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Fortran : Don't warn for LOGICAL kind conversion PR96319
[official-gcc.git] / libsanitizer / interception / interception_win.cpp
blob1a1c327e61240867869f0b749f99d6813f62f279
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 equilavent 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 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 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 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 // Returns 0 on error.
402 static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
403 switch (*(u64*)address) {
404 case 0x90909090909006EB: // stub: jmp over 6 x nop.
405 return 8;
406 }
407
408 switch (*(u8*)address) {
409 case 0x90: // 90 : nop
410 return 1;
411
412 case 0x50: // push eax / rax
413 case 0x51: // push ecx / rcx
414 case 0x52: // push edx / rdx
415 case 0x53: // push ebx / rbx
416 case 0x54: // push esp / rsp
417 case 0x55: // push ebp / rbp
418 case 0x56: // push esi / rsi
419 case 0x57: // push edi / rdi
420 case 0x5D: // pop ebp / rbp
421 return 1;
422
423 case 0x6A: // 6A XX = push XX
424 return 2;
425
426 case 0xb8: // b8 XX XX XX XX : mov eax, XX XX XX XX
427 case 0xB9: // b9 XX XX XX XX : mov ecx, XX XX XX XX
428 return 5;
429
430 // Cannot overwrite control-instruction. Return 0 to indicate failure.
431 case 0xE9: // E9 XX XX XX XX : jmp <label>
432 case 0xE8: // E8 XX XX XX XX : call <func>
433 case 0xC3: // C3 : ret
434 case 0xEB: // EB XX : jmp XX (short jump)
435 case 0x70: // 7Y YY : jy XX (short conditional jump)
436 case 0x71:
437 case 0x72:
438 case 0x73:
439 case 0x74:
440 case 0x75:
441 case 0x76:
442 case 0x77:
443 case 0x78:
444 case 0x79:
445 case 0x7A:
446 case 0x7B:
447 case 0x7C:
448 case 0x7D:
449 case 0x7E:
450 case 0x7F:
451 return 0;
452 }
453
454 switch (*(u16*)(address)) {
455 case 0x018A: // 8A 01 : mov al, byte ptr [ecx]
456 case 0xFF8B: // 8B FF : mov edi, edi
457 case 0xEC8B: // 8B EC : mov ebp, esp
458 case 0xc889: // 89 C8 : mov eax, ecx
459 case 0xC18B: // 8B C1 : mov eax, ecx
460 case 0xC033: // 33 C0 : xor eax, eax
461 case 0xC933: // 33 C9 : xor ecx, ecx
462 case 0xD233: // 33 D2 : xor edx, edx
463 return 2;
464
465 // Cannot overwrite control-instruction. Return 0 to indicate failure.
466 case 0x25FF: // FF 25 XX XX XX XX : jmp [XXXXXXXX]
467 return 0;
468 }
469
470 switch (0x00FFFFFF & *(u32*)address) {
471 case 0x24A48D: // 8D A4 24 XX XX XX XX : lea esp, [esp + XX XX XX XX]
472 return 7;
473 }
474
475 #if SANITIZER_WINDOWS64
476 switch (*(u8*)address) {
477 case 0xA1: // A1 XX XX XX XX XX XX XX XX :
478 // movabs eax, dword ptr ds:[XXXXXXXX]
479 return 9;
480 }
481
482 switch (*(u16*)address) {
483 case 0x5040: // push rax
484 case 0x5140: // push rcx
485 case 0x5240: // push rdx
486 case 0x5340: // push rbx
487 case 0x5440: // push rsp
488 case 0x5540: // push rbp
489 case 0x5640: // push rsi
490 case 0x5740: // push rdi
491 case 0x5441: // push r12
492 case 0x5541: // push r13
493 case 0x5641: // push r14
494 case 0x5741: // push r15
495 case 0x9066: // Two-byte NOP
496 return 2;
497
498 case 0x058B: // 8B 05 XX XX XX XX : mov eax, dword ptr [XX XX XX XX]
499 if (rel_offset)
500 *rel_offset = 2;
501 return 6;
502 }
503
504 switch (0x00FFFFFF & *(u32*)address) {
505 case 0xe58948: // 48 8b c4 : mov rbp, rsp
506 case 0xc18b48: // 48 8b c1 : mov rax, rcx
507 case 0xc48b48: // 48 8b c4 : mov rax, rsp
508 case 0xd9f748: // 48 f7 d9 : neg rcx
509 case 0xd12b48: // 48 2b d1 : sub rdx, rcx
510 case 0x07c1f6: // f6 c1 07 : test cl, 0x7
511 case 0xc98548: // 48 85 C9 : test rcx, rcx
512 case 0xc0854d: // 4d 85 c0 : test r8, r8
513 case 0xc2b60f: // 0f b6 c2 : movzx eax, dl
514 case 0xc03345: // 45 33 c0 : xor r8d, r8d
515 case 0xc93345: // 45 33 c9 : xor r9d, r9d
516 case 0xdb3345: // 45 33 DB : xor r11d, r11d
517 case 0xd98b4c: // 4c 8b d9 : mov r11, rcx
518 case 0xd28b4c: // 4c 8b d2 : mov r10, rdx
519 case 0xc98b4c: // 4C 8B C9 : mov r9, rcx
520 case 0xc18b4c: // 4C 8B C1 : mov r8, rcx
521 case 0xd2b60f: // 0f b6 d2 : movzx edx, dl
522 case 0xca2b48: // 48 2b ca : sub rcx, rdx
523 case 0x10b70f: // 0f b7 10 : movzx edx, WORD PTR [rax]
524 case 0xc00b4d: // 3d 0b c0 : or r8, r8
525 case 0xd18b48: // 48 8b d1 : mov rdx, rcx
526 case 0xdc8b4c: // 4c 8b dc : mov r11, rsp
527 case 0xd18b4c: // 4c 8b d1 : mov r10, rcx
528 case 0xE0E483: // 83 E4 E0 : and esp, 0xFFFFFFE0
529 return 3;
530
531 case 0xec8348: // 48 83 ec XX : sub rsp, XX
532 case 0xf88349: // 49 83 f8 XX : cmp r8, XX
533 case 0x588948: // 48 89 58 XX : mov QWORD PTR[rax + XX], rbx
534 return 4;
535
536 case 0xec8148: // 48 81 EC XX XX XX XX : sub rsp, XXXXXXXX
537 return 7;
538
539 case 0x058b48: // 48 8b 05 XX XX XX XX :
540 // mov rax, QWORD PTR [rip + XXXXXXXX]
541 case 0x25ff48: // 48 ff 25 XX XX XX XX :
542 // rex.W jmp QWORD PTR [rip + XXXXXXXX]
543
544 // Instructions having offset relative to 'rip' need offset adjustment.
545 if (rel_offset)
546 *rel_offset = 3;
547 return 7;
548
549 case 0x2444c7: // C7 44 24 XX YY YY YY YY
550 // mov dword ptr [rsp + XX], YYYYYYYY
551 return 8;
552 }
553
554 switch (*(u32*)(address)) {
555 case 0x24448b48: // 48 8b 44 24 XX : mov rax, QWORD ptr [rsp + XX]
556 case 0x246c8948: // 48 89 6C 24 XX : mov QWORD ptr [rsp + XX], rbp
557 case 0x245c8948: // 48 89 5c 24 XX : mov QWORD PTR [rsp + XX], rbx
558 case 0x24748948: // 48 89 74 24 XX : mov QWORD PTR [rsp + XX], rsi
559 case 0x244C8948: // 48 89 4C 24 XX : mov QWORD PTR [rsp + XX], rcx
560 case 0x24548948: // 48 89 54 24 XX : mov QWORD PTR [rsp + XX], rdx
561 case 0x244c894c: // 4c 89 4c 24 XX : mov QWORD PTR [rsp + XX], r9
562 case 0x2444894c: // 4c 89 44 24 XX : mov QWORD PTR [rsp + XX], r8
563 return 5;
564 case 0x24648348: // 48 83 64 24 XX : and QWORD PTR [rsp + XX], YY
565 return 6;
566 }
567
568 #else
569
570 switch (*(u8*)address) {
571 case 0xA1: // A1 XX XX XX XX : mov eax, dword ptr ds:[XXXXXXXX]
572 return 5;
573 }
574 switch (*(u16*)address) {
575 case 0x458B: // 8B 45 XX : mov eax, dword ptr [ebp + XX]
576 case 0x5D8B: // 8B 5D XX : mov ebx, dword ptr [ebp + XX]
577 case 0x7D8B: // 8B 7D XX : mov edi, dword ptr [ebp + XX]
578 case 0xEC83: // 83 EC XX : sub esp, XX
579 case 0x75FF: // FF 75 XX : push dword ptr [ebp + XX]
580 return 3;
581 case 0xC1F7: // F7 C1 XX YY ZZ WW : test ecx, WWZZYYXX
582 case 0x25FF: // FF 25 XX YY ZZ WW : jmp dword ptr ds:[WWZZYYXX]
583 return 6;
584 case 0x3D83: // 83 3D XX YY ZZ WW TT : cmp TT, WWZZYYXX
585 return 7;
586 case 0x7D83: // 83 7D XX YY : cmp dword ptr [ebp + XX], YY
587 return 4;
588 }
589
590 switch (0x00FFFFFF & *(u32*)address) {
591 case 0x24448A: // 8A 44 24 XX : mov eal, dword ptr [esp + XX]
592 case 0x24448B: // 8B 44 24 XX : mov eax, dword ptr [esp + XX]
593 case 0x244C8B: // 8B 4C 24 XX : mov ecx, dword ptr [esp + XX]
594 case 0x24548B: // 8B 54 24 XX : mov edx, dword ptr [esp + XX]
595 case 0x24748B: // 8B 74 24 XX : mov esi, dword ptr [esp + XX]
596 case 0x247C8B: // 8B 7C 24 XX : mov edi, dword ptr [esp + XX]
597 return 4;
598 }
599
600 switch (*(u32*)address) {
601 case 0x2444B60F: // 0F B6 44 24 XX : movzx eax, byte ptr [esp + XX]
602 return 5;
603 }
604 #endif
605
606 // Unknown instruction!
607 // FIXME: Unknown instruction failures might happen when we add a new
608 // interceptor or a new compiler version. In either case, they should result
609 // in visible and readable error messages. However, merely calling abort()
610 // leads to an infinite recursion in CheckFailed.
611 InterceptionFailed();
612 return 0;
613 }
614
615 // Returns 0 on error.
616 static size_t RoundUpToInstrBoundary(size_t size, uptr address) {
617 size_t cursor = 0;
618 while (cursor < size) {
619 size_t instruction_size = GetInstructionSize(address + cursor);
620 if (!instruction_size)
621 return 0;
622 cursor += instruction_size;
623 }
624 return cursor;
625 }
626
627 static bool CopyInstructions(uptr to, uptr from, size_t size) {
628 size_t cursor = 0;
629 while (cursor != size) {
630 size_t rel_offset = 0;
631 size_t instruction_size = GetInstructionSize(from + cursor, &rel_offset);
632 _memcpy((void*)(to + cursor), (void*)(from + cursor),
633 (size_t)instruction_size);
634 if (rel_offset) {
635 uptr delta = to - from;
636 uptr relocated_offset = *(u32*)(to + cursor + rel_offset) - delta;
637 #if SANITIZER_WINDOWS64
638 if (relocated_offset + 0x80000000U >= 0xFFFFFFFFU)
639 return false;
640 #endif
641 *(u32*)(to + cursor + rel_offset) = relocated_offset;
642 }
643 cursor += instruction_size;
644 }
645 return true;
646 }
647
648
649 #if !SANITIZER_WINDOWS64
650 bool OverrideFunctionWithDetour(
651 uptr old_func, uptr new_func, uptr *orig_old_func) {
652 const int kDetourHeaderLen = 5;
653 const u16 kDetourInstruction = 0xFF8B;
654
655 uptr header = (uptr)old_func - kDetourHeaderLen;
656 uptr patch_length = kDetourHeaderLen + kShortJumpInstructionLength;
657
658 // Validate that the function is hookable.
659 if (*(u16*)old_func != kDetourInstruction ||
660 !IsMemoryPadding(header, kDetourHeaderLen))
661 return false;
662
663 // Change memory protection to writable.
664 DWORD protection = 0;
665 if (!ChangeMemoryProtection(header, patch_length, &protection))
666 return false;
667
668 // Write a relative jump to the redirected function.
669 WriteJumpInstruction(header, new_func);
670
671 // Write the short jump to the function prefix.
672 WriteShortJumpInstruction(old_func, header);
673
674 // Restore previous memory protection.
675 if (!RestoreMemoryProtection(header, patch_length, protection))
676 return false;
677
678 if (orig_old_func)
679 *orig_old_func = old_func + kShortJumpInstructionLength;
680
681 return true;
682 }
683 #endif
684
685 bool OverrideFunctionWithRedirectJump(
686 uptr old_func, uptr new_func, uptr *orig_old_func) {
687 // Check whether the first instruction is a relative jump.
688 if (*(u8*)old_func != 0xE9)
689 return false;
690
691 if (orig_old_func) {
692 uptr relative_offset = *(u32*)(old_func + 1);
693 uptr absolute_target = old_func + relative_offset + kJumpInstructionLength;
694 *orig_old_func = absolute_target;
695 }
696
697 #if SANITIZER_WINDOWS64
698 // If needed, get memory space for a trampoline jump.
699 uptr trampoline = AllocateMemoryForTrampoline(old_func, kDirectBranchLength);
700 if (!trampoline)
701 return false;
702 WriteDirectBranch(trampoline, new_func);
703 #endif
704
705 // Change memory protection to writable.
706 DWORD protection = 0;
707 if (!ChangeMemoryProtection(old_func, kJumpInstructionLength, &protection))
708 return false;
709
710 // Write a relative jump to the redirected function.
711 WriteJumpInstruction(old_func, FIRST_32_SECOND_64(new_func, trampoline));
712
713 // Restore previous memory protection.
714 if (!RestoreMemoryProtection(old_func, kJumpInstructionLength, protection))
715 return false;
716
717 return true;
718 }
719
720 bool OverrideFunctionWithHotPatch(
721 uptr old_func, uptr new_func, uptr *orig_old_func) {
722 const int kHotPatchHeaderLen = kBranchLength;
723
724 uptr header = (uptr)old_func - kHotPatchHeaderLen;
725 uptr patch_length = kHotPatchHeaderLen + kShortJumpInstructionLength;
726
727 // Validate that the function is hot patchable.
728 size_t instruction_size = GetInstructionSize(old_func);
729 if (instruction_size < kShortJumpInstructionLength ||
730 !FunctionHasPadding(old_func, kHotPatchHeaderLen))
731 return false;
732
733 if (orig_old_func) {
734 // Put the needed instructions into the trampoline bytes.
735 uptr trampoline_length = instruction_size + kDirectBranchLength;
736 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
737 if (!trampoline)
738 return false;
739 if (!CopyInstructions(trampoline, old_func, instruction_size))
740 return false;
741 WriteDirectBranch(trampoline + instruction_size,
742 old_func + instruction_size);
743 *orig_old_func = trampoline;
744 }
745
746 // If needed, get memory space for indirect address.
747 uptr indirect_address = 0;
748 #if SANITIZER_WINDOWS64
749 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
750 if (!indirect_address)
751 return false;
752 #endif
753
754 // Change memory protection to writable.
755 DWORD protection = 0;
756 if (!ChangeMemoryProtection(header, patch_length, &protection))
757 return false;
758
759 // Write jumps to the redirected function.
760 WriteBranch(header, indirect_address, new_func);
761 WriteShortJumpInstruction(old_func, header);
762
763 // Restore previous memory protection.
764 if (!RestoreMemoryProtection(header, patch_length, protection))
765 return false;
766
767 return true;
768 }
769
770 bool OverrideFunctionWithTrampoline(
771 uptr old_func, uptr new_func, uptr *orig_old_func) {
772
773 size_t instructions_length = kBranchLength;
774 size_t padding_length = 0;
775 uptr indirect_address = 0;
776
777 if (orig_old_func) {
778 // Find out the number of bytes of the instructions we need to copy
779 // to the trampoline.
780 instructions_length = RoundUpToInstrBoundary(kBranchLength, old_func);
781 if (!instructions_length)
782 return false;
783
784 // Put the needed instructions into the trampoline bytes.
785 uptr trampoline_length = instructions_length + kDirectBranchLength;
786 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
787 if (!trampoline)
788 return false;
789 if (!CopyInstructions(trampoline, old_func, instructions_length))
790 return false;
791 WriteDirectBranch(trampoline + instructions_length,
792 old_func + instructions_length);
793 *orig_old_func = trampoline;
794 }
795
796 #if SANITIZER_WINDOWS64
797 // Check if the targeted address can be encoded in the function padding.
798 // Otherwise, allocate it in the trampoline region.
799 if (IsMemoryPadding(old_func - kAddressLength, kAddressLength)) {
800 indirect_address = old_func - kAddressLength;
801 padding_length = kAddressLength;
802 } else {
803 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
804 if (!indirect_address)
805 return false;
806 }
807 #endif
808
809 // Change memory protection to writable.
810 uptr patch_address = old_func - padding_length;
811 uptr patch_length = instructions_length + padding_length;
812 DWORD protection = 0;
813 if (!ChangeMemoryProtection(patch_address, patch_length, &protection))
814 return false;
815
816 // Patch the original function.
817 WriteBranch(old_func, indirect_address, new_func);
818
819 // Restore previous memory protection.
820 if (!RestoreMemoryProtection(patch_address, patch_length, protection))
821 return false;
822
823 return true;
824 }
825
826 bool OverrideFunction(
827 uptr old_func, uptr new_func, uptr *orig_old_func) {
828 #if !SANITIZER_WINDOWS64
829 if (OverrideFunctionWithDetour(old_func, new_func, orig_old_func))
830 return true;
831 #endif
832 if (OverrideFunctionWithRedirectJump(old_func, new_func, orig_old_func))
833 return true;
834 if (OverrideFunctionWithHotPatch(old_func, new_func, orig_old_func))
835 return true;
836 if (OverrideFunctionWithTrampoline(old_func, new_func, orig_old_func))
837 return true;
838 return false;
839 }
840
841 static void **InterestingDLLsAvailable() {
842 static const char *InterestingDLLs[] = {
843 "kernel32.dll",
844 "msvcr100.dll", // VS2010
845 "msvcr110.dll", // VS2012
846 "msvcr120.dll", // VS2013
847 "vcruntime140.dll", // VS2015
848 "ucrtbase.dll", // Universal CRT
849 // NTDLL should go last as it exports some functions that we should
850 // override in the CRT [presumably only used internally].
851 "ntdll.dll", NULL};
852 static void *result[ARRAY_SIZE(InterestingDLLs)] = { 0 };
853 if (!result[0]) {
854 for (size_t i = 0, j = 0; InterestingDLLs[i]; ++i) {
855 if (HMODULE h = GetModuleHandleA(InterestingDLLs[i]))
856 result[j++] = (void *)h;
857 }
858 }
859 return &result[0];
860 }
861
862 namespace {
863 // Utility for reading loaded PE images.
864 template <typename T> class RVAPtr {
865 public:
866 RVAPtr(void *module, uptr rva)
867 : ptr_(reinterpret_cast<T *>(reinterpret_cast<char *>(module) + rva)) {}
868 operator T *() { return ptr_; }
869 T *operator->() { return ptr_; }
870 T *operator++() { return ++ptr_; }
871
872 private:
873 T *ptr_;
874 };
875 } // namespace
876
877 // Internal implementation of GetProcAddress. At least since Windows 8,
878 // GetProcAddress appears to initialize DLLs before returning function pointers
879 // into them. This is problematic for the sanitizers, because they typically
880 // want to intercept malloc *before* MSVCRT initializes. Our internal
881 // implementation walks the export list manually without doing initialization.
882 uptr InternalGetProcAddress(void *module, const char *func_name) {
883 // Check that the module header is full and present.
884 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
885 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
886 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
887 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
888 headers->FileHeader.SizeOfOptionalHeader <
889 sizeof(IMAGE_OPTIONAL_HEADER)) {
890 return 0;
891 }
892
893 IMAGE_DATA_DIRECTORY *export_directory =
894 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
895 if (export_directory->Size == 0)
896 return 0;
897 RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
898 export_directory->VirtualAddress);
899 RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);
900 RVAPtr<DWORD> names(module, exports->AddressOfNames);
901 RVAPtr<WORD> ordinals(module, exports->AddressOfNameOrdinals);
902
903 for (DWORD i = 0; i < exports->NumberOfNames; i++) {
904 RVAPtr<char> name(module, names[i]);
905 if (!strcmp(func_name, name)) {
906 DWORD index = ordinals[i];
907 RVAPtr<char> func(module, functions[index]);
908
909 // Handle forwarded functions.
910 DWORD offset = functions[index];
911 if (offset >= export_directory->VirtualAddress &&
912 offset < export_directory->VirtualAddress + export_directory->Size) {
913 // An entry for a forwarded function is a string with the following
914 // format: "<module> . <function_name>" that is stored into the
915 // exported directory.
916 char function_name[256];
917 size_t funtion_name_length = _strlen(func);
918 if (funtion_name_length >= sizeof(function_name) - 1)
919 InterceptionFailed();
920
921 _memcpy(function_name, func, funtion_name_length);
922 function_name[funtion_name_length] = '\0';
923 char* separator = _strchr(function_name, '.');
924 if (!separator)
925 InterceptionFailed();
926 *separator = '\0';
927
928 void* redirected_module = GetModuleHandleA(function_name);
929 if (!redirected_module)
930 InterceptionFailed();
931 return InternalGetProcAddress(redirected_module, separator + 1);
932 }
933
934 return (uptr)(char *)func;
935 }
936 }
937
938 return 0;
939 }
940
941 bool OverrideFunction(
942 const char *func_name, uptr new_func, uptr *orig_old_func) {
943 bool hooked = false;
944 void **DLLs = InterestingDLLsAvailable();
945 for (size_t i = 0; DLLs[i]; ++i) {
946 uptr func_addr = InternalGetProcAddress(DLLs[i], func_name);
947 if (func_addr &&
948 OverrideFunction(func_addr, new_func, orig_old_func)) {
949 hooked = true;
950 }
951 }
952 return hooked;
953 }
954
955 bool OverrideImportedFunction(const char *module_to_patch,
956 const char *imported_module,
957 const char *function_name, uptr new_function,
958 uptr *orig_old_func) {
959 HMODULE module = GetModuleHandleA(module_to_patch);
960 if (!module)
961 return false;
962
963 // Check that the module header is full and present.
964 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
965 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
966 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
967 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
968 headers->FileHeader.SizeOfOptionalHeader <
969 sizeof(IMAGE_OPTIONAL_HEADER)) {
970 return false;
971 }
972
973 IMAGE_DATA_DIRECTORY *import_directory =
974 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
975
976 // Iterate the list of imported DLLs. FirstThunk will be null for the last
977 // entry.
978 RVAPtr<IMAGE_IMPORT_DESCRIPTOR> imports(module,
979 import_directory->VirtualAddress);
980 for (; imports->FirstThunk != 0; ++imports) {
981 RVAPtr<const char> modname(module, imports->Name);
982 if (_stricmp(&*modname, imported_module) == 0)
983 break;
984 }
985 if (imports->FirstThunk == 0)
986 return false;
987
988 // We have two parallel arrays: the import address table (IAT) and the table
989 // of names. They start out containing the same data, but the loader rewrites
990 // the IAT to hold imported addresses and leaves the name table in
991 // OriginalFirstThunk alone.
992 RVAPtr<IMAGE_THUNK_DATA> name_table(module, imports->OriginalFirstThunk);
993 RVAPtr<IMAGE_THUNK_DATA> iat(module, imports->FirstThunk);
994 for (; name_table->u1.Ordinal != 0; ++name_table, ++iat) {
995 if (!IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
996 RVAPtr<IMAGE_IMPORT_BY_NAME> import_by_name(
997 module, name_table->u1.ForwarderString);
998 const char *funcname = &import_by_name->Name[0];
999 if (strcmp(funcname, function_name) == 0)
1000 break;
1001 }
1002 }
1003 if (name_table->u1.Ordinal == 0)
1004 return false;
1005
1006 // Now we have the correct IAT entry. Do the swap. We have to make the page
1007 // read/write first.
1008 if (orig_old_func)
1009 *orig_old_func = iat->u1.AddressOfData;
1010 DWORD old_prot, unused_prot;
1011 if (!VirtualProtect(&iat->u1.AddressOfData, 4, PAGE_EXECUTE_READWRITE,
1012 &old_prot))
1013 return false;
1014 iat->u1.AddressOfData = new_function;
1015 if (!VirtualProtect(&iat->u1.AddressOfData, 4, old_prot, &unused_prot))
1016 return false; // Not clear if this failure bothers us.
1017 return true;
1018 }
1019
1020 } // namespace __interception
1021
1022 #endif // SANITIZER_MAC
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