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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.
22 SANITIZER_WEAK_DEFAULT_IMPL
__sanitizer_malloc_hook(void * ptr,uptr size)23 void __sanitizer_malloc_hook(void *ptr, uptr size) {
24   (void)ptr;
25   (void)size;
26 }
27 
28 SANITIZER_WEAK_DEFAULT_IMPL
__sanitizer_free_hook(void * ptr)29 void __sanitizer_free_hook(void *ptr) {
30   (void)ptr;
31 }
32 
33 namespace __tsan {
34 
35 struct MapUnmapCallback {
OnMap__tsan::MapUnmapCallback36   void OnMap(uptr p, uptr size) const { }
OnUnmap__tsan::MapUnmapCallback37   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 
61 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
allocator()62 Allocator *allocator() {
63   return reinterpret_cast<Allocator*>(&allocator_placeholder);
64 }
65 
66 struct GlobalProc {
67   Mutex mtx;
68   Processor *proc;
69 
GlobalProc__tsan::GlobalProc70   GlobalProc()
71       : mtx(MutexTypeGlobalProc, StatMtxGlobalProc)
72       , proc(ProcCreate()) {
73   }
74 };
75 
76 static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
global_proc()77 GlobalProc *global_proc() {
78   return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
79 }
80 
ScopedGlobalProcessor()81 ScopedGlobalProcessor::ScopedGlobalProcessor() {
82   GlobalProc *gp = global_proc();
83   ThreadState *thr = cur_thread();
84   if (thr->proc())
85     return;
86   // If we don't have a proc, use the global one.
87   // There are currently only two known case where this path is triggered:
88   //   __interceptor_free
89   //   __nptl_deallocate_tsd
90   //   start_thread
91   //   clone
92   // and:
93   //   ResetRange
94   //   __interceptor_munmap
95   //   __deallocate_stack
96   //   start_thread
97   //   clone
98   // Ideally, we destroy thread state (and unwire proc) when a thread actually
99   // exits (i.e. when we join/wait it). Then we would not need the global proc
100   gp->mtx.Lock();
101   ProcWire(gp->proc, thr);
102 }
103 
~ScopedGlobalProcessor()104 ScopedGlobalProcessor::~ScopedGlobalProcessor() {
105   GlobalProc *gp = global_proc();
106   ThreadState *thr = cur_thread();
107   if (thr->proc() != gp->proc)
108     return;
109   ProcUnwire(gp->proc, thr);
110   gp->mtx.Unlock();
111 }
112 
InitializeAllocator()113 void InitializeAllocator() {
114   allocator()->Init(common_flags()->allocator_may_return_null);
115 }
116 
InitializeAllocatorLate()117 void InitializeAllocatorLate() {
118   new(global_proc()) GlobalProc();
119 }
120 
AllocatorProcStart(Processor * proc)121 void AllocatorProcStart(Processor *proc) {
122   allocator()->InitCache(&proc->alloc_cache);
123   internal_allocator()->InitCache(&proc->internal_alloc_cache);
124 }
125 
AllocatorProcFinish(Processor * proc)126 void AllocatorProcFinish(Processor *proc) {
127   allocator()->DestroyCache(&proc->alloc_cache);
128   internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
129 }
130 
AllocatorPrintStats()131 void AllocatorPrintStats() {
132   allocator()->PrintStats();
133 }
134 
SignalUnsafeCall(ThreadState * thr,uptr pc)135 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
136   if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
137       !flags()->report_signal_unsafe)
138     return;
139   VarSizeStackTrace stack;
140   ObtainCurrentStack(thr, pc, &stack);
141   if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
142     return;
143   ThreadRegistryLock l(ctx->thread_registry);
144   ScopedReport rep(ReportTypeSignalUnsafe);
145   rep.AddStack(stack, true);
146   OutputReport(thr, rep);
147 }
148 
user_alloc(ThreadState * thr,uptr pc,uptr sz,uptr align,bool signal)149 void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align, bool signal) {
150   if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
151     return allocator()->ReturnNullOrDie();
152   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
153   if (p == 0)
154     return 0;
155   if (ctx && ctx->initialized)
156     OnUserAlloc(thr, pc, (uptr)p, sz, true);
157   if (signal)
158     SignalUnsafeCall(thr, pc);
159   return p;
160 }
161 
user_calloc(ThreadState * thr,uptr pc,uptr size,uptr n)162 void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
163   if (CallocShouldReturnNullDueToOverflow(size, n))
164     return allocator()->ReturnNullOrDie();
165   void *p = user_alloc(thr, pc, n * size);
166   if (p)
167     internal_memset(p, 0, n * size);
168   return p;
169 }
170 
user_free(ThreadState * thr,uptr pc,void * p,bool signal)171 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
172   ScopedGlobalProcessor sgp;
173   if (ctx && ctx->initialized)
174     OnUserFree(thr, pc, (uptr)p, true);
175   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
176   if (signal)
177     SignalUnsafeCall(thr, pc);
178 }
179 
OnUserAlloc(ThreadState * thr,uptr pc,uptr p,uptr sz,bool write)180 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
181   DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
182   ctx->metamap.AllocBlock(thr, pc, p, sz);
183   if (write && thr->ignore_reads_and_writes == 0)
184     MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
185   else
186     MemoryResetRange(thr, pc, (uptr)p, sz);
187 }
188 
OnUserFree(ThreadState * thr,uptr pc,uptr p,bool write)189 void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
190   CHECK_NE(p, (void*)0);
191   uptr sz = ctx->metamap.FreeBlock(thr->proc(), p);
192   DPrintf("#%d: free(%p, %zu)\n", thr->tid, p, sz);
193   if (write && thr->ignore_reads_and_writes == 0)
194     MemoryRangeFreed(thr, pc, (uptr)p, sz);
195 }
196 
user_realloc(ThreadState * thr,uptr pc,void * p,uptr sz)197 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
198   void *p2 = 0;
199   // FIXME: Handle "shrinking" more efficiently,
200   // it seems that some software actually does this.
201   if (sz) {
202     p2 = user_alloc(thr, pc, sz);
203     if (p2 == 0)
204       return 0;
205     if (p) {
206       uptr oldsz = user_alloc_usable_size(p);
207       internal_memcpy(p2, p, min(oldsz, sz));
208     }
209   }
210   if (p)
211     user_free(thr, pc, p);
212   return p2;
213 }
214 
user_alloc_usable_size(const void * p)215 uptr user_alloc_usable_size(const void *p) {
216   if (p == 0)
217     return 0;
218   MBlock *b = ctx->metamap.GetBlock((uptr)p);
219   if (!b)
220     return 0;  // Not a valid pointer.
221   if (b->siz == 0)
222     return 1;  // Zero-sized allocations are actually 1 byte.
223   return b->siz;
224 }
225 
invoke_malloc_hook(void * ptr,uptr size)226 void invoke_malloc_hook(void *ptr, uptr size) {
227   ThreadState *thr = cur_thread();
228   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
229     return;
230   __sanitizer_malloc_hook(ptr, size);
231   RunMallocHooks(ptr, size);
232 }
233 
invoke_free_hook(void * ptr)234 void invoke_free_hook(void *ptr) {
235   ThreadState *thr = cur_thread();
236   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
237     return;
238   __sanitizer_free_hook(ptr);
239   RunFreeHooks(ptr);
240 }
241 
internal_alloc(MBlockType typ,uptr sz)242 void *internal_alloc(MBlockType typ, uptr sz) {
243   ThreadState *thr = cur_thread();
244   if (thr->nomalloc) {
245     thr->nomalloc = 0;  // CHECK calls internal_malloc().
246     CHECK(0);
247   }
248   return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
249 }
250 
internal_free(void * p)251 void internal_free(void *p) {
252   ThreadState *thr = cur_thread();
253   if (thr->nomalloc) {
254     thr->nomalloc = 0;  // CHECK calls internal_malloc().
255     CHECK(0);
256   }
257   InternalFree(p, &thr->proc()->internal_alloc_cache);
258 }
259 
260 }  // namespace __tsan
261 
262 using namespace __tsan;
263 
264 extern "C" {
__sanitizer_get_current_allocated_bytes()265 uptr __sanitizer_get_current_allocated_bytes() {
266   uptr stats[AllocatorStatCount];
267   allocator()->GetStats(stats);
268   return stats[AllocatorStatAllocated];
269 }
270 
__sanitizer_get_heap_size()271 uptr __sanitizer_get_heap_size() {
272   uptr stats[AllocatorStatCount];
273   allocator()->GetStats(stats);
274   return stats[AllocatorStatMapped];
275 }
276 
__sanitizer_get_free_bytes()277 uptr __sanitizer_get_free_bytes() {
278   return 1;
279 }
280 
__sanitizer_get_unmapped_bytes()281 uptr __sanitizer_get_unmapped_bytes() {
282   return 1;
283 }
284 
__sanitizer_get_estimated_allocated_size(uptr size)285 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
286   return size;
287 }
288 
__sanitizer_get_ownership(const void * p)289 int __sanitizer_get_ownership(const void *p) {
290   return allocator()->GetBlockBegin(p) != 0;
291 }
292 
__sanitizer_get_allocated_size(const void * p)293 uptr __sanitizer_get_allocated_size(const void *p) {
294   return user_alloc_usable_size(p);
295 }
296 
__tsan_on_thread_idle()297 void __tsan_on_thread_idle() {
298   ThreadState *thr = cur_thread();
299   allocator()->SwallowCache(&thr->proc()->alloc_cache);
300   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
301   ctx->metamap.OnProcIdle(thr->proc());
302 }
303 }  // extern "C"
304