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Add initial support for x86-64 relocations

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This commit is contained in:
Luke Street
2025-03-09 22:45:29 -06:00
parent 3965a035fa
commit c6971f3f2d
7 changed files with 1914 additions and 34 deletions
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123
objdiff-core/src/arch/x86.rs
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@@ -15,17 +15,36 @@ use crate::{
#[derive(Debug)]
pub struct ArchX86 {
bits: u32,
arch: Architecture,
endianness: object::Endianness,
}
#[derive(Debug)]
enum Architecture {
X86,
X86_64,
}
impl ArchX86 {
pub fn new(object: &object::File) -> Result<Self> {
Ok(Self { bits: if object.is_64() { 64 } else { 32 }, endianness: object.endianness() })
let arch = match object.architecture() {
object::Architecture::I386 => Architecture::X86,
object::Architecture::X86_64 => Architecture::X86_64,
_ => bail!("Unsupported architecture for ArchX86: {:?}", object.architecture()),
};
Ok(Self { arch, endianness: object.endianness() })
}
fn decoder<'a>(&self, code: &'a [u8], address: u64) -> Decoder<'a> {
Decoder::with_ip(self.bits, code, address, DecoderOptions::NONE)
Decoder::with_ip(
match self.arch {
Architecture::X86 => 32,
Architecture::X86_64 => 64,
},
code,
address,
DecoderOptions::NONE,
)
}
fn formatter(&self, diff_config: &DiffObjConfig) -> Box<dyn iced_x86::Formatter> {
@@ -38,6 +57,27 @@ impl ArchX86 {
formatter.options_mut().set_space_after_operand_separator(diff_config.space_between_args);
formatter
}
fn reloc_size(&self, flags: RelocationFlags) -> Option<usize> {
match self.arch {
Architecture::X86 => match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_I386_DIR16 | pe::IMAGE_REL_I386_REL16 => Some(2),
pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32 => Some(4),
_ => None,
},
_ => None,
},
Architecture::X86_64 => match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_AMD64_ADDR32NB | pe::IMAGE_REL_AMD64_REL32 => Some(4),
pe::IMAGE_REL_AMD64_ADDR64 => Some(8),
_ => None,
},
_ => None,
},
}
}
}
impl Arch for ArchX86 {
@@ -88,10 +128,9 @@ impl Arch for ArchX86 {
// memory operand.
let mut reloc_replace = None;
if let Some(reloc) = resolved.relocation {
const PLACEHOLDER: u64 = 0x7BDE3E7D; // chosen by fair dice roll.
// guaranteed to be random.
const PLACEHOLDER: u64 = 0x7BDE3E7D; // chosen by fair dice roll. guaranteed to be random.
let reloc_offset = reloc.relocation.address - resolved.ins_ref.address;
let reloc_size = reloc_size(reloc.relocation.flags).unwrap_or(usize::MAX);
let reloc_size = self.reloc_size(reloc.relocation.flags).unwrap_or(usize::MAX);
let offsets = decoder.get_constant_offsets(&instruction);
if reloc_offset == offsets.displacement_offset() as u64
&& reloc_size == offsets.displacement_size()
@@ -148,12 +187,28 @@ impl Arch for ArchX86 {
_relocation: &object::Relocation,
flags: RelocationFlags,
) -> Result<i64> {
match flags {
RelocationFlags::Coff(pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32) => {
let data = section.data()?[address as usize..address as usize + 4].try_into()?;
Ok(self.endianness.read_i32_bytes(data) as i64)
}
flags => bail!("Unsupported x86 implicit relocation {flags:?}"),
match self.arch {
Architecture::X86 => match flags {
RelocationFlags::Coff(pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32) => {
let data =
section.data()?[address as usize..address as usize + 4].try_into()?;
Ok(self.endianness.read_i32_bytes(data) as i64)
}
flags => bail!("Unsupported x86 implicit relocation {flags:?}"),
},
Architecture::X86_64 => match flags {
RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR32NB | pe::IMAGE_REL_AMD64_REL32) => {
let data =
section.data()?[address as usize..address as usize + 4].try_into()?;
Ok(self.endianness.read_i32_bytes(data) as i64)
}
RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR64) => {
let data =
section.data()?[address as usize..address as usize + 8].try_into()?;
Ok(self.endianness.read_i64_bytes(data))
}
flags => bail!("Unsupported x86-64 implicit relocation {flags:?}"),
},
}
}
@@ -168,27 +223,29 @@ impl Arch for ArchX86 {
}
fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_I386_DIR32 => Some("IMAGE_REL_I386_DIR32"),
pe::IMAGE_REL_I386_REL32 => Some("IMAGE_REL_I386_REL32"),
match self.arch {
Architecture::X86 => match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_I386_DIR32 => Some("IMAGE_REL_I386_DIR32"),
pe::IMAGE_REL_I386_REL32 => Some("IMAGE_REL_I386_REL32"),
_ => None,
},
_ => None,
},
Architecture::X86_64 => match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_AMD64_ADDR64 => Some("IMAGE_REL_AMD64_ADDR64"),
pe::IMAGE_REL_AMD64_ADDR32NB => Some("IMAGE_REL_AMD64_ADDR32NB"),
pe::IMAGE_REL_AMD64_REL32 => Some("IMAGE_REL_AMD64_REL32"),
_ => None,
},
_ => None,
},
_ => None,
}
}
fn data_reloc_size(&self, flags: RelocationFlags) -> usize { reloc_size(flags).unwrap_or(1) }
}
fn reloc_size(flags: RelocationFlags) -> Option<usize> {
match flags {
RelocationFlags::Coff(typ) => match typ {
pe::IMAGE_REL_I386_DIR16 | pe::IMAGE_REL_I386_REL16 => Some(2),
pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32 => Some(4),
_ => None,
},
_ => None,
fn data_reloc_size(&self, flags: RelocationFlags) -> usize {
self.reloc_size(flags).unwrap_or(1)
}
}
@@ -343,7 +400,7 @@ mod test {
#[test]
fn test_scan_instructions() {
let arch = ArchX86 { bits: 32, endianness: object::Endianness::Little };
let arch = ArchX86 { arch: Architecture::X86, endianness: object::Endianness::Little };
let code = [
0xc7, 0x85, 0x68, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x8b, 0x04, 0x85, 0x00,
0x00, 0x00, 0x00,
@@ -362,7 +419,7 @@ mod test {
#[test]
fn test_process_instruction() {
let arch = ArchX86 { bits: 32, endianness: object::Endianness::Little };
let arch = ArchX86 { arch: Architecture::X86, endianness: object::Endianness::Little };
let code = [0xc7, 0x85, 0x68, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00];
let opcode = iced_x86::Mnemonic::Mov as u16;
let mut parts = Vec::new();
@@ -398,7 +455,7 @@ mod test {
#[test]
fn test_process_instruction_with_reloc_1() {
let arch = ArchX86 { bits: 32, endianness: object::Endianness::Little };
let arch = ArchX86 { arch: Architecture::X86, endianness: object::Endianness::Little };
let code = [0xc7, 0x85, 0x68, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00];
let opcode = iced_x86::Mnemonic::Mov as u16;
let mut parts = Vec::new();
@@ -443,7 +500,7 @@ mod test {
#[test]
fn test_process_instruction_with_reloc_2() {
let arch = ArchX86 { bits: 32, endianness: object::Endianness::Little };
let arch = ArchX86 { arch: Architecture::X86, endianness: object::Endianness::Little };
let code = [0x8b, 0x04, 0x85, 0x00, 0x00, 0x00, 0x00];
let opcode = iced_x86::Mnemonic::Mov as u16;
let mut parts = Vec::new();
@@ -486,7 +543,7 @@ mod test {
#[test]
fn test_process_instruction_with_reloc_3() {
let arch = ArchX86 { bits: 32, endianness: object::Endianness::Little };
let arch = ArchX86 { arch: Architecture::X86, endianness: object::Endianness::Little };
let code = [0xe8, 0x00, 0x00, 0x00, 0x00];
let opcode = iced_x86::Mnemonic::Call as u16;
let mut parts = Vec::new();