1 //===-- tsan_external.cpp -------------------------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file is a part of ThreadSanitizer (TSan), a race detector.
11 //===----------------------------------------------------------------------===//
13 #include "tsan_interceptors.h"
17 #define CALLERPC ((uptr)__builtin_return_address(0))
20 const char *object_type
;
24 static TagData registered_tags
[kExternalTagMax
] = {
26 {"Swift variable", "Swift access race"},
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
];
35 const char *GetObjectTypeFromTag(uptr tag
) {
36 TagData
*tag_data
= GetTagData(tag
);
37 return tag_data
? tag_data
->object_type
: nullptr;
40 const char *GetReportHeaderFromTag(uptr tag
) {
41 TagData
*tag_data
= GetTagData(tag
);
42 return tag_data
? tag_data
->header
: nullptr;
45 void InsertShadowStackFrameForTag(ThreadState
*thr
, uptr tag
) {
46 FuncEntry(thr
, (uptr
)®istered_tags
[tag
]);
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))
54 return (TagData
*)pc_ptr
- GetTagData(0);
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
);
66 if (!caller_pc
|| !libignore()->IsIgnored((uptr
)caller_pc
, &in_ignored_lib
)) {
67 access(thr
, CALLERPC
, (uptr
)addr
, kSizeLog1
);
70 if (caller_pc
) FuncExit(thr
);
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
;
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
);
93 (char *)atomic_exchange(header_ptr
, (uptr
)header
, memory_order_seq_cst
);
94 if (old_header
) internal_free(old_header
);
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();
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
);
111 SANITIZER_INTERFACE_ATTRIBUTE
112 void __tsan_external_read(void *addr
, void *caller_pc
, void *tag
) {
113 ExternalAccess(addr
, caller_pc
, tag
, MemoryRead
);
116 SANITIZER_INTERFACE_ATTRIBUTE
117 void __tsan_external_write(void *addr
, void *caller_pc
, void *tag
) {
118 ExternalAccess(addr
, caller_pc
, tag
, MemoryWrite
);
122 #endif // !SANITIZER_GO
124 } // namespace __tsan