Index: courgette/rel32_finder_x64.cc |
diff --git a/courgette/disassembler_win32_x64.cc b/courgette/rel32_finder_x64.cc |
similarity index 52% |
copy from courgette/disassembler_win32_x64.cc |
copy to courgette/rel32_finder_x64.cc |
index c4d89e452e62875fe402af773f60110710691236..080d68f59d1f02867b0b6167b7c8a834a73a0f96 100644 |
--- a/courgette/disassembler_win32_x64.cc |
+++ b/courgette/rel32_finder_x64.cc |
@@ -1,72 +1,37 @@ |
-// Copyright 2013 The Chromium Authors. All rights reserved. |
+// Copyright 2016 The Chromium Authors. All rights reserved. |
// Use of this source code is governed by a BSD-style license that can be |
// found in the LICENSE file. |
-#include "courgette/disassembler_win32_x64.h" |
- |
-#include <algorithm> |
- |
-#include "base/logging.h" |
-#include "base/numerics/safe_conversions.h" |
-#include "courgette/assembly_program.h" |
-#include "courgette/courgette.h" |
- |
-#if COURGETTE_HISTOGRAM_TARGETS |
-#include <iostream> |
-#endif |
+#include "courgette/rel32_finder_x64.h" |
namespace courgette { |
-DisassemblerWin32X64::DisassemblerWin32X64(const void* start, size_t length) |
- : DisassemblerWin32(start, length) {} |
- |
-RVA DisassemblerWin32X64::PointerToTargetRVA(const uint8_t* p) const { |
- return Address64ToRVA(Read64LittleEndian(p)); |
-} |
- |
-RVA DisassemblerWin32X64::Address64ToRVA(uint64_t address) const { |
- if (address < image_base() || address >= image_base() + size_of_image_) |
- return kNoRVA; |
- return base::checked_cast<RVA>(address - image_base()); |
-} |
- |
-CheckBool DisassemblerWin32X64::EmitAbs(Label* label, |
- AssemblyProgram* program) { |
- return program->EmitAbs64(label); |
-} |
- |
-void DisassemblerWin32X64::ParseRel32RelocsFromSection(const Section* section) { |
- // TODO(sra): use characteristic. |
- bool isCode = strcmp(section->name, ".text") == 0; |
- if (!isCode) |
- return; |
- |
- FileOffset start_file_offset = section->file_offset_of_raw_data; |
- FileOffset end_file_offset = start_file_offset + section->size_of_raw_data; |
- RVA relocs_start_rva = base_relocation_table().address_; |
- |
- const uint8_t* start_pointer = FileOffsetToPointer(start_file_offset); |
- const uint8_t* end_pointer = FileOffsetToPointer(end_file_offset); |
- |
- RVA start_rva = FileOffsetToRVA(start_file_offset); |
- RVA end_rva = start_rva + section->virtual_size; |
+Rel32FinderX64::Rel32FinderX64(RVA relocs_start_rva, RVA relocs_end_rva) |
+ : Rel32Finder(relocs_start_rva, relocs_end_rva) {} |
+void Rel32FinderX64::Find(const uint8_t* start_pointer, |
+ const uint8_t* end_pointer, |
+ RVA start_rva, |
+ RVA end_rva, |
+ uint32_t size_of_image, |
+ const std::vector<RVA>& abs32_locations) { |
// Quick way to convert from Pointer to RVA within a single Section is to |
- // subtract |pointer_to_rva|. |
+ // subtract 'pointer_to_rva'. |
huangs
2016/05/26 22:11:17
NIT: |adjust_pointer_to_rva|.
etiennep
2016/05/27 18:12:34
Done.
|
const uint8_t* const adjust_pointer_to_rva = start_pointer - start_rva; |
- std::vector<RVA>::iterator abs32_pos = abs32_locations_.begin(); |
+ std::vector<RVA>::const_iterator abs32_pos = abs32_locations.begin(); |
// Find the rel32 relocations. |
const uint8_t* p = start_pointer; |
while (p < end_pointer) { |
RVA current_rva = static_cast<RVA>(p - adjust_pointer_to_rva); |
- if (current_rva == relocs_start_rva) { |
- uint32_t relocs_size = base_relocation_table().size_; |
- if (relocs_size) { |
- p += relocs_size; |
- continue; |
- } |
+ |
+ // Skip the base reloation table if we encounter it. |
+ // Note: We're not bothering to handle the edge case where a Rel32 pointer |
+ // collides with |relocs_start_rva_| by being {1, 2, 3}-bytes before it. |
+ if (current_rva >= relocs_start_rva_ && current_rva < relocs_end_rva_) { |
+ p += relocs_end_rva_ - current_rva; |
+ continue; |
} |
// Heuristic discovery of rel32 locations in instruction stream: are the |
@@ -81,7 +46,7 @@ void DisassemblerWin32X64::ParseRel32RelocsFromSection(const Section* section) { |
} |
if (p + 6 <= end_pointer) { |
if (*p == 0x0F && (*(p + 1) & 0xF0) == 0x80) { // Jcc long form |
- if (p[1] != 0x8A && p[1] != 0x8B) // JPE/JPO unlikely |
+ if (p[1] != 0x8A && p[1] != 0x8B) // JPE/JPO unlikely |
rel32 = p + 2; |
} else if (*p == 0xFF && (*(p + 1) == 0x15 || *(p + 1) == 0x25)) { |
// rip relative call/jmp |
@@ -107,24 +72,23 @@ void DisassemblerWin32X64::ParseRel32RelocsFromSection(const Section* section) { |
RVA rel32_rva = static_cast<RVA>(rel32 - adjust_pointer_to_rva); |
// Is there an abs32 reloc overlapping the candidate? |
- while (abs32_pos != abs32_locations_.end() && *abs32_pos < rel32_rva - 3) |
+ while (abs32_pos != abs32_locations.end() && *abs32_pos < rel32_rva - 3) |
++abs32_pos; |
// Now: (*abs32_pos > rel32_rva - 4) i.e. the lowest addressed 4-byte |
// region that could overlap rel32_rva. |
- if (abs32_pos != abs32_locations_.end()) { |
+ if (abs32_pos != abs32_locations.end()) { |
if (*abs32_pos < rel32_rva + 4) { |
// Beginning of abs32 reloc is before end of rel32 reloc so they |
- // overlap. Skip four bytes past the abs32 reloc. |
+ // overlap. Skip four bytes past the abs32 reloc. |
huangs
2016/05/26 22:11:17
NIT: Remove space before "Skip".
etiennep
2016/05/27 18:12:34
Done.
|
p += (*abs32_pos + 4) - current_rva; |
continue; |
} |
} |
huangs
2016/05/26 22:40:55
Why did the comment disappear?
etiennep
2016/05/27 18:12:34
Idk, it's back now!
|
- // + 4 since offset is relative to start of next instruction. |
RVA target_rva = rel32_rva + 4 + Read32LittleEndian(rel32); |
// To be valid, rel32 target must be within image, and within this |
// section. |
- if (target_rva < size_of_image_ && // Subsumes rva != kUnassignedRVA. |
+ if (target_rva < size_of_image && // Subsumes rva != kUnassignedRVA. |
huangs
2016/05/26 22:40:55
target_rva < size_of_image
seems kinda bogus and
etiennep
2016/05/27 18:12:34
I moved size_of_image as an member variable. It wo
|
(is_rip_relative || |
(start_rva <= target_rva && target_rva < end_rva))) { |
rel32_locations_.push_back(rel32_rva); |