1//===-- tsan_mman.cc ------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of ThreadSanitizer (TSan), a race detector.
11//
12//===----------------------------------------------------------------------===//
13#include "sanitizer_common/sanitizer_allocator_interface.h"
14#include "sanitizer_common/sanitizer_common.h"
15#include "sanitizer_common/sanitizer_placement_new.h"
16#include "tsan_mman.h"
17#include "tsan_rtl.h"
18#include "tsan_report.h"
19#include "tsan_flags.h"
20
21// May be overriden by front-end.
22SANITIZER_WEAK_DEFAULT_IMPL
23void __sanitizer_malloc_hook(void *ptr, uptr size) {
24  (void)ptr;
25  (void)size;
26}
27
28SANITIZER_WEAK_DEFAULT_IMPL
29void __sanitizer_free_hook(void *ptr) {
30  (void)ptr;
31}
32
33namespace __tsan {
34
35struct MapUnmapCallback {
36  void OnMap(uptr p, uptr size) const { }
37  void OnUnmap(uptr p, uptr size) const {
38    // We are about to unmap a chunk of user memory.
39    // Mark the corresponding shadow memory as not needed.
40    DontNeedShadowFor(p, size);
41    // Mark the corresponding meta shadow memory as not needed.
42    // Note the block does not contain any meta info at this point
43    // (this happens after free).
44    const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
45    const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
46    // Block came from LargeMmapAllocator, so must be large.
47    // We rely on this in the calculations below.
48    CHECK_GE(size, 2 * kPageSize);
49    uptr diff = RoundUp(p, kPageSize) - p;
50    if (diff != 0) {
51      p += diff;
52      size -= diff;
53    }
54    diff = p + size - RoundDown(p + size, kPageSize);
55    if (diff != 0)
56      size -= diff;
57    FlushUnneededShadowMemory((uptr)MemToMeta(p), size / kMetaRatio);
58  }
59};
60
61static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
62Allocator *allocator() {
63  return reinterpret_cast<Allocator*>(&allocator_placeholder);
64}
65
66void InitializeAllocator() {
67  allocator()->Init(common_flags()->allocator_may_return_null);
68}
69
70void AllocatorThreadStart(ThreadState *thr) {
71  allocator()->InitCache(&thr->alloc_cache);
72  internal_allocator()->InitCache(&thr->internal_alloc_cache);
73}
74
75void AllocatorThreadFinish(ThreadState *thr) {
76  allocator()->DestroyCache(&thr->alloc_cache);
77  internal_allocator()->DestroyCache(&thr->internal_alloc_cache);
78}
79
80void AllocatorPrintStats() {
81  allocator()->PrintStats();
82}
83
84static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
85  if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
86      !flags()->report_signal_unsafe)
87    return;
88  VarSizeStackTrace stack;
89  ObtainCurrentStack(thr, pc, &stack);
90  if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
91    return;
92  ThreadRegistryLock l(ctx->thread_registry);
93  ScopedReport rep(ReportTypeSignalUnsafe);
94  rep.AddStack(stack, true);
95  OutputReport(thr, rep);
96}
97
98void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align, bool signal) {
99  if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
100    return allocator()->ReturnNullOrDie();
101  void *p = allocator()->Allocate(&thr->alloc_cache, sz, align);
102  if (p == 0)
103    return 0;
104  if (ctx && ctx->initialized)
105    OnUserAlloc(thr, pc, (uptr)p, sz, true);
106  if (signal)
107    SignalUnsafeCall(thr, pc);
108  return p;
109}
110
111void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
112  if (CallocShouldReturnNullDueToOverflow(size, n))
113    return allocator()->ReturnNullOrDie();
114  void *p = user_alloc(thr, pc, n * size);
115  if (p)
116    internal_memset(p, 0, n * size);
117  return p;
118}
119
120void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
121  if (ctx && ctx->initialized)
122    OnUserFree(thr, pc, (uptr)p, true);
123  allocator()->Deallocate(&thr->alloc_cache, p);
124  if (signal)
125    SignalUnsafeCall(thr, pc);
126}
127
128void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
129  DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
130  ctx->metamap.AllocBlock(thr, pc, p, sz);
131  if (write && thr->ignore_reads_and_writes == 0)
132    MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
133  else
134    MemoryResetRange(thr, pc, (uptr)p, sz);
135}
136
137void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
138  CHECK_NE(p, (void*)0);
139  uptr sz = ctx->metamap.FreeBlock(thr, pc, p);
140  DPrintf("#%d: free(%p, %zu)\n", thr->tid, p, sz);
141  if (write && thr->ignore_reads_and_writes == 0)
142    MemoryRangeFreed(thr, pc, (uptr)p, sz);
143}
144
145void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
146  void *p2 = 0;
147  // FIXME: Handle "shrinking" more efficiently,
148  // it seems that some software actually does this.
149  if (sz) {
150    p2 = user_alloc(thr, pc, sz);
151    if (p2 == 0)
152      return 0;
153    if (p) {
154      uptr oldsz = user_alloc_usable_size(p);
155      internal_memcpy(p2, p, min(oldsz, sz));
156    }
157  }
158  if (p)
159    user_free(thr, pc, p);
160  return p2;
161}
162
163uptr user_alloc_usable_size(const void *p) {
164  if (p == 0)
165    return 0;
166  MBlock *b = ctx->metamap.GetBlock((uptr)p);
167  return b ? b->siz : 0;
168}
169
170void invoke_malloc_hook(void *ptr, uptr size) {
171  ThreadState *thr = cur_thread();
172  if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
173    return;
174  __sanitizer_malloc_hook(ptr, size);
175}
176
177void invoke_free_hook(void *ptr) {
178  ThreadState *thr = cur_thread();
179  if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
180    return;
181  __sanitizer_free_hook(ptr);
182}
183
184void *internal_alloc(MBlockType typ, uptr sz) {
185  ThreadState *thr = cur_thread();
186  if (thr->nomalloc) {
187    thr->nomalloc = 0;  // CHECK calls internal_malloc().
188    CHECK(0);
189  }
190  return InternalAlloc(sz, &thr->internal_alloc_cache);
191}
192
193void internal_free(void *p) {
194  ThreadState *thr = cur_thread();
195  if (thr->nomalloc) {
196    thr->nomalloc = 0;  // CHECK calls internal_malloc().
197    CHECK(0);
198  }
199  InternalFree(p, &thr->internal_alloc_cache);
200}
201
202}  // namespace __tsan
203
204using namespace __tsan;
205
206extern "C" {
207uptr __sanitizer_get_current_allocated_bytes() {
208  uptr stats[AllocatorStatCount];
209  allocator()->GetStats(stats);
210  return stats[AllocatorStatAllocated];
211}
212
213uptr __sanitizer_get_heap_size() {
214  uptr stats[AllocatorStatCount];
215  allocator()->GetStats(stats);
216  return stats[AllocatorStatMapped];
217}
218
219uptr __sanitizer_get_free_bytes() {
220  return 1;
221}
222
223uptr __sanitizer_get_unmapped_bytes() {
224  return 1;
225}
226
227uptr __sanitizer_get_estimated_allocated_size(uptr size) {
228  return size;
229}
230
231int __sanitizer_get_ownership(const void *p) {
232  return allocator()->GetBlockBegin(p) != 0;
233}
234
235uptr __sanitizer_get_allocated_size(const void *p) {
236  return user_alloc_usable_size(p);
237}
238
239void __tsan_on_thread_idle() {
240  ThreadState *thr = cur_thread();
241  allocator()->SwallowCache(&thr->alloc_cache);
242  internal_allocator()->SwallowCache(&thr->internal_alloc_cache);
243  ctx->metamap.OnThreadIdle(thr);
244}
245}  // extern "C"
246