?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Consistently use "rG" constraint for copy instruction in move patterns
[official-gcc.git] / libsanitizer / interception / interception_win.cpp
blob38b8c058246a251c0a9d5c8e7f962002599bbdfa
1 //===-- interception_linux.cpp ----------------------------------*- C++ -*-===//
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // Windows-specific interception methods.
12 //
13 // This file is implementing several hooking techniques to intercept calls
14 // to functions. The hooks are dynamically installed by modifying the assembly
15 // code.
16 //
17 // The hooking techniques are making assumptions on the way the code is
18 // generated and are safe under these assumptions.
19 //
20 // On 64-bit architecture, there is no direct 64-bit jump instruction. To allow
21 // arbitrary branching on the whole memory space, the notion of trampoline
22 // region is used. A trampoline region is a memory space withing 2G boundary
23 // where it is safe to add custom assembly code to build 64-bit jumps.
24 //
25 // Hooking techniques
26 // ==================
27 //
28 // 1) Detour
29 //
30 // The Detour hooking technique is assuming the presence of an header with
31 // padding and an overridable 2-bytes nop instruction (mov edi, edi). The
32 // nop instruction can safely be replaced by a 2-bytes jump without any need
33 // to save the instruction. A jump to the target is encoded in the function
34 // header and the nop instruction is replaced by a short jump to the header.
35 //
36 // head: 5 x nop head: jmp <hook>
37 // func: mov edi, edi --> func: jmp short <head>
38 // [...] real: [...]
39 //
40 // This technique is only implemented on 32-bit architecture.
41 // Most of the time, Windows API are hookable with the detour technique.
42 //
43 // 2) Redirect Jump
44 //
45 // The redirect jump is applicable when the first instruction is a direct
46 // jump. The instruction is replaced by jump to the hook.
47 //
48 // func: jmp <label> --> func: jmp <hook>
49 //
50 // On an 64-bit architecture, a trampoline is inserted.
51 //
52 // func: jmp <label> --> func: jmp <tramp>
53 // [...]
54 //
55 // [trampoline]
56 // tramp: jmp QWORD [addr]
57 // addr: .bytes <hook>
58 //
59 // Note: <real> is equivalent to <label>.
60 //
61 // 3) HotPatch
62 //
63 // The HotPatch hooking is assuming the presence of an header with padding
64 // and a first instruction with at least 2-bytes.
65 //
66 // The reason to enforce the 2-bytes limitation is to provide the minimal
67 // space to encode a short jump. HotPatch technique is only rewriting one
68 // instruction to avoid breaking a sequence of instructions containing a
69 // branching target.
70 //
71 // Assumptions are enforced by MSVC compiler by using the /HOTPATCH flag.
72 // see: https://msdn.microsoft.com/en-us/library/ms173507.aspx
73 // Default padding length is 5 bytes in 32-bits and 6 bytes in 64-bits.
74 //
75 // head: 5 x nop head: jmp <hook>
76 // func: <instr> --> func: jmp short <head>
77 // [...] body: [...]
78 //
79 // [trampoline]
80 // real: <instr>
81 // jmp <body>
82 //
83 // On an 64-bit architecture:
84 //
85 // head: 6 x nop head: jmp QWORD [addr1]
86 // func: <instr> --> func: jmp short <head>
87 // [...] body: [...]
88 //
89 // [trampoline]
90 // addr1: .bytes <hook>
91 // real: <instr>
92 // jmp QWORD [addr2]
93 // addr2: .bytes <body>
94 //
95 // 4) Trampoline
96 //
97 // The Trampoline hooking technique is the most aggressive one. It is
98 // assuming that there is a sequence of instructions that can be safely
99 // replaced by a jump (enough room and no incoming branches).
100 //
101 // Unfortunately, these assumptions can't be safely presumed and code may
102 // be broken after hooking.
103 //
104 // func: <instr> --> func: jmp <hook>
105 // <instr>
106 // [...] body: [...]
107 //
108 // [trampoline]
109 // real: <instr>
110 // <instr>
111 // jmp <body>
112 //
113 // On an 64-bit architecture:
114 //
115 // func: <instr> --> func: jmp QWORD [addr1]
116 // <instr>
117 // [...] body: [...]
118 //
119 // [trampoline]
120 // addr1: .bytes <hook>
121 // real: <instr>
122 // <instr>
123 // jmp QWORD [addr2]
124 // addr2: .bytes <body>
125 //===----------------------------------------------------------------------===//
126
127 #include "interception.h"
128
129 #if SANITIZER_WINDOWS
130 #include "sanitizer_common/sanitizer_platform.h"
131 #define WIN32_LEAN_AND_MEAN
132 #include <windows.h>
133
134 namespace __interception {
135
136 static const int kAddressLength = FIRST_32_SECOND_64(4, 8);
137 static const int kJumpInstructionLength = 5;
138 static const int kShortJumpInstructionLength = 2;
139 UNUSED static const int kIndirectJumpInstructionLength = 6;
140 static const int kBranchLength =
141 FIRST_32_SECOND_64(kJumpInstructionLength, kIndirectJumpInstructionLength);
142 static const int kDirectBranchLength = kBranchLength + kAddressLength;
143
144 static void InterceptionFailed() {
145 // Do we have a good way to abort with an error message here?
146 __debugbreak();
147 }
148
149 static bool DistanceIsWithin2Gig(uptr from, uptr target) {
150 #if SANITIZER_WINDOWS64
151 if (from < target)
152 return target - from <= (uptr)0x7FFFFFFFU;
153 else
154 return from - target <= (uptr)0x80000000U;
155 #else
156 // In a 32-bit address space, the address calculation will wrap, so this check
157 // is unnecessary.
158 return true;
159 #endif
160 }
161
162 static uptr GetMmapGranularity() {
163 SYSTEM_INFO si;
164 GetSystemInfo(&si);
165 return si.dwAllocationGranularity;
166 }
167
168 UNUSED static uptr RoundUpTo(uptr size, uptr boundary) {
169 return (size + boundary - 1) & ~(boundary - 1);
170 }
171
172 // FIXME: internal_str* and internal_mem* functions should be moved from the
173 // ASan sources into interception/.
174
175 static size_t _strlen(const char *str) {
176 const char* p = str;
177 while (*p != '\0') ++p;
178 return p - str;
179 }
180
181 static char* _strchr(char* str, char c) {
182 while (*str) {
183 if (*str == c)
184 return str;
185 ++str;
186 }
187 return nullptr;
188 }
189
190 static void _memset(void *p, int value, size_t sz) {
191 for (size_t i = 0; i < sz; ++i)
192 ((char*)p)[i] = (char)value;
193 }
194
195 static void _memcpy(void *dst, void *src, size_t sz) {
196 char *dst_c = (char*)dst,
197 *src_c = (char*)src;
198 for (size_t i = 0; i < sz; ++i)
199 dst_c[i] = src_c[i];
200 }
201
202 static bool ChangeMemoryProtection(
203 uptr address, uptr size, DWORD *old_protection) {
204 return ::VirtualProtect((void*)address, size,
205 PAGE_EXECUTE_READWRITE,
206 old_protection) != FALSE;
207 }
208
209 static bool RestoreMemoryProtection(
210 uptr address, uptr size, DWORD old_protection) {
211 DWORD unused;
212 return ::VirtualProtect((void*)address, size,
213 old_protection,
214 &unused) != FALSE;
215 }
216
217 static bool IsMemoryPadding(uptr address, uptr size) {
218 u8* function = (u8*)address;
219 for (size_t i = 0; i < size; ++i)
220 if (function[i] != 0x90 && function[i] != 0xCC)
221 return false;
222 return true;
223 }
224
225 static const u8 kHintNop8Bytes[] = {
226 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00
227 };
228
229 template<class T>
230 static bool FunctionHasPrefix(uptr address, const T &pattern) {
231 u8* function = (u8*)address - sizeof(pattern);
232 for (size_t i = 0; i < sizeof(pattern); ++i)
233 if (function[i] != pattern[i])
234 return false;
235 return true;
236 }
237
238 static bool FunctionHasPadding(uptr address, uptr size) {
239 if (IsMemoryPadding(address - size, size))
240 return true;
241 if (size <= sizeof(kHintNop8Bytes) &&
242 FunctionHasPrefix(address, kHintNop8Bytes))
243 return true;
244 return false;
245 }
246
247 static void WritePadding(uptr from, uptr size) {
248 _memset((void*)from, 0xCC, (size_t)size);
249 }
250
251 static void WriteJumpInstruction(uptr from, uptr target) {
252 if (!DistanceIsWithin2Gig(from + kJumpInstructionLength, target))
253 InterceptionFailed();
254 ptrdiff_t offset = target - from - kJumpInstructionLength;
255 *(u8*)from = 0xE9;
256 *(u32*)(from + 1) = offset;
257 }
258
259 static void WriteShortJumpInstruction(uptr from, uptr target) {
260 sptr offset = target - from - kShortJumpInstructionLength;
261 if (offset < -128 || offset > 127)
262 InterceptionFailed();
263 *(u8*)from = 0xEB;
264 *(u8*)(from + 1) = (u8)offset;
265 }
266
267 #if SANITIZER_WINDOWS64
268 static void WriteIndirectJumpInstruction(uptr from, uptr indirect_target) {
269 // jmp [rip + <offset>] = FF 25 <offset> where <offset> is a relative
270 // offset.
271 // The offset is the distance from then end of the jump instruction to the
272 // memory location containing the targeted address. The displacement is still
273 // 32-bit in x64, so indirect_target must be located within +/- 2GB range.
274 int offset = indirect_target - from - kIndirectJumpInstructionLength;
275 if (!DistanceIsWithin2Gig(from + kIndirectJumpInstructionLength,
276 indirect_target)) {
277 InterceptionFailed();
278 }
279 *(u16*)from = 0x25FF;
280 *(u32*)(from + 2) = offset;
281 }
282 #endif
283
284 static void WriteBranch(
285 uptr from, uptr indirect_target, uptr target) {
286 #if SANITIZER_WINDOWS64
287 WriteIndirectJumpInstruction(from, indirect_target);
288 *(u64*)indirect_target = target;
289 #else
290 (void)indirect_target;
291 WriteJumpInstruction(from, target);
292 #endif
293 }
294
295 static void WriteDirectBranch(uptr from, uptr target) {
296 #if SANITIZER_WINDOWS64
297 // Emit an indirect jump through immediately following bytes:
298 // jmp [rip + kBranchLength]
299 // .quad <target>
300 WriteBranch(from, from + kBranchLength, target);
301 #else
302 WriteJumpInstruction(from, target);
303 #endif
304 }
305
306 struct TrampolineMemoryRegion {
307 uptr content;
308 uptr allocated_size;
309 uptr max_size;
310 };
311
312 UNUSED static const uptr kTrampolineScanLimitRange = 1 << 31; // 2 gig
313 static const int kMaxTrampolineRegion = 1024;
314 static TrampolineMemoryRegion TrampolineRegions[kMaxTrampolineRegion];
315
316 static void *AllocateTrampolineRegion(uptr image_address, size_t granularity) {
317 #if SANITIZER_WINDOWS64
318 uptr address = image_address;
319 uptr scanned = 0;
320 while (scanned < kTrampolineScanLimitRange) {
321 MEMORY_BASIC_INFORMATION info;
322 if (!::VirtualQuery((void*)address, &info, sizeof(info)))
323 return nullptr;
324
325 // Check whether a region can be allocated at |address|.
326 if (info.State == MEM_FREE && info.RegionSize >= granularity) {
327 void *page = ::VirtualAlloc((void*)RoundUpTo(address, granularity),
328 granularity,
329 MEM_RESERVE | MEM_COMMIT,
330 PAGE_EXECUTE_READWRITE);
331 return page;
332 }
333
334 // Move to the next region.
335 address = (uptr)info.BaseAddress + info.RegionSize;
336 scanned += info.RegionSize;
337 }
338 return nullptr;
339 #else
340 return ::VirtualAlloc(nullptr,
341 granularity,
342 MEM_RESERVE | MEM_COMMIT,
343 PAGE_EXECUTE_READWRITE);
344 #endif
345 }
346
347 // Used by unittests to release mapped memory space.
348 void TestOnlyReleaseTrampolineRegions() {
349 for (size_t bucket = 0; bucket < kMaxTrampolineRegion; ++bucket) {
350 TrampolineMemoryRegion *current = &TrampolineRegions[bucket];
351 if (current->content == 0)
352 return;
353 ::VirtualFree((void*)current->content, 0, MEM_RELEASE);
354 current->content = 0;
355 }
356 }
357
358 static uptr AllocateMemoryForTrampoline(uptr image_address, size_t size) {
359 // Find a region within 2G with enough space to allocate |size| bytes.
360 TrampolineMemoryRegion *region = nullptr;
361 for (size_t bucket = 0; bucket < kMaxTrampolineRegion; ++bucket) {
362 TrampolineMemoryRegion* current = &TrampolineRegions[bucket];
363 if (current->content == 0) {
364 // No valid region found, allocate a new region.
365 size_t bucket_size = GetMmapGranularity();
366 void *content = AllocateTrampolineRegion(image_address, bucket_size);
367 if (content == nullptr)
368 return 0U;
369
370 current->content = (uptr)content;
371 current->allocated_size = 0;
372 current->max_size = bucket_size;
373 region = current;
374 break;
375 } else if (current->max_size - current->allocated_size > size) {
376 #if SANITIZER_WINDOWS64
377 // In 64-bits, the memory space must be allocated within 2G boundary.
378 uptr next_address = current->content + current->allocated_size;
379 if (next_address < image_address ||
380 next_address - image_address >= 0x7FFF0000)
381 continue;
382 #endif
383 // The space can be allocated in the current region.
384 region = current;
385 break;
386 }
387 }
388
389 // Failed to find a region.
390 if (region == nullptr)
391 return 0U;
392
393 // Allocate the space in the current region.
394 uptr allocated_space = region->content + region->allocated_size;
395 region->allocated_size += size;
396 WritePadding(allocated_space, size);
397
398 return allocated_space;
399 }
400
401 // The following prologues cannot be patched because of the short jump
402 // jumping to the patching region.
403
404 // ntdll!wcslen in Win11
405 // 488bc1 mov rax,rcx
406 // 0fb710 movzx edx,word ptr [rax]
407 // 4883c002 add rax,2
408 // 6685d2 test dx,dx
409 // 75f4 jne -12
410 static const u8 kPrologueWithShortJump1[] = {
411 0x48, 0x8b, 0xc1, 0x0f, 0xb7, 0x10, 0x48, 0x83,
412 0xc0, 0x02, 0x66, 0x85, 0xd2, 0x75, 0xf4,
413 };
414
415 // ntdll!strrchr in Win11
416 // 4c8bc1 mov r8,rcx
417 // 8a01 mov al,byte ptr [rcx]
418 // 48ffc1 inc rcx
419 // 84c0 test al,al
420 // 75f7 jne -9
421 static const u8 kPrologueWithShortJump2[] = {
422 0x4c, 0x8b, 0xc1, 0x8a, 0x01, 0x48, 0xff, 0xc1,
423 0x84, 0xc0, 0x75, 0xf7,
424 };
425
426 // Returns 0 on error.
427 static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
428 #if SANITIZER_WINDOWS64
429 if (memcmp((u8*)address, kPrologueWithShortJump1,
430 sizeof(kPrologueWithShortJump1)) == 0 ||
431 memcmp((u8*)address, kPrologueWithShortJump2,
432 sizeof(kPrologueWithShortJump2)) == 0) {
433 return 0;
434 }
435 #endif
436
437 switch (*(u64*)address) {
438 case 0x90909090909006EB: // stub: jmp over 6 x nop.
439 return 8;
440 }
441
442 switch (*(u8*)address) {
443 case 0x90: // 90 : nop
444 return 1;
445
446 case 0x50: // push eax / rax
447 case 0x51: // push ecx / rcx
448 case 0x52: // push edx / rdx
449 case 0x53: // push ebx / rbx
450 case 0x54: // push esp / rsp
451 case 0x55: // push ebp / rbp
452 case 0x56: // push esi / rsi
453 case 0x57: // push edi / rdi
454 case 0x5D: // pop ebp / rbp
455 return 1;
456
457 case 0x6A: // 6A XX = push XX
458 return 2;
459
460 case 0xb8: // b8 XX XX XX XX : mov eax, XX XX XX XX
461 case 0xB9: // b9 XX XX XX XX : mov ecx, XX XX XX XX
462 return 5;
463
464 // Cannot overwrite control-instruction. Return 0 to indicate failure.
465 case 0xE9: // E9 XX XX XX XX : jmp <label>
466 case 0xE8: // E8 XX XX XX XX : call <func>
467 case 0xC3: // C3 : ret
468 case 0xEB: // EB XX : jmp XX (short jump)
469 case 0x70: // 7Y YY : jy XX (short conditional jump)
470 case 0x71:
471 case 0x72:
472 case 0x73:
473 case 0x74:
474 case 0x75:
475 case 0x76:
476 case 0x77:
477 case 0x78:
478 case 0x79:
479 case 0x7A:
480 case 0x7B:
481 case 0x7C:
482 case 0x7D:
483 case 0x7E:
484 case 0x7F:
485 return 0;
486 }
487
488 switch (*(u16*)(address)) {
489 case 0x018A: // 8A 01 : mov al, byte ptr [ecx]
490 case 0xFF8B: // 8B FF : mov edi, edi
491 case 0xEC8B: // 8B EC : mov ebp, esp
492 case 0xc889: // 89 C8 : mov eax, ecx
493 case 0xC18B: // 8B C1 : mov eax, ecx
494 case 0xC033: // 33 C0 : xor eax, eax
495 case 0xC933: // 33 C9 : xor ecx, ecx
496 case 0xD233: // 33 D2 : xor edx, edx
497 return 2;
498
499 // Cannot overwrite control-instruction. Return 0 to indicate failure.
500 case 0x25FF: // FF 25 XX XX XX XX : jmp [XXXXXXXX]
501 return 0;
502 }
503
504 switch (0x00FFFFFF & *(u32*)address) {
505 case 0x24A48D: // 8D A4 24 XX XX XX XX : lea esp, [esp + XX XX XX XX]
506 return 7;
507 }
508
509 #if SANITIZER_WINDOWS64
510 switch (*(u8*)address) {
511 case 0xA1: // A1 XX XX XX XX XX XX XX XX :
512 // movabs eax, dword ptr ds:[XXXXXXXX]
513 return 9;
514
515 case 0x83:
516 const u8 next_byte = *(u8*)(address + 1);
517 const u8 mod = next_byte >> 6;
518 const u8 rm = next_byte & 7;
519 if (mod == 1 && rm == 4)
520 return 5; // 83 ModR/M SIB Disp8 Imm8
521 // add|or|adc|sbb|and|sub|xor|cmp [r+disp8], imm8
522 }
523
524 switch (*(u16*)address) {
525 case 0x5040: // push rax
526 case 0x5140: // push rcx
527 case 0x5240: // push rdx
528 case 0x5340: // push rbx
529 case 0x5440: // push rsp
530 case 0x5540: // push rbp
531 case 0x5640: // push rsi
532 case 0x5740: // push rdi
533 case 0x5441: // push r12
534 case 0x5541: // push r13
535 case 0x5641: // push r14
536 case 0x5741: // push r15
537 case 0x9066: // Two-byte NOP
538 case 0xc084: // test al, al
539 case 0x018a: // mov al, byte ptr [rcx]
540 return 2;
541
542 case 0x058B: // 8B 05 XX XX XX XX : mov eax, dword ptr [XX XX XX XX]
543 if (rel_offset)
544 *rel_offset = 2;
545 return 6;
546 }
547
548 switch (0x00FFFFFF & *(u32*)address) {
549 case 0xe58948: // 48 8b c4 : mov rbp, rsp
550 case 0xc18b48: // 48 8b c1 : mov rax, rcx
551 case 0xc48b48: // 48 8b c4 : mov rax, rsp
552 case 0xd9f748: // 48 f7 d9 : neg rcx
553 case 0xd12b48: // 48 2b d1 : sub rdx, rcx
554 case 0x07c1f6: // f6 c1 07 : test cl, 0x7
555 case 0xc98548: // 48 85 C9 : test rcx, rcx
556 case 0xd28548: // 48 85 d2 : test rdx, rdx
557 case 0xc0854d: // 4d 85 c0 : test r8, r8
558 case 0xc2b60f: // 0f b6 c2 : movzx eax, dl
559 case 0xc03345: // 45 33 c0 : xor r8d, r8d
560 case 0xc93345: // 45 33 c9 : xor r9d, r9d
561 case 0xdb3345: // 45 33 DB : xor r11d, r11d
562 case 0xd98b4c: // 4c 8b d9 : mov r11, rcx
563 case 0xd28b4c: // 4c 8b d2 : mov r10, rdx
564 case 0xc98b4c: // 4C 8B C9 : mov r9, rcx
565 case 0xc18b4c: // 4C 8B C1 : mov r8, rcx
566 case 0xd2b60f: // 0f b6 d2 : movzx edx, dl
567 case 0xca2b48: // 48 2b ca : sub rcx, rdx
568 case 0x10b70f: // 0f b7 10 : movzx edx, WORD PTR [rax]
569 case 0xc00b4d: // 3d 0b c0 : or r8, r8
570 case 0xc08b41: // 41 8b c0 : mov eax, r8d
571 case 0xd18b48: // 48 8b d1 : mov rdx, rcx
572 case 0xdc8b4c: // 4c 8b dc : mov r11, rsp
573 case 0xd18b4c: // 4c 8b d1 : mov r10, rcx
574 case 0xE0E483: // 83 E4 E0 : and esp, 0xFFFFFFE0
575 return 3;
576
577 case 0xec8348: // 48 83 ec XX : sub rsp, XX
578 case 0xf88349: // 49 83 f8 XX : cmp r8, XX
579 case 0x588948: // 48 89 58 XX : mov QWORD PTR[rax + XX], rbx
580 return 4;
581
582 case 0xec8148: // 48 81 EC XX XX XX XX : sub rsp, XXXXXXXX
583 return 7;
584
585 case 0x058b48: // 48 8b 05 XX XX XX XX :
586 // mov rax, QWORD PTR [rip + XXXXXXXX]
587 case 0x25ff48: // 48 ff 25 XX XX XX XX :
588 // rex.W jmp QWORD PTR [rip + XXXXXXXX]
589
590 // Instructions having offset relative to 'rip' need offset adjustment.
591 if (rel_offset)
592 *rel_offset = 3;
593 return 7;
594
595 case 0x2444c7: // C7 44 24 XX YY YY YY YY
596 // mov dword ptr [rsp + XX], YYYYYYYY
597 return 8;
598 }
599
600 switch (*(u32*)(address)) {
601 case 0x24448b48: // 48 8b 44 24 XX : mov rax, QWORD ptr [rsp + XX]
602 case 0x246c8948: // 48 89 6C 24 XX : mov QWORD ptr [rsp + XX], rbp
603 case 0x245c8948: // 48 89 5c 24 XX : mov QWORD PTR [rsp + XX], rbx
604 case 0x24748948: // 48 89 74 24 XX : mov QWORD PTR [rsp + XX], rsi
605 case 0x244C8948: // 48 89 4C 24 XX : mov QWORD PTR [rsp + XX], rcx
606 case 0x24548948: // 48 89 54 24 XX : mov QWORD PTR [rsp + XX], rdx
607 case 0x244c894c: // 4c 89 4c 24 XX : mov QWORD PTR [rsp + XX], r9
608 case 0x2444894c: // 4c 89 44 24 XX : mov QWORD PTR [rsp + XX], r8
609 return 5;
610 case 0x24648348: // 48 83 64 24 XX : and QWORD PTR [rsp + XX], YY
611 return 6;
612 }
613
614 #else
615
616 switch (*(u8*)address) {
617 case 0xA1: // A1 XX XX XX XX : mov eax, dword ptr ds:[XXXXXXXX]
618 return 5;
619 }
620 switch (*(u16*)address) {
621 case 0x458B: // 8B 45 XX : mov eax, dword ptr [ebp + XX]
622 case 0x5D8B: // 8B 5D XX : mov ebx, dword ptr [ebp + XX]
623 case 0x7D8B: // 8B 7D XX : mov edi, dword ptr [ebp + XX]
624 case 0xEC83: // 83 EC XX : sub esp, XX
625 case 0x75FF: // FF 75 XX : push dword ptr [ebp + XX]
626 return 3;
627 case 0xC1F7: // F7 C1 XX YY ZZ WW : test ecx, WWZZYYXX
628 case 0x25FF: // FF 25 XX YY ZZ WW : jmp dword ptr ds:[WWZZYYXX]
629 return 6;
630 case 0x3D83: // 83 3D XX YY ZZ WW TT : cmp TT, WWZZYYXX
631 return 7;
632 case 0x7D83: // 83 7D XX YY : cmp dword ptr [ebp + XX], YY
633 return 4;
634 }
635
636 switch (0x00FFFFFF & *(u32*)address) {
637 case 0x24448A: // 8A 44 24 XX : mov eal, dword ptr [esp + XX]
638 case 0x24448B: // 8B 44 24 XX : mov eax, dword ptr [esp + XX]
639 case 0x244C8B: // 8B 4C 24 XX : mov ecx, dword ptr [esp + XX]
640 case 0x24548B: // 8B 54 24 XX : mov edx, dword ptr [esp + XX]
641 case 0x24748B: // 8B 74 24 XX : mov esi, dword ptr [esp + XX]
642 case 0x247C8B: // 8B 7C 24 XX : mov edi, dword ptr [esp + XX]
643 return 4;
644 }
645
646 switch (*(u32*)address) {
647 case 0x2444B60F: // 0F B6 44 24 XX : movzx eax, byte ptr [esp + XX]
648 return 5;
649 }
650 #endif
651
652 // Unknown instruction!
653 // FIXME: Unknown instruction failures might happen when we add a new
654 // interceptor or a new compiler version. In either case, they should result
655 // in visible and readable error messages. However, merely calling abort()
656 // leads to an infinite recursion in CheckFailed.
657 InterceptionFailed();
658 return 0;
659 }
660
661 // Returns 0 on error.
662 static size_t RoundUpToInstrBoundary(size_t size, uptr address) {
663 size_t cursor = 0;
664 while (cursor < size) {
665 size_t instruction_size = GetInstructionSize(address + cursor);
666 if (!instruction_size)
667 return 0;
668 cursor += instruction_size;
669 }
670 return cursor;
671 }
672
673 static bool CopyInstructions(uptr to, uptr from, size_t size) {
674 size_t cursor = 0;
675 while (cursor != size) {
676 size_t rel_offset = 0;
677 size_t instruction_size = GetInstructionSize(from + cursor, &rel_offset);
678 _memcpy((void*)(to + cursor), (void*)(from + cursor),
679 (size_t)instruction_size);
680 if (rel_offset) {
681 uptr delta = to - from;
682 uptr relocated_offset = *(u32*)(to + cursor + rel_offset) - delta;
683 #if SANITIZER_WINDOWS64
684 if (relocated_offset + 0x80000000U >= 0xFFFFFFFFU)
685 return false;
686 #endif
687 *(u32*)(to + cursor + rel_offset) = relocated_offset;
688 }
689 cursor += instruction_size;
690 }
691 return true;
692 }
693
694
695 #if !SANITIZER_WINDOWS64
696 bool OverrideFunctionWithDetour(
697 uptr old_func, uptr new_func, uptr *orig_old_func) {
698 const int kDetourHeaderLen = 5;
699 const u16 kDetourInstruction = 0xFF8B;
700
701 uptr header = (uptr)old_func - kDetourHeaderLen;
702 uptr patch_length = kDetourHeaderLen + kShortJumpInstructionLength;
703
704 // Validate that the function is hookable.
705 if (*(u16*)old_func != kDetourInstruction ||
706 !IsMemoryPadding(header, kDetourHeaderLen))
707 return false;
708
709 // Change memory protection to writable.
710 DWORD protection = 0;
711 if (!ChangeMemoryProtection(header, patch_length, &protection))
712 return false;
713
714 // Write a relative jump to the redirected function.
715 WriteJumpInstruction(header, new_func);
716
717 // Write the short jump to the function prefix.
718 WriteShortJumpInstruction(old_func, header);
719
720 // Restore previous memory protection.
721 if (!RestoreMemoryProtection(header, patch_length, protection))
722 return false;
723
724 if (orig_old_func)
725 *orig_old_func = old_func + kShortJumpInstructionLength;
726
727 return true;
728 }
729 #endif
730
731 bool OverrideFunctionWithRedirectJump(
732 uptr old_func, uptr new_func, uptr *orig_old_func) {
733 // Check whether the first instruction is a relative jump.
734 if (*(u8*)old_func != 0xE9)
735 return false;
736
737 if (orig_old_func) {
738 uptr relative_offset = *(u32*)(old_func + 1);
739 uptr absolute_target = old_func + relative_offset + kJumpInstructionLength;
740 *orig_old_func = absolute_target;
741 }
742
743 #if SANITIZER_WINDOWS64
744 // If needed, get memory space for a trampoline jump.
745 uptr trampoline = AllocateMemoryForTrampoline(old_func, kDirectBranchLength);
746 if (!trampoline)
747 return false;
748 WriteDirectBranch(trampoline, new_func);
749 #endif
750
751 // Change memory protection to writable.
752 DWORD protection = 0;
753 if (!ChangeMemoryProtection(old_func, kJumpInstructionLength, &protection))
754 return false;
755
756 // Write a relative jump to the redirected function.
757 WriteJumpInstruction(old_func, FIRST_32_SECOND_64(new_func, trampoline));
758
759 // Restore previous memory protection.
760 if (!RestoreMemoryProtection(old_func, kJumpInstructionLength, protection))
761 return false;
762
763 return true;
764 }
765
766 bool OverrideFunctionWithHotPatch(
767 uptr old_func, uptr new_func, uptr *orig_old_func) {
768 const int kHotPatchHeaderLen = kBranchLength;
769
770 uptr header = (uptr)old_func - kHotPatchHeaderLen;
771 uptr patch_length = kHotPatchHeaderLen + kShortJumpInstructionLength;
772
773 // Validate that the function is hot patchable.
774 size_t instruction_size = GetInstructionSize(old_func);
775 if (instruction_size < kShortJumpInstructionLength ||
776 !FunctionHasPadding(old_func, kHotPatchHeaderLen))
777 return false;
778
779 if (orig_old_func) {
780 // Put the needed instructions into the trampoline bytes.
781 uptr trampoline_length = instruction_size + kDirectBranchLength;
782 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
783 if (!trampoline)
784 return false;
785 if (!CopyInstructions(trampoline, old_func, instruction_size))
786 return false;
787 WriteDirectBranch(trampoline + instruction_size,
788 old_func + instruction_size);
789 *orig_old_func = trampoline;
790 }
791
792 // If needed, get memory space for indirect address.
793 uptr indirect_address = 0;
794 #if SANITIZER_WINDOWS64
795 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
796 if (!indirect_address)
797 return false;
798 #endif
799
800 // Change memory protection to writable.
801 DWORD protection = 0;
802 if (!ChangeMemoryProtection(header, patch_length, &protection))
803 return false;
804
805 // Write jumps to the redirected function.
806 WriteBranch(header, indirect_address, new_func);
807 WriteShortJumpInstruction(old_func, header);
808
809 // Restore previous memory protection.
810 if (!RestoreMemoryProtection(header, patch_length, protection))
811 return false;
812
813 return true;
814 }
815
816 bool OverrideFunctionWithTrampoline(
817 uptr old_func, uptr new_func, uptr *orig_old_func) {
818
819 size_t instructions_length = kBranchLength;
820 size_t padding_length = 0;
821 uptr indirect_address = 0;
822
823 if (orig_old_func) {
824 // Find out the number of bytes of the instructions we need to copy
825 // to the trampoline.
826 instructions_length = RoundUpToInstrBoundary(kBranchLength, old_func);
827 if (!instructions_length)
828 return false;
829
830 // Put the needed instructions into the trampoline bytes.
831 uptr trampoline_length = instructions_length + kDirectBranchLength;
832 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
833 if (!trampoline)
834 return false;
835 if (!CopyInstructions(trampoline, old_func, instructions_length))
836 return false;
837 WriteDirectBranch(trampoline + instructions_length,
838 old_func + instructions_length);
839 *orig_old_func = trampoline;
840 }
841
842 #if SANITIZER_WINDOWS64
843 // Check if the targeted address can be encoded in the function padding.
844 // Otherwise, allocate it in the trampoline region.
845 if (IsMemoryPadding(old_func - kAddressLength, kAddressLength)) {
846 indirect_address = old_func - kAddressLength;
847 padding_length = kAddressLength;
848 } else {
849 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
850 if (!indirect_address)
851 return false;
852 }
853 #endif
854
855 // Change memory protection to writable.
856 uptr patch_address = old_func - padding_length;
857 uptr patch_length = instructions_length + padding_length;
858 DWORD protection = 0;
859 if (!ChangeMemoryProtection(patch_address, patch_length, &protection))
860 return false;
861
862 // Patch the original function.
863 WriteBranch(old_func, indirect_address, new_func);
864
865 // Restore previous memory protection.
866 if (!RestoreMemoryProtection(patch_address, patch_length, protection))
867 return false;
868
869 return true;
870 }
871
872 bool OverrideFunction(
873 uptr old_func, uptr new_func, uptr *orig_old_func) {
874 #if !SANITIZER_WINDOWS64
875 if (OverrideFunctionWithDetour(old_func, new_func, orig_old_func))
876 return true;
877 #endif
878 if (OverrideFunctionWithRedirectJump(old_func, new_func, orig_old_func))
879 return true;
880 if (OverrideFunctionWithHotPatch(old_func, new_func, orig_old_func))
881 return true;
882 if (OverrideFunctionWithTrampoline(old_func, new_func, orig_old_func))
883 return true;
884 return false;
885 }
886
887 static void **InterestingDLLsAvailable() {
888 static const char *InterestingDLLs[] = {
889 "kernel32.dll",
890 "msvcr100.dll", // VS2010
891 "msvcr110.dll", // VS2012
892 "msvcr120.dll", // VS2013
893 "vcruntime140.dll", // VS2015
894 "ucrtbase.dll", // Universal CRT
895 // NTDLL should go last as it exports some functions that we should
896 // override in the CRT [presumably only used internally].
897 "ntdll.dll", NULL};
898 static void *result[ARRAY_SIZE(InterestingDLLs)] = { 0 };
899 if (!result[0]) {
900 for (size_t i = 0, j = 0; InterestingDLLs[i]; ++i) {
901 if (HMODULE h = GetModuleHandleA(InterestingDLLs[i]))
902 result[j++] = (void *)h;
903 }
904 }
905 return &result[0];
906 }
907
908 namespace {
909 // Utility for reading loaded PE images.
910 template <typename T> class RVAPtr {
911 public:
912 RVAPtr(void *module, uptr rva)
913 : ptr_(reinterpret_cast<T *>(reinterpret_cast<char *>(module) + rva)) {}
914 operator T *() { return ptr_; }
915 T *operator->() { return ptr_; }
916 T *operator++() { return ++ptr_; }
917
918 private:
919 T *ptr_;
920 };
921 } // namespace
922
923 // Internal implementation of GetProcAddress. At least since Windows 8,
924 // GetProcAddress appears to initialize DLLs before returning function pointers
925 // into them. This is problematic for the sanitizers, because they typically
926 // want to intercept malloc *before* MSVCRT initializes. Our internal
927 // implementation walks the export list manually without doing initialization.
928 uptr InternalGetProcAddress(void *module, const char *func_name) {
929 // Check that the module header is full and present.
930 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
931 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
932 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
933 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
934 headers->FileHeader.SizeOfOptionalHeader <
935 sizeof(IMAGE_OPTIONAL_HEADER)) {
936 return 0;
937 }
938
939 IMAGE_DATA_DIRECTORY *export_directory =
940 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
941 if (export_directory->Size == 0)
942 return 0;
943 RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
944 export_directory->VirtualAddress);
945 RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);
946 RVAPtr<DWORD> names(module, exports->AddressOfNames);
947 RVAPtr<WORD> ordinals(module, exports->AddressOfNameOrdinals);
948
949 for (DWORD i = 0; i < exports->NumberOfNames; i++) {
950 RVAPtr<char> name(module, names[i]);
951 if (!strcmp(func_name, name)) {
952 DWORD index = ordinals[i];
953 RVAPtr<char> func(module, functions[index]);
954
955 // Handle forwarded functions.
956 DWORD offset = functions[index];
957 if (offset >= export_directory->VirtualAddress &&
958 offset < export_directory->VirtualAddress + export_directory->Size) {
959 // An entry for a forwarded function is a string with the following
960 // format: "<module> . <function_name>" that is stored into the
961 // exported directory.
962 char function_name[256];
963 size_t funtion_name_length = _strlen(func);
964 if (funtion_name_length >= sizeof(function_name) - 1)
965 InterceptionFailed();
966
967 _memcpy(function_name, func, funtion_name_length);
968 function_name[funtion_name_length] = '\0';
969 char* separator = _strchr(function_name, '.');
970 if (!separator)
971 InterceptionFailed();
972 *separator = '\0';
973
974 void* redirected_module = GetModuleHandleA(function_name);
975 if (!redirected_module)
976 InterceptionFailed();
977 return InternalGetProcAddress(redirected_module, separator + 1);
978 }
979
980 return (uptr)(char *)func;
981 }
982 }
983
984 return 0;
985 }
986
987 bool OverrideFunction(
988 const char *func_name, uptr new_func, uptr *orig_old_func) {
989 bool hooked = false;
990 void **DLLs = InterestingDLLsAvailable();
991 for (size_t i = 0; DLLs[i]; ++i) {
992 uptr func_addr = InternalGetProcAddress(DLLs[i], func_name);
993 if (func_addr &&
994 OverrideFunction(func_addr, new_func, orig_old_func)) {
995 hooked = true;
996 }
997 }
998 return hooked;
999 }
1000
1001 bool OverrideImportedFunction(const char *module_to_patch,
1002 const char *imported_module,
1003 const char *function_name, uptr new_function,
1004 uptr *orig_old_func) {
1005 HMODULE module = GetModuleHandleA(module_to_patch);
1006 if (!module)
1007 return false;
1008
1009 // Check that the module header is full and present.
1010 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
1011 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
1012 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
1013 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
1014 headers->FileHeader.SizeOfOptionalHeader <
1015 sizeof(IMAGE_OPTIONAL_HEADER)) {
1016 return false;
1017 }
1018
1019 IMAGE_DATA_DIRECTORY *import_directory =
1020 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
1021
1022 // Iterate the list of imported DLLs. FirstThunk will be null for the last
1023 // entry.
1024 RVAPtr<IMAGE_IMPORT_DESCRIPTOR> imports(module,
1025 import_directory->VirtualAddress);
1026 for (; imports->FirstThunk != 0; ++imports) {
1027 RVAPtr<const char> modname(module, imports->Name);
1028 if (_stricmp(&*modname, imported_module) == 0)
1029 break;
1030 }
1031 if (imports->FirstThunk == 0)
1032 return false;
1033
1034 // We have two parallel arrays: the import address table (IAT) and the table
1035 // of names. They start out containing the same data, but the loader rewrites
1036 // the IAT to hold imported addresses and leaves the name table in
1037 // OriginalFirstThunk alone.
1038 RVAPtr<IMAGE_THUNK_DATA> name_table(module, imports->OriginalFirstThunk);
1039 RVAPtr<IMAGE_THUNK_DATA> iat(module, imports->FirstThunk);
1040 for (; name_table->u1.Ordinal != 0; ++name_table, ++iat) {
1041 if (!IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
1042 RVAPtr<IMAGE_IMPORT_BY_NAME> import_by_name(
1043 module, name_table->u1.ForwarderString);
1044 const char *funcname = &import_by_name->Name[0];
1045 if (strcmp(funcname, function_name) == 0)
1046 break;
1047 }
1048 }
1049 if (name_table->u1.Ordinal == 0)
1050 return false;
1051
1052 // Now we have the correct IAT entry. Do the swap. We have to make the page
1053 // read/write first.
1054 if (orig_old_func)
1055 *orig_old_func = iat->u1.AddressOfData;
1056 DWORD old_prot, unused_prot;
1057 if (!VirtualProtect(&iat->u1.AddressOfData, 4, PAGE_EXECUTE_READWRITE,
1058 &old_prot))
1059 return false;
1060 iat->u1.AddressOfData = new_function;
1061 if (!VirtualProtect(&iat->u1.AddressOfData, 4, old_prot, &unused_prot))
1062 return false; // Not clear if this failure bothers us.
1063 return true;
1064 }
1065
1066 } // namespace __interception
1067
1068 #endif // SANITIZER_MAC
Mirror of the offical gcc git repository hosted at gcc.gnu.org