1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
|
//===-- asan_mac.cc -------------------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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_mac.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 <crt_externs.h> // for _NSGetArgv
#include <dlfcn.h> // for dladdr()
#include <mach-o/dyld.h>
#include <mach-o/loader.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <sys/ucontext.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdlib.h> // for free()
#include <unistd.h>
#include <libkern/OSAtomic.h>
namespace __asan {
void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
ucontext_t *ucontext = (ucontext_t*)context;
# if SANITIZER_WORDSIZE == 64
*pc = ucontext->uc_mcontext->__ss.__rip;
*bp = ucontext->uc_mcontext->__ss.__rbp;
*sp = ucontext->uc_mcontext->__ss.__rsp;
# else
*pc = ucontext->uc_mcontext->__ss.__eip;
*bp = ucontext->uc_mcontext->__ss.__ebp;
*sp = ucontext->uc_mcontext->__ss.__esp;
# endif // SANITIZER_WORDSIZE
}
MacosVersion cached_macos_version = MACOS_VERSION_UNINITIALIZED;
MacosVersion GetMacosVersionInternal() {
int mib[2] = { CTL_KERN, KERN_OSRELEASE };
char version[100];
uptr len = 0, maxlen = sizeof(version) / sizeof(version[0]);
for (uptr i = 0; i < maxlen; i++) version[i] = '\0';
// Get the version length.
CHECK_NE(sysctl(mib, 2, 0, &len, 0, 0), -1);
CHECK_LT(len, maxlen);
CHECK_NE(sysctl(mib, 2, version, &len, 0, 0), -1);
switch (version[0]) {
case '9': return MACOS_VERSION_LEOPARD;
case '1': {
switch (version[1]) {
case '0': return MACOS_VERSION_SNOW_LEOPARD;
case '1': return MACOS_VERSION_LION;
case '2': return MACOS_VERSION_MOUNTAIN_LION;
case '3': return MACOS_VERSION_MAVERICKS;
default: return MACOS_VERSION_UNKNOWN;
}
}
default: return MACOS_VERSION_UNKNOWN;
}
}
MacosVersion GetMacosVersion() {
atomic_uint32_t *cache =
reinterpret_cast<atomic_uint32_t*>(&cached_macos_version);
MacosVersion result =
static_cast<MacosVersion>(atomic_load(cache, memory_order_acquire));
if (result == MACOS_VERSION_UNINITIALIZED) {
result = GetMacosVersionInternal();
atomic_store(cache, result, memory_order_release);
}
return result;
}
bool PlatformHasDifferentMemcpyAndMemmove() {
// On OS X 10.7 memcpy() and memmove() are both resolved
// into memmove$VARIANT$sse42.
// See also http://code.google.com/p/address-sanitizer/issues/detail?id=34.
// TODO(glider): need to check dynamically that memcpy() and memmove() are
// actually the same function.
return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
}
extern "C"
void __asan_init();
static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES";
LowLevelAllocator allocator_for_env;
// Change the value of the env var |name|, leaking the original value.
// If |name_value| is NULL, the variable is deleted from the environment,
// otherwise the corresponding "NAME=value" string is replaced with
// |name_value|.
void LeakyResetEnv(const char *name, const char *name_value) {
char ***env_ptr = _NSGetEnviron();
CHECK(env_ptr);
char **environ = *env_ptr;
CHECK(environ);
uptr name_len = internal_strlen(name);
while (*environ != 0) {
uptr len = internal_strlen(*environ);
if (len > name_len) {
const char *p = *environ;
if (!internal_memcmp(p, name, name_len) && p[name_len] == '=') {
// Match.
if (name_value) {
// Replace the old value with the new one.
*environ = const_cast<char*>(name_value);
} else {
// Shift the subsequent pointers back.
char **del = environ;
do {
del[0] = del[1];
} while (*del++);
}
}
}
environ++;
}
}
void MaybeReexec() {
if (!flags()->allow_reexec) return;
// Make sure the dynamic ASan runtime library is preloaded so that the
// wrappers work. If it is not, set DYLD_INSERT_LIBRARIES and re-exec
// ourselves.
Dl_info info;
CHECK(dladdr((void*)((uptr)__asan_init), &info));
char *dyld_insert_libraries =
const_cast<char*>(GetEnv(kDyldInsertLibraries));
uptr old_env_len = dyld_insert_libraries ?
internal_strlen(dyld_insert_libraries) : 0;
uptr fname_len = internal_strlen(info.dli_fname);
if (!dyld_insert_libraries ||
!REAL(strstr)(dyld_insert_libraries, info.dli_fname)) {
// DYLD_INSERT_LIBRARIES is not set or does not contain the runtime
// library.
char program_name[1024];
uint32_t buf_size = sizeof(program_name);
_NSGetExecutablePath(program_name, &buf_size);
char *new_env = const_cast<char*>(info.dli_fname);
if (dyld_insert_libraries) {
// Append the runtime dylib name to the existing value of
// DYLD_INSERT_LIBRARIES.
new_env = (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2);
internal_strncpy(new_env, dyld_insert_libraries, old_env_len);
new_env[old_env_len] = ':';
// Copy fname_len and add a trailing zero.
internal_strncpy(new_env + old_env_len + 1, info.dli_fname,
fname_len + 1);
// Ok to use setenv() since the wrappers don't depend on the value of
// asan_inited.
setenv(kDyldInsertLibraries, new_env, /*overwrite*/1);
} else {
// Set DYLD_INSERT_LIBRARIES equal to the runtime dylib name.
setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0);
}
if (flags()->verbosity >= 1) {
Report("exec()-ing the program with\n");
Report("%s=%s\n", kDyldInsertLibraries, new_env);
Report("to enable ASan wrappers.\n");
Report("Set ASAN_OPTIONS=allow_reexec=0 to disable this.\n");
}
execv(program_name, *_NSGetArgv());
} else {
// DYLD_INSERT_LIBRARIES is set and contains the runtime library.
if (old_env_len == fname_len) {
// It's just the runtime library name - fine to unset the variable.
LeakyResetEnv(kDyldInsertLibraries, NULL);
} else {
uptr env_name_len = internal_strlen(kDyldInsertLibraries);
// Allocate memory to hold the previous env var name, its value, the '='
// sign and the '\0' char.
char *new_env = (char*)allocator_for_env.Allocate(
old_env_len + 2 + env_name_len);
CHECK(new_env);
internal_memset(new_env, '\0', old_env_len + 2 + env_name_len);
internal_strncpy(new_env, kDyldInsertLibraries, env_name_len);
new_env[env_name_len] = '=';
char *new_env_pos = new_env + env_name_len + 1;
// Iterate over colon-separated pieces of |dyld_insert_libraries|.
char *piece_start = dyld_insert_libraries;
char *piece_end = NULL;
char *old_env_end = dyld_insert_libraries + old_env_len;
do {
if (piece_start[0] == ':') piece_start++;
piece_end = REAL(strchr)(piece_start, ':');
if (!piece_end) piece_end = dyld_insert_libraries + old_env_len;
if ((uptr)(piece_start - dyld_insert_libraries) > old_env_len) break;
uptr piece_len = piece_end - piece_start;
// If the current piece isn't the runtime library name,
// append it to new_env.
if ((piece_len != fname_len) ||
(internal_strncmp(piece_start, info.dli_fname, fname_len) != 0)) {
if (new_env_pos != new_env + env_name_len + 1) {
new_env_pos[0] = ':';
new_env_pos++;
}
internal_strncpy(new_env_pos, piece_start, piece_len);
}
// Move on to the next piece.
new_env_pos += piece_len;
piece_start = piece_end;
} while (piece_start < old_env_end);
// Can't use setenv() here, because it requires the allocator to be
// initialized.
// FIXME: instead of filtering DYLD_INSERT_LIBRARIES here, do it in
// a separate function called after InitializeAllocator().
LeakyResetEnv(kDyldInsertLibraries, new_env);
}
}
}
// No-op. Mac does not support static linkage anyway.
void *AsanDoesNotSupportStaticLinkage() {
return 0;
}
bool AsanInterceptsSignal(int signum) {
return (signum == SIGSEGV || signum == SIGBUS) && flags()->handle_segv;
}
void AsanPlatformThreadInit() {
}
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(0, 0);
CreateThreadContextArgs args = { t, stack };
asanThreadRegistry().CreateThread(*(uptr*)t, true, parent_tid, &args);
t->Init();
asanThreadRegistry().StartThread(t->tid(), 0, 0);
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;
if (flags()->verbosity >= 2) {
Report("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; // NOLINT
// 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,
StackTrace *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 (flags()->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 (flags()->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 (flags()->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" {
// FIXME: consolidate these declarations with asan_intercepted_functions.h.
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)) {
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)) {
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)) {
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)) {
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)) {
GET_ASAN_BLOCK(work);
REAL(dispatch_source_set_event_handler)(ds, asan_block);
}
#endif
#endif // SANITIZER_MAC
|