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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of ThreadSanitizer (TSan), a race detector. 10 // 11 //===----------------------------------------------------------------------===// 12 #include "tsan_rtl.h" 13 #include "tsan_interceptors.h" 14 15 namespace __tsan { 16 17 #define CALLERPC ((uptr)__builtin_return_address(0)) 18 19 struct TagData { 20 const char *object_type; 21 const char *header; 22 }; 23 24 static TagData registered_tags[kExternalTagMax] = { 25 {}, 26 {"Swift variable", "Swift access race"}, 27 }; 28 static atomic_uint32_t used_tags{kExternalTagFirstUserAvailable}; 29 static TagData *GetTagData(uptr tag) { 30 // Invalid/corrupted tag? Better return NULL and let the caller deal with it. 31 if (tag >= atomic_load(&used_tags, memory_order_relaxed)) return nullptr; 32 return ®istered_tags[tag]; 33 } 34 35 const char *GetObjectTypeFromTag(uptr tag) { 36 TagData *tag_data = GetTagData(tag); 37 return tag_data ? tag_data->object_type : nullptr; 38 } 39 40 const char *GetReportHeaderFromTag(uptr tag) { 41 TagData *tag_data = GetTagData(tag); 42 return tag_data ? tag_data->header : nullptr; 43 } 44 45 void InsertShadowStackFrameForTag(ThreadState *thr, uptr tag) { 46 FuncEntry(thr, (uptr)®istered_tags[tag]); 47 } 48 49 uptr 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_GO 58 59 typedef void(*AccessFunc)(ThreadState *, uptr, uptr, int); 60 void ExternalAccess(void *addr, void *caller_pc, void *tag, AccessFunc access) { 61 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed)); 62 ThreadState *thr = cur_thread(); 63 if (caller_pc) FuncEntry(thr, (uptr)caller_pc); 64 InsertShadowStackFrameForTag(thr, (uptr)tag); 65 bool in_ignored_lib; 66 if (!caller_pc || !libignore()->IsIgnored((uptr)caller_pc, &in_ignored_lib)) { 67 access(thr, CALLERPC, (uptr)addr, kSizeLog1); 68 } 69 FuncExit(thr); 70 if (caller_pc) FuncExit(thr); 71 } 72 73 extern "C" { 74 SANITIZER_INTERFACE_ATTRIBUTE 75 void *__tsan_external_register_tag(const char *object_type) { 76 uptr new_tag = atomic_fetch_add(&used_tags, 1, memory_order_relaxed); 77 CHECK_LT(new_tag, kExternalTagMax); 78 GetTagData(new_tag)->object_type = internal_strdup(object_type); 79 char header[127] = {0}; 80 internal_snprintf(header, sizeof(header), "race on %s", object_type); 81 GetTagData(new_tag)->header = internal_strdup(header); 82 return (void *)new_tag; 83 } 84 85 SANITIZER_INTERFACE_ATTRIBUTE 86 void __tsan_external_register_header(void *tag, const char *header) { 87 CHECK_GE((uptr)tag, kExternalTagFirstUserAvailable); 88 CHECK_LT((uptr)tag, kExternalTagMax); 89 atomic_uintptr_t *header_ptr = 90 (atomic_uintptr_t *)&GetTagData((uptr)tag)->header; 91 header = internal_strdup(header); 92 char *old_header = 93 (char *)atomic_exchange(header_ptr, (uptr)header, memory_order_seq_cst); 94 if (old_header) internal_free(old_header); 95 } 96 97 SANITIZER_INTERFACE_ATTRIBUTE 98 void __tsan_external_assign_tag(void *addr, void *tag) { 99 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed)); 100 Allocator *a = allocator(); 101 MBlock *b = nullptr; 102 if (a->PointerIsMine((void *)addr)) { 103 void *block_begin = a->GetBlockBegin((void *)addr); 104 if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin); 105 } 106 if (b) { 107 b->tag = (uptr)tag; 108 } 109 } 110 111 SANITIZER_INTERFACE_ATTRIBUTE 112 void __tsan_external_read(void *addr, void *caller_pc, void *tag) { 113 ExternalAccess(addr, caller_pc, tag, MemoryRead); 114 } 115 116 SANITIZER_INTERFACE_ATTRIBUTE 117 void __tsan_external_write(void *addr, void *caller_pc, void *tag) { 118 ExternalAccess(addr, caller_pc, tag, MemoryWrite); 119 } 120 } // extern "C" 121 122 #endif // !SANITIZER_GO 123 124 } // namespace __tsan 125