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//===-- tsan_external.cc --------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#include "tsan_rtl.h"
#include "tsan_interceptors.h"
namespace __tsan {
#define CALLERPC ((uptr)__builtin_return_address(0))
const char *registered_tags[kExternalTagMax];
static atomic_uint32_t used_tags{kExternalTagFirstUserAvailable}; // NOLINT.
const char *GetObjectTypeFromTag(uptr tag) {
if (tag == 0) return nullptr;
// Invalid/corrupted tag? Better return NULL and let the caller deal with it.
if (tag >= atomic_load(&used_tags, memory_order_relaxed)) return nullptr;
return registered_tags[tag];
}
void InsertShadowStackFrameForTag(ThreadState *thr, uptr tag) {
FuncEntry(thr, (uptr)®istered_tags[tag]);
}
uptr TagFromShadowStackFrame(uptr pc) {
uptr tag_count = atomic_load(&used_tags, memory_order_relaxed);
void *pc_ptr = (void *)pc;
if (pc_ptr < ®istered_tags[0] || pc_ptr >= ®istered_tags[tag_count])
return 0;
return (const char **)pc_ptr - ®istered_tags[0];
}
#if !SANITIZER_GO
typedef void(*AccessFunc)(ThreadState *, uptr, uptr, int);
void ExternalAccess(void *addr, void *caller_pc, void *tag, AccessFunc access) {
CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));
ThreadState *thr = cur_thread();
if (caller_pc) FuncEntry(thr, (uptr)caller_pc);
InsertShadowStackFrameForTag(thr, (uptr)tag);
bool in_ignored_lib;
if (!caller_pc || !libignore()->IsIgnored((uptr)caller_pc, &in_ignored_lib)) {
access(thr, CALLERPC, (uptr)addr, kSizeLog1);
}
FuncExit(thr);
if (caller_pc) FuncExit(thr);
}
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
void *__tsan_external_register_tag(const char *object_type) {
uptr new_tag = atomic_fetch_add(&used_tags, 1, memory_order_relaxed);
CHECK_LT(new_tag, kExternalTagMax);
registered_tags[new_tag] = internal_strdup(object_type);
return (void *)new_tag;
}
SANITIZER_INTERFACE_ATTRIBUTE
void __tsan_external_assign_tag(void *addr, void *tag) {
CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));
Allocator *a = allocator();
MBlock *b = nullptr;
if (a->PointerIsMine((void *)addr)) {
void *block_begin = a->GetBlockBegin((void *)addr);
if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin);
}
if (b) {
b->tag = (uptr)tag;
}
}
SANITIZER_INTERFACE_ATTRIBUTE
void __tsan_external_read(void *addr, void *caller_pc, void *tag) {
ExternalAccess(addr, caller_pc, tag, MemoryRead);
}
SANITIZER_INTERFACE_ATTRIBUTE
void __tsan_external_write(void *addr, void *caller_pc, void *tag) {
ExternalAccess(addr, caller_pc, tag, MemoryWrite);
}
} // extern "C"
#endif // !SANITIZER_GO
} // namespace __tsan
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