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Diffstat (limited to 'lib/asan/asan_mac.cpp')
| -rw-r--r-- | lib/asan/asan_mac.cpp | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/lib/asan/asan_mac.cpp b/lib/asan/asan_mac.cpp new file mode 100644 index 000000000000..a8d3f5d3473c --- /dev/null +++ b/lib/asan/asan_mac.cpp @@ -0,0 +1,331 @@ +//===-- asan_mac.cpp ------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of AddressSanitizer, an address sanity checker. +// +// Mac-specific details. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_platform.h" +#if SANITIZER_MAC + +#include "asan_interceptors.h" +#include "asan_internal.h" +#include "asan_mapping.h" +#include "asan_stack.h" +#include "asan_thread.h" +#include "sanitizer_common/sanitizer_atomic.h" +#include "sanitizer_common/sanitizer_libc.h" +#include "sanitizer_common/sanitizer_mac.h" + +#include <dlfcn.h> +#include <fcntl.h> +#include <libkern/OSAtomic.h> +#include <mach-o/dyld.h> +#include <mach-o/getsect.h> +#include <mach-o/loader.h> +#include <pthread.h> +#include <stdlib.h> // for free() +#include <sys/mman.h> +#include <sys/resource.h> +#include <sys/sysctl.h> +#include <sys/ucontext.h> +#include <unistd.h> + +// from <crt_externs.h>, but we don't have that file on iOS +extern "C" { + extern char ***_NSGetArgv(void); + extern char ***_NSGetEnviron(void); +} + +namespace __asan { + +void InitializePlatformInterceptors() {} +void InitializePlatformExceptionHandlers() {} +bool IsSystemHeapAddress (uptr addr) { return false; } + +// No-op. Mac does not support static linkage anyway. +void *AsanDoesNotSupportStaticLinkage() { + return 0; +} + +uptr FindDynamicShadowStart() { + uptr granularity = GetMmapGranularity(); + uptr alignment = 8 * granularity; + uptr left_padding = granularity; + uptr space_size = kHighShadowEnd + left_padding; + + uptr largest_gap_found = 0; + uptr max_occupied_addr = 0; + VReport(2, "FindDynamicShadowStart, space_size = %p\n", space_size); + uptr shadow_start = + FindAvailableMemoryRange(space_size, alignment, granularity, + &largest_gap_found, &max_occupied_addr); + // If the shadow doesn't fit, restrict the address space to make it fit. + if (shadow_start == 0) { + VReport( + 2, + "Shadow doesn't fit, largest_gap_found = %p, max_occupied_addr = %p\n", + largest_gap_found, max_occupied_addr); + uptr new_max_vm = RoundDownTo(largest_gap_found << SHADOW_SCALE, alignment); + if (new_max_vm < max_occupied_addr) { + Report("Unable to find a memory range for dynamic shadow.\n"); + Report( + "space_size = %p, largest_gap_found = %p, max_occupied_addr = %p, " + "new_max_vm = %p\n", + space_size, largest_gap_found, max_occupied_addr, new_max_vm); + CHECK(0 && "cannot place shadow"); + } + RestrictMemoryToMaxAddress(new_max_vm); + kHighMemEnd = new_max_vm - 1; + space_size = kHighShadowEnd + left_padding; + VReport(2, "FindDynamicShadowStart, space_size = %p\n", space_size); + shadow_start = FindAvailableMemoryRange(space_size, alignment, granularity, + nullptr, nullptr); + if (shadow_start == 0) { + Report("Unable to find a memory range after restricting VM.\n"); + CHECK(0 && "cannot place shadow after restricting vm"); + } + } + CHECK_NE((uptr)0, shadow_start); + CHECK(IsAligned(shadow_start, alignment)); + return shadow_start; +} + +// No-op. Mac does not support static linkage anyway. +void AsanCheckDynamicRTPrereqs() {} + +// No-op. Mac does not support static linkage anyway. +void AsanCheckIncompatibleRT() {} + +void AsanApplyToGlobals(globals_op_fptr op, const void *needle) { + // Find the Mach-O header for the image containing the needle + Dl_info info; + int err = dladdr(needle, &info); + if (err == 0) return; + +#if __LP64__ + const struct mach_header_64 *mh = (struct mach_header_64 *)info.dli_fbase; +#else + const struct mach_header *mh = (struct mach_header *)info.dli_fbase; +#endif + + // Look up the __asan_globals section in that image and register its globals + unsigned long size = 0; + __asan_global *globals = (__asan_global *)getsectiondata( + mh, + "__DATA", "__asan_globals", + &size); + + if (!globals) return; + if (size % sizeof(__asan_global) != 0) return; + op(globals, size / sizeof(__asan_global)); +} + +void ReadContextStack(void *context, uptr *stack, uptr *ssize) { + UNIMPLEMENTED(); +} + +// Support for the following functions from libdispatch on Mac OS: +// dispatch_async_f() +// dispatch_async() +// dispatch_sync_f() +// dispatch_sync() +// dispatch_after_f() +// dispatch_after() +// dispatch_group_async_f() +// dispatch_group_async() +// TODO(glider): libdispatch API contains other functions that we don't support +// yet. +// +// dispatch_sync() and dispatch_sync_f() are synchronous, although chances are +// they can cause jobs to run on a thread different from the current one. +// TODO(glider): if so, we need a test for this (otherwise we should remove +// them). +// +// The following functions use dispatch_barrier_async_f() (which isn't a library +// function but is exported) and are thus supported: +// dispatch_source_set_cancel_handler_f() +// dispatch_source_set_cancel_handler() +// dispatch_source_set_event_handler_f() +// dispatch_source_set_event_handler() +// +// The reference manual for Grand Central Dispatch is available at +// http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html +// The implementation details are at +// http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c + +typedef void* dispatch_group_t; +typedef void* dispatch_queue_t; +typedef void* dispatch_source_t; +typedef u64 dispatch_time_t; +typedef void (*dispatch_function_t)(void *block); +typedef void* (*worker_t)(void *block); + +// A wrapper for the ObjC blocks used to support libdispatch. +typedef struct { + void *block; + dispatch_function_t func; + u32 parent_tid; +} asan_block_context_t; + +ALWAYS_INLINE +void asan_register_worker_thread(int parent_tid, StackTrace *stack) { + AsanThread *t = GetCurrentThread(); + if (!t) { + t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr, + parent_tid, stack, /* detached */ true); + t->Init(); + asanThreadRegistry().StartThread(t->tid(), GetTid(), ThreadType::Worker, + nullptr); + SetCurrentThread(t); + } +} + +// For use by only those functions that allocated the context via +// alloc_asan_context(). +extern "C" +void asan_dispatch_call_block_and_release(void *block) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *context = (asan_block_context_t*)block; + VReport(2, + "asan_dispatch_call_block_and_release(): " + "context: %p, pthread_self: %p\n", + block, pthread_self()); + asan_register_worker_thread(context->parent_tid, &stack); + // Call the original dispatcher for the block. + context->func(context->block); + asan_free(context, &stack, FROM_MALLOC); +} + +} // namespace __asan + +using namespace __asan; + +// Wrap |ctxt| and |func| into an asan_block_context_t. +// The caller retains control of the allocated context. +extern "C" +asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func, + BufferedStackTrace *stack) { + asan_block_context_t *asan_ctxt = + (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack); + asan_ctxt->block = ctxt; + asan_ctxt->func = func; + asan_ctxt->parent_tid = GetCurrentTidOrInvalid(); + return asan_ctxt; +} + +// Define interceptor for dispatch_*_f function with the three most common +// parameters: dispatch_queue_t, context, dispatch_function_t. +#define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f) \ + INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt, \ + dispatch_function_t func) { \ + GET_STACK_TRACE_THREAD; \ + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \ + if (Verbosity() >= 2) { \ + Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n", \ + asan_ctxt, pthread_self()); \ + PRINT_CURRENT_STACK(); \ + } \ + return REAL(dispatch_x_f)(dq, (void*)asan_ctxt, \ + asan_dispatch_call_block_and_release); \ + } + +INTERCEPT_DISPATCH_X_F_3(dispatch_async_f) +INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f) +INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f) + +INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, + dispatch_queue_t dq, void *ctxt, + dispatch_function_t func) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); + if (Verbosity() >= 2) { + Report("dispatch_after_f: %p\n", asan_ctxt); + PRINT_CURRENT_STACK(); + } + return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt, + asan_dispatch_call_block_and_release); +} + +INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group, + dispatch_queue_t dq, void *ctxt, + dispatch_function_t func) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); + if (Verbosity() >= 2) { + Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n", + asan_ctxt, pthread_self()); + PRINT_CURRENT_STACK(); + } + REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt, + asan_dispatch_call_block_and_release); +} + +#if !defined(MISSING_BLOCKS_SUPPORT) +extern "C" { +void dispatch_async(dispatch_queue_t dq, void(^work)(void)); +void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq, + void(^work)(void)); +void dispatch_after(dispatch_time_t when, dispatch_queue_t queue, + void(^work)(void)); +void dispatch_source_set_cancel_handler(dispatch_source_t ds, + void(^work)(void)); +void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void)); +} + +#define GET_ASAN_BLOCK(work) \ + void (^asan_block)(void); \ + int parent_tid = GetCurrentTidOrInvalid(); \ + asan_block = ^(void) { \ + GET_STACK_TRACE_THREAD; \ + asan_register_worker_thread(parent_tid, &stack); \ + work(); \ + } + +INTERCEPTOR(void, dispatch_async, + dispatch_queue_t dq, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_async)(dq, asan_block); +} + +INTERCEPTOR(void, dispatch_group_async, + dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_group_async)(dg, dq, asan_block); +} + +INTERCEPTOR(void, dispatch_after, + dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_after)(when, queue, asan_block); +} + +INTERCEPTOR(void, dispatch_source_set_cancel_handler, + dispatch_source_t ds, void(^work)(void)) { + if (!work) { + REAL(dispatch_source_set_cancel_handler)(ds, work); + return; + } + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_source_set_cancel_handler)(ds, asan_block); +} + +INTERCEPTOR(void, dispatch_source_set_event_handler, + dispatch_source_t ds, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_source_set_event_handler)(ds, asan_block); +} +#endif + +#endif // SANITIZER_MAC |