diff options
| -rw-r--r-- | include/sanitizer/coverage_interface.h | 17 | ||||
| -rw-r--r-- | lib/sanitizer_common/sanitizer_coverage_libcdep.cc | 94 |
2 files changed, 110 insertions, 1 deletions
diff --git a/include/sanitizer/coverage_interface.h b/include/sanitizer/coverage_interface.h index 88a7e4800..404b71e30 100644 --- a/include/sanitizer/coverage_interface.h +++ b/include/sanitizer/coverage_interface.h @@ -39,6 +39,23 @@ extern "C" { // Some of the entries in *data will be zero. uintptr_t __sanitizer_get_coverage_guards(uintptr_t **data); + // The coverage instrumentation may optionally provide imprecise counters. + // Rather than exposing the counter values to the user we instead map + // the counters to a bitset. + // Every counter is associated with 8 bits in the bitset. + // We define 8 value ranges: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+ + // The i-th bit is set to 1 if the counter value is in the i-th range. + // This counter-based coverage implementation is *not* thread-safe. + + // Returns the number of registered coverage counters. + uintptr_t __sanitizer_get_number_of_counters(); + // Updates the counter 'bitset', clears the counters and returns the number of + // new bits in 'bitset'. + // If 'bitset' is nullptr, only clears the counters. + // Otherwise 'bitset' should be at least + // __sanitizer_get_number_of_counters bytes long and 8-aligned. + uintptr_t + __sanitizer_update_counter_bitset_and_clear_counters(uint8_t *bitset); #ifdef __cplusplus } // extern "C" #endif diff --git a/lib/sanitizer_common/sanitizer_coverage_libcdep.cc b/lib/sanitizer_common/sanitizer_coverage_libcdep.cc index 49887b1e9..7197b4c6a 100644 --- a/lib/sanitizer_common/sanitizer_coverage_libcdep.cc +++ b/lib/sanitizer_common/sanitizer_coverage_libcdep.cc @@ -83,7 +83,10 @@ class CoverageData { void InitializeGuardArray(s32 *guards); void InitializeGuards(s32 *guards, uptr n, const char *module_name); + void InitializeCounters(u8 *counters, uptr n); void ReinitializeGuards(); + uptr GetNumberOf8bitCounters(); + uptr Update8bitCounterBitsetAndClearCounters(u8 *bitset); uptr *data(); uptr size(); @@ -113,6 +116,14 @@ class CoverageData { // Vector of module (compilation unit) names. InternalMmapVectorNoCtor<const char*> comp_unit_name_vec; + struct CounterAndSize { + u8 *counters; + uptr n; + }; + + InternalMmapVectorNoCtor<CounterAndSize> counters_vec; + uptr num_8bit_counters; + // Caller-Callee (cc) array, size and current index. static const uptr kCcArrayMaxSize = FIRST_32_SECOND_64(1 << 18, 1 << 24); uptr **cc_array; @@ -184,6 +195,8 @@ void CoverageData::Enable() { GetMmapGranularity()); tr_event_array_size = kTrEventArrayMaxSize; tr_event_pointer = tr_event_array; + + num_8bit_counters = 0; } void CoverageData::InitializeGuardArray(s32 *guards) { @@ -289,6 +302,15 @@ void CoverageData::Extend(uptr npcs) { atomic_store(&pc_array_size, size, memory_order_release); } +void CoverageData::InitializeCounters(u8 *counters, uptr n) { + if (!counters) return; + CHECK_EQ(reinterpret_cast<uptr>(counters) % 16, 0); + n = RoundUpTo(n, 16); // The compiler must ensure that counters is 16-aligned. + SpinMutexLock l(&mu); + counters_vec.push_back({counters, n}); + num_8bit_counters += n; +} + void CoverageData::InitializeGuards(s32 *guards, uptr n, const char *module_name) { // The array 'guards' has n+1 elements, we use the element zero @@ -354,6 +376,64 @@ void CoverageData::IndirCall(uptr caller, uptr callee, uptr callee_cache[], } } +uptr CoverageData::GetNumberOf8bitCounters() { + return num_8bit_counters; +} + +// Map every 8bit counter to a 8-bit bitset and clear the counter. +uptr CoverageData::Update8bitCounterBitsetAndClearCounters(u8 *bitset) { + uptr num_new_bits = 0; + uptr cur = 0; + // For better speed we map 8 counters to 8 bytes of bitset at once. + static const uptr kBatchSize = 8; + CHECK_EQ(reinterpret_cast<uptr>(bitset) % kBatchSize, 0); + for (uptr i = 0, len = counters_vec.size(); i < len; i++) { + u8 *c = counters_vec[i].counters; + uptr n = counters_vec[i].n; + CHECK_EQ(n % 16, 0); + CHECK_EQ(cur % kBatchSize, 0); + CHECK_EQ(reinterpret_cast<uptr>(c) % kBatchSize, 0); + if (!bitset) { + internal_bzero_aligned16(c, n); + cur += n; + continue; + } + for (uptr j = 0; j < n; j += kBatchSize, cur += kBatchSize) { + CHECK_LT(cur, num_8bit_counters); + u64 *pc64 = reinterpret_cast<u64*>(c + j); + u64 *pb64 = reinterpret_cast<u64*>(bitset + cur); + u64 c64 = *pc64; + u64 old_bits_64 = *pb64; + u64 new_bits_64 = old_bits_64; + if (c64) { + *pc64 = 0; + for (uptr k = 0; k < kBatchSize; k++) { + u64 x = (c64 >> (8 * k)) & 0xff; + if (x) { + u64 bit = 0; + /**/ if (x >= 128) bit = 128; + else if (x >= 32) bit = 64; + else if (x >= 16) bit = 32; + else if (x >= 8) bit = 16; + else if (x >= 4) bit = 8; + else if (x >= 3) bit = 4; + else if (x >= 2) bit = 2; + else if (x >= 1) bit = 1; + u64 mask = bit << (8 * k); + if (!(new_bits_64 & mask)) { + num_new_bits++; + new_bits_64 |= mask; + } + } + } + *pb64 = new_bits_64; + } + } + } + CHECK_EQ(cur, num_8bit_counters); + return num_new_bits; +} + uptr *CoverageData::data() { return pc_array; } @@ -689,8 +769,10 @@ SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_init() { } SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() { CovDump(); } SANITIZER_INTERFACE_ATTRIBUTE void -__sanitizer_cov_module_init(s32 *guards, uptr npcs, const char *module_name) { +__sanitizer_cov_module_init(s32 *guards, uptr npcs, u8 *counters, + const char *module_name) { coverage_data.InitializeGuards(guards, npcs, module_name); + coverage_data.InitializeCounters(counters, npcs); if (!common_flags()->coverage_direct) return; if (SANITIZER_ANDROID && coverage_enabled) { // dlopen/dlclose interceptors do not work on Android, so we rely on @@ -728,4 +810,14 @@ uptr __sanitizer_get_coverage_guards(uptr **data) { *data = coverage_data.data(); return coverage_data.size(); } + +SANITIZER_INTERFACE_ATTRIBUTE +uptr __sanitizer_get_number_of_counters() { + return coverage_data.GetNumberOf8bitCounters(); +} + +SANITIZER_INTERFACE_ATTRIBUTE +uptr __sanitizer_update_counter_bitset_and_clear_counters(u8 *bitset) { + return coverage_data.Update8bitCounterBitsetAndClearCounters(bitset); +} } // extern "C" |