diff options
Diffstat (limited to 'vendor/backtrace/src/symbolize/gimli/elf.rs')
| -rw-r--r-- | vendor/backtrace/src/symbolize/gimli/elf.rs | 495 |
1 files changed, 0 insertions, 495 deletions
diff --git a/vendor/backtrace/src/symbolize/gimli/elf.rs b/vendor/backtrace/src/symbolize/gimli/elf.rs deleted file mode 100644 index b0eec07..0000000 --- a/vendor/backtrace/src/symbolize/gimli/elf.rs +++ /dev/null @@ -1,495 +0,0 @@ -use super::mystd::ffi::{OsStr, OsString}; -use super::mystd::fs; -use super::mystd::os::unix::ffi::{OsStrExt, OsStringExt}; -use super::mystd::path::{Path, PathBuf}; -use super::Either; -use super::{gimli, Context, Endian, EndianSlice, Mapping, Stash, Vec}; -use alloc::sync::Arc; -use core::convert::{TryFrom, TryInto}; -use core::str; -use object::elf::{ELFCOMPRESS_ZLIB, ELF_NOTE_GNU, NT_GNU_BUILD_ID, SHF_COMPRESSED}; -use object::read::elf::{CompressionHeader, FileHeader, SectionHeader, SectionTable, Sym}; -use object::read::StringTable; -use object::{BigEndian, Bytes, NativeEndian}; - -#[cfg(target_pointer_width = "32")] -type Elf = object::elf::FileHeader32<NativeEndian>; -#[cfg(target_pointer_width = "64")] -type Elf = object::elf::FileHeader64<NativeEndian>; - -impl Mapping { - pub fn new(path: &Path) -> Option<Mapping> { - let map = super::mmap(path)?; - Mapping::mk_or_other(map, |map, stash| { - let object = Object::parse(&map)?; - - // Try to locate an external debug file using the build ID. - if let Some(path_debug) = object.build_id().and_then(locate_build_id) { - if let Some(mapping) = Mapping::new_debug(path, path_debug, None) { - return Some(Either::A(mapping)); - } - } - - // Try to locate an external debug file using the GNU debug link section. - if let Some((path_debug, crc)) = object.gnu_debuglink_path(path) { - if let Some(mapping) = Mapping::new_debug(path, path_debug, Some(crc)) { - return Some(Either::A(mapping)); - } - } - - let dwp = Mapping::load_dwarf_package(path, stash); - - Context::new(stash, object, None, dwp).map(Either::B) - }) - } - - /// Load debuginfo from an external debug file. - fn new_debug(original_path: &Path, path: PathBuf, crc: Option<u32>) -> Option<Mapping> { - let map = super::mmap(&path)?; - Mapping::mk(map, |map, stash| { - let object = Object::parse(&map)?; - - if let Some(_crc) = crc { - // TODO: check crc - } - - // Try to locate a supplementary object file. - let mut sup = None; - if let Some((path_sup, build_id_sup)) = object.gnu_debugaltlink_path(&path) { - if let Some(map_sup) = super::mmap(&path_sup) { - let map_sup = stash.cache_mmap(map_sup); - if let Some(sup_) = Object::parse(map_sup) { - if sup_.build_id() == Some(build_id_sup) { - sup = Some(sup_); - } - } - } - } - - let dwp = Mapping::load_dwarf_package(original_path, stash); - - Context::new(stash, object, sup, dwp) - }) - } - - /// Try to locate a DWARF package file. - fn load_dwarf_package<'data>(path: &Path, stash: &'data Stash) -> Option<Object<'data>> { - let mut path_dwp = path.to_path_buf(); - let dwp_extension = path - .extension() - .map(|previous_extension| { - let mut previous_extension = previous_extension.to_os_string(); - previous_extension.push(".dwp"); - previous_extension - }) - .unwrap_or_else(|| "dwp".into()); - path_dwp.set_extension(dwp_extension); - if let Some(map_dwp) = super::mmap(&path_dwp) { - let map_dwp = stash.cache_mmap(map_dwp); - if let Some(dwp_) = Object::parse(map_dwp) { - return Some(dwp_); - } - } - - None - } -} - -struct ParsedSym { - address: u64, - size: u64, - name: u32, -} - -pub struct Object<'a> { - /// Zero-sized type representing the native endianness. - /// - /// We could use a literal instead, but this helps ensure correctness. - endian: NativeEndian, - /// The entire file data. - data: &'a [u8], - sections: SectionTable<'a, Elf>, - strings: StringTable<'a>, - /// List of pre-parsed and sorted symbols by base address. - syms: Vec<ParsedSym>, -} - -impl<'a> Object<'a> { - fn parse(data: &'a [u8]) -> Option<Object<'a>> { - let elf = Elf::parse(data).ok()?; - let endian = elf.endian().ok()?; - let sections = elf.sections(endian, data).ok()?; - let mut syms = sections - .symbols(endian, data, object::elf::SHT_SYMTAB) - .ok()?; - if syms.is_empty() { - syms = sections - .symbols(endian, data, object::elf::SHT_DYNSYM) - .ok()?; - } - let strings = syms.strings(); - - let mut syms = syms - .iter() - // Only look at function/object symbols. This mirrors what - // libbacktrace does and in general we're only symbolicating - // function addresses in theory. Object symbols correspond - // to data, and maybe someone's crazy enough to have a - // function go into static data? - .filter(|sym| { - let st_type = sym.st_type(); - st_type == object::elf::STT_FUNC || st_type == object::elf::STT_OBJECT - }) - // skip anything that's in an undefined section header, - // since it means it's an imported function and we're only - // symbolicating with locally defined functions. - .filter(|sym| sym.st_shndx(endian) != object::elf::SHN_UNDEF) - .map(|sym| { - let address = sym.st_value(endian).into(); - let size = sym.st_size(endian).into(); - let name = sym.st_name(endian); - ParsedSym { - address, - size, - name, - } - }) - .collect::<Vec<_>>(); - syms.sort_unstable_by_key(|s| s.address); - Some(Object { - endian, - data, - sections, - strings, - syms, - }) - } - - pub fn section(&self, stash: &'a Stash, name: &str) -> Option<&'a [u8]> { - if let Some(section) = self.section_header(name) { - let mut data = Bytes(section.data(self.endian, self.data).ok()?); - - // Check for DWARF-standard (gABI) compression, i.e., as generated - // by ld's `--compress-debug-sections=zlib-gabi` flag. - let flags: u64 = section.sh_flags(self.endian).into(); - if (flags & u64::from(SHF_COMPRESSED)) == 0 { - // Not compressed. - return Some(data.0); - } - - let header = data.read::<<Elf as FileHeader>::CompressionHeader>().ok()?; - if header.ch_type(self.endian) != ELFCOMPRESS_ZLIB { - // Zlib compression is the only known type. - return None; - } - let size = usize::try_from(header.ch_size(self.endian)).ok()?; - let buf = stash.allocate(size); - decompress_zlib(data.0, buf)?; - return Some(buf); - } - - // Check for the nonstandard GNU compression format, i.e., as generated - // by ld's `--compress-debug-sections=zlib-gnu` flag. This means that if - // we're actually asking for `.debug_info` then we need to look up a - // section named `.zdebug_info`. - if !name.starts_with(".debug_") { - return None; - } - let debug_name = name[7..].as_bytes(); - let compressed_section = self - .sections - .iter() - .filter_map(|header| { - let name = self.sections.section_name(self.endian, header).ok()?; - if name.starts_with(b".zdebug_") && &name[8..] == debug_name { - Some(header) - } else { - None - } - }) - .next()?; - let mut data = Bytes(compressed_section.data(self.endian, self.data).ok()?); - if data.read_bytes(8).ok()?.0 != b"ZLIB\0\0\0\0" { - return None; - } - let size = usize::try_from(data.read::<object::U32Bytes<_>>().ok()?.get(BigEndian)).ok()?; - let buf = stash.allocate(size); - decompress_zlib(data.0, buf)?; - Some(buf) - } - - fn section_header(&self, name: &str) -> Option<&<Elf as FileHeader>::SectionHeader> { - self.sections - .section_by_name(self.endian, name.as_bytes()) - .map(|(_index, section)| section) - } - - pub fn search_symtab<'b>(&'b self, addr: u64) -> Option<&'b [u8]> { - // Same sort of binary search as Windows above - let i = match self.syms.binary_search_by_key(&addr, |sym| sym.address) { - Ok(i) => i, - Err(i) => i.checked_sub(1)?, - }; - let sym = self.syms.get(i)?; - if sym.address <= addr && addr <= sym.address + sym.size { - self.strings.get(sym.name).ok() - } else { - None - } - } - - pub(super) fn search_object_map(&self, _addr: u64) -> Option<(&Context<'_>, u64)> { - None - } - - fn build_id(&self) -> Option<&'a [u8]> { - for section in self.sections.iter() { - if let Ok(Some(mut notes)) = section.notes(self.endian, self.data) { - while let Ok(Some(note)) = notes.next() { - if note.name() == ELF_NOTE_GNU && note.n_type(self.endian) == NT_GNU_BUILD_ID { - return Some(note.desc()); - } - } - } - } - None - } - - // The contents of the ".gnu_debuglink" section is documented at: - // https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html - fn gnu_debuglink_path(&self, path: &Path) -> Option<(PathBuf, u32)> { - let section = self.section_header(".gnu_debuglink")?; - let data = section.data(self.endian, self.data).ok()?; - let len = data.iter().position(|x| *x == 0)?; - let filename = &data[..len]; - let offset = (len + 1 + 3) & !3; - let crc_bytes = data - .get(offset..offset + 4) - .and_then(|bytes| bytes.try_into().ok())?; - let crc = u32::from_ne_bytes(crc_bytes); - let path_debug = locate_debuglink(path, filename)?; - Some((path_debug, crc)) - } - - // The format of the ".gnu_debugaltlink" section is based on gdb. - fn gnu_debugaltlink_path(&self, path: &Path) -> Option<(PathBuf, &'a [u8])> { - let section = self.section_header(".gnu_debugaltlink")?; - let data = section.data(self.endian, self.data).ok()?; - let len = data.iter().position(|x| *x == 0)?; - let filename = &data[..len]; - let build_id = &data[len + 1..]; - let path_sup = locate_debugaltlink(path, filename, build_id)?; - Some((path_sup, build_id)) - } -} - -fn decompress_zlib(input: &[u8], output: &mut [u8]) -> Option<()> { - use miniz_oxide::inflate::core::inflate_flags::{ - TINFL_FLAG_PARSE_ZLIB_HEADER, TINFL_FLAG_USING_NON_WRAPPING_OUTPUT_BUF, - }; - use miniz_oxide::inflate::core::{decompress, DecompressorOxide}; - use miniz_oxide::inflate::TINFLStatus; - - let (status, in_read, out_read) = decompress( - &mut DecompressorOxide::new(), - input, - output, - 0, - TINFL_FLAG_USING_NON_WRAPPING_OUTPUT_BUF | TINFL_FLAG_PARSE_ZLIB_HEADER, - ); - if status == TINFLStatus::Done && in_read == input.len() && out_read == output.len() { - Some(()) - } else { - None - } -} - -const DEBUG_PATH: &[u8] = b"/usr/lib/debug"; - -fn debug_path_exists() -> bool { - cfg_if::cfg_if! { - if #[cfg(any(target_os = "freebsd", target_os = "linux"))] { - use core::sync::atomic::{AtomicU8, Ordering}; - static DEBUG_PATH_EXISTS: AtomicU8 = AtomicU8::new(0); - - let mut exists = DEBUG_PATH_EXISTS.load(Ordering::Relaxed); - if exists == 0 { - exists = if Path::new(OsStr::from_bytes(DEBUG_PATH)).is_dir() { - 1 - } else { - 2 - }; - DEBUG_PATH_EXISTS.store(exists, Ordering::Relaxed); - } - exists == 1 - } else { - false - } - } -} - -/// Locate a debug file based on its build ID. -/// -/// The format of build id paths is documented at: -/// https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html -fn locate_build_id(build_id: &[u8]) -> Option<PathBuf> { - const BUILD_ID_PATH: &[u8] = b"/usr/lib/debug/.build-id/"; - const BUILD_ID_SUFFIX: &[u8] = b".debug"; - - if build_id.len() < 2 { - return None; - } - - if !debug_path_exists() { - return None; - } - - let mut path = - Vec::with_capacity(BUILD_ID_PATH.len() + BUILD_ID_SUFFIX.len() + build_id.len() * 2 + 1); - path.extend(BUILD_ID_PATH); - path.push(hex(build_id[0] >> 4)); - path.push(hex(build_id[0] & 0xf)); - path.push(b'/'); - for byte in &build_id[1..] { - path.push(hex(byte >> 4)); - path.push(hex(byte & 0xf)); - } - path.extend(BUILD_ID_SUFFIX); - Some(PathBuf::from(OsString::from_vec(path))) -} - -fn hex(byte: u8) -> u8 { - if byte < 10 { - b'0' + byte - } else { - b'a' + byte - 10 - } -} - -/// Locate a file specified in a `.gnu_debuglink` section. -/// -/// `path` is the file containing the section. -/// `filename` is from the contents of the section. -/// -/// Search order is based on gdb, documented at: -/// https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html -/// -/// gdb also allows the user to customize the debug search path, but we don't. -/// -/// gdb also supports debuginfod, but we don't yet. -fn locate_debuglink(path: &Path, filename: &[u8]) -> Option<PathBuf> { - let path = fs::canonicalize(path).ok()?; - let parent = path.parent()?; - let mut f = PathBuf::from(OsString::with_capacity( - DEBUG_PATH.len() + parent.as_os_str().len() + filename.len() + 2, - )); - let filename = Path::new(OsStr::from_bytes(filename)); - - // Try "/parent/filename" if it differs from "path" - f.push(parent); - f.push(filename); - if f != path && f.is_file() { - return Some(f); - } - - // Try "/parent/.debug/filename" - let mut s = OsString::from(f); - s.clear(); - f = PathBuf::from(s); - f.push(parent); - f.push(".debug"); - f.push(filename); - if f.is_file() { - return Some(f); - } - - if debug_path_exists() { - // Try "/usr/lib/debug/parent/filename" - let mut s = OsString::from(f); - s.clear(); - f = PathBuf::from(s); - f.push(OsStr::from_bytes(DEBUG_PATH)); - f.push(parent.strip_prefix("/").unwrap()); - f.push(filename); - if f.is_file() { - return Some(f); - } - } - - None -} - -/// Locate a file specified in a `.gnu_debugaltlink` section. -/// -/// `path` is the file containing the section. -/// `filename` and `build_id` are the contents of the section. -/// -/// Search order is based on gdb: -/// - filename, which is either absolute or relative to `path` -/// - the build ID path under `BUILD_ID_PATH` -/// -/// gdb also allows the user to customize the debug search path, but we don't. -/// -/// gdb also supports debuginfod, but we don't yet. -fn locate_debugaltlink(path: &Path, filename: &[u8], build_id: &[u8]) -> Option<PathBuf> { - let filename = Path::new(OsStr::from_bytes(filename)); - if filename.is_absolute() { - if filename.is_file() { - return Some(filename.into()); - } - } else { - let path = fs::canonicalize(path).ok()?; - let parent = path.parent()?; - let mut f = PathBuf::from(parent); - f.push(filename); - if f.is_file() { - return Some(f); - } - } - - locate_build_id(build_id) -} - -fn convert_path<R: gimli::Reader>(r: &R) -> Result<PathBuf, gimli::Error> { - let bytes = r.to_slice()?; - Ok(PathBuf::from(OsStr::from_bytes(&bytes))) -} - -pub(super) fn handle_split_dwarf<'data>( - package: Option<&gimli::DwarfPackage<EndianSlice<'data, Endian>>>, - stash: &'data Stash, - load: addr2line::SplitDwarfLoad<EndianSlice<'data, Endian>>, -) -> Option<Arc<gimli::Dwarf<EndianSlice<'data, Endian>>>> { - if let Some(dwp) = package.as_ref() { - if let Ok(Some(cu)) = dwp.find_cu(load.dwo_id, &load.parent) { - return Some(Arc::new(cu)); - } - } - - let mut path = PathBuf::new(); - if let Some(p) = load.comp_dir.as_ref() { - path.push(convert_path(p).ok()?); - } - - path.push(convert_path(load.path.as_ref()?).ok()?); - - if let Some(map_dwo) = super::mmap(&path) { - let map_dwo = stash.cache_mmap(map_dwo); - if let Some(dwo) = Object::parse(map_dwo) { - return gimli::Dwarf::load(|id| -> Result<_, ()> { - let data = id - .dwo_name() - .and_then(|name| dwo.section(stash, name)) - .unwrap_or(&[]); - Ok(EndianSlice::new(data, Endian)) - }) - .ok() - .map(|mut dwo_dwarf| { - dwo_dwarf.make_dwo(&load.parent); - Arc::new(dwo_dwarf) - }); - } - } - - None -} |