aboutsummaryrefslogtreecommitdiffstats
path: root/lib/asan/asan_mac.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/asan/asan_mac.cpp')
-rw-r--r--lib/asan/asan_mac.cpp331
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