned_norace.cc b/compiler-rt/test/tsan/unaligned_norace.cc index 20cb545..94df1cf 100644 --- a/compiler-rt/test/tsan/unaligned_norace.cc +++ b/compiler-rt/test/tsan/unaligned_norace.cc @@ -7,20 +7,20 @@ uint64_t objs[8*3*3*2][3]; extern "C" { -uint16_t __tsan_unaligned_read2(void *addr); -uint32_t __tsan_unaligned_read4(void *addr); -uint64_t __tsan_unaligned_read8(void *addr); -void __tsan_unaligned_write2(void *addr, uint16_t v); -void __tsan_unaligned_write4(void *addr, uint32_t v); -void __tsan_unaligned_write8(void *addr, uint64_t v); +void __tsan_unaligned_read2(void *addr); +void __tsan_unaligned_read4(void *addr); +void __tsan_unaligned_read8(void *addr); +void __tsan_unaligned_write2(void *addr); +void __tsan_unaligned_write4(void *addr); +void __tsan_unaligned_write8(void *addr); } static void access(char *p, int sz, int rw) { if (rw) { switch (sz) { - case 0: __tsan_unaligned_write2(p, 0); break; - case 1: __tsan_unaligned_write4(p, 0); break; - case 2: __tsan_unaligned_write8(p, 0); break; + case 0: __tsan_unaligned_write2(p); break; + case 1: __tsan_unaligned_write4(p); break; + case 2: __tsan_unaligned_write8(p); break; default: exit(1); } } else { -- 2.7.4