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jrmuizeljrmuizel
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Display the absolute address for relative jumps on x86
yaxpeax doesn't have support for doing this natively so just shim it on top.
1 parent d4b3fa2 commit 1a8461f

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+83
-14
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2 files changed

+83
-14
lines changed

‎fixtures/snapshots/asm_x86_64.txt

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1 +1 @@
1-
{"startAddress":"0x17a20","size":"0x3d","arch":"x86_64","syntax":["Intel","C style"],"instructions":[[0,"jl $-0x64","if /* signed */ less(rflags) then jmp $-0x64"],[2,"add eax, dword [rax]","eax += [rax]"],[4,"mov edx, 0x38","edx = 0x38"],[9,"mov rcx, r15","rcx = r15"],[12,"call 0x39c6f","0x39c6f = call(0x39c6f)"],[17,"xor eax, eax","eax ^= eax"],[19,"jmp $+0x9a","jmp $+0x9a"],[24,"mov rbx, qword [r15]","rbx = [r15]"],[27,"cmp rbx, rax","rflags = flags(rbx - rax)"],[30,"jz $+0x35","if zero(rflags) then jmp $+0x35"],[32,"mov rdx, qword [r15 + 0x8]","rdx = [r15 + 0x8]"],[36,"mov qword [rdx], rbx","[rdx] = rbx"],[39,"mov rdx, qword [rbx + 0x8]","rdx = [rbx + 0x8]"],[43,"mov qword [rdx], rax","[rdx] = rax"],[46,"mov rdx, qword [rax + 0x8]","rdx = [rax + 0x8]"],[50,"mov qword [rdx], r15","[rdx] = r15"],[53,"mov rdx, qword [rax + 0x8]","rdx = [rax + 0x8]"],[57,"mov rbp, qword [rbx + 0x8]","rbp = [rbx + 0x8]"]]}
1+
{"startAddress":"0x17a20","size":"0x3d","arch":"x86_64","syntax":["Intel","C style"],"instructions":[[0,"jl 0x179be","jl 0x179be"],[2,"add eax, dword [rax]","eax += [rax]"],[4,"mov edx, 0x38","edx = 0x38"],[9,"mov rcx, r15","rcx = r15"],[12,"call 0x39c6f","0x39c6f = call(0x39c6f)"],[17,"xor eax, eax","eax ^= eax"],[19,"jmp 0x17ad2","jmp 0x17ad2"],[24,"mov rbx, qword [r15]","rbx = [r15]"],[27,"cmp rbx, rax","rflags = flags(rbx - rax)"],[30,"jz 0x17a75","jz 0x17a75"],[32,"mov rdx, qword [r15 + 0x8]","rdx = [r15 + 0x8]"],[36,"mov qword [rdx], rbx","[rdx] = rbx"],[39,"mov rdx, qword [rbx + 0x8]","rdx = [rbx + 0x8]"],[43,"mov qword [rdx], rax","[rdx] = rax"],[46,"mov rdx, qword [rax + 0x8]","rdx = [rax + 0x8]"],[50,"mov qword [rdx], r15","[rdx] = r15"],[53,"mov rdx, qword [rax + 0x8]","rdx = [rax + 0x8]"],[57,"mov rbp, qword [rbx + 0x8]","rbp = [rbx + 0x8]"]]}

‎samply-api/src/asm/mod.rs

Lines changed: 82 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,8 @@ use samply_symbols::{
55
FileAndPathHelperError, LibraryInfo, SymbolManager,
66
};
77
use serde_json::json;
8-
use yaxpeax_arch::{Arch, DecodeError, Reader, U8Reader};
8+
use yaxpeax_arch::{Arch, DecodeError, LengthedInstruction, Reader, U8Reader};
9+
use yaxpeax_x86::amd64::{Opcode, Operand};
910

1011
use crate::asm::response_json::DecodedInstruction;
1112

@@ -192,7 +193,8 @@ trait InstructionDecoding: Arch {
192193
const SYNTAX: &'static [&'static str];
193194
const ADJUST_BY_AFTER_ERROR: usize;
194195
fn make_decoder() -> Self::Decoder;
195-
fn stringify_inst(offset: u32, inst: Self::Instruction) -> DecodedInstruction;
196+
fn stringify_inst(rel_address: u32, offset: u32, inst: Self::Instruction)
197+
-> DecodedInstruction;
196198
}
197199

198200
impl InstructionDecoding for yaxpeax_x86::amd64::Arch {
@@ -204,15 +206,70 @@ impl InstructionDecoding for yaxpeax_x86::amd64::Arch {
204206
yaxpeax_x86::amd64::InstDecoder::default()
205207
}
206208

207-
fn stringify_inst(offset: u32, inst: Self::Instruction) -> DecodedInstruction {
209+
fn stringify_inst(
210+
rel_address: u32,
211+
offset: u32,
212+
inst: Self::Instruction,
213+
) -> DecodedInstruction {
214+
let (mut intel_insn, mut c_insn) = (
215+
inst.display_with(yaxpeax_x86::amd64::DisplayStyle::Intel)
216+
.to_string(),
217+
inst.display_with(yaxpeax_x86::amd64::DisplayStyle::C)
218+
.to_string(),
219+
);
220+
221+
fn is_relative_branch(opcode: Opcode) -> bool {
222+
matches!(
223+
opcode,
224+
Opcode::JMP
225+
| Opcode::JRCXZ
226+
| Opcode::LOOP
227+
| Opcode::LOOPZ
228+
| Opcode::LOOPNZ
229+
| Opcode::JO
230+
| Opcode::JNO
231+
| Opcode::JB
232+
| Opcode::JNB
233+
| Opcode::JZ
234+
| Opcode::JNZ
235+
| Opcode::JNA
236+
| Opcode::JA
237+
| Opcode::JS
238+
| Opcode::JNS
239+
| Opcode::JP
240+
| Opcode::JNP
241+
| Opcode::JL
242+
| Opcode::JGE
243+
| Opcode::JLE
244+
| Opcode::JG
245+
)
246+
}
247+
248+
if is_relative_branch(inst.opcode()) {
249+
match inst.operand(0) {
250+
Operand::ImmediateI8(rel) => {
251+
let dest = rel_address as i64
252+
+ offset as i64
253+
+ inst.len().to_const() as i64
254+
+ rel as i64;
255+
intel_insn = format!("{} 0x{:x}", inst.opcode(), dest);
256+
c_insn = intel_insn.clone();
257+
}
258+
Operand::ImmediateI32(rel) => {
259+
let dest = rel_address as i64
260+
+ offset as i64
261+
+ inst.len().to_const() as i64
262+
+ rel as i64;
263+
intel_insn = format!("{} 0x{:x}", inst.opcode(), dest);
264+
c_insn = intel_insn.clone();
265+
}
266+
_ => {}
267+
};
268+
}
269+
208270
DecodedInstruction {
209271
offset,
210-
decoded_string_per_syntax: vec![
211-
inst.display_with(yaxpeax_x86::amd64::DisplayStyle::Intel)
212-
.to_string(),
213-
inst.display_with(yaxpeax_x86::amd64::DisplayStyle::C)
214-
.to_string(),
215-
],
272+
decoded_string_per_syntax: vec![intel_insn, c_insn],
216273
}
217274
}
218275
}
@@ -226,7 +283,11 @@ impl InstructionDecoding for yaxpeax_x86::protected_mode::Arch {
226283
yaxpeax_x86::protected_mode::InstDecoder::default()
227284
}
228285

229-
fn stringify_inst(offset: u32, inst: Self::Instruction) -> DecodedInstruction {
286+
fn stringify_inst(
287+
_rel_address: u32,
288+
offset: u32,
289+
inst: Self::Instruction,
290+
) -> DecodedInstruction {
230291
DecodedInstruction {
231292
offset,
232293
decoded_string_per_syntax: vec![inst.to_string()],
@@ -243,7 +304,11 @@ impl InstructionDecoding for yaxpeax_arm::armv8::a64::ARMv8 {
243304
yaxpeax_arm::armv8::a64::InstDecoder::default()
244305
}
245306

246-
fn stringify_inst(offset: u32, inst: Self::Instruction) -> DecodedInstruction {
307+
fn stringify_inst(
308+
_rel_address: u32,
309+
offset: u32,
310+
inst: Self::Instruction,
311+
) -> DecodedInstruction {
247312
DecodedInstruction {
248313
offset,
249314
decoded_string_per_syntax: vec![inst.to_string()],
@@ -271,7 +336,11 @@ impl InstructionDecoding for yaxpeax_arm::armv7::ARMv7 {
271336
yaxpeax_arm::armv7::InstDecoder::default_thumb()
272337
}
273338

274-
fn stringify_inst(offset: u32, inst: Self::Instruction) -> DecodedInstruction {
339+
fn stringify_inst(
340+
_rel_address: u32,
341+
offset: u32,
342+
inst: Self::Instruction,
343+
) -> DecodedInstruction {
275344
DecodedInstruction {
276345
offset,
277346
decoded_string_per_syntax: vec![inst.to_string()],
@@ -300,7 +369,7 @@ where
300369
let before = u64::from(reader.total_offset()) as u32;
301370
match decoder.decode(&mut reader) {
302371
Ok(inst) => {
303-
instructions.push(A::stringify_inst(offset, inst));
372+
instructions.push(A::stringify_inst(rel_address, offset, inst));
304373
let after = u64::from(reader.total_offset()) as u32;
305374
offset += after - before;
306375
}

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