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 "sanitizer_common/sanitizer_ptrauth.h" 14 15 #if !SANITIZER_GO 16 # include "tsan_interceptors.h" 17 #endif 18 19 namespace __tsan { 20 21 #define CALLERPC ((uptr)__builtin_return_address(0)) 22 23 struct TagData { 24 const char *object_type; 25 const char *header; 26 }; 27 28 static TagData registered_tags[kExternalTagMax] = { 29 {}, 30 {"Swift variable", "Swift access race"}, 31 }; 32 static atomic_uint32_t used_tags{kExternalTagFirstUserAvailable}; 33 static 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 39 const char *GetObjectTypeFromTag(uptr tag) { 40 TagData *tag_data = GetTagData(tag); 41 return tag_data ? tag_data->object_type : nullptr; 42 } 43 44 const char *GetReportHeaderFromTag(uptr tag) { 45 TagData *tag_data = GetTagData(tag); 46 return tag_data ? tag_data->header : nullptr; 47 } 48 49 void InsertShadowStackFrameForTag(ThreadState *thr, uptr tag) { 50 FuncEntry(thr, (uptr)®istered_tags[tag]); 51 } 52 53 uptr TagFromShadowStackFrame(uptr pc) { 54 uptr tag_count = atomic_load(&used_tags, memory_order_relaxed); 55 void *pc_ptr = (void *)pc; 56 if (pc_ptr < GetTagData(0) || pc_ptr > GetTagData(tag_count - 1)) 57 return 0; 58 return (TagData *)pc_ptr - GetTagData(0); 59 } 60 61 #if !SANITIZER_GO 62 63 void ExternalAccess(void *addr, uptr caller_pc, void *tag, AccessType typ) { 64 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed)); 65 ThreadState *thr = cur_thread(); 66 if (caller_pc) FuncEntry(thr, caller_pc); 67 InsertShadowStackFrameForTag(thr, (uptr)tag); 68 bool in_ignored_lib; 69 if (!caller_pc || !libignore()->IsIgnored(caller_pc, &in_ignored_lib)) 70 MemoryAccess(thr, CALLERPC, (uptr)addr, 1, typ); 71 FuncExit(thr); 72 if (caller_pc) FuncExit(thr); 73 } 74 75 extern "C" { 76 SANITIZER_INTERFACE_ATTRIBUTE 77 void *__tsan_external_register_tag(const char *object_type) { 78 uptr new_tag = atomic_fetch_add(&used_tags, 1, memory_order_relaxed); 79 CHECK_LT(new_tag, kExternalTagMax); 80 GetTagData(new_tag)->object_type = internal_strdup(object_type); 81 char header[127] = {0}; 82 internal_snprintf(header, sizeof(header), "race on %s", object_type); 83 GetTagData(new_tag)->header = internal_strdup(header); 84 return (void *)new_tag; 85 } 86 87 SANITIZER_INTERFACE_ATTRIBUTE 88 void __tsan_external_register_header(void *tag, const char *header) { 89 CHECK_GE((uptr)tag, kExternalTagFirstUserAvailable); 90 CHECK_LT((uptr)tag, kExternalTagMax); 91 atomic_uintptr_t *header_ptr = 92 (atomic_uintptr_t *)&GetTagData((uptr)tag)->header; 93 header = internal_strdup(header); 94 char *old_header = 95 (char *)atomic_exchange(header_ptr, (uptr)header, memory_order_seq_cst); 96 Free(old_header); 97 } 98 99 SANITIZER_INTERFACE_ATTRIBUTE 100 void __tsan_external_assign_tag(void *addr, void *tag) { 101 CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed)); 102 Allocator *a = allocator(); 103 MBlock *b = nullptr; 104 if (a->PointerIsMine((void *)addr)) { 105 void *block_begin = a->GetBlockBegin((void *)addr); 106 if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin); 107 } 108 if (b) { 109 b->tag = (uptr)tag; 110 } 111 } 112 113 SANITIZER_INTERFACE_ATTRIBUTE 114 void __tsan_external_read(void *addr, void *caller_pc, void *tag) { 115 ExternalAccess(addr, STRIP_PAC_PC(caller_pc), tag, kAccessRead); 116 } 117 118 SANITIZER_INTERFACE_ATTRIBUTE 119 void __tsan_external_write(void *addr, void *caller_pc, void *tag) { 120 ExternalAccess(addr, STRIP_PAC_PC(caller_pc), tag, kAccessWrite); 121 } 122 } // extern "C" 123 124 #endif // !SANITIZER_GO 125 126 } // namespace __tsan 127