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Cleanup & move extab code into ppc arch

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This commit is contained in:
Luke Street
2024-09-09 19:43:10 -06:00
parent c7e6394628
commit dcf209aac5
7 changed files with 207 additions and 186 deletions
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139
objdiff-core/src/obj/read.rs
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@@ -1,15 +1,14 @@
use std::{collections::HashSet, fs, io::Cursor, mem::size_of, path::Path};
use anyhow::{anyhow, bail, ensure, Context, Result};
use cwextab::decode_extab;
use filetime::FileTime;
use flagset::Flags;
use object::{
endian::LittleEndian as LE,
pe::{ImageAuxSymbolFunctionBeginEnd, ImageLinenumber},
read::coff::{CoffFile, CoffHeader, ImageSymbol},
Architecture, BinaryFormat, File, Object, ObjectSection, ObjectSymbol, RelocationTarget,
SectionIndex, SectionKind, Symbol, SymbolIndex, SymbolKind, SymbolScope, SymbolSection,
BinaryFormat, File, Object, ObjectSection, ObjectSymbol, RelocationTarget, SectionIndex,
SectionKind, Symbol, SymbolIndex, SymbolKind, SymbolScope, SymbolSection,
};
use crate::{
@@ -17,8 +16,7 @@ use crate::{
diff::DiffObjConfig,
obj::{
split_meta::{SplitMeta, SPLITMETA_SECTION},
ObjExtab, ObjInfo, ObjReloc, ObjSection, ObjSectionKind, ObjSymbol, ObjSymbolFlagSet,
ObjSymbolFlags,
ObjInfo, ObjReloc, ObjSection, ObjSectionKind, ObjSymbol, ObjSymbolFlagSet, ObjSymbolFlags,
},
util::{read_u16, read_u32},
};
@@ -60,6 +58,13 @@ fn to_obj_symbol(
if obj_file.format() == BinaryFormat::Elf && symbol.scope() == SymbolScope::Linkage {
flags = ObjSymbolFlagSet(flags.0 | ObjSymbolFlags::Hidden);
}
if arch
.ppc()
.and_then(|a| a.extab.as_ref())
.map_or(false, |e| e.contains_key(&symbol.index().0))
{
flags = ObjSymbolFlagSet(flags.0 | ObjSymbolFlags::HasExtra);
}
let address = arch.symbol_address(symbol);
let section_address = if let Some(section) =
symbol.section_index().and_then(|idx| obj_file.section_by_index(idx).ok())
@@ -76,9 +81,6 @@ fn to_obj_symbol(
Ok(ObjSymbol {
name: name.to_string(),
demangled_name,
has_extab: false,
extab_name: None,
extabindex_name: None,
address,
section_address,
size: symbol.size(),
@@ -86,6 +88,7 @@ fn to_obj_symbol(
flags,
addend,
virtual_address,
original_index: Some(symbol.index().0),
})
}
@@ -168,9 +171,6 @@ fn symbols_by_section(
result.push(ObjSymbol {
name: format!("[{}]", section.name),
demangled_name: None,
has_extab: false,
extab_name: None,
extabindex_name: None,
address: 0,
section_address: 0,
size: section.size,
@@ -178,6 +178,7 @@ fn symbols_by_section(
flags: Default::default(),
addend: 0,
virtual_address: None,
original_index: None,
});
}
Ok(result)
@@ -195,111 +196,6 @@ fn common_symbols(
.collect::<Result<Vec<ObjSymbol>>>()
}
fn section_by_name<'a>(sections: &'a mut [ObjSection], name: &str) -> Option<&'a mut ObjSection> {
sections.iter_mut().find(|section| section.name == name)
}
fn exception_tables(
sections: &mut [ObjSection],
obj_file: &File<'_>,
) -> Result<Option<Vec<ObjExtab>>> {
//PowerPC only
if obj_file.architecture() != Architecture::PowerPc {
return Ok(None);
}
//Find the extab/extabindex sections
let extab_section = match section_by_name(sections, "extab") {
Some(section) => section.clone(),
None => {
return Ok(None);
}
};
let extabindex_section = match section_by_name(sections, "extabindex") {
Some(section) => section.clone(),
None => {
return Ok(None);
}
};
let text_section = match section_by_name(sections, ".text") {
Some(section) => section,
None => bail!(".text section is somehow missing, this should not happen"),
};
let mut result: Vec<ObjExtab> = vec![];
let extab_symbol_count = extab_section.symbols.len();
let extabindex_symbol_count = extabindex_section.symbols.len();
let extab_reloc_count = extab_section.relocations.len();
let table_count = extab_symbol_count;
let mut extab_reloc_index: usize = 0;
//Make sure that the number of symbols in the extab/extabindex section matches. If not, exit early
if extab_symbol_count != extabindex_symbol_count {
bail!("Extab/Extabindex symbol counts do not match");
}
//Convert the extab/extabindex section data
//Go through each extabindex entry
for i in 0..table_count {
let extabindex = &extabindex_section.symbols[i];
/* Get the function symbol and extab symbol from the extabindex relocations array. Each extabindex
entry has two relocations (the first for the function, the second for the extab entry) */
let extab_func = extabindex_section.relocations[i * 2].target.clone();
let extab = &extabindex_section.relocations[(i * 2) + 1].target;
let extab_start_addr = extab.address;
let extab_end_addr = extab_start_addr + extab.size;
//Find the function in the text section, and set the has extab flag
for i in 0..text_section.symbols.len() {
let func = &mut text_section.symbols[i];
if func.name == extab_func.name {
func.has_extab = true;
func.extab_name = Some(extab.name.clone());
func.extabindex_name = Some(extabindex.name.clone());
}
}
/* Iterate through the list of extab relocations, continuing until we hit a relocation
that isn't within the current extab symbol. Get the target dtor function symbol from
each relocation used, and add them to the list. */
let mut dtors: Vec<ObjSymbol> = vec![];
while extab_reloc_index < extab_reloc_count {
let extab_reloc = &extab_section.relocations[extab_reloc_index];
//If the current entry is past the current extab table, stop here
if extab_reloc.address >= extab_end_addr {
break;
}
//Otherwise, the current relocation is used by the current table
dtors.push(extab_reloc.target.clone());
//Go to the next entry
extab_reloc_index += 1;
}
//Decode the extab data
let start_index = extab_start_addr as usize;
let end_index = extab_end_addr as usize;
let extab_data = extab_section.data[start_index..end_index].try_into().unwrap();
let data = match decode_extab(extab_data) {
Some(decoded_data) => decoded_data,
None => {
log::warn!("Exception table decoding failed for function {}", extab_func.name);
return Ok(None);
}
};
//Add the new entry to the list
let entry = ObjExtab { func: extab_func, data, dtors };
result.push(entry);
}
Ok(Some(result))
}
fn find_section_symbol(
arch: &dyn ObjArch,
obj_file: &File<'_>,
@@ -335,9 +231,6 @@ fn find_section_symbol(
Ok(ObjSymbol {
name: name.to_string(),
demangled_name: None,
has_extab: false,
extab_name: None,
extabindex_name: None,
address: offset,
section_address: address - section.address(),
size: 0,
@@ -345,6 +238,7 @@ fn find_section_symbol(
flags: Default::default(),
addend: offset_addr as i64,
virtual_address: None,
original_index: None,
})
}
@@ -615,9 +509,6 @@ fn update_combined_symbol(symbol: ObjSymbol, address_change: i64) -> Result<ObjS
Ok(ObjSymbol {
name: symbol.name,
demangled_name: symbol.demangled_name,
has_extab: symbol.has_extab,
extab_name: symbol.extab_name,
extabindex_name: symbol.extabindex_name,
address: (symbol.address as i64 + address_change).try_into()?,
section_address: (symbol.section_address as i64 + address_change).try_into()?,
size: symbol.size,
@@ -629,6 +520,7 @@ fn update_combined_symbol(symbol: ObjSymbol, address_change: i64) -> Result<ObjS
} else {
None
},
original_index: symbol.original_index,
})
}
@@ -740,8 +632,7 @@ pub fn parse(data: &[u8], config: &DiffObjConfig) -> Result<ObjInfo> {
}
line_info(&obj_file, &mut sections, data)?;
let common = common_symbols(arch.as_ref(), &obj_file, split_meta.as_ref())?;
let extab = exception_tables(&mut sections, &obj_file)?;
Ok(ObjInfo { arch, path: None, timestamp: None, sections, common, extab, split_meta })
Ok(ObjInfo { arch, path: None, timestamp: None, sections, common, split_meta })
}
pub fn has_function(obj_path: &Path, symbol_name: &str) -> Result<bool> {