asan_stats.cpp revision 360784 
1//===-- asan_stats.cpp ----------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of AddressSanitizer, an address sanity checker.
10//
11// Code related to statistics collected by AddressSanitizer.
12//===----------------------------------------------------------------------===//
13#include "asan_interceptors.h"
14#include "asan_internal.h"
15#include "asan_stats.h"
16#include "asan_thread.h"
17#include "sanitizer_common/sanitizer_allocator_interface.h"
18#include "sanitizer_common/sanitizer_mutex.h"
19#include "sanitizer_common/sanitizer_stackdepot.h"
20
21namespace __asan {
22
23AsanStats::AsanStats() {
24  Clear();
25}
26
27void AsanStats::Clear() {
28  CHECK(REAL(memset));
29  REAL(memset)(this, 0, sizeof(AsanStats));
30}
31
32static void PrintMallocStatsArray(const char *prefix,
33                                  uptr (&array)[kNumberOfSizeClasses]) {
34  Printf("%s", prefix);
35  for (uptr i = 0; i < kNumberOfSizeClasses; i++) {
36    if (!array[i]) continue;
37    Printf("%zu:%zu; ", i, array[i]);
38  }
39  Printf("\n");
40}
41
42void AsanStats::Print() {
43  Printf("Stats: %zuM malloced (%zuM for red zones) by %zu calls\n",
44             malloced>>20, malloced_redzones>>20, mallocs);
45  Printf("Stats: %zuM realloced by %zu calls\n", realloced>>20, reallocs);
46  Printf("Stats: %zuM freed by %zu calls\n", freed>>20, frees);
47  Printf("Stats: %zuM really freed by %zu calls\n",
48             really_freed>>20, real_frees);
49  Printf("Stats: %zuM (%zuM-%zuM) mmaped; %zu maps, %zu unmaps\n",
50             (mmaped-munmaped)>>20, mmaped>>20, munmaped>>20,
51             mmaps, munmaps);
52
53  PrintMallocStatsArray("  mallocs by size class: ", malloced_by_size);
54  Printf("Stats: malloc large: %zu\n", malloc_large);
55}
56
57void AsanStats::MergeFrom(const AsanStats *stats) {
58  uptr *dst_ptr = reinterpret_cast<uptr*>(this);
59  const uptr *src_ptr = reinterpret_cast<const uptr*>(stats);
60  uptr num_fields = sizeof(*this) / sizeof(uptr);
61  for (uptr i = 0; i < num_fields; i++)
62    dst_ptr[i] += src_ptr[i];
63}
64
65static BlockingMutex print_lock(LINKER_INITIALIZED);
66
67static AsanStats unknown_thread_stats(LINKER_INITIALIZED);
68static AsanStats dead_threads_stats(LINKER_INITIALIZED);
69static BlockingMutex dead_threads_stats_lock(LINKER_INITIALIZED);
70// Required for malloc_zone_statistics() on OS X. This can't be stored in
71// per-thread AsanStats.
72static uptr max_malloced_memory;
73
74static void MergeThreadStats(ThreadContextBase *tctx_base, void *arg) {
75  AsanStats *accumulated_stats = reinterpret_cast<AsanStats*>(arg);
76  AsanThreadContext *tctx = static_cast<AsanThreadContext*>(tctx_base);
77  if (AsanThread *t = tctx->thread)
78    accumulated_stats->MergeFrom(&t->stats());
79}
80
81static void GetAccumulatedStats(AsanStats *stats) {
82  stats->Clear();
83  {
84    ThreadRegistryLock l(&asanThreadRegistry());
85    asanThreadRegistry()
86        .RunCallbackForEachThreadLocked(MergeThreadStats, stats);
87  }
88  stats->MergeFrom(&unknown_thread_stats);
89  {
90    BlockingMutexLock lock(&dead_threads_stats_lock);
91    stats->MergeFrom(&dead_threads_stats);
92  }
93  // This is not very accurate: we may miss allocation peaks that happen
94  // between two updates of accumulated_stats_. For more accurate bookkeeping
95  // the maximum should be updated on every malloc(), which is unacceptable.
96  if (max_malloced_memory < stats->malloced) {
97    max_malloced_memory = stats->malloced;
98  }
99}
100
101void FlushToDeadThreadStats(AsanStats *stats) {
102  BlockingMutexLock lock(&dead_threads_stats_lock);
103  dead_threads_stats.MergeFrom(stats);
104  stats->Clear();
105}
106
107void FillMallocStatistics(AsanMallocStats *malloc_stats) {
108  AsanStats stats;
109  GetAccumulatedStats(&stats);
110  malloc_stats->blocks_in_use = stats.mallocs;
111  malloc_stats->size_in_use = stats.malloced;
112  malloc_stats->max_size_in_use = max_malloced_memory;
113  malloc_stats->size_allocated = stats.mmaped;
114}
115
116AsanStats &GetCurrentThreadStats() {
117  AsanThread *t = GetCurrentThread();
118  return (t) ? t->stats() : unknown_thread_stats;
119}
120
121static void PrintAccumulatedStats() {
122  AsanStats stats;
123  GetAccumulatedStats(&stats);
124  // Use lock to keep reports from mixing up.
125  BlockingMutexLock lock(&print_lock);
126  stats.Print();
127  StackDepotStats *stack_depot_stats = StackDepotGetStats();
128  Printf("Stats: StackDepot: %zd ids; %zdM allocated\n",
129         stack_depot_stats->n_uniq_ids, stack_depot_stats->allocated >> 20);
130  PrintInternalAllocatorStats();
131}
132
133}  // namespace __asan
134
135// ---------------------- Interface ---------------- {{{1
136using namespace __asan;
137
138uptr __sanitizer_get_current_allocated_bytes() {
139  AsanStats stats;
140  GetAccumulatedStats(&stats);
141  uptr malloced = stats.malloced;
142  uptr freed = stats.freed;
143  // Return sane value if malloced < freed due to racy
144  // way we update accumulated stats.
145  return (malloced > freed) ? malloced - freed : 1;
146}
147
148uptr __sanitizer_get_heap_size() {
149  AsanStats stats;
150  GetAccumulatedStats(&stats);
151  return stats.mmaped - stats.munmaped;
152}
153
154uptr __sanitizer_get_free_bytes() {
155  AsanStats stats;
156  GetAccumulatedStats(&stats);
157  uptr total_free = stats.mmaped
158                  - stats.munmaped
159                  + stats.really_freed;
160  uptr total_used = stats.malloced
161                  + stats.malloced_redzones;
162  // Return sane value if total_free < total_used due to racy
163  // way we update accumulated stats.
164  return (total_free > total_used) ? total_free - total_used : 1;
165}
166
167uptr __sanitizer_get_unmapped_bytes() {
168  return 0;
169}
170
171void __asan_print_accumulated_stats() {
172  PrintAccumulatedStats();
173}
174