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llvm-project/compiler-rt/lib/lsan/lsan_common.cpp

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//=-- 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)
class LeakSuppressionContext {
bool parsed = false;
SuppressionContext context;
bool suppressed_stacks_sorted = true;
InternalMmapVector<u32> suppressed_stacks;
Suppression *GetSuppressionForAddr(uptr addr);
void LazyInit();
public:
LeakSuppressionContext(const char *supprression_types[],
int suppression_types_num)
: context(supprression_types, suppression_types_num) {}
Suppression *GetSuppressionForStack(u32 stack_trace_id);
const InternalMmapVector<u32> &GetSortedSuppressedStacks() {
if (!suppressed_stacks_sorted) {
suppressed_stacks_sorted = true;
SortAndDedup(suppressed_stacks);
}
return suppressed_stacks;
}
void PrintMatchedSuppressions();
};
ALIGNED(64) static char suppression_placeholder[sizeof(LeakSuppressionContext)];
static LeakSuppressionContext *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)
LeakSuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes));
}
void LeakSuppressionContext::LazyInit() {
if (!parsed) {
parsed = true;
context.ParseFromFile(flags()->suppressions);
if (&__lsan_default_suppressions)
context.Parse(__lsan_default_suppressions());
context.Parse(kStdSuppressions);
}
}
static LeakSuppressionContext *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>();
}
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);
}
#if SANITIZER_FUCHSIA
// Fuchsia handles all threads together with its own callback.
static void ProcessThreads(SuspendedThreadsList const &, Frontier *) {}
#else
#if SANITIZER_ANDROID
// FIXME: Move this out into *libcdep.cpp
extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_iterate_dynamic_tls(
pid_t, void (*cb)(void *, void *, uptr, void *), void *);
#endif
static void ProcessThreadRegistry(Frontier *frontier) {
InternalMmapVector<uptr> ptrs;
GetThreadRegistryLocked()->RunCallbackForEachThreadLocked(
GetAdditionalThreadContextPtrs, &ptrs);
for (uptr i = 0; i < ptrs.size(); ++i) {
void *ptr = reinterpret_cast<void *>(ptrs[i]);
uptr chunk = PointsIntoChunk(ptr);
if (!chunk)
continue;
LsanMetadata m(chunk);
if (!m.allocated())
continue;
// Mark as reachable and add to frontier.
LOG_POINTERS("Treating pointer %p from ThreadContext as reachable\n", ptr);
m.set_tag(kReachable);
frontier->push_back(chunk);
}
}
// Scans thread data (stacks and TLS) for heap pointers.
static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
Frontier *frontier) {
InternalMmapVector<uptr> registers;
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, &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) {
uptr registers_begin = reinterpret_cast<uptr>(registers.data());
uptr registers_end =
reinterpret_cast<uptr>(registers.data() + registers.size());
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 SANITIZER_ANDROID
auto *cb = +[](void *dtls_begin, void *dtls_end, uptr /*dso_idd*/,
void *arg) -> void {
ScanRangeForPointers(reinterpret_cast<uptr>(dtls_begin),
reinterpret_cast<uptr>(dtls_end),
reinterpret_cast<Frontier *>(arg), "DTLS",
kReachable);
};
// FIXME: There might be a race-condition here (and in Bionic) if the
// thread is suspended in the middle of updating its DTLS. IOWs, we
// could scan already freed memory. (probably fine for now)
__libc_iterate_dynamic_tls(os_id, cb, frontier);
#else
if (dtls && !DTLSInDestruction(dtls)) {
ForEachDVT(dtls, [&](const DTLS::DTV &dtv, int id) {
uptr dtls_beg = dtv.beg;
uptr dtls_end = dtls_beg + dtv.size;
if (dtls_beg < dtls_end) {
LOG_THREADS("DTLS %zu at %p-%p.\n", id, 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);
}
#endif
}
}
// Add pointers reachable from ThreadContexts
ProcessThreadRegistry(frontier);
}
#endif // SANITIZER_FUCHSIA
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);
}
}
static void IgnoredSuppressedCb(uptr chunk, void *arg) {
CHECK(arg);
chunk = GetUserBegin(chunk);
LsanMetadata m(chunk);
if (!m.allocated() || m.tag() == kIgnored)
return;
const InternalMmapVector<u32> &suppressed =
*static_cast<const InternalMmapVector<u32> *>(arg);
uptr idx = InternalLowerBound(suppressed, m.stack_trace_id());
if (idx >= suppressed.size() || m.stack_trace_id() != suppressed[idx])
return;
LOG_POINTERS("Suppressed: chunk %p-%p of size %zu.\n", chunk,
chunk + m.requested_size(), m.requested_size());
m.set_tag(kIgnored);
}
// 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,
Frontier *frontier) {
const InternalMmapVector<u32> &suppressed_stacks =
GetSuppressionContext()->GetSortedSuppressedStacks();
if (!suppressed_stacks.empty()) {
ForEachChunk(IgnoredSuppressedCb,
const_cast<InternalMmapVector<u32> *>(&suppressed_stacks));
}
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());
}
}
void LeakSuppressionContext::PrintMatchedSuppressions() {
InternalMmapVector<Suppression *> matched;
context.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);
}
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, tctx->os_id);
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);
}
}
#if SANITIZER_FUCHSIA
// Fuchsia provides a libc interface that guarantees all threads are
// covered, and SuspendedThreadList is never really used.
static void ReportUnsuspendedThreads(const SuspendedThreadsList &) {}
#else // !SANITIZER_FUCHSIA
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);
}
#endif // !SANITIZER_FUCHSIA
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, &param->frontier);
ForEachChunk(CollectLeaksCb, &param->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 PrintResults(LeakReport &report) {
uptr unsuppressed_count = report.UnsuppressedLeakCount();
if (unsuppressed_count) {
Decorator d;
Printf(
"\n"
"================================================================="
"\n");
Printf("%s", d.Error());
Report("ERROR: LeakSanitizer: detected memory leaks\n");
Printf("%s", d.Default());
report.ReportTopLeaks(flags()->max_leaks);
}
if (common_flags()->print_suppressions)
GetSuppressionContext()->PrintMatchedSuppressions();
if (unsuppressed_count > 0) {
report.PrintSummary();
return true;
}
return false;
}
static bool CheckForLeaks() {
if (&__lsan_is_turned_off && __lsan_is_turned_off())
return false;
// Inside LockStuffAndStopTheWorld we can't run symbolizer, so we can't match
// suppressions. However if a stack id was previously suppressed, it should be
// suppressed in future checks as well.
for (int i = 0;; ++i) {
EnsureMainThreadIDIsCorrect();
CheckForLeaksParam param;
LockStuffAndStopTheWorld(CheckForLeaksCallback, &param);
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();
}
// No new suppressions stacks, so rerun will not help and we can report.
if (!param.leak_report.ApplySuppressions())
return PrintResults(param.leak_report);
// No indirect leaks to report, so we are done here.
if (!param.leak_report.IndirectUnsuppressedLeakCount())
return PrintResults(param.leak_report);
if (i >= 8) {
Report("WARNING: LeakSanitizer gave up on indirect leaks suppression.\n");
return PrintResults(param.leak_report);
}
// We found a new previously unseen suppressed call stack. Rerun to make
// sure it does not hold indirect leaks.
VReport(1, "Rerun with %zu suppressed stacks.",
GetSuppressionContext()->GetSortedSuppressedStacks().size());
}
}
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(); }
Suppression *LeakSuppressionContext::GetSuppressionForAddr(uptr addr) {
Suppression *s = nullptr;
// Suppress by module name.
if (const char *module_name =
Symbolizer::GetOrInit()->GetModuleNameForPc(addr))
if (context.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 (context.Match(cur->info.function, kSuppressionLeak, &s) ||
context.Match(cur->info.file, kSuppressionLeak, &s)) {
break;
}
}
frames->ClearAll();
return s;
}
Suppression *LeakSuppressionContext::GetSuppressionForStack(
u32 stack_trace_id) {
LazyInit();
StackTrace stack = StackDepotGet(stack_trace_id);
for (uptr i = 0; i < stack.size; i++) {
Suppression *s = GetSuppressionForAddr(
StackTrace::GetPreviousInstructionPc(stack.trace[i]));
if (s) {
suppressed_stacks_sorted = false;
suppressed_stacks.push_back(stack_trace_id);
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;
summary.append("%zu byte(s) leaked in %zu allocation(s).", bytes,
allocations);
ReportErrorSummary(summary.data());
}
uptr LeakReport::ApplySuppressions() {
LeakSuppressionContext *suppressions = GetSuppressionContext();
uptr new_suppressions = false;
for (uptr i = 0; i < leaks_.size(); i++) {
Suppression *s =
suppressions->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;
++new_suppressions;
}
}
return new_suppressions;
}
uptr LeakReport::UnsuppressedLeakCount() {
uptr result = 0;
for (uptr i = 0; i < leaks_.size(); i++)
if (!leaks_[i].is_suppressed) result++;
return result;
}
uptr LeakReport::IndirectUnsuppressedLeakCount() {
uptr result = 0;
for (uptr i = 0; i < leaks_.size(); i++)
if (!leaks_[i].is_suppressed && !leaks_[i].is_directly_leaked)
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;
}
SANITIZER_INTERFACE_WEAK_DEF(const char *, __lsan_default_options, void) {
return "";
}
#if !SANITIZER_SUPPORTS_WEAK_HOOKS
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"
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