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 (GetCurrentThreadId() == kInvalidTid) { 71 u32 tid = ThreadCreate(parent_tid, true); 72 ThreadStart(tid, GetTid()); 73 } 74 } 75 76 // For use by only those functions that allocated the context via 77 // alloc_lsan_context(). 78 extern "C" void lsan_dispatch_call_block_and_release(void *block) { 79 lsan_block_context_t *context = (lsan_block_context_t *)block; 80 VReport(2, 81 "lsan_dispatch_call_block_and_release(): " 82 "context: %p, pthread_self: %p\n", 83 block, (void*)pthread_self()); 84 lsan_register_worker_thread(context->parent_tid); 85 // Call the original dispatcher for the block. 86 context->func(context->block); 87 lsan_free(context); 88 } 89 90 } // namespace __lsan 91 92 using namespace __lsan; 93 94 // Wrap |ctxt| and |func| into an lsan_block_context_t. 95 // The caller retains control of the allocated context. 96 extern "C" lsan_block_context_t *alloc_lsan_context(void *ctxt, 97 dispatch_function_t func) { 98 GET_STACK_TRACE_THREAD; 99 lsan_block_context_t *lsan_ctxt = 100 (lsan_block_context_t *)lsan_malloc(sizeof(lsan_block_context_t), stack); 101 lsan_ctxt->block = ctxt; 102 lsan_ctxt->func = func; 103 lsan_ctxt->parent_tid = GetCurrentThreadId(); 104 return lsan_ctxt; 105 } 106 107 // Define interceptor for dispatch_*_f function with the three most common 108 // parameters: dispatch_queue_t, context, dispatch_function_t. 109 #define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f) \ 110 INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt, \ 111 dispatch_function_t func) { \ 112 lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func); \ 113 return REAL(dispatch_x_f)(dq, (void *)lsan_ctxt, \ 114 lsan_dispatch_call_block_and_release); \ 115 } 116 117 INTERCEPT_DISPATCH_X_F_3(dispatch_async_f) 118 INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f) 119 INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f) 120 121 INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, dispatch_queue_t dq, 122 void *ctxt, dispatch_function_t func) { 123 lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func); 124 return REAL(dispatch_after_f)(when, dq, (void *)lsan_ctxt, 125 lsan_dispatch_call_block_and_release); 126 } 127 128 INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group, 129 dispatch_queue_t dq, void *ctxt, dispatch_function_t func) { 130 lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func); 131 REAL(dispatch_group_async_f) 132 (group, dq, (void *)lsan_ctxt, lsan_dispatch_call_block_and_release); 133 } 134 135 #if !defined(MISSING_BLOCKS_SUPPORT) 136 extern "C" { 137 void dispatch_async(dispatch_queue_t dq, void (^work)(void)); 138 void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq, 139 void (^work)(void)); 140 void dispatch_after(dispatch_time_t when, dispatch_queue_t queue, 141 void (^work)(void)); 142 void dispatch_source_set_cancel_handler(dispatch_source_t ds, 143 void (^work)(void)); 144 void dispatch_source_set_event_handler(dispatch_source_t ds, 145 void (^work)(void)); 146 } 147 148 # define GET_LSAN_BLOCK(work) \ 149 void (^lsan_block)(void); \ 150 int parent_tid = GetCurrentThreadId(); \ 151 lsan_block = ^(void) { \ 152 lsan_register_worker_thread(parent_tid); \ 153 work(); \ 154 } 155 156 INTERCEPTOR(void, dispatch_async, dispatch_queue_t dq, void (^work)(void)) { 157 GET_LSAN_BLOCK(work); 158 REAL(dispatch_async)(dq, lsan_block); 159 } 160 161 INTERCEPTOR(void, dispatch_group_async, dispatch_group_t dg, 162 dispatch_queue_t dq, void (^work)(void)) { 163 GET_LSAN_BLOCK(work); 164 REAL(dispatch_group_async)(dg, dq, lsan_block); 165 } 166 167 INTERCEPTOR(void, dispatch_after, dispatch_time_t when, dispatch_queue_t queue, 168 void (^work)(void)) { 169 GET_LSAN_BLOCK(work); 170 REAL(dispatch_after)(when, queue, lsan_block); 171 } 172 173 INTERCEPTOR(void, dispatch_source_set_cancel_handler, dispatch_source_t ds, 174 void (^work)(void)) { 175 if (!work) { 176 REAL(dispatch_source_set_cancel_handler)(ds, work); 177 return; 178 } 179 GET_LSAN_BLOCK(work); 180 REAL(dispatch_source_set_cancel_handler)(ds, lsan_block); 181 } 182 183 INTERCEPTOR(void, dispatch_source_set_event_handler, dispatch_source_t ds, 184 void (^work)(void)) { 185 GET_LSAN_BLOCK(work); 186 REAL(dispatch_source_set_event_handler)(ds, lsan_block); 187 } 188 #endif 189 190 #endif // SANITIZER_APPLE 191