aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/clang16-rt/lib/asan/asan_win.cpp
blob: 7dbd7ab98a17b6383de99a1022e7f77f22026226 (plain) (blame)
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
//===-- asan_win.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.
//
// Windows-specific details.
//===----------------------------------------------------------------------===//

#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_WINDOWS
#  define WIN32_LEAN_AND_MEAN
#  include <stdlib.h>
#  include <windows.h>

#  include "asan_interceptors.h"
#  include "asan_internal.h"
#  include "asan_mapping.h"
#  include "asan_report.h"
#  include "asan_stack.h"
#  include "asan_thread.h"
#  include "sanitizer_common/sanitizer_libc.h"
#  include "sanitizer_common/sanitizer_mutex.h"
#  include "sanitizer_common/sanitizer_win.h"
#  include "sanitizer_common/sanitizer_win_defs.h"

using namespace __asan;

extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
int __asan_should_detect_stack_use_after_return() {
  __asan_init();
  return __asan_option_detect_stack_use_after_return;
}

SANITIZER_INTERFACE_ATTRIBUTE
uptr __asan_get_shadow_memory_dynamic_address() {
  __asan_init();
  return __asan_shadow_memory_dynamic_address;
}
}  // extern "C"

// ---------------------- Windows-specific interceptors ---------------- {{{
static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
static LPTOP_LEVEL_EXCEPTION_FILTER user_seh_handler;

extern "C" SANITIZER_INTERFACE_ATTRIBUTE long __asan_unhandled_exception_filter(
    EXCEPTION_POINTERS *info) {
  EXCEPTION_RECORD *exception_record = info->ExceptionRecord;
  CONTEXT *context = info->ContextRecord;

  // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.

  SignalContext sig(exception_record, context);
  ReportDeadlySignal(sig);
  UNREACHABLE("returned from reporting deadly signal");
}

// Wrapper SEH Handler. If the exception should be handled by asan, we call
// __asan_unhandled_exception_filter, otherwise, we execute the user provided
// exception handler or the default.
static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) {
  DWORD exception_code = info->ExceptionRecord->ExceptionCode;
  if (__sanitizer::IsHandledDeadlyException(exception_code))
    return __asan_unhandled_exception_filter(info);
  if (user_seh_handler)
    return user_seh_handler(info);
  // Bubble out to the default exception filter.
  if (default_seh_handler)
    return default_seh_handler(info);
  return EXCEPTION_CONTINUE_SEARCH;
}

INTERCEPTOR_WINAPI(LPTOP_LEVEL_EXCEPTION_FILTER, SetUnhandledExceptionFilter,
                   LPTOP_LEVEL_EXCEPTION_FILTER ExceptionFilter) {
  CHECK(REAL(SetUnhandledExceptionFilter));
  if (ExceptionFilter == &SEHHandler)
    return REAL(SetUnhandledExceptionFilter)(ExceptionFilter);
  // We record the user provided exception handler to be called for all the
  // exceptions unhandled by asan.
  Swap(ExceptionFilter, user_seh_handler);
  return ExceptionFilter;
}

INTERCEPTOR_WINAPI(void, RtlRaiseException, EXCEPTION_RECORD *ExceptionRecord) {
  CHECK(REAL(RtlRaiseException));
  // This is a noreturn function, unless it's one of the exceptions raised to
  // communicate with the debugger, such as the one from OutputDebugString.
  if (ExceptionRecord->ExceptionCode != DBG_PRINTEXCEPTION_C)
    __asan_handle_no_return();
  REAL(RtlRaiseException)(ExceptionRecord);
}

INTERCEPTOR_WINAPI(void, RaiseException, void *a, void *b, void *c, void *d) {
  CHECK(REAL(RaiseException));
  __asan_handle_no_return();
  REAL(RaiseException)(a, b, c, d);
}

#ifdef _WIN64

INTERCEPTOR_WINAPI(EXCEPTION_DISPOSITION, __C_specific_handler,
                   _EXCEPTION_RECORD *a, void *b, _CONTEXT *c,
                   _DISPATCHER_CONTEXT *d) {
  CHECK(REAL(__C_specific_handler));
  __asan_handle_no_return();
  return REAL(__C_specific_handler)(a, b, c, d);
}

#else

INTERCEPTOR(int, _except_handler3, void *a, void *b, void *c, void *d) {
  CHECK(REAL(_except_handler3));
  __asan_handle_no_return();
  return REAL(_except_handler3)(a, b, c, d);
}

#if ASAN_DYNAMIC
// This handler is named differently in -MT and -MD CRTs.
#define _except_handler4 _except_handler4_common
#endif
INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
  CHECK(REAL(_except_handler4));
  __asan_handle_no_return();
  return REAL(_except_handler4)(a, b, c, d);
}
#endif

static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
  AsanThread *t = (AsanThread *)arg;
  SetCurrentThread(t);
  return t->ThreadStart(GetTid());
}

INTERCEPTOR_WINAPI(HANDLE, CreateThread, LPSECURITY_ATTRIBUTES security,
                   SIZE_T stack_size, LPTHREAD_START_ROUTINE start_routine,
                   void *arg, DWORD thr_flags, DWORD *tid) {
  // Strict init-order checking is thread-hostile.
  if (flags()->strict_init_order)
    StopInitOrderChecking();
  GET_STACK_TRACE_THREAD;
  // FIXME: The CreateThread interceptor is not the same as a pthread_create
  // one.  This is a bandaid fix for PR22025.
  bool detached = false;  // FIXME: how can we determine it on Windows?
  u32 current_tid = GetCurrentTidOrInvalid();
  AsanThread *t =
      AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
  return REAL(CreateThread)(security, stack_size, asan_thread_start, t,
                            thr_flags, tid);
}

// }}}

namespace __asan {

void InitializePlatformInterceptors() {
  // The interceptors were not designed to be removable, so we have to keep this
  // module alive for the life of the process.
  HMODULE pinned;
  CHECK(GetModuleHandleExW(
      GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_PIN,
      (LPCWSTR)&InitializePlatformInterceptors, &pinned));

  ASAN_INTERCEPT_FUNC(CreateThread);
  ASAN_INTERCEPT_FUNC(SetUnhandledExceptionFilter);

#ifdef _WIN64
  ASAN_INTERCEPT_FUNC(__C_specific_handler);
#else
  ASAN_INTERCEPT_FUNC(_except_handler3);
  ASAN_INTERCEPT_FUNC(_except_handler4);
#endif

  // Try to intercept kernel32!RaiseException, and if that fails, intercept
  // ntdll!RtlRaiseException instead.
  if (!::__interception::OverrideFunction("RaiseException",
                                          (uptr)WRAP(RaiseException),
                                          (uptr *)&REAL(RaiseException))) {
    CHECK(::__interception::OverrideFunction("RtlRaiseException",
                                             (uptr)WRAP(RtlRaiseException),
                                             (uptr *)&REAL(RtlRaiseException)));
  }
}

void InstallAtExitCheckLeaks() {}

void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
  UNIMPLEMENTED();
}

void FlushUnneededASanShadowMemory(uptr p, uptr size) {
  // Since asan's mapping is compacting, the shadow chunk may be
  // not page-aligned, so we only flush the page-aligned portion.
  ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));
}

// ---------------------- TSD ---------------- {{{
static bool tsd_key_inited = false;

static __declspec(thread) void *fake_tsd = 0;

// https://docs.microsoft.com/en-us/windows/desktop/api/winternl/ns-winternl-_teb
// "[This structure may be altered in future versions of Windows. Applications
// should use the alternate functions listed in this topic.]"
typedef struct _TEB {
  PVOID Reserved1[12];
  // PVOID ThreadLocalStoragePointer; is here, at the last field in Reserved1.
  PVOID ProcessEnvironmentBlock;
  PVOID Reserved2[399];
  BYTE Reserved3[1952];
  PVOID TlsSlots[64];
  BYTE Reserved4[8];
  PVOID Reserved5[26];
  PVOID ReservedForOle;
  PVOID Reserved6[4];
  PVOID TlsExpansionSlots;
} TEB, *PTEB;

constexpr size_t TEB_RESERVED_FIELDS_THREAD_LOCAL_STORAGE_OFFSET = 11;
BOOL IsTlsInitialized() {
  PTEB teb = (PTEB)NtCurrentTeb();
  return teb->Reserved1[TEB_RESERVED_FIELDS_THREAD_LOCAL_STORAGE_OFFSET] !=
         nullptr;
}

void AsanTSDInit(void (*destructor)(void *tsd)) {
  // FIXME: we're ignoring the destructor for now.
  tsd_key_inited = true;
}

void *AsanTSDGet() {
  CHECK(tsd_key_inited);
  return IsTlsInitialized() ? fake_tsd : nullptr;
}

void AsanTSDSet(void *tsd) {
  CHECK(tsd_key_inited);
  fake_tsd = tsd;
}

void PlatformTSDDtor(void *tsd) { AsanThread::TSDDtor(tsd); }
// }}}

// ---------------------- Various stuff ---------------- {{{
void *AsanDoesNotSupportStaticLinkage() {
#if defined(_DEBUG)
#error Please build the runtime with a non-debug CRT: /MD or /MT
#endif
  return 0;
}

uptr FindDynamicShadowStart() {
  return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,
                          /*min_shadow_base_alignment*/ 0, kHighMemEnd);
}

void AsanCheckDynamicRTPrereqs() {}

void AsanCheckIncompatibleRT() {}

void AsanOnDeadlySignal(int, void *siginfo, void *context) { UNIMPLEMENTED(); }

bool PlatformUnpoisonStacks() { return false; }

#if SANITIZER_WINDOWS64
// Exception handler for dealing with shadow memory.
static LONG CALLBACK
ShadowExceptionHandler(PEXCEPTION_POINTERS exception_pointers) {
  uptr page_size = GetPageSizeCached();
  // Only handle access violations.
  if (exception_pointers->ExceptionRecord->ExceptionCode !=
          EXCEPTION_ACCESS_VIOLATION ||
      exception_pointers->ExceptionRecord->NumberParameters < 2) {
    __asan_handle_no_return();
    return EXCEPTION_CONTINUE_SEARCH;
  }

  // Only handle access violations that land within the shadow memory.
  uptr addr =
      (uptr)(exception_pointers->ExceptionRecord->ExceptionInformation[1]);

  // Check valid shadow range.
  if (!AddrIsInShadow(addr)) {
    __asan_handle_no_return();
    return EXCEPTION_CONTINUE_SEARCH;
  }

  // This is an access violation while trying to read from the shadow. Commit
  // the relevant page and let execution continue.

  // Determine the address of the page that is being accessed.
  uptr page = RoundDownTo(addr, page_size);

  // Commit the page.
  uptr result =
      (uptr)::VirtualAlloc((LPVOID)page, page_size, MEM_COMMIT, PAGE_READWRITE);
  if (result != page)
    return EXCEPTION_CONTINUE_SEARCH;

  // The page mapping succeeded, so continue execution as usual.
  return EXCEPTION_CONTINUE_EXECUTION;
}

#endif

void InitializePlatformExceptionHandlers() {
#if SANITIZER_WINDOWS64
  // On Win64, we map memory on demand with access violation handler.
  // Install our exception handler.
  CHECK(AddVectoredExceptionHandler(TRUE, &ShadowExceptionHandler));
#endif
}

bool IsSystemHeapAddress(uptr addr) {
  return ::HeapValidate(GetProcessHeap(), 0, (void *)addr) != FALSE;
}

// We want to install our own exception handler (EH) to print helpful reports
// on access violations and whatnot.  Unfortunately, the CRT initializers assume
// they are run before any user code and drop any previously-installed EHs on
// the floor, so we can't install our handler inside __asan_init.
// (See crt0dat.c in the CRT sources for the details)
//
// Things get even more complicated with the dynamic runtime, as it finishes its
// initialization before the .exe module CRT begins to initialize.
//
// For the static runtime (-MT), it's enough to put a callback to
// __asan_set_seh_filter in the last section for C initializers.
//
// For the dynamic runtime (-MD), we want link the same
// asan_dynamic_runtime_thunk.lib to all the modules, thus __asan_set_seh_filter
// will be called for each instrumented module.  This ensures that at least one
// __asan_set_seh_filter call happens after the .exe module CRT is initialized.
extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __asan_set_seh_filter() {
  // We should only store the previous handler if it's not our own handler in
  // order to avoid loops in the EH chain.
  auto prev_seh_handler = SetUnhandledExceptionFilter(SEHHandler);
  if (prev_seh_handler != &SEHHandler)
    default_seh_handler = prev_seh_handler;
  return 0;
}

bool HandleDlopenInit() {
  // Not supported on this platform.
  static_assert(!SANITIZER_SUPPORTS_INIT_FOR_DLOPEN,
                "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be false");
  return false;
}

#if !ASAN_DYNAMIC
// The CRT runs initializers in this order:
// - C initializers, from XIA to XIZ
// - C++ initializers, from XCA to XCZ
// Prior to 2015, the CRT set the unhandled exception filter at priority XIY,
// near the end of C initialization. Starting in 2015, it was moved to the
// beginning of C++ initialization. We set our priority to XCAB to run
// immediately after the CRT runs. This way, our exception filter is called
// first and we can delegate to their filter if appropriate.
#pragma section(".CRT$XCAB", long, read)
__declspec(allocate(".CRT$XCAB")) int (*__intercept_seh)() =
    __asan_set_seh_filter;

// Piggyback on the TLS initialization callback directory to initialize asan as
// early as possible. Initializers in .CRT$XL* are called directly by ntdll,
// which run before the CRT. Users also add code to .CRT$XLC, so it's important
// to run our initializers first.
static void NTAPI asan_thread_init(void *module, DWORD reason, void *reserved) {
  if (reason == DLL_PROCESS_ATTACH)
    __asan_init();
}

#pragma section(".CRT$XLAB", long, read)
__declspec(allocate(".CRT$XLAB")) void(NTAPI *__asan_tls_init)(
    void *, unsigned long, void *) = asan_thread_init;
#endif

static void NTAPI asan_thread_exit(void *module, DWORD reason, void *reserved) {
  if (reason == DLL_THREAD_DETACH) {
    // Unpoison the thread's stack because the memory may be re-used.
    NT_TIB *tib = (NT_TIB *)NtCurrentTeb();
    uptr stackSize = (uptr)tib->StackBase - (uptr)tib->StackLimit;
    __asan_unpoison_memory_region(tib->StackLimit, stackSize);
  }
}

#pragma section(".CRT$XLY", long, read)
__declspec(allocate(".CRT$XLY")) void(NTAPI *__asan_tls_exit)(
    void *, unsigned long, void *) = asan_thread_exit;

WIN_FORCE_LINK(__asan_dso_reg_hook)

// }}}
}  // namespace __asan

#endif  // SANITIZER_WINDOWS