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Issue 2008253004: Refactor rel32 searching process for x64 to make it more similar to x86. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Correct far away ptr in rel32_x64_03.txt test case Created 4 years, 6 months ago
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1 // Copyright 2015 The Chromium Authors. All rights reserved. 1 // Copyright 2015 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 4
5 #include <stdint.h> 5 #include "courgette/rel32_finder_x86.h"
6
7 #include "courgette/rel32_finder_win32_x86.h"
8 6
9 namespace courgette { 7 namespace courgette {
10 8
11 Rel32FinderWin32X86::Rel32FinderWin32X86(RVA relocs_start_rva, 9 Rel32FinderX86::Rel32FinderX86(RVA relocs_start_rva, RVA relocs_end_rva)
12 RVA relocs_end_rva) 10 : Rel32Finder(relocs_start_rva, relocs_end_rva) {}
13 : relocs_start_rva_(relocs_start_rva), relocs_end_rva_(relocs_end_rva) {
14 }
15 11
16 Rel32FinderWin32X86::~Rel32FinderWin32X86() { 12 // Scan for opcodes matching the following instructions :
17 } 13 // rel32 JMP/CALL
18 14 // Jcc (excluding JPO/JPE)
19 void Rel32FinderWin32X86::SwapRel32Locations(std::vector<RVA>* dest) { 15 // Falsely detected rel32 that collide with known abs32 or that point outside
20 dest->swap(rel32_locations_); 16 // valid regions are discarded.
21 } 17 void Rel32FinderX86::Find(const uint8_t* start_pointer,
22 18 const uint8_t* end_pointer,
23 #if COURGETTE_HISTOGRAM_TARGETS 19 RVA start_rva,
24 void Rel32FinderWin32X86::SwapRel32TargetRVAs(std::map<RVA, int>* dest) { 20 RVA end_rva,
25 dest->swap(rel32_target_rvas_); 21 const std::vector<RVA>& abs32_locations) {
26 }
27 #endif
28
29 Rel32FinderWin32X86_Basic::Rel32FinderWin32X86_Basic(RVA relocs_start_rva,
30 RVA relocs_end_rva)
31 : Rel32FinderWin32X86(relocs_start_rva, relocs_end_rva) {
32 }
33
34 Rel32FinderWin32X86_Basic::~Rel32FinderWin32X86_Basic() {
35 }
36
37 void Rel32FinderWin32X86_Basic::Find(const uint8_t* start_pointer,
38 const uint8_t* end_pointer,
39 RVA start_rva,
40 RVA end_rva,
41 const std::vector<RVA>& abs32_locations) {
42 // Quick way to convert from Pointer to RVA within a single Section is to 22 // Quick way to convert from Pointer to RVA within a single Section is to
43 // subtract 'pointer_to_rva'. 23 // subtract |adjust_pointer_to_rva|.
44 const uint8_t* const adjust_pointer_to_rva = start_pointer - start_rva; 24 const uint8_t* const adjust_pointer_to_rva = start_pointer - start_rva;
45 25
46 std::vector<RVA>::const_iterator abs32_pos = abs32_locations.begin(); 26 std::vector<RVA>::const_iterator abs32_pos = abs32_locations.begin();
47 27
48 // Find the rel32 relocations. 28 // Find the rel32 relocations.
49 const uint8_t* p = start_pointer; 29 const uint8_t* p = start_pointer;
50 while (p < end_pointer) { 30 while (p < end_pointer) {
51 RVA current_rva = static_cast<RVA>(p - adjust_pointer_to_rva); 31 RVA current_rva = static_cast<RVA>(p - adjust_pointer_to_rva);
52 32
53 // Skip the base reloation table if we encounter it. 33 // Skip the base reloation table if we encounter it.
54 // Note: We're not bothering to handle the edge case where a Rel32 pointer 34 // Note: We're not bothering to handle the edge case where a Rel32 pointer
55 // collides with |relocs_start_rva_| by being {1, 2, 3}-bytes before it. 35 // collides with |relocs_start_rva_| by being {1, 2, 3}-bytes before it.
56 if (current_rva == relocs_start_rva_) { 36 if (current_rva >= relocs_start_rva_ && current_rva < relocs_end_rva_) {
57 if (relocs_start_rva_ < relocs_end_rva_) { 37 p += relocs_end_rva_ - current_rva;
58 p += relocs_end_rva_ - relocs_start_rva_; 38 continue;
59 continue;
60 }
61 } 39 }
62 40
63 // Heuristic discovery of rel32 locations in instruction stream: are the 41 // Heuristic discovery of rel32 locations in instruction stream: are the
64 // next few bytes the start of an instruction containing a rel32 42 // next few bytes the start of an instruction containing a rel32
65 // addressing mode? 43 // addressing mode?
66 const uint8_t* rel32 = nullptr; 44 const uint8_t* rel32 = nullptr;
67 45
68 if (p + 5 <= end_pointer) { 46 if (p + 5 <= end_pointer) {
69 if (*p == 0xE8 || *p == 0xE9) { // jmp rel32 and call rel32 47 if (p[0] == 0xE8 || p[0] == 0xE9) { // jmp rel32 and call rel32
70 rel32 = p + 1; 48 rel32 = p + 1;
71 } 49 }
72 } 50 }
73 if (p + 6 <= end_pointer) { 51 if (p + 6 <= end_pointer) {
74 if (*p == 0x0F && (*(p+1) & 0xF0) == 0x80) { // Jcc long form 52 if (p[0] == 0x0F && (p[1] & 0xF0) == 0x80) { // Jcc long form
75 if (p[1] != 0x8A && p[1] != 0x8B) // JPE/JPO unlikely 53 if (p[1] != 0x8A && p[1] != 0x8B) // JPE/JPO unlikely
76 rel32 = p + 2; 54 rel32 = p + 2;
77 } 55 }
78 } 56 }
79 if (rel32) { 57 if (rel32) {
80 RVA rel32_rva = static_cast<RVA>(rel32 - adjust_pointer_to_rva); 58 RVA rel32_rva = static_cast<RVA>(rel32 - adjust_pointer_to_rva);
81 59
82 // Is there an abs32 reloc overlapping the candidate? 60 // Is there an abs32 reloc overlapping the candidate?
83 while (abs32_pos != abs32_locations.end() && *abs32_pos < rel32_rva - 3) 61 while (abs32_pos != abs32_locations.end() && *abs32_pos < rel32_rva - 3)
84 ++abs32_pos; 62 ++abs32_pos;
85 // Now: (*abs32_pos > rel32_rva - 4) i.e. the lowest addressed 4-byte 63 // Now: (*abs32_pos > rel32_rva - 4) i.e. the lowest addressed 4-byte
(...skipping 18 matching lines...) Expand all
104 #endif 82 #endif
105 p = rel32 + 4; 83 p = rel32 + 4;
106 continue; 84 continue;
107 } 85 }
108 } 86 }
109 p += 1; 87 p += 1;
110 } 88 }
111 } 89 }
112 90
113 } // namespace courgette 91 } // namespace courgette
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