134 lines · cpp
1//===-- tsan_external.cpp -------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of ThreadSanitizer (TSan), a race detector.10//11//===----------------------------------------------------------------------===//12#include "tsan_rtl.h"13#include "sanitizer_common/sanitizer_ptrauth.h"14 15#if !SANITIZER_GO16# include "tsan_interceptors.h"17#endif18 19namespace __tsan {20 21#define CALLERPC ((uptr)__builtin_return_address(0))22 23struct TagData {24 const char *object_type;25 const char *header;26};27 28static TagData registered_tags[kExternalTagMax] = {29 {},30 {"Swift variable", "Swift access race"},31};32static atomic_uint32_t used_tags{kExternalTagFirstUserAvailable};33static TagData *GetTagData(uptr tag) {34 // Invalid/corrupted tag? Better return NULL and let the caller deal with it.35 if (tag >= atomic_load(&used_tags, memory_order_relaxed)) return nullptr;36 return ®istered_tags[tag];37}38 39const char *GetObjectTypeFromTag(uptr tag) {40 TagData *tag_data = GetTagData(tag);41 return tag_data ? tag_data->object_type : nullptr;42}43 44const char *GetReportHeaderFromTag(uptr tag) {45 TagData *tag_data = GetTagData(tag);46 return tag_data ? tag_data->header : nullptr;47}48 49uptr TagFromShadowStackFrame(uptr pc) {50 uptr tag_count = atomic_load(&used_tags, memory_order_relaxed);51 void *pc_ptr = (void *)pc;52 if (pc_ptr < GetTagData(0) || pc_ptr > GetTagData(tag_count - 1))53 return 0;54 return (TagData *)pc_ptr - GetTagData(0);55}56 57#if !SANITIZER_GO58 59// We need to track tags for individual memory accesses, but there is no space60// in the shadow cells for them. Instead we push/pop them onto the thread61// traces and ignore the extra tag frames when printing reports.62static void PushTag(ThreadState *thr, uptr tag) {63 FuncEntry(thr, (uptr)®istered_tags[tag]);64}65static void PopTag(ThreadState *thr) { FuncExit(thr); }66 67static void ExternalAccess(void *addr, uptr caller_pc, uptr tsan_caller_pc,68 void *tag, AccessType typ) {69 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));70 bool in_ignored_lib;71 if (caller_pc && libignore()->IsIgnored(caller_pc, &in_ignored_lib))72 return;73 74 ThreadState *thr = cur_thread();75 if (caller_pc) FuncEntry(thr, caller_pc);76 PushTag(thr, (uptr)tag);77 MemoryAccess(thr, tsan_caller_pc, (uptr)addr, 1, typ);78 PopTag(thr);79 if (caller_pc) FuncExit(thr);80}81 82extern "C" {83SANITIZER_INTERFACE_ATTRIBUTE84void *__tsan_external_register_tag(const char *object_type) {85 uptr new_tag = atomic_fetch_add(&used_tags, 1, memory_order_relaxed);86 CHECK_LT(new_tag, kExternalTagMax);87 GetTagData(new_tag)->object_type = internal_strdup(object_type);88 char header[127] = {0};89 internal_snprintf(header, sizeof(header), "race on %s", object_type);90 GetTagData(new_tag)->header = internal_strdup(header);91 return (void *)new_tag;92}93 94SANITIZER_INTERFACE_ATTRIBUTE95void __tsan_external_register_header(void *tag, const char *header) {96 CHECK_GE((uptr)tag, kExternalTagFirstUserAvailable);97 CHECK_LT((uptr)tag, kExternalTagMax);98 atomic_uintptr_t *header_ptr =99 (atomic_uintptr_t *)&GetTagData((uptr)tag)->header;100 header = internal_strdup(header);101 char *old_header =102 (char *)atomic_exchange(header_ptr, (uptr)header, memory_order_seq_cst);103 Free(old_header);104}105 106SANITIZER_INTERFACE_ATTRIBUTE107void __tsan_external_assign_tag(void *addr, void *tag) {108 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));109 Allocator *a = allocator();110 MBlock *b = nullptr;111 if (a->PointerIsMine((void *)addr)) {112 void *block_begin = a->GetBlockBegin((void *)addr);113 if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin);114 }115 if (b) {116 b->tag = (uptr)tag;117 }118}119 120SANITIZER_INTERFACE_ATTRIBUTE121void __tsan_external_read(void *addr, void *caller_pc, void *tag) {122 ExternalAccess(addr, STRIP_PAC_PC(caller_pc), CALLERPC, tag, kAccessRead);123}124 125SANITIZER_INTERFACE_ATTRIBUTE126void __tsan_external_write(void *addr, void *caller_pc, void *tag) {127 ExternalAccess(addr, STRIP_PAC_PC(caller_pc), CALLERPC, tag, kAccessWrite);128}129} // extern "C"130 131#endif // !SANITIZER_GO132 133} // namespace __tsan134