libsanitizer/lsan/lsan_mac.cpp

   1 //===-- lsan_mac.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 LeakSanitizer, a memory leak checker.
  10 //
  11 // Mac-specific details.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_common/sanitizer_platform.h"
  15 #if SANITIZER_APPLE
  16
  17 #include "interception/interception.h"
  18 #include "lsan.h"
  19 #include "lsan_allocator.h"
  20 #include "lsan_thread.h"
  21
  22 #include <pthread.h>
  23
  24 namespace __lsan {
  25 // Support for the following functions from libdispatch on Mac OS:
  26 //   dispatch_async_f()
  27 //   dispatch_async()
  28 //   dispatch_sync_f()
  29 //   dispatch_sync()
  30 //   dispatch_after_f()
  31 //   dispatch_after()
  32 //   dispatch_group_async_f()
  33 //   dispatch_group_async()
  34 // TODO(glider): libdispatch API contains other functions that we don't support
  35 // yet.
  36 //
  37 // dispatch_sync() and dispatch_sync_f() are synchronous, although chances are
  38 // they can cause jobs to run on a thread different from the current one.
  39 // TODO(glider): if so, we need a test for this (otherwise we should remove
  40 // them).
  41 //
  42 // The following functions use dispatch_barrier_async_f() (which isn't a library
  43 // function but is exported) and are thus supported:
  44 //   dispatch_source_set_cancel_handler_f()
  45 //   dispatch_source_set_cancel_handler()
  46 //   dispatch_source_set_event_handler_f()
  47 //   dispatch_source_set_event_handler()
  48 //
  49 // The reference manual for Grand Central Dispatch is available at
  50 //   http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html
  51 // The implementation details are at
  52 //   http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c
  53
  54 typedef void *dispatch_group_t;
  55 typedef void *dispatch_queue_t;
  56 typedef void *dispatch_source_t;
  57 typedef u64 dispatch_time_t;
  58 typedef void (*dispatch_function_t)(void *block);
  59 typedef void *(*worker_t)(void *block);
  60
  61 // A wrapper for the ObjC blocks used to support libdispatch.
  62 typedef struct {
  63   void *block;
  64   dispatch_function_t func;
  65   u32 parent_tid;
  66 } lsan_block_context_t;
  67
  68 ALWAYS_INLINE
  69 void lsan_register_worker_thread(int parent_tid) {
  70   if (GetCurrentThread() == kInvalidTid) {
  71     u32 tid = ThreadCreate(parent_tid, true);
  72     ThreadStart(tid, GetTid());
  73     SetCurrentThread(tid);
  74   }
  75 }
  76
  77 // For use by only those functions that allocated the context via
  78 // alloc_lsan_context().
  79 extern "C" void lsan_dispatch_call_block_and_release(void *block) {
  80   lsan_block_context_t *context = (lsan_block_context_t *)block;
  81   VReport(2,
  82           "lsan_dispatch_call_block_and_release(): "
  83           "context: %p, pthread_self: %p\n",
  84           block, pthread_self());
  85   lsan_register_worker_thread(context->parent_tid);
  86   // Call the original dispatcher for the block.
  87   context->func(context->block);
  88   lsan_free(context);
  89 }
  90
  91 }  // namespace __lsan
  92
  93 using namespace __lsan;
  94
  95 // Wrap |ctxt| and |func| into an lsan_block_context_t.
  96 // The caller retains control of the allocated context.
  97 extern "C" lsan_block_context_t *alloc_lsan_context(void *ctxt,
  98                                                     dispatch_function_t func) {
  99   GET_STACK_TRACE_THREAD;
 100   lsan_block_context_t *lsan_ctxt =
 101       (lsan_block_context_t *)lsan_malloc(sizeof(lsan_block_context_t), stack);
 102   lsan_ctxt->block = ctxt;
 103   lsan_ctxt->func = func;
 104   lsan_ctxt->parent_tid = GetCurrentThread();
 105   return lsan_ctxt;
 106 }
 107
 108 // Define interceptor for dispatch_*_f function with the three most common
 109 // parameters: dispatch_queue_t, context, dispatch_function_t.
 110 #define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f)                        \
 111   INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt,    \
 112               dispatch_function_t func) {                             \
 113     lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func); \
 114     return REAL(dispatch_x_f)(dq, (void *)lsan_ctxt,                  \
 115                               lsan_dispatch_call_block_and_release);  \
 116   }
 117
 118 INTERCEPT_DISPATCH_X_F_3(dispatch_async_f)
 119 INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f)
 120 INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f)
 121
 122 INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, dispatch_queue_t dq,
 123             void *ctxt, dispatch_function_t func) {
 124   lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func);
 125   return REAL(dispatch_after_f)(when, dq, (void *)lsan_ctxt,
 126                                 lsan_dispatch_call_block_and_release);
 127 }
 128
 129 INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
 130             dispatch_queue_t dq, void *ctxt, dispatch_function_t func) {
 131   lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func);
 132   REAL(dispatch_group_async_f)
 133   (group, dq, (void *)lsan_ctxt, lsan_dispatch_call_block_and_release);
 134 }
 135
 136 #if !defined(MISSING_BLOCKS_SUPPORT)
 137 extern "C" {
 138 void dispatch_async(dispatch_queue_t dq, void (^work)(void));
 139 void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,
 140                           void (^work)(void));
 141 void dispatch_after(dispatch_time_t when, dispatch_queue_t queue,
 142                     void (^work)(void));
 143 void dispatch_source_set_cancel_handler(dispatch_source_t ds,
 144                                         void (^work)(void));
 145 void dispatch_source_set_event_handler(dispatch_source_t ds,
 146                                        void (^work)(void));
 147 }
 148
 149 #define GET_LSAN_BLOCK(work)                 \
 150   void (^lsan_block)(void);                  \
 151   int parent_tid = GetCurrentThread();       \
 152   lsan_block = ^(void) {                     \
 153     lsan_register_worker_thread(parent_tid); \
 154     work();                                  \
 155   }
 156
 157 INTERCEPTOR(void, dispatch_async, dispatch_queue_t dq, void (^work)(void)) {
 158   GET_LSAN_BLOCK(work);
 159   REAL(dispatch_async)(dq, lsan_block);
 160 }
 161
 162 INTERCEPTOR(void, dispatch_group_async, dispatch_group_t dg,
 163             dispatch_queue_t dq, void (^work)(void)) {
 164   GET_LSAN_BLOCK(work);
 165   REAL(dispatch_group_async)(dg, dq, lsan_block);
 166 }
 167
 168 INTERCEPTOR(void, dispatch_after, dispatch_time_t when, dispatch_queue_t queue,
 169             void (^work)(void)) {
 170   GET_LSAN_BLOCK(work);
 171   REAL(dispatch_after)(when, queue, lsan_block);
 172 }
 173
 174 INTERCEPTOR(void, dispatch_source_set_cancel_handler, dispatch_source_t ds,
 175             void (^work)(void)) {
 176   if (!work) {
 177     REAL(dispatch_source_set_cancel_handler)(ds, work);
 178     return;
 179   }
 180   GET_LSAN_BLOCK(work);
 181   REAL(dispatch_source_set_cancel_handler)(ds, lsan_block);
 182 }
 183
 184 INTERCEPTOR(void, dispatch_source_set_event_handler, dispatch_source_t ds,
 185             void (^work)(void)) {
 186   GET_LSAN_BLOCK(work);
 187   REAL(dispatch_source_set_event_handler)(ds, lsan_block);
 188 }
 189 #endif
 190
 191 #endif  // SANITIZER_APPLE