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Diffstat (limited to 'lib/lsan/lsan_common.cpp')
| -rw-r--r-- | lib/lsan/lsan_common.cpp | 900 |
1 files changed, 900 insertions, 0 deletions
diff --git a/lib/lsan/lsan_common.cpp b/lib/lsan/lsan_common.cpp new file mode 100644 index 000000000000..9ff9f4c5d1c9 --- /dev/null +++ b/lib/lsan/lsan_common.cpp @@ -0,0 +1,900 @@ +//=-- lsan_common.cpp -----------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of LeakSanitizer. +// Implementation of common leak checking functionality. +// +//===----------------------------------------------------------------------===// + +#include "lsan_common.h" + +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_flag_parser.h" +#include "sanitizer_common/sanitizer_flags.h" +#include "sanitizer_common/sanitizer_placement_new.h" +#include "sanitizer_common/sanitizer_procmaps.h" +#include "sanitizer_common/sanitizer_report_decorator.h" +#include "sanitizer_common/sanitizer_stackdepot.h" +#include "sanitizer_common/sanitizer_stacktrace.h" +#include "sanitizer_common/sanitizer_suppressions.h" +#include "sanitizer_common/sanitizer_thread_registry.h" +#include "sanitizer_common/sanitizer_tls_get_addr.h" + +#if CAN_SANITIZE_LEAKS +namespace __lsan { + +// This mutex is used to prevent races between DoLeakCheck and IgnoreObject, and +// also to protect the global list of root regions. +BlockingMutex global_mutex(LINKER_INITIALIZED); + +Flags lsan_flags; + +void DisableCounterUnderflow() { + if (common_flags()->detect_leaks) { + Report("Unmatched call to __lsan_enable().\n"); + Die(); + } +} + +void Flags::SetDefaults() { +#define LSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue; +#include "lsan_flags.inc" +#undef LSAN_FLAG +} + +void RegisterLsanFlags(FlagParser *parser, Flags *f) { +#define LSAN_FLAG(Type, Name, DefaultValue, Description) \ + RegisterFlag(parser, #Name, Description, &f->Name); +#include "lsan_flags.inc" +#undef LSAN_FLAG +} + +#define LOG_POINTERS(...) \ + do { \ + if (flags()->log_pointers) Report(__VA_ARGS__); \ + } while (0) + +#define LOG_THREADS(...) \ + do { \ + if (flags()->log_threads) Report(__VA_ARGS__); \ + } while (0) + +ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)]; +static SuppressionContext *suppression_ctx = nullptr; +static const char kSuppressionLeak[] = "leak"; +static const char *kSuppressionTypes[] = { kSuppressionLeak }; +static const char kStdSuppressions[] = +#if SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT + // For more details refer to the SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT + // definition. + "leak:*pthread_exit*\n" +#endif // SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT +#if SANITIZER_MAC + // For Darwin and os_log/os_trace: https://reviews.llvm.org/D35173 + "leak:*_os_trace*\n" +#endif + // TLS leak in some glibc versions, described in + // https://sourceware.org/bugzilla/show_bug.cgi?id=12650. + "leak:*tls_get_addr*\n"; + +void InitializeSuppressions() { + CHECK_EQ(nullptr, suppression_ctx); + suppression_ctx = new (suppression_placeholder) + SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes)); + suppression_ctx->ParseFromFile(flags()->suppressions); + if (&__lsan_default_suppressions) + suppression_ctx->Parse(__lsan_default_suppressions()); + suppression_ctx->Parse(kStdSuppressions); +} + +static SuppressionContext *GetSuppressionContext() { + CHECK(suppression_ctx); + return suppression_ctx; +} + +static InternalMmapVector<RootRegion> *root_regions; + +InternalMmapVector<RootRegion> const *GetRootRegions() { return root_regions; } + +void InitializeRootRegions() { + CHECK(!root_regions); + ALIGNED(64) static char placeholder[sizeof(InternalMmapVector<RootRegion>)]; + root_regions = new (placeholder) InternalMmapVector<RootRegion>(); +} + +const char *MaybeCallLsanDefaultOptions() { + return (&__lsan_default_options) ? __lsan_default_options() : ""; +} + +void InitCommonLsan() { + InitializeRootRegions(); + if (common_flags()->detect_leaks) { + // Initialization which can fail or print warnings should only be done if + // LSan is actually enabled. + InitializeSuppressions(); + InitializePlatformSpecificModules(); + } +} + +class Decorator: public __sanitizer::SanitizerCommonDecorator { + public: + Decorator() : SanitizerCommonDecorator() { } + const char *Error() { return Red(); } + const char *Leak() { return Blue(); } +}; + +static inline bool CanBeAHeapPointer(uptr p) { + // Since our heap is located in mmap-ed memory, we can assume a sensible lower + // bound on heap addresses. + const uptr kMinAddress = 4 * 4096; + if (p < kMinAddress) return false; +#if defined(__x86_64__) + // Accept only canonical form user-space addresses. + return ((p >> 47) == 0); +#elif defined(__mips64) + return ((p >> 40) == 0); +#elif defined(__aarch64__) + unsigned runtimeVMA = + (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1); + return ((p >> runtimeVMA) == 0); +#else + return true; +#endif +} + +// Scans the memory range, looking for byte patterns that point into allocator +// chunks. Marks those chunks with |tag| and adds them to |frontier|. +// There are two usage modes for this function: finding reachable chunks +// (|tag| = kReachable) and finding indirectly leaked chunks +// (|tag| = kIndirectlyLeaked). In the second case, there's no flood fill, +// so |frontier| = 0. +void ScanRangeForPointers(uptr begin, uptr end, + Frontier *frontier, + const char *region_type, ChunkTag tag) { + CHECK(tag == kReachable || tag == kIndirectlyLeaked); + const uptr alignment = flags()->pointer_alignment(); + LOG_POINTERS("Scanning %s range %p-%p.\n", region_type, begin, end); + uptr pp = begin; + if (pp % alignment) + pp = pp + alignment - pp % alignment; + for (; pp + sizeof(void *) <= end; pp += alignment) { + void *p = *reinterpret_cast<void **>(pp); + if (!CanBeAHeapPointer(reinterpret_cast<uptr>(p))) continue; + uptr chunk = PointsIntoChunk(p); + if (!chunk) continue; + // Pointers to self don't count. This matters when tag == kIndirectlyLeaked. + if (chunk == begin) continue; + LsanMetadata m(chunk); + if (m.tag() == kReachable || m.tag() == kIgnored) continue; + + // Do this check relatively late so we can log only the interesting cases. + if (!flags()->use_poisoned && WordIsPoisoned(pp)) { + LOG_POINTERS( + "%p is poisoned: ignoring %p pointing into chunk %p-%p of size " + "%zu.\n", + pp, p, chunk, chunk + m.requested_size(), m.requested_size()); + continue; + } + + m.set_tag(tag); + LOG_POINTERS("%p: found %p pointing into chunk %p-%p of size %zu.\n", pp, p, + chunk, chunk + m.requested_size(), m.requested_size()); + if (frontier) + frontier->push_back(chunk); + } +} + +// Scans a global range for pointers +void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier) { + uptr allocator_begin = 0, allocator_end = 0; + GetAllocatorGlobalRange(&allocator_begin, &allocator_end); + if (begin <= allocator_begin && allocator_begin < end) { + CHECK_LE(allocator_begin, allocator_end); + CHECK_LE(allocator_end, end); + if (begin < allocator_begin) + ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL", + kReachable); + if (allocator_end < end) + ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL", kReachable); + } else { + ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable); + } +} + +void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg) { + Frontier *frontier = reinterpret_cast<Frontier *>(arg); + ScanRangeForPointers(begin, end, frontier, "FAKE STACK", kReachable); +} + +// Scans thread data (stacks and TLS) for heap pointers. +static void ProcessThreads(SuspendedThreadsList const &suspended_threads, + Frontier *frontier) { + InternalMmapVector<uptr> registers(suspended_threads.RegisterCount()); + uptr registers_begin = reinterpret_cast<uptr>(registers.data()); + uptr registers_end = + reinterpret_cast<uptr>(registers.data() + registers.size()); + for (uptr i = 0; i < suspended_threads.ThreadCount(); i++) { + tid_t os_id = static_cast<tid_t>(suspended_threads.GetThreadID(i)); + LOG_THREADS("Processing thread %d.\n", os_id); + uptr stack_begin, stack_end, tls_begin, tls_end, cache_begin, cache_end; + DTLS *dtls; + bool thread_found = GetThreadRangesLocked(os_id, &stack_begin, &stack_end, + &tls_begin, &tls_end, + &cache_begin, &cache_end, &dtls); + if (!thread_found) { + // If a thread can't be found in the thread registry, it's probably in the + // process of destruction. Log this event and move on. + LOG_THREADS("Thread %d not found in registry.\n", os_id); + continue; + } + uptr sp; + PtraceRegistersStatus have_registers = + suspended_threads.GetRegistersAndSP(i, registers.data(), &sp); + if (have_registers != REGISTERS_AVAILABLE) { + Report("Unable to get registers from thread %d.\n", os_id); + // If unable to get SP, consider the entire stack to be reachable unless + // GetRegistersAndSP failed with ESRCH. + if (have_registers == REGISTERS_UNAVAILABLE_FATAL) continue; + sp = stack_begin; + } + + if (flags()->use_registers && have_registers) + ScanRangeForPointers(registers_begin, registers_end, frontier, + "REGISTERS", kReachable); + + if (flags()->use_stacks) { + LOG_THREADS("Stack at %p-%p (SP = %p).\n", stack_begin, stack_end, sp); + if (sp < stack_begin || sp >= stack_end) { + // SP is outside the recorded stack range (e.g. the thread is running a + // signal handler on alternate stack, or swapcontext was used). + // Again, consider the entire stack range to be reachable. + LOG_THREADS("WARNING: stack pointer not in stack range.\n"); + uptr page_size = GetPageSizeCached(); + int skipped = 0; + while (stack_begin < stack_end && + !IsAccessibleMemoryRange(stack_begin, 1)) { + skipped++; + stack_begin += page_size; + } + LOG_THREADS("Skipped %d guard page(s) to obtain stack %p-%p.\n", + skipped, stack_begin, stack_end); + } else { + // Shrink the stack range to ignore out-of-scope values. + stack_begin = sp; + } + ScanRangeForPointers(stack_begin, stack_end, frontier, "STACK", + kReachable); + ForEachExtraStackRange(os_id, ForEachExtraStackRangeCb, frontier); + } + + if (flags()->use_tls) { + if (tls_begin) { + LOG_THREADS("TLS at %p-%p.\n", tls_begin, tls_end); + // If the tls and cache ranges don't overlap, scan full tls range, + // otherwise, only scan the non-overlapping portions + if (cache_begin == cache_end || tls_end < cache_begin || + tls_begin > cache_end) { + ScanRangeForPointers(tls_begin, tls_end, frontier, "TLS", kReachable); + } else { + if (tls_begin < cache_begin) + ScanRangeForPointers(tls_begin, cache_begin, frontier, "TLS", + kReachable); + if (tls_end > cache_end) + ScanRangeForPointers(cache_end, tls_end, frontier, "TLS", + kReachable); + } + } + if (dtls && !DTLSInDestruction(dtls)) { + for (uptr j = 0; j < dtls->dtv_size; ++j) { + uptr dtls_beg = dtls->dtv[j].beg; + uptr dtls_end = dtls_beg + dtls->dtv[j].size; + if (dtls_beg < dtls_end) { + LOG_THREADS("DTLS %zu at %p-%p.\n", j, dtls_beg, dtls_end); + ScanRangeForPointers(dtls_beg, dtls_end, frontier, "DTLS", + kReachable); + } + } + } else { + // We are handling a thread with DTLS under destruction. Log about + // this and continue. + LOG_THREADS("Thread %d has DTLS under destruction.\n", os_id); + } + } + } +} + +void ScanRootRegion(Frontier *frontier, const RootRegion &root_region, + uptr region_begin, uptr region_end, bool is_readable) { + uptr intersection_begin = Max(root_region.begin, region_begin); + uptr intersection_end = Min(region_end, root_region.begin + root_region.size); + if (intersection_begin >= intersection_end) return; + LOG_POINTERS("Root region %p-%p intersects with mapped region %p-%p (%s)\n", + root_region.begin, root_region.begin + root_region.size, + region_begin, region_end, + is_readable ? "readable" : "unreadable"); + if (is_readable) + ScanRangeForPointers(intersection_begin, intersection_end, frontier, "ROOT", + kReachable); +} + +static void ProcessRootRegion(Frontier *frontier, + const RootRegion &root_region) { + MemoryMappingLayout proc_maps(/*cache_enabled*/ true); + MemoryMappedSegment segment; + while (proc_maps.Next(&segment)) { + ScanRootRegion(frontier, root_region, segment.start, segment.end, + segment.IsReadable()); + } +} + +// Scans root regions for heap pointers. +static void ProcessRootRegions(Frontier *frontier) { + if (!flags()->use_root_regions) return; + CHECK(root_regions); + for (uptr i = 0; i < root_regions->size(); i++) { + ProcessRootRegion(frontier, (*root_regions)[i]); + } +} + +static void FloodFillTag(Frontier *frontier, ChunkTag tag) { + while (frontier->size()) { + uptr next_chunk = frontier->back(); + frontier->pop_back(); + LsanMetadata m(next_chunk); + ScanRangeForPointers(next_chunk, next_chunk + m.requested_size(), frontier, + "HEAP", tag); + } +} + +// ForEachChunk callback. If the chunk is marked as leaked, marks all chunks +// which are reachable from it as indirectly leaked. +static void MarkIndirectlyLeakedCb(uptr chunk, void *arg) { + chunk = GetUserBegin(chunk); + LsanMetadata m(chunk); + if (m.allocated() && m.tag() != kReachable) { + ScanRangeForPointers(chunk, chunk + m.requested_size(), + /* frontier */ nullptr, "HEAP", kIndirectlyLeaked); + } +} + +// ForEachChunk callback. If chunk is marked as ignored, adds its address to +// frontier. +static void CollectIgnoredCb(uptr chunk, void *arg) { + CHECK(arg); + chunk = GetUserBegin(chunk); + LsanMetadata m(chunk); + if (m.allocated() && m.tag() == kIgnored) { + LOG_POINTERS("Ignored: chunk %p-%p of size %zu.\n", + chunk, chunk + m.requested_size(), m.requested_size()); + reinterpret_cast<Frontier *>(arg)->push_back(chunk); + } +} + +static uptr GetCallerPC(u32 stack_id, StackDepotReverseMap *map) { + CHECK(stack_id); + StackTrace stack = map->Get(stack_id); + // The top frame is our malloc/calloc/etc. The next frame is the caller. + if (stack.size >= 2) + return stack.trace[1]; + return 0; +} + +struct InvalidPCParam { + Frontier *frontier; + StackDepotReverseMap *stack_depot_reverse_map; + bool skip_linker_allocations; +}; + +// ForEachChunk callback. If the caller pc is invalid or is within the linker, +// mark as reachable. Called by ProcessPlatformSpecificAllocations. +static void MarkInvalidPCCb(uptr chunk, void *arg) { + CHECK(arg); + InvalidPCParam *param = reinterpret_cast<InvalidPCParam *>(arg); + chunk = GetUserBegin(chunk); + LsanMetadata m(chunk); + if (m.allocated() && m.tag() != kReachable && m.tag() != kIgnored) { + u32 stack_id = m.stack_trace_id(); + uptr caller_pc = 0; + if (stack_id > 0) + caller_pc = GetCallerPC(stack_id, param->stack_depot_reverse_map); + // If caller_pc is unknown, this chunk may be allocated in a coroutine. Mark + // it as reachable, as we can't properly report its allocation stack anyway. + if (caller_pc == 0 || (param->skip_linker_allocations && + GetLinker()->containsAddress(caller_pc))) { + m.set_tag(kReachable); + param->frontier->push_back(chunk); + } + } +} + +// On Linux, treats all chunks allocated from ld-linux.so as reachable, which +// covers dynamically allocated TLS blocks, internal dynamic loader's loaded +// modules accounting etc. +// Dynamic TLS blocks contain the TLS variables of dynamically loaded modules. +// They are allocated with a __libc_memalign() call in allocate_and_init() +// (elf/dl-tls.c). Glibc won't tell us the address ranges occupied by those +// blocks, but we can make sure they come from our own allocator by intercepting +// __libc_memalign(). On top of that, there is no easy way to reach them. Their +// addresses are stored in a dynamically allocated array (the DTV) which is +// referenced from the static TLS. Unfortunately, we can't just rely on the DTV +// being reachable from the static TLS, and the dynamic TLS being reachable from +// the DTV. This is because the initial DTV is allocated before our interception +// mechanism kicks in, and thus we don't recognize it as allocated memory. We +// can't special-case it either, since we don't know its size. +// Our solution is to include in the root set all allocations made from +// ld-linux.so (which is where allocate_and_init() is implemented). This is +// guaranteed to include all dynamic TLS blocks (and possibly other allocations +// which we don't care about). +// On all other platforms, this simply checks to ensure that the caller pc is +// valid before reporting chunks as leaked. +void ProcessPC(Frontier *frontier) { + StackDepotReverseMap stack_depot_reverse_map; + InvalidPCParam arg; + arg.frontier = frontier; + arg.stack_depot_reverse_map = &stack_depot_reverse_map; + arg.skip_linker_allocations = + flags()->use_tls && flags()->use_ld_allocations && GetLinker() != nullptr; + ForEachChunk(MarkInvalidPCCb, &arg); +} + +// Sets the appropriate tag on each chunk. +static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) { + // Holds the flood fill frontier. + Frontier frontier; + + ForEachChunk(CollectIgnoredCb, &frontier); + ProcessGlobalRegions(&frontier); + ProcessThreads(suspended_threads, &frontier); + ProcessRootRegions(&frontier); + FloodFillTag(&frontier, kReachable); + + CHECK_EQ(0, frontier.size()); + ProcessPC(&frontier); + + // The check here is relatively expensive, so we do this in a separate flood + // fill. That way we can skip the check for chunks that are reachable + // otherwise. + LOG_POINTERS("Processing platform-specific allocations.\n"); + ProcessPlatformSpecificAllocations(&frontier); + FloodFillTag(&frontier, kReachable); + + // Iterate over leaked chunks and mark those that are reachable from other + // leaked chunks. + LOG_POINTERS("Scanning leaked chunks.\n"); + ForEachChunk(MarkIndirectlyLeakedCb, nullptr); +} + +// ForEachChunk callback. Resets the tags to pre-leak-check state. +static void ResetTagsCb(uptr chunk, void *arg) { + (void)arg; + chunk = GetUserBegin(chunk); + LsanMetadata m(chunk); + if (m.allocated() && m.tag() != kIgnored) + m.set_tag(kDirectlyLeaked); +} + +static void PrintStackTraceById(u32 stack_trace_id) { + CHECK(stack_trace_id); + StackDepotGet(stack_trace_id).Print(); +} + +// ForEachChunk callback. Aggregates information about unreachable chunks into +// a LeakReport. +static void CollectLeaksCb(uptr chunk, void *arg) { + CHECK(arg); + LeakReport *leak_report = reinterpret_cast<LeakReport *>(arg); + chunk = GetUserBegin(chunk); + LsanMetadata m(chunk); + if (!m.allocated()) return; + if (m.tag() == kDirectlyLeaked || m.tag() == kIndirectlyLeaked) { + u32 resolution = flags()->resolution; + u32 stack_trace_id = 0; + if (resolution > 0) { + StackTrace stack = StackDepotGet(m.stack_trace_id()); + stack.size = Min(stack.size, resolution); + stack_trace_id = StackDepotPut(stack); + } else { + stack_trace_id = m.stack_trace_id(); + } + leak_report->AddLeakedChunk(chunk, stack_trace_id, m.requested_size(), + m.tag()); + } +} + +static void PrintMatchedSuppressions() { + InternalMmapVector<Suppression *> matched; + GetSuppressionContext()->GetMatched(&matched); + if (!matched.size()) + return; + const char *line = "-----------------------------------------------------"; + Printf("%s\n", line); + Printf("Suppressions used:\n"); + Printf(" count bytes template\n"); + for (uptr i = 0; i < matched.size(); i++) + Printf("%7zu %10zu %s\n", static_cast<uptr>(atomic_load_relaxed( + &matched[i]->hit_count)), matched[i]->weight, matched[i]->templ); + Printf("%s\n\n", line); +} + +struct CheckForLeaksParam { + bool success; + LeakReport leak_report; +}; + +static void ReportIfNotSuspended(ThreadContextBase *tctx, void *arg) { + const InternalMmapVector<tid_t> &suspended_threads = + *(const InternalMmapVector<tid_t> *)arg; + if (tctx->status == ThreadStatusRunning) { + uptr i = InternalLowerBound(suspended_threads, 0, suspended_threads.size(), + tctx->os_id, CompareLess<int>()); + if (i >= suspended_threads.size() || suspended_threads[i] != tctx->os_id) + Report("Running thread %d was not suspended. False leaks are possible.\n", + tctx->os_id); + } +} + +static void ReportUnsuspendedThreads( + const SuspendedThreadsList &suspended_threads) { + InternalMmapVector<tid_t> threads(suspended_threads.ThreadCount()); + for (uptr i = 0; i < suspended_threads.ThreadCount(); ++i) + threads[i] = suspended_threads.GetThreadID(i); + + Sort(threads.data(), threads.size()); + + GetThreadRegistryLocked()->RunCallbackForEachThreadLocked( + &ReportIfNotSuspended, &threads); +} + +static void CheckForLeaksCallback(const SuspendedThreadsList &suspended_threads, + void *arg) { + CheckForLeaksParam *param = reinterpret_cast<CheckForLeaksParam *>(arg); + CHECK(param); + CHECK(!param->success); + ReportUnsuspendedThreads(suspended_threads); + ClassifyAllChunks(suspended_threads); + ForEachChunk(CollectLeaksCb, ¶m->leak_report); + // Clean up for subsequent leak checks. This assumes we did not overwrite any + // kIgnored tags. + ForEachChunk(ResetTagsCb, nullptr); + param->success = true; +} + +static bool CheckForLeaks() { + if (&__lsan_is_turned_off && __lsan_is_turned_off()) + return false; + EnsureMainThreadIDIsCorrect(); + CheckForLeaksParam param; + param.success = false; + LockStuffAndStopTheWorld(CheckForLeaksCallback, ¶m); + + if (!param.success) { + Report("LeakSanitizer has encountered a fatal error.\n"); + Report( + "HINT: For debugging, try setting environment variable " + "LSAN_OPTIONS=verbosity=1:log_threads=1\n"); + Report( + "HINT: LeakSanitizer does not work under ptrace (strace, gdb, etc)\n"); + Die(); + } + param.leak_report.ApplySuppressions(); + uptr unsuppressed_count = param.leak_report.UnsuppressedLeakCount(); + if (unsuppressed_count > 0) { + Decorator d; + Printf("\n" + "=================================================================" + "\n"); + Printf("%s", d.Error()); + Report("ERROR: LeakSanitizer: detected memory leaks\n"); + Printf("%s", d.Default()); + param.leak_report.ReportTopLeaks(flags()->max_leaks); + } + if (common_flags()->print_suppressions) + PrintMatchedSuppressions(); + if (unsuppressed_count > 0) { + param.leak_report.PrintSummary(); + return true; + } + return false; +} + +static bool has_reported_leaks = false; +bool HasReportedLeaks() { return has_reported_leaks; } + +void DoLeakCheck() { + BlockingMutexLock l(&global_mutex); + static bool already_done; + if (already_done) return; + already_done = true; + has_reported_leaks = CheckForLeaks(); + if (has_reported_leaks) HandleLeaks(); +} + +static int DoRecoverableLeakCheck() { + BlockingMutexLock l(&global_mutex); + bool have_leaks = CheckForLeaks(); + return have_leaks ? 1 : 0; +} + +void DoRecoverableLeakCheckVoid() { DoRecoverableLeakCheck(); } + +static Suppression *GetSuppressionForAddr(uptr addr) { + Suppression *s = nullptr; + + // Suppress by module name. + SuppressionContext *suppressions = GetSuppressionContext(); + if (const char *module_name = + Symbolizer::GetOrInit()->GetModuleNameForPc(addr)) + if (suppressions->Match(module_name, kSuppressionLeak, &s)) + return s; + + // Suppress by file or function name. + SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(addr); + for (SymbolizedStack *cur = frames; cur; cur = cur->next) { + if (suppressions->Match(cur->info.function, kSuppressionLeak, &s) || + suppressions->Match(cur->info.file, kSuppressionLeak, &s)) { + break; + } + } + frames->ClearAll(); + return s; +} + +static Suppression *GetSuppressionForStack(u32 stack_trace_id) { + StackTrace stack = StackDepotGet(stack_trace_id); + for (uptr i = 0; i < stack.size; i++) { + Suppression *s = GetSuppressionForAddr( + StackTrace::GetPreviousInstructionPc(stack.trace[i])); + if (s) return s; + } + return nullptr; +} + +///// LeakReport implementation. ///// + +// A hard limit on the number of distinct leaks, to avoid quadratic complexity +// in LeakReport::AddLeakedChunk(). We don't expect to ever see this many leaks +// in real-world applications. +// FIXME: Get rid of this limit by changing the implementation of LeakReport to +// use a hash table. +const uptr kMaxLeaksConsidered = 5000; + +void LeakReport::AddLeakedChunk(uptr chunk, u32 stack_trace_id, + uptr leaked_size, ChunkTag tag) { + CHECK(tag == kDirectlyLeaked || tag == kIndirectlyLeaked); + bool is_directly_leaked = (tag == kDirectlyLeaked); + uptr i; + for (i = 0; i < leaks_.size(); i++) { + if (leaks_[i].stack_trace_id == stack_trace_id && + leaks_[i].is_directly_leaked == is_directly_leaked) { + leaks_[i].hit_count++; + leaks_[i].total_size += leaked_size; + break; + } + } + if (i == leaks_.size()) { + if (leaks_.size() == kMaxLeaksConsidered) return; + Leak leak = { next_id_++, /* hit_count */ 1, leaked_size, stack_trace_id, + is_directly_leaked, /* is_suppressed */ false }; + leaks_.push_back(leak); + } + if (flags()->report_objects) { + LeakedObject obj = {leaks_[i].id, chunk, leaked_size}; + leaked_objects_.push_back(obj); + } +} + +static bool LeakComparator(const Leak &leak1, const Leak &leak2) { + if (leak1.is_directly_leaked == leak2.is_directly_leaked) + return leak1.total_size > leak2.total_size; + else + return leak1.is_directly_leaked; +} + +void LeakReport::ReportTopLeaks(uptr num_leaks_to_report) { + CHECK(leaks_.size() <= kMaxLeaksConsidered); + Printf("\n"); + if (leaks_.size() == kMaxLeaksConsidered) + Printf("Too many leaks! Only the first %zu leaks encountered will be " + "reported.\n", + kMaxLeaksConsidered); + + uptr unsuppressed_count = UnsuppressedLeakCount(); + if (num_leaks_to_report > 0 && num_leaks_to_report < unsuppressed_count) + Printf("The %zu top leak(s):\n", num_leaks_to_report); + Sort(leaks_.data(), leaks_.size(), &LeakComparator); + uptr leaks_reported = 0; + for (uptr i = 0; i < leaks_.size(); i++) { + if (leaks_[i].is_suppressed) continue; + PrintReportForLeak(i); + leaks_reported++; + if (leaks_reported == num_leaks_to_report) break; + } + if (leaks_reported < unsuppressed_count) { + uptr remaining = unsuppressed_count - leaks_reported; + Printf("Omitting %zu more leak(s).\n", remaining); + } +} + +void LeakReport::PrintReportForLeak(uptr index) { + Decorator d; + Printf("%s", d.Leak()); + Printf("%s leak of %zu byte(s) in %zu object(s) allocated from:\n", + leaks_[index].is_directly_leaked ? "Direct" : "Indirect", + leaks_[index].total_size, leaks_[index].hit_count); + Printf("%s", d.Default()); + + PrintStackTraceById(leaks_[index].stack_trace_id); + + if (flags()->report_objects) { + Printf("Objects leaked above:\n"); + PrintLeakedObjectsForLeak(index); + Printf("\n"); + } +} + +void LeakReport::PrintLeakedObjectsForLeak(uptr index) { + u32 leak_id = leaks_[index].id; + for (uptr j = 0; j < leaked_objects_.size(); j++) { + if (leaked_objects_[j].leak_id == leak_id) + Printf("%p (%zu bytes)\n", leaked_objects_[j].addr, + leaked_objects_[j].size); + } +} + +void LeakReport::PrintSummary() { + CHECK(leaks_.size() <= kMaxLeaksConsidered); + uptr bytes = 0, allocations = 0; + for (uptr i = 0; i < leaks_.size(); i++) { + if (leaks_[i].is_suppressed) continue; + bytes += leaks_[i].total_size; + allocations += leaks_[i].hit_count; + } + InternalScopedString summary(kMaxSummaryLength); + summary.append("%zu byte(s) leaked in %zu allocation(s).", bytes, + allocations); + ReportErrorSummary(summary.data()); +} + +void LeakReport::ApplySuppressions() { + for (uptr i = 0; i < leaks_.size(); i++) { + Suppression *s = GetSuppressionForStack(leaks_[i].stack_trace_id); + if (s) { + s->weight += leaks_[i].total_size; + atomic_store_relaxed(&s->hit_count, atomic_load_relaxed(&s->hit_count) + + leaks_[i].hit_count); + leaks_[i].is_suppressed = true; + } + } +} + +uptr LeakReport::UnsuppressedLeakCount() { + uptr result = 0; + for (uptr i = 0; i < leaks_.size(); i++) + if (!leaks_[i].is_suppressed) result++; + return result; +} + +} // namespace __lsan +#else // CAN_SANITIZE_LEAKS +namespace __lsan { +void InitCommonLsan() { } +void DoLeakCheck() { } +void DoRecoverableLeakCheckVoid() { } +void DisableInThisThread() { } +void EnableInThisThread() { } +} +#endif // CAN_SANITIZE_LEAKS + +using namespace __lsan; + +extern "C" { +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_ignore_object(const void *p) { +#if CAN_SANITIZE_LEAKS + if (!common_flags()->detect_leaks) + return; + // Cannot use PointsIntoChunk or LsanMetadata here, since the allocator is not + // locked. + BlockingMutexLock l(&global_mutex); + IgnoreObjectResult res = IgnoreObjectLocked(p); + if (res == kIgnoreObjectInvalid) + VReport(1, "__lsan_ignore_object(): no heap object found at %p", p); + if (res == kIgnoreObjectAlreadyIgnored) + VReport(1, "__lsan_ignore_object(): " + "heap object at %p is already being ignored\n", p); + if (res == kIgnoreObjectSuccess) + VReport(1, "__lsan_ignore_object(): ignoring heap object at %p\n", p); +#endif // CAN_SANITIZE_LEAKS +} + +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_register_root_region(const void *begin, uptr size) { +#if CAN_SANITIZE_LEAKS + BlockingMutexLock l(&global_mutex); + CHECK(root_regions); + RootRegion region = {reinterpret_cast<uptr>(begin), size}; + root_regions->push_back(region); + VReport(1, "Registered root region at %p of size %llu\n", begin, size); +#endif // CAN_SANITIZE_LEAKS +} + +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_unregister_root_region(const void *begin, uptr size) { +#if CAN_SANITIZE_LEAKS + BlockingMutexLock l(&global_mutex); + CHECK(root_regions); + bool removed = false; + for (uptr i = 0; i < root_regions->size(); i++) { + RootRegion region = (*root_regions)[i]; + if (region.begin == reinterpret_cast<uptr>(begin) && region.size == size) { + removed = true; + uptr last_index = root_regions->size() - 1; + (*root_regions)[i] = (*root_regions)[last_index]; + root_regions->pop_back(); + VReport(1, "Unregistered root region at %p of size %llu\n", begin, size); + break; + } + } + if (!removed) { + Report( + "__lsan_unregister_root_region(): region at %p of size %llu has not " + "been registered.\n", + begin, size); + Die(); + } +#endif // CAN_SANITIZE_LEAKS +} + +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_disable() { +#if CAN_SANITIZE_LEAKS + __lsan::DisableInThisThread(); +#endif +} + +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_enable() { +#if CAN_SANITIZE_LEAKS + __lsan::EnableInThisThread(); +#endif +} + +SANITIZER_INTERFACE_ATTRIBUTE +void __lsan_do_leak_check() { +#if CAN_SANITIZE_LEAKS + if (common_flags()->detect_leaks) + __lsan::DoLeakCheck(); +#endif // CAN_SANITIZE_LEAKS +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __lsan_do_recoverable_leak_check() { +#if CAN_SANITIZE_LEAKS + if (common_flags()->detect_leaks) + return __lsan::DoRecoverableLeakCheck(); +#endif // CAN_SANITIZE_LEAKS + return 0; +} + +#if !SANITIZER_SUPPORTS_WEAK_HOOKS +SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE +const char * __lsan_default_options() { + return ""; +} + +SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE +int __lsan_is_turned_off() { + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE +const char *__lsan_default_suppressions() { + return ""; +} +#endif +} // extern "C" |