380 lines · cpp
1//===-- asan_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-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of AddressSanitizer, an address sanity checker.10//11// Mac-specific details.12//===----------------------------------------------------------------------===//13 14#include "sanitizer_common/sanitizer_platform.h"15#if SANITIZER_APPLE16 17#include "asan_interceptors.h"18#include "asan_internal.h"19#include "asan_mapping.h"20#include "asan_stack.h"21#include "asan_thread.h"22#include "sanitizer_common/sanitizer_atomic.h"23#include "sanitizer_common/sanitizer_libc.h"24#include "sanitizer_common/sanitizer_mac.h"25 26#include <dlfcn.h>27#include <fcntl.h>28#include <libkern/OSAtomic.h>29#include <mach-o/dyld.h>30#include <mach-o/getsect.h>31#include <mach-o/loader.h>32#include <pthread.h>33#include <stdlib.h> // for free()34#include <sys/mman.h>35#include <sys/resource.h>36#include <sys/sysctl.h>37#include <sys/ucontext.h>38#include <unistd.h>39 40// from <crt_externs.h>, but we don't have that file on iOS41extern "C" {42 extern char ***_NSGetArgv(void);43 extern char ***_NSGetEnviron(void);44}45 46namespace __asan {47 48void InitializePlatformInterceptors() {}49void InitializePlatformExceptionHandlers() {}50bool IsSystemHeapAddress (uptr addr) { return false; }51 52uptr FindDynamicShadowStart() {53 return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,54 /*min_shadow_base_alignment*/ 0, kHighMemEnd,55 GetMmapGranularity());56}57 58// Not used.59void TryReExecWithoutASLR() {}60 61// No-op. Mac does not support static linkage anyway.62void AsanCheckDynamicRTPrereqs() {}63 64// No-op. Mac does not support static linkage anyway.65void AsanCheckIncompatibleRT() {}66 67void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {68 // Find the Mach-O header for the image containing the needle69 Dl_info info;70 int err = dladdr(needle, &info);71 if (err == 0) return;72 73#if __LP64__74 const struct mach_header_64 *mh = (struct mach_header_64 *)info.dli_fbase;75#else76 const struct mach_header *mh = (struct mach_header *)info.dli_fbase;77#endif78 79 // Look up the __asan_globals section in that image and register its globals80 unsigned long size = 0;81 __asan_global *globals = (__asan_global *)getsectiondata(82 mh,83 "__DATA", "__asan_globals",84 &size);85 86 if (!globals) return;87 if (size % sizeof(__asan_global) != 0) return;88 op(globals, size / sizeof(__asan_global));89}90 91void FlushUnneededASanShadowMemory(uptr p, uptr size) {92 // Since asan's mapping is compacting, the shadow chunk may be93 // not page-aligned, so we only flush the page-aligned portion.94 ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));95}96 97// Support for the following functions from libdispatch on Mac OS:98// dispatch_async_f()99// dispatch_async()100// dispatch_sync_f()101// dispatch_sync()102// dispatch_after_f()103// dispatch_after()104// dispatch_group_async_f()105// dispatch_group_async()106// dispatch_apply()107// dispatch_apply_f()108// TODO(glider): libdispatch API contains other functions that we don't support109// yet.110//111// dispatch_sync() and dispatch_sync_f() are synchronous, although chances are112// they can cause jobs to run on a thread different from the current one.113// TODO(glider): if so, we need a test for this (otherwise we should remove114// them).115//116// The following functions use dispatch_barrier_async_f() (which isn't a library117// function but is exported) and are thus supported:118// dispatch_source_set_cancel_handler_f()119// dispatch_source_set_cancel_handler()120// dispatch_source_set_event_handler_f()121// dispatch_source_set_event_handler()122//123// The reference manual for Grand Central Dispatch is available at124// http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html125// The implementation details are at126// http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c127 128typedef void* dispatch_group_t;129typedef void* dispatch_queue_t;130typedef void* dispatch_source_t;131typedef u64 dispatch_time_t;132typedef void (*dispatch_function_t)(void *block);133typedef void (*dispatch_apply_function_t)(void *, size_t);134typedef void* (*worker_t)(void *block);135typedef unsigned long dispatch_mach_reason;136typedef void *dispatch_mach_msg_t;137typedef int mach_error_t;138typedef void *dispatch_mach_t;139 140typedef void (*dispatch_mach_handler_function_t)(void *context,141 dispatch_mach_reason reason,142 dispatch_mach_msg_t message,143 mach_error_t error);144# if !defined(MISSING_BLOCKS_SUPPORT)145typedef void (^dispatch_mach_handler_t)(dispatch_mach_reason reason,146 dispatch_mach_msg_t message,147 mach_error_t error);148# endif149 150// A wrapper for the ObjC blocks used to support libdispatch.151typedef struct {152 void *block;153 union {154 dispatch_function_t dispatch_func;155 dispatch_apply_function_t dispatch_apply_func;156 static_assert(sizeof(dispatch_func) == sizeof(dispatch_apply_func));157 };158 u32 parent_tid;159} asan_block_context_t;160 161ALWAYS_INLINE162void asan_register_worker_thread(int parent_tid, StackTrace *stack) {163 AsanThread *t = GetCurrentThread();164 if (!t) {165 t = AsanThread::Create(parent_tid, stack, /* detached */ true);166 t->Init();167 asanThreadRegistry().StartThread(t->tid(), GetTid(), ThreadType::Worker,168 nullptr);169 SetCurrentThread(t);170 }171}172 173// For use by only those functions that allocated the context via174// alloc_asan_context().175extern "C"176void asan_dispatch_call_block_and_release(void *block) {177 GET_STACK_TRACE_THREAD;178 asan_block_context_t *context = (asan_block_context_t*)block;179 VReport(2,180 "asan_dispatch_call_block_and_release(): "181 "context: %p, pthread_self: %p\n",182 block, (void*)pthread_self());183 asan_register_worker_thread(context->parent_tid, &stack);184 // Call the original dispatcher for the block.185 context->dispatch_func(context->block);186 asan_free(context, &stack);187}188 189} // namespace __asan190 191using namespace __asan;192 193// Wrap |ctxt| and |func| into an asan_block_context_t.194// The caller retains control of the allocated context.195extern "C"196asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func,197 BufferedStackTrace *stack) {198 asan_block_context_t *asan_ctxt =199 (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack);200 asan_ctxt->block = ctxt;201 asan_ctxt->dispatch_func = func;202 asan_ctxt->parent_tid = GetCurrentTidOrInvalid();203 return asan_ctxt;204}205 206// Define interceptor for dispatch_*_f function with the three most common207// parameters: dispatch_queue_t, context, dispatch_function_t.208#define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f) \209 INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt, \210 dispatch_function_t func) { \211 GET_STACK_TRACE_THREAD; \212 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \213 if (Verbosity() >= 2) { \214 Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n", \215 (void*)asan_ctxt, (void*)pthread_self()); \216 PRINT_CURRENT_STACK(); \217 } \218 return REAL(dispatch_x_f)(dq, (void*)asan_ctxt, \219 asan_dispatch_call_block_and_release); \220 }221 222INTERCEPT_DISPATCH_X_F_3(dispatch_async_f)223INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f)224INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f)225 226INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when,227 dispatch_queue_t dq, void *ctxt,228 dispatch_function_t func) {229 GET_STACK_TRACE_THREAD;230 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);231 if (Verbosity() >= 2) {232 Report("dispatch_after_f: %p\n", (void*)asan_ctxt);233 PRINT_CURRENT_STACK();234 }235 return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt,236 asan_dispatch_call_block_and_release);237}238 239INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,240 dispatch_queue_t dq, void *ctxt,241 dispatch_function_t func) {242 GET_STACK_TRACE_THREAD;243 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);244 if (Verbosity() >= 2) {245 Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n",246 (void*)asan_ctxt, (void*)pthread_self());247 PRINT_CURRENT_STACK();248 }249 REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt,250 asan_dispatch_call_block_and_release);251}252 253extern "C" void asan_dispatch_apply_f_work(void *context, size_t iteration) {254 GET_STACK_TRACE_THREAD;255 asan_block_context_t *asan_ctxt = (asan_block_context_t *)context;256 asan_register_worker_thread(asan_ctxt->parent_tid, &stack);257 asan_ctxt->dispatch_apply_func(asan_ctxt->block, iteration);258}259 260INTERCEPTOR(void, dispatch_apply_f, size_t iterations, dispatch_queue_t queue,261 void *ctxt, dispatch_apply_function_t work) {262 GET_STACK_TRACE_THREAD;263 asan_block_context_t *asan_ctxt =264 (asan_block_context_t *)asan_malloc(sizeof(asan_block_context_t), &stack);265 asan_ctxt->block = ctxt;266 asan_ctxt->dispatch_apply_func = work;267 asan_ctxt->parent_tid = GetCurrentTidOrInvalid();268 REAL(dispatch_apply_f)(iterations, queue, (void *)asan_ctxt,269 asan_dispatch_apply_f_work);270}271 272# if !defined(MISSING_BLOCKS_SUPPORT)273extern "C" {274void dispatch_async(dispatch_queue_t dq, void(^work)(void));275void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,276 void(^work)(void));277void dispatch_after(dispatch_time_t when, dispatch_queue_t queue,278 void(^work)(void));279void dispatch_apply(size_t iterations, dispatch_queue_t queue,280 void (^block)(size_t iteration));281void dispatch_source_set_cancel_handler(dispatch_source_t ds,282 void(^work)(void));283void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void));284dispatch_mach_t dispatch_mach_create(const char *label, dispatch_queue_t queue,285 dispatch_mach_handler_t handler);286}287 288#define GET_ASAN_BLOCK(work) \289 void (^asan_block)(void); \290 int parent_tid = GetCurrentTidOrInvalid(); \291 asan_block = ^(void) { \292 GET_STACK_TRACE_THREAD; \293 asan_register_worker_thread(parent_tid, &stack); \294 work(); \295 }296 297INTERCEPTOR(void, dispatch_async,298 dispatch_queue_t dq, void(^work)(void)) {299 ENABLE_FRAME_POINTER;300 GET_ASAN_BLOCK(work);301 REAL(dispatch_async)(dq, asan_block);302}303 304INTERCEPTOR(void, dispatch_group_async,305 dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) {306 ENABLE_FRAME_POINTER;307 GET_ASAN_BLOCK(work);308 REAL(dispatch_group_async)(dg, dq, asan_block);309}310 311INTERCEPTOR(void, dispatch_after,312 dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) {313 ENABLE_FRAME_POINTER;314 GET_ASAN_BLOCK(work);315 REAL(dispatch_after)(when, queue, asan_block);316}317 318INTERCEPTOR(void, dispatch_source_set_cancel_handler,319 dispatch_source_t ds, void(^work)(void)) {320 if (!work) {321 REAL(dispatch_source_set_cancel_handler)(ds, work);322 return;323 }324 ENABLE_FRAME_POINTER;325 GET_ASAN_BLOCK(work);326 REAL(dispatch_source_set_cancel_handler)(ds, asan_block);327}328 329INTERCEPTOR(void, dispatch_source_set_event_handler,330 dispatch_source_t ds, void(^work)(void)) {331 ENABLE_FRAME_POINTER;332 GET_ASAN_BLOCK(work);333 REAL(dispatch_source_set_event_handler)(ds, asan_block);334}335 336INTERCEPTOR(void *, dispatch_mach_create, const char *label,337 dispatch_queue_t dq, dispatch_mach_handler_t handler) {338 int parent_tid = GetCurrentTidOrInvalid();339 return REAL(dispatch_mach_create)(340 label, dq,341 ^(dispatch_mach_reason reason, dispatch_mach_msg_t message,342 mach_error_t error) {343 GET_STACK_TRACE_THREAD;344 asan_register_worker_thread(parent_tid, &stack);345 handler(reason, message, error);346 });347}348 349INTERCEPTOR(void *, dispatch_mach_create_f, const char *label,350 dispatch_queue_t dq, void *ctxt,351 dispatch_mach_handler_function_t handler) {352 int parent_tid = GetCurrentTidOrInvalid();353 return REAL(dispatch_mach_create)(354 label, dq,355 ^(dispatch_mach_reason reason, dispatch_mach_msg_t message,356 mach_error_t error) {357 GET_STACK_TRACE_THREAD;358 asan_register_worker_thread(parent_tid, &stack);359 handler(ctxt, reason, message, error);360 });361}362 363INTERCEPTOR(void, dispatch_apply, size_t iterations, dispatch_queue_t queue,364 void (^block)(size_t iteration)) {365 ENABLE_FRAME_POINTER;366 int parent_tid = GetCurrentTidOrInvalid();367 368 void (^asan_block)(size_t) = ^(size_t iteration) {369 GET_STACK_TRACE_THREAD;370 asan_register_worker_thread(parent_tid, &stack);371 block(iteration);372 };373 374 REAL(dispatch_apply)(iterations, queue, asan_block);375}376 377# endif378 379#endif // SANITIZER_APPLE380