Noratrieb/uwuwind
1
0
Fork 0
mirror of https://github.com/Noratrieb/uwuwind.git synced 2026-01-16 01:25:07 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

parse more

Browse source
This commit is contained in:
nora 2023-06-18 00:25:05 +02:00
parent e7e9689e66
commit f8cf93c92b
2 changed files with 136 additions and 115 deletions
Download patch file Download diff file Expand all files Collapse all files

112
src/dwarf/divination.rs
View file

@ -13,9 +13,10 @@
#![allow(non_camel_case_types)]
use core::{ffi, fmt};
use core::ffi;
use crate::{stdext::with_last_os_error_str, Addr};
use super::parse::Encoding;
use crate::{dwarf::parse::read_encoded, stdext::with_last_os_error_str, Addr};
#[repr(C)]
struct dl_find_object {
@ -36,6 +37,7 @@ extern "C" {
/// See <https://refspecs.linuxfoundation.org/LSB_1.3.0/gLSB/gLSB/ehframehdr.html>
/// and <https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html>.
#[derive(Debug)]
#[repr(C)]
struct EhFrameHeader {
version: u8,
eh_frame_ptr_enc: Encoding,
@ -78,6 +80,8 @@ pub(crate) fn eh_frame(addr: Addr) -> Option<*const u8> {
unsafe {
let ptr = eh_frame_hdr_ptr(addr)?;
let header = ptr.read();
// ptr now points to `eh_frame_ptr`.
let ptr = ptr.cast::<u8>().add(4);
if header.version != 1 {
@ -87,8 +91,9 @@ pub(crate) fn eh_frame(addr: Addr) -> Option<*const u8> {
trace!("eh_frame_hdr: {:#?}", header);
let (ptr, eh_frame_ptr) = read_encoded(ptr, header.eh_frame_ptr_enc);
let (_ptr, fde_count) = read_encoded(ptr, header.fde_count_enc);
let (read_size, eh_frame_ptr) = read_encoded(ptr, header.eh_frame_ptr_enc);
let ptr = ptr.add(read_size);
let (_read_size, fde_count) = read_encoded(ptr, header.fde_count_enc);
trace!("eh_frame: {eh_frame_ptr:?}");
trace!("fde_count: {fde_count:?}");
@ -103,102 +108,3 @@ pub(crate) fn eh_frame(addr: Addr) -> Option<*const u8> {
Some(eh_frame_ptr as *const u8)
}
}
unsafe fn read_encoded(ptr: *const u8, encoding: Encoding) -> (*const u8, usize) {
let (new_ptr, value) = match encoding.format() {
ValueFormat::DW_EH_PE_uleb128 => todo!("uleb128"),
ValueFormat::DW_EH_PE_udata2 => (ptr.add(2), ptr.cast::<u16>().read_unaligned() as usize),
ValueFormat::DW_EH_PE_udata4 => (ptr.add(4), ptr.cast::<u32>().read_unaligned() as usize),
ValueFormat::DW_EH_PE_udata8 => (ptr.add(8), ptr.cast::<u64>().read_unaligned() as usize),
ValueFormat::DW_EH_PE_sleb128 => todo!("sleb128"),
ValueFormat::DW_EH_PE_sdata2 => (ptr.add(2), ptr.cast::<i16>().read_unaligned() as usize),
ValueFormat::DW_EH_PE_sdata4 => (ptr.add(4), ptr.cast::<i32>().read_unaligned() as usize),
ValueFormat::DW_EH_PE_sdata8 => (ptr.add(8), ptr.cast::<i64>().read_unaligned() as usize),
};
let value = match encoding.application() {
ValueApplication::DW_EH_PE_absptr => value,
ValueApplication::DW_EH_PE_pcrel => ((value as isize) + (ptr as isize)) as usize,
ValueApplication::DW_EH_PE_textrel => todo!("textrel"),
ValueApplication::DW_EH_PE_datarel => todo!("datarel"),
ValueApplication::DW_EH_PE_funcrel => todo!("funcrel"),
ValueApplication::DW_EH_PE_aligned => todo!("aligned"),
};
(new_ptr, value)
}
struct Encoding(u8);
impl Encoding {
fn format(&self) -> ValueFormat {
match self.0 & 0b1111 {
0x01 => ValueFormat::DW_EH_PE_uleb128,
0x02 => ValueFormat::DW_EH_PE_udata2,
0x03 => ValueFormat::DW_EH_PE_udata4,
0x04 => ValueFormat::DW_EH_PE_udata8,
0x09 => ValueFormat::DW_EH_PE_sleb128,
0x0A => ValueFormat::DW_EH_PE_sdata2,
0x0B => ValueFormat::DW_EH_PE_sdata4,
0x0C => ValueFormat::DW_EH_PE_sdata8,
_ => panic!("Invalid header value format"),
}
}
fn application(&self) -> ValueApplication {
match self.0 >> 4 {
0x0 => ValueApplication::DW_EH_PE_absptr,
0x1 => ValueApplication::DW_EH_PE_pcrel,
0x2 => ValueApplication::DW_EH_PE_textrel,
0x3 => ValueApplication::DW_EH_PE_datarel,
0x4 => ValueApplication::DW_EH_PE_funcrel,
0x5 => ValueApplication::DW_EH_PE_aligned,
v => panic!("invalid header value application: {v}"),
}
}
}
impl fmt::Debug for Encoding {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?} | {:?}", self.application(), self.format())
}
}
#[derive(Debug, Clone, Copy)]
#[repr(u8)]
enum ValueFormat {
/// Unsigned value is encoded using the Little Endian Base 128 (LEB128) as
/// defined by DWARF Debugging Information Format, Revision 2.0.0 (July 27,
/// 1993).
DW_EH_PE_uleb128 = 0x01,
/// A 2 bytes unsigned value.
DW_EH_PE_udata2 = 0x02,
/// A 4 bytes unsigned value.
DW_EH_PE_udata4 = 0x03,
/// An 8 bytes unsigned value.
DW_EH_PE_udata8 = 0x04,
/// Signed value is encoded using the Little Endian Base 128 (LEB128) as
/// defined by DWARF Debugging Information Format, Revision 2.0.0 (July 27,
/// 1993).
DW_EH_PE_sleb128 = 0x09,
/// A 2 bytes signed value.
DW_EH_PE_sdata2 = 0x0A,
/// A 4 bytes signed value.
DW_EH_PE_sdata4 = 0x0B,
/// An 8 bytes signed value.
DW_EH_PE_sdata8 = 0x0C,
}
#[derive(Debug)]
#[repr(u8)]
enum ValueApplication {
DW_EH_PE_absptr = 0x00,
/// Value is relative to the current program counter.
DW_EH_PE_pcrel = 0x10,
/// Value is relative to the beginning of the .text section.
DW_EH_PE_textrel = 0x20,
/// Value is relative to the beginning of the .got or .eh_frame_hdr section.
DW_EH_PE_datarel = 0x30,
/// Value is relative to the beginning of the function.
DW_EH_PE_funcrel = 0x40,
/// Value is aligned to an address unit sized boundary.
DW_EH_PE_aligned = 0x50,
}