| //===-- sanitizer_coverage.cc ---------------------------------------------===// |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Sanitizer Coverage. |
| // This file implements run-time support for a poor man's coverage tool. |
| // |
| // Compiler instrumentation: |
| // For every function F the compiler injects the following code: |
| // if (*Guard) { |
| // __sanitizer_cov(&F); |
| // *Guard = 1; |
| // } |
| // It's fine to call __sanitizer_cov more than once for a given function. |
| // |
| // Run-time: |
| // - __sanitizer_cov(pc): record that we've executed a given PC. |
| // - __sanitizer_cov_dump: dump the coverage data to disk. |
| // For every module of the current process that has coverage data |
| // this will create a file module_name.PID.sancov. The file format is simple: |
| // it's just a sorted sequence of 4-byte offsets in the module. |
| // |
| // Eventually, this coverage implementation should be obsoleted by a more |
| // powerful general purpose Clang/LLVM coverage instrumentation. |
| // Consider this implementation as prototype. |
| // |
| // FIXME: support (or at least test with) dlclose. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_allocator_internal.h" |
| #include "sanitizer_common.h" |
| #include "sanitizer_libc.h" |
| #include "sanitizer_mutex.h" |
| #include "sanitizer_procmaps.h" |
| #include "sanitizer_flags.h" |
| |
| struct CovData { |
| BlockingMutex mu; |
| InternalMmapVector<uptr> v; |
| }; |
| |
| static uptr cov_data_placeholder[sizeof(CovData) / sizeof(uptr)]; |
| COMPILER_CHECK(sizeof(cov_data_placeholder) >= sizeof(CovData)); |
| static CovData *cov_data = reinterpret_cast<CovData*>(cov_data_placeholder); |
| |
| namespace __sanitizer { |
| |
| // Simply add the pc into the vector under lock. If the function is called more |
| // than once for a given PC it will be inserted multiple times, which is fine. |
| static void CovAdd(uptr pc) { |
| BlockingMutexLock lock(&cov_data->mu); |
| cov_data->v.push_back(pc); |
| } |
| |
| static inline bool CompareLess(const uptr &a, const uptr &b) { |
| return a < b; |
| } |
| |
| // Dump the coverage on disk. |
| void CovDump() { |
| #if !SANITIZER_WINDOWS |
| BlockingMutexLock lock(&cov_data->mu); |
| InternalMmapVector<uptr> &v = cov_data->v; |
| InternalSort(&v, v.size(), CompareLess); |
| InternalMmapVector<u32> offsets(v.size()); |
| const uptr *vb = v.data(); |
| const uptr *ve = vb + v.size(); |
| MemoryMappingLayout proc_maps(/*cache_enabled*/false); |
| uptr mb, me, off, prot; |
| InternalScopedBuffer<char> module(4096); |
| InternalScopedBuffer<char> path(4096 * 2); |
| for (int i = 0; |
| proc_maps.Next(&mb, &me, &off, module.data(), module.size(), &prot); |
| i++) { |
| if ((prot & MemoryMappingLayout::kProtectionExecute) == 0) |
| continue; |
| if (vb >= ve) break; |
| if (mb <= *vb && *vb < me) { |
| offsets.clear(); |
| const uptr *old_vb = vb; |
| CHECK_LE(off, *vb); |
| for (; vb < ve && *vb < me; vb++) { |
| uptr diff = *vb - (i ? mb : 0) + off; |
| CHECK_LE(diff, 0xffffffffU); |
| offsets.push_back(static_cast<u32>(diff)); |
| } |
| char *module_name = StripModuleName(module.data()); |
| internal_snprintf((char *)path.data(), path.size(), "%s.%zd.sancov", |
| module_name, internal_getpid()); |
| InternalFree(module_name); |
| uptr fd = OpenFile(path.data(), true); |
| internal_write(fd, offsets.data(), offsets.size() * sizeof(u32)); |
| internal_close(fd); |
| if (common_flags()->verbosity) |
| Report(" CovDump: %s: %zd PCs written\n", path.data(), vb - old_vb); |
| } |
| } |
| #endif // !SANITIZER_WINDOWS |
| } |
| |
| } // namespace __sanitizer |
| |
| extern "C" { |
| SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov(void *pc) { |
| CovAdd(reinterpret_cast<uptr>(pc)); |
| } |
| SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() { CovDump(); } |
| } // extern "C" |