Speedy_Lex
1312 lines
44 KiB
Rust
1312 lines
44 KiB
Rust
//! See:
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//! * <https://refspecs.linuxfoundation.org/elf/elf.pdf>
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//! * <https://www.akkadia.org/drepper/dsohowto.pdf>
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use object::{
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NativeEndian, Object, StringTable, SymbolIndex, elf,
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read::elf::{
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Dyn as _, GnuHashTable, HashTable as SysVHashTable, ProgramHeader as _, Rel as _,
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Rela as _, Sym as _, Version, VersionTable,
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},
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};
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#[cfg(any(target_arch = "aarch64", target_arch = "x86_64"))]
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use super::tcb::Tcb;
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use super::{
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debug::{_r_debug, RTLDDebug},
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linker::{__plt_resolve_trampoline, GLOBAL_SCOPE, Resolve, Scope, Symbol},
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tcb::Master,
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};
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use crate::{
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header::{dl_tls::__tls_get_addr, sys_mman},
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platform::{Pal, Sys, types::c_void},
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};
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use alloc::{
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boxed::Box,
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string::{String, ToString},
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sync::Arc,
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vec::Vec,
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};
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#[cfg(any(target_arch = "aarch64", target_arch = "x86_64"))]
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use core::mem::offset_of;
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use core::{
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ffi::c_char,
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mem::size_of,
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ptr::{self, NonNull},
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slice,
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sync::atomic::{AtomicBool, Ordering},
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};
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pub const CHAR_BITS: usize = c_char::BITS as usize;
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pub type Relr = usize;
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#[cfg(target_pointer_width = "32")]
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mod shim {
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use object::{NativeEndian, elf::*, read::elf::ElfFile32};
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pub type Dyn = Dyn32<NativeEndian>;
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pub type Rel = Rel32<NativeEndian>;
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pub type Rela = Rela32<NativeEndian>;
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pub type Sym = Sym32<NativeEndian>;
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pub type FileHeader = FileHeader32<NativeEndian>;
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pub type ProgramHeader = ProgramHeader32<NativeEndian>;
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pub type ElfFile<'a> = ElfFile32<'a, NativeEndian>;
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}
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#[cfg(target_pointer_width = "64")]
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mod shim {
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use object::{NativeEndian, elf::*, read::elf::ElfFile64};
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pub type Dyn = Dyn64<NativeEndian>;
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pub type Rel = Rel64<NativeEndian>;
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pub type Rela = Rela64<NativeEndian>;
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pub type Sym = Sym64<NativeEndian>;
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pub type FileHeader = FileHeader64<NativeEndian>;
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pub type ProgramHeader = ProgramHeader64<NativeEndian>;
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pub type ElfFile<'a> = ElfFile64<'a, NativeEndian>;
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}
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pub use shim::*;
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// TODO: missing from the `object` crate
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pub const DT_RELRSZ: u32 = 35;
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pub const DT_RELR: u32 = 36;
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pub const DT_RELRENT: u32 = 37;
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/// Undefined Symbol Index
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pub const STN_UNDEF: SymbolIndex = SymbolIndex(0);
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enum HashTable<'a> {
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Gnu(GnuHashTable<'a, FileHeader>),
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Sysv(SysVHashTable<'a, FileHeader>),
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}
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impl<'a> HashTable<'a> {
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/// Use the hash table to find the symbol table entry with the given name, hash, and version.
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#[inline]
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pub fn find(
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&self,
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name: &str,
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version: Option<&Version<'_>>,
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symbols: &'a [Sym],
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strings: StringTable<'a>,
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versions: &VersionTable<'a, FileHeader>,
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) -> Option<(SymbolIndex, &'a Sym)> {
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let name = name.as_bytes();
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match self {
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Self::Gnu(hash_table) => {
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let hash = elf::gnu_hash(name);
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hash_table.find(
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NativeEndian,
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name,
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hash,
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version,
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symbols,
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strings,
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versions,
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)
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}
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Self::Sysv(hash_table) => {
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let hash = elf::hash(name);
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hash_table.find(
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NativeEndian,
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name,
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hash,
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version,
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symbols,
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strings,
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versions,
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)
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}
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}
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}
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fn symbol_table_length(&self) -> usize {
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match self {
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Self::Gnu(hash_table) => hash_table
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.symbol_table_length(NativeEndian)
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.expect("empty GNU symbol hash table")
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as usize,
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Self::Sysv(hash_table) => hash_table.symbol_table_length() as usize,
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}
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}
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}
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type InitFn = unsafe extern "C" fn();
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pub(super) struct Dynamic<'data> {
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runpath: Option<String>,
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got: Option<NonNull<usize>>,
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needed: Vec<&'data str>,
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pub(super) jmprel: usize,
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hash_table: HashTable<'data>,
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pub(super) dynstrtab: StringTable<'data>,
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soname: Option<&'data str>,
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init_array: &'data [unsafe extern "C" fn()],
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fini_array: &'data [unsafe extern "C" fn()],
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rela: &'data [Rela],
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relr: &'data [Relr],
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rel: &'data [Rel],
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symbols: &'data [Sym],
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explicit_addend: bool,
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pltrelsz: usize,
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}
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impl<'data> Dynamic<'data> {
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pub fn symbol(&self, index: SymbolIndex) -> Option<&'data Sym> {
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// Symbol table entry for index 0 is reserved.
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assert!(index != SymbolIndex(0));
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self.symbols.get(index.0)
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}
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fn symbol_name(&self, index: SymbolIndex) -> Option<&'data str> {
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let sym = self.symbol(index)?;
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let name = sym.name(NativeEndian, self.dynstrtab).ok()?;
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Some(core::str::from_utf8(name).expect("non UTF-8 ELF symbol name"))
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}
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fn static_relocations(&self) -> impl Iterator<Item = Relocation> + '_ {
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self.rela
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.iter()
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.map(Relocation::from)
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.chain(self.rel.iter().map(Relocation::from))
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}
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}
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unsafe impl Send for Dynamic<'_> {}
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unsafe impl Sync for Dynamic<'_> {}
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#[derive(Debug)]
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pub(super) struct Relocation {
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pub(super) offset: usize,
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pub(super) addend: Option<usize>,
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pub(super) sym: SymbolIndex,
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pub(super) kind: RelocationKind,
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}
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#[cfg(target_pointer_width = "32")]
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impl From<&Rela> for Relocation {
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fn from(reloc: &Rela) -> Self {
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Self {
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offset: reloc.r_offset(NativeEndian) as usize,
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addend: Some(reloc.r_addend(NativeEndian) as usize),
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sym: SymbolIndex(reloc.r_sym(NativeEndian) as usize),
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kind: RelocationKind::new(reloc.r_type(NativeEndian)),
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}
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}
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}
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#[cfg(target_pointer_width = "64")]
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impl From<&Rela> for Relocation {
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fn from(reloc: &Rela) -> Self {
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let is_mips64el = cfg!(all(target_arch = "mips64", target_endian = "little"));
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Self {
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offset: reloc.r_offset(NativeEndian) as usize,
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addend: Some(reloc.r_addend(NativeEndian) as usize),
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sym: SymbolIndex(reloc.r_sym(NativeEndian, is_mips64el) as usize),
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kind: RelocationKind::new(reloc.r_type(NativeEndian, is_mips64el)),
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}
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}
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}
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impl From<&Rel> for Relocation {
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fn from(reloc: &Rel) -> Self {
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Self {
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offset: reloc.r_offset(NativeEndian) as usize,
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addend: None,
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sym: SymbolIndex(reloc.r_sym(NativeEndian) as usize),
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kind: RelocationKind::new(reloc.r_type(NativeEndian)),
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}
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}
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}
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// This is matched up to REL_* constants used by musl for ease of comparison
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#[allow(dead_code)]
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#[derive(Clone, Copy, Debug, PartialEq)]
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pub enum RelocationKind {
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COPY,
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DTPMOD,
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DTPOFF,
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GOT,
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IRELATIVE,
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OFFSET,
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PLT,
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RELATIVE,
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SYMBOLIC,
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TLSDESC,
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TPOFF,
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UNKNOWN(u32),
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}
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impl RelocationKind {
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#[cfg(target_arch = "aarch64")]
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pub fn new(kind: u32) -> Self {
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//WARNING: Only use R_AARCH64_* constants here!
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match kind {
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elf::R_AARCH64_COPY => Self::COPY,
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elf::R_AARCH64_TLS_DTPMOD => Self::DTPMOD,
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elf::R_AARCH64_TLS_DTPREL => Self::DTPOFF,
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elf::R_AARCH64_GLOB_DAT => Self::GOT,
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elf::R_AARCH64_IRELATIVE => Self::IRELATIVE,
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elf::R_AARCH64_JUMP_SLOT => Self::PLT,
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elf::R_AARCH64_RELATIVE => Self::RELATIVE,
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elf::R_AARCH64_ABS64 => Self::SYMBOLIC,
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elf::R_AARCH64_TLSDESC => Self::TLSDESC,
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elf::R_AARCH64_TLS_TPREL => Self::TPOFF,
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_ => Self::UNKNOWN(kind),
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}
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}
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#[cfg(target_arch = "riscv64")]
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pub fn new(kind: u32) -> Self {
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//WARNING: Only use R_RISCV_* constants here!
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match kind {
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elf::R_RISCV_COPY => Self::COPY,
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elf::R_RISCV_TLS_DTPMOD64 => Self::DTPMOD,
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elf::R_RISCV_TLS_DTPREL64 => Self::DTPOFF,
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elf::R_RISCV_IRELATIVE => Self::IRELATIVE,
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elf::R_RISCV_JUMP_SLOT => Self::PLT,
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elf::R_RISCV_RELATIVE => Self::RELATIVE,
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elf::R_RISCV_64 => Self::SYMBOLIC,
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//TODO: not defined, should be 12: elf::R_RISCV_TLSDESC => Self::TLSDESC,
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elf::R_RISCV_TLS_TPREL64 => Self::TPOFF,
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_ => Self::UNKNOWN(kind),
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}
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}
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#[cfg(target_arch = "x86")]
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pub fn new(kind: u32) -> Self {
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//WARNING: Only use R_386_* constants here!
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match kind {
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elf::R_386_COPY => Self::COPY,
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elf::R_386_TLS_DTPMOD32 => Self::DTPMOD,
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elf::R_386_TLS_DTPOFF32 => Self::DTPOFF,
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elf::R_386_GLOB_DAT => Self::GOT,
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elf::R_386_IRELATIVE => Self::IRELATIVE,
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elf::R_386_JMP_SLOT => Self::PLT,
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elf::R_386_PC32 => Self::OFFSET,
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elf::R_386_RELATIVE => Self::RELATIVE,
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elf::R_386_32 => Self::SYMBOLIC,
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elf::R_386_TLS_DESC => Self::TLSDESC,
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elf::R_386_TLS_TPOFF => Self::TPOFF,
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_ => Self::UNKNOWN(kind),
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}
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}
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#[cfg(target_arch = "x86_64")]
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pub fn new(kind: u32) -> Self {
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//WARNING: Only use R_X86_64_* constants here!
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match kind {
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elf::R_X86_64_COPY => Self::COPY,
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elf::R_X86_64_DTPMOD64 => Self::DTPMOD,
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elf::R_X86_64_DTPOFF64 => Self::DTPOFF,
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elf::R_X86_64_GLOB_DAT => Self::GOT,
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elf::R_X86_64_IRELATIVE => Self::IRELATIVE,
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elf::R_X86_64_JUMP_SLOT => Self::PLT,
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elf::R_X86_64_RELATIVE => Self::RELATIVE,
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elf::R_X86_64_64 => Self::SYMBOLIC,
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elf::R_X86_64_TLSDESC => Self::TLSDESC,
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elf::R_X86_64_TPOFF64 => Self::TPOFF,
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_ => Self::UNKNOWN(kind),
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}
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}
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}
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#[derive(Debug, PartialEq)]
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#[repr(u8)]
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pub enum SymbolBinding {
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/// Global symbols are visible to all object files being combined. One
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/// file's definition of a global symbol will satisfy another file's
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/// undefined reference to the same global symbol.
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Global = elf::STB_GLOBAL,
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/// Weak symbols resemble global symbols, but their definitions have lower
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/// precedence.
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Weak = elf::STB_WEAK,
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}
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impl SymbolBinding {
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#[inline]
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pub fn is_global(&self) -> bool {
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matches!(self, Self::Global)
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}
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}
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/// Use to represent a library as well as all the symbols that is loaded withen it.
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pub struct DSO {
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pub name: String,
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pub id: usize,
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pub dlopened: bool,
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pub entry_point: usize,
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/// Loaded library in-memory data
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pub mmap: &'static [u8],
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pub tls_module_id: usize,
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pub tls_offset: usize,
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pub(super) dynamic: Dynamic<'static>,
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pub scope: spin::Once<Scope>,
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/// Position Independent Executable.
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pub pie: bool,
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/// Whether this DSO *and* its dependencies have been successfully loaded.
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is_ready: AtomicBool,
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}
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impl DSO {
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pub fn new(
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path: &str,
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data: &[u8],
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base_addr: Option<usize>,
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dlopened: bool,
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id: usize,
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tls_module_id: usize,
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tls_offset: usize,
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) -> Result<(DSO, Option<Master>, Vec<ProgramHeader>), String> {
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let elf = ElfFile::parse(data).map_err(|err| err.to_string())?;
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let (mmap, tcb_master, dynamic) =
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DSO::mmap_and_copy(path, &elf, data, base_addr, tls_offset)?;
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let name = match dynamic.soname {
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Some(soname) => soname.to_string(),
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_ => basename(path),
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};
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let tls_offset = match tcb_master {
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Some(ref master) => master.offset,
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_ => 0,
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};
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let entry_point = if is_pie_enabled(&elf) {
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mmap.as_ptr() as usize + elf.entry() as usize
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} else {
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elf.entry() as usize
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};
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let dso = DSO {
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name,
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id,
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dlopened,
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entry_point,
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mmap,
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tls_module_id: if tcb_master.is_some() {
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tls_module_id
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} else {
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0
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},
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tls_offset,
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pie: is_pie_enabled(&elf),
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dynamic,
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scope: spin::Once::new(),
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is_ready: AtomicBool::new(false),
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};
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Ok((dso, tcb_master, elf.elf_program_headers().to_vec()))
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}
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#[inline]
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pub fn mark_ready(&self) {
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self.is_ready.store(true, Ordering::SeqCst);
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}
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#[inline]
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pub fn scope(&self) -> &Scope {
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self.scope.get().expect("scope not initialized")
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}
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/// Global Offset Table
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#[inline]
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pub fn got(&self) -> Option<NonNull<usize>> {
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self.dynamic.got
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}
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#[inline]
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pub fn runpath(&self) -> Option<&String> {
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self.dynamic.runpath.as_ref()
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}
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#[inline]
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pub fn dependencies(&self) -> &[&str] {
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&self.dynamic.needed
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}
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pub fn get_sym<'a>(&self, name: &'a str) -> Option<(Symbol<'a>, SymbolBinding)> {
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let (_, sym) = self.dynamic.hash_table.find(
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name,
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None,
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self.dynamic.symbols,
|
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self.dynamic.dynstrtab,
|
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&VersionTable::default(),
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)?;
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|
|
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if sym.st_shndx(NativeEndian) == elf::SHN_UNDEF {
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return None;
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}
|
|
|
|
Some((
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Symbol {
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name,
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|
base: if self.pie {
|
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self.mmap.as_ptr() as usize
|
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} else {
|
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0
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|
},
|
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value: sym.st_value(NativeEndian) as usize,
|
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size: sym.st_size(NativeEndian) as usize,
|
|
sym_type: sym.st_type(),
|
|
},
|
|
// TODO(andypython): move this into [`Symbol`]
|
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match sym.st_bind() {
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elf::STB_GLOBAL => SymbolBinding::Global,
|
|
elf::STB_WEAK => SymbolBinding::Weak,
|
|
bind => unreachable!("get_sym bind {bind}"),
|
|
},
|
|
))
|
|
}
|
|
|
|
pub fn run_init(&self) {
|
|
for f in self.dynamic.init_array {
|
|
unsafe { f() }
|
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}
|
|
}
|
|
|
|
pub fn run_fini(&self) {
|
|
for f in self.dynamic.fini_array.iter().rev() {
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unsafe { f() }
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}
|
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}
|
|
|
|
fn mmap_and_copy<'a>(
|
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path: &str,
|
|
elf: &ElfFile<'a>,
|
|
data: &'a [u8],
|
|
base_addr: Option<usize>,
|
|
tls_offset: usize,
|
|
) -> Result<(&'static [u8], Option<Master>, Dynamic<'static>), String> {
|
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let endian = elf.endian();
|
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log::trace!("# {}", path);
|
|
// data for struct LinkMap
|
|
let mut l_ld = 0;
|
|
// Calculate virtual memory bounds
|
|
let bounds = {
|
|
let mut bounds_opt: Option<(usize, usize)> = None;
|
|
for ph in elf.elf_program_headers() {
|
|
let voff = ph.p_vaddr(endian) % ph.p_align(endian);
|
|
let vaddr = (ph.p_vaddr(endian) - voff) as usize;
|
|
let vsize = ((ph.p_memsz(endian) + voff) as usize)
|
|
.next_multiple_of(ph.p_align(endian) as usize);
|
|
|
|
match ph.p_type(endian) {
|
|
elf::PT_DYNAMIC => {
|
|
l_ld = ph.p_vaddr(endian);
|
|
}
|
|
elf::PT_LOAD => {
|
|
log::trace!(" load {:#x}, {:#x}: {:x?}", vaddr, vsize, ph);
|
|
if let Some(ref mut bounds) = bounds_opt {
|
|
if vaddr < bounds.0 {
|
|
bounds.0 = vaddr;
|
|
}
|
|
if vaddr + vsize > bounds.1 {
|
|
bounds.1 = vaddr + vsize;
|
|
}
|
|
} else {
|
|
bounds_opt = Some((vaddr, vaddr + vsize));
|
|
}
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
bounds_opt.ok_or_else(|| "Unable to find PT_LOAD section".to_string())?
|
|
};
|
|
log::trace!(" bounds {:#x}, {:#x}", bounds.0, bounds.1);
|
|
// Allocate memory
|
|
let mmap = unsafe {
|
|
if let Some(addr) = base_addr {
|
|
let size = if is_pie_enabled(elf) {
|
|
bounds.1
|
|
} else {
|
|
bounds.1 - bounds.0
|
|
};
|
|
_r_debug
|
|
.lock()
|
|
.insert_first(addr + bounds.0, path, addr + l_ld as usize);
|
|
slice::from_raw_parts_mut((addr + bounds.0) as *mut u8, size)
|
|
} else {
|
|
let (start, end) = bounds;
|
|
let size = end - start;
|
|
let mut flags = sys_mman::MAP_ANONYMOUS | sys_mman::MAP_PRIVATE;
|
|
if start != 0 {
|
|
flags |= sys_mman::MAP_FIXED_NOREPLACE;
|
|
}
|
|
log::trace!(" mmap({:#x}, {:x}, {:x})", start, size, flags);
|
|
let ptr = Sys::mmap(
|
|
start as *mut c_void,
|
|
size,
|
|
//TODO: Make it possible to not specify PROT_EXEC on Redox
|
|
sys_mman::PROT_READ | sys_mman::PROT_WRITE,
|
|
flags,
|
|
-1,
|
|
0,
|
|
)
|
|
.map_err(|e| format!("failed to map {}. errno: {}", path, e.0))?;
|
|
|
|
if !(start as *mut c_void).is_null() {
|
|
assert_eq!(
|
|
ptr, start as *mut c_void,
|
|
"mmap must always map on the destination we requested"
|
|
);
|
|
}
|
|
log::trace!(" = {:p}", ptr);
|
|
_r_debug
|
|
.lock()
|
|
.insert(ptr as usize, path, ptr as usize + l_ld as usize);
|
|
slice::from_raw_parts_mut(ptr.cast::<u8>(), size)
|
|
}
|
|
};
|
|
|
|
let skip_load_segment_copy = base_addr.is_some();
|
|
let mut tcb_master = None;
|
|
|
|
// Copy data
|
|
let mut dynamic = None;
|
|
for ph in elf.elf_program_headers() {
|
|
match ph.p_type(endian) {
|
|
elf::PT_LOAD => {
|
|
if skip_load_segment_copy {
|
|
continue;
|
|
}
|
|
let obj_data = {
|
|
let (offset, size) = ph.file_range(endian);
|
|
let offset = offset as usize;
|
|
let range = offset..(offset + size as usize);
|
|
match data.get(range.clone()) {
|
|
Some(some) => some,
|
|
None => return Err(format!("failed to read {:x?}", range)),
|
|
}
|
|
};
|
|
|
|
let mmap_data = {
|
|
let range = if is_pie_enabled(elf) {
|
|
let addr = ph.p_vaddr(endian) as usize;
|
|
addr..addr + obj_data.len()
|
|
} else {
|
|
let addr = ph.p_vaddr(endian) as usize - mmap.as_ptr() as usize;
|
|
addr..addr + obj_data.len()
|
|
};
|
|
match mmap.get_mut(range.clone()) {
|
|
Some(some) => some,
|
|
None => {
|
|
return Err(format!("failed to write {:x?}", range));
|
|
}
|
|
}
|
|
};
|
|
let _voff = ph.p_vaddr(endian) % ph.p_align(endian);
|
|
let _vsize = ((ph.p_memsz(endian) + _voff) as usize)
|
|
.next_multiple_of(ph.p_align(endian) as usize);
|
|
log::trace!(
|
|
" copy {:#x}, {:#x}: {:#x}, {:#x}",
|
|
ph.p_vaddr(endian) - _voff,
|
|
_vsize,
|
|
_voff,
|
|
obj_data.len()
|
|
);
|
|
mmap_data.copy_from_slice(obj_data);
|
|
}
|
|
elf::PT_TLS => {
|
|
let ptr = unsafe {
|
|
if is_pie_enabled(elf) {
|
|
mmap.as_ptr().add(ph.p_vaddr(endian) as usize)
|
|
} else {
|
|
ph.p_vaddr(endian) as *const u8
|
|
}
|
|
};
|
|
tcb_master = Some(Master {
|
|
ptr,
|
|
image_size: ph.p_filesz(endian) as usize,
|
|
segment_size: ph.p_memsz(endian) as usize,
|
|
offset: tls_offset + ph.p_memsz(endian) as usize,
|
|
});
|
|
log::trace!(" tcb master {:x?}", tcb_master);
|
|
}
|
|
|
|
elf::PT_DYNAMIC => {
|
|
let entries = ph
|
|
.dynamic(endian, data)
|
|
.map_err(|err| err.to_string())?
|
|
.ok_or_else(|| "Unable to parse PT_DYNAMIC section".to_string())?;
|
|
dynamic = Some((ph, entries));
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
|
|
let dynamic = dynamic.ok_or_else(|| "Unable to find PT_DYNAMIC section".to_string())?;
|
|
|
|
let (parsed_dynamic, debug) = Self::parse_dynamic(path, mmap, is_pie_enabled(elf), dynamic)
|
|
.map_err(|e| e.to_string())?;
|
|
|
|
if let Some(i) = debug {
|
|
// FIXME: cleanup
|
|
let (ph, _) = dynamic;
|
|
let vaddr = ph.p_vaddr(endian) as usize;
|
|
let bytes: [u8; size_of::<Dyn>() / 2] =
|
|
((&raw const _r_debug).cast::<*const RTLDDebug>() as usize).to_ne_bytes();
|
|
let start = if is_pie_enabled(elf) {
|
|
vaddr + i * size_of::<Dyn>() + size_of::<Dyn>() / 2
|
|
} else {
|
|
vaddr + i * size_of::<Dyn>() + size_of::<Dyn>() / 2
|
|
- mmap.as_ptr().cast_mut() as usize
|
|
};
|
|
unsafe {
|
|
ptr::copy_nonoverlapping(
|
|
bytes.as_ptr(),
|
|
mmap.as_ptr().cast_mut().add(start),
|
|
bytes.len(),
|
|
);
|
|
}
|
|
}
|
|
|
|
Ok((mmap, tcb_master, parsed_dynamic))
|
|
}
|
|
|
|
fn parse_dynamic<'a>(
|
|
path: &str,
|
|
mmap: &'a [u8],
|
|
is_pie: bool,
|
|
(_, entries): (&ProgramHeader, &[Dyn]),
|
|
) -> object::Result<(Dynamic<'a>, Option<usize>)> {
|
|
let mut runpath = None;
|
|
let mut got = None;
|
|
let mut needed = vec![];
|
|
let mut jmprel = None;
|
|
let mut soname = None;
|
|
let mut hash_table = None;
|
|
let mut explicit_addend = None;
|
|
let mut pltrelsz = None;
|
|
let mut debug = None;
|
|
let mut symtab_ptr = None;
|
|
let (mut rel_ptr, mut rel_len) = (None, None);
|
|
let (mut relr_ptr, mut relr_len) = (None, None);
|
|
let (mut strtab_offset, mut strtab_size) = (None, None);
|
|
let (mut init_array_ptr, mut init_array_len) = (None, None);
|
|
let (mut fini_array_ptr, mut fini_array_len) = (None, None);
|
|
let (mut rela_offset, mut rela_len) = (None, None);
|
|
|
|
for (i, entry) in entries.iter().enumerate() {
|
|
let val = entry.d_val(NativeEndian);
|
|
let relative_idx = val as usize - if is_pie { 0 } else { mmap.as_ptr() as usize };
|
|
let ptr = (val as usize + if is_pie { mmap.as_ptr() as usize } else { 0 }) as *const u8;
|
|
let tag = entry.d_tag(NativeEndian) as u32;
|
|
|
|
match tag {
|
|
elf::DT_DEBUG => debug = Some(i),
|
|
|
|
// {Gnu,SysV}HashTable::parse()
|
|
//
|
|
// > The header does not contain a length field, and so all of
|
|
// > `data` will be used as the hash table values. It does not
|
|
// > matter if this is longer than needed...
|
|
elf::DT_GNU_HASH => {
|
|
let value = GnuHashTable::parse(NativeEndian, &mmap[relative_idx..])?;
|
|
hash_table = Some(HashTable::Gnu(value));
|
|
}
|
|
|
|
// XXX: Both GNU_HASH and HASH may be present, we give priority
|
|
// to GNU_HASH as it is significantly faster.
|
|
elf::DT_HASH if hash_table.is_none() => {
|
|
let value = SysVHashTable::parse(NativeEndian, &mmap[relative_idx..])?;
|
|
hash_table = Some(HashTable::Sysv(value));
|
|
}
|
|
|
|
elf::DT_PLTGOT => {
|
|
got = Some(NonNull::new(ptr as *mut usize).expect("DT_PLTGOT is NULL"));
|
|
}
|
|
|
|
elf::DT_NEEDED => needed.push(entry),
|
|
elf::DT_JMPREL => jmprel = Some(ptr as usize),
|
|
elf::DT_RUNPATH => runpath = Some(entry), // FIXME(andypython): rpath
|
|
elf::DT_STRTAB => strtab_offset = Some(relative_idx),
|
|
elf::DT_STRSZ => strtab_size = Some(val),
|
|
elf::DT_SONAME => soname = Some(entry),
|
|
|
|
elf::DT_RELA => rela_offset = Some(ptr.cast::<Rela>()),
|
|
elf::DT_RELASZ => rela_len = Some(val as usize / size_of::<Rela>()),
|
|
elf::DT_RELAENT => {
|
|
assert_eq!(val, size_of::<Rela>() as _)
|
|
}
|
|
|
|
elf::DT_REL => rel_ptr = Some(ptr.cast::<Rel>()),
|
|
elf::DT_RELSZ => rel_len = Some(val as usize / size_of::<Rel>()),
|
|
elf::DT_RELENT => {
|
|
assert_eq!(val, size_of::<Rel>() as _)
|
|
}
|
|
|
|
DT_RELR => relr_ptr = Some(ptr.cast::<Relr>()),
|
|
DT_RELRSZ => relr_len = Some(val as usize / size_of::<Relr>()),
|
|
DT_RELRENT => {
|
|
assert_eq!(val, size_of::<Relr>() as _)
|
|
}
|
|
|
|
elf::DT_PLTREL => {
|
|
let val = val as u32;
|
|
if val == elf::DT_RELA {
|
|
explicit_addend = Some(true);
|
|
} else {
|
|
assert_eq!(val, elf::DT_REL);
|
|
explicit_addend = Some(false);
|
|
}
|
|
}
|
|
elf::DT_PLTRELSZ => pltrelsz = Some(val as usize),
|
|
|
|
elf::DT_INIT_ARRAY if val != 0 => init_array_ptr = Some(ptr.cast::<InitFn>()),
|
|
elf::DT_INIT_ARRAYSZ => init_array_len = Some(val as usize / size_of::<InitFn>()),
|
|
|
|
elf::DT_FINI_ARRAY if val != 0 => fini_array_ptr = Some(ptr.cast::<InitFn>()),
|
|
elf::DT_FINI_ARRAYSZ => fini_array_len = Some(val as usize / size_of::<InitFn>()),
|
|
|
|
elf::DT_SYMTAB => symtab_ptr = Some(ptr.cast::<Sym>()),
|
|
elf::DT_SYMENT => {
|
|
assert_eq!(val as usize, size_of::<Sym>());
|
|
}
|
|
|
|
_ => {}
|
|
}
|
|
}
|
|
|
|
let strtab_offset = strtab_offset.expect("mandatory DT_STRTAB not present");
|
|
let strtab_size = strtab_size.expect("mandatory DT_STRSZ not present");
|
|
|
|
#[expect(clippy::unnecessary_cast, reason="needed on i586")]
|
|
let dynstrtab = StringTable::new(
|
|
mmap,
|
|
strtab_offset as u64,
|
|
strtab_offset as u64 + strtab_size as u64,
|
|
);
|
|
|
|
let get_str = |entry: &Dyn| {
|
|
entry
|
|
.string(NativeEndian, dynstrtab)
|
|
.map(|bytes| core::str::from_utf8(bytes).expect("non utf-8 elf symbol name"))
|
|
};
|
|
|
|
unsafe fn get_array<'a, T>(ptr: Option<*const T>, len: Option<usize>) -> &'a [T] {
|
|
if let Some(ptr) = ptr {
|
|
let len = len.expect("dynamic entry was present without it's corresponding size");
|
|
unsafe { core::slice::from_raw_parts(ptr, len) }
|
|
} else {
|
|
assert!(len.is_none());
|
|
&[]
|
|
}
|
|
}
|
|
|
|
let needed = needed
|
|
.into_iter()
|
|
.map(get_str)
|
|
.collect::<object::Result<Vec<_>>>()?;
|
|
|
|
let base = dirname(path);
|
|
|
|
let runpath = runpath
|
|
.map(get_str)
|
|
.transpose()?
|
|
.map(|value| value.replace("$ORIGIN", &base));
|
|
|
|
let soname = soname.map(get_str).transpose()?;
|
|
|
|
let jmprel = jmprel.unwrap_or_default();
|
|
let hash_table = hash_table.expect("either DT_GNU_HASH and/or DT_HASH mut be present");
|
|
|
|
let init_array = unsafe { get_array(init_array_ptr, init_array_len) };
|
|
let fini_array = unsafe { get_array(fini_array_ptr, fini_array_len) };
|
|
let rela = unsafe { get_array(rela_offset, rela_len) };
|
|
let relr = unsafe { get_array(relr_ptr, relr_len) };
|
|
let rel = unsafe { get_array(rel_ptr, rel_len) };
|
|
|
|
Ok((
|
|
Dynamic {
|
|
symbols: unsafe { get_array(symtab_ptr, Some(hash_table.symbol_table_length())) },
|
|
runpath,
|
|
got,
|
|
needed,
|
|
jmprel,
|
|
soname,
|
|
hash_table,
|
|
dynstrtab,
|
|
init_array,
|
|
fini_array,
|
|
rela,
|
|
rel,
|
|
relr,
|
|
explicit_addend: explicit_addend.unwrap_or_default(),
|
|
pltrelsz: pltrelsz.unwrap_or_default(),
|
|
},
|
|
debug,
|
|
))
|
|
}
|
|
|
|
/// `TLSDESC` relocation being an extension to the original TLS ABI spec can
|
|
/// be present in either `.rela.plt` (handled in [`Self::static_relocate`])
|
|
/// or `.rela.dyn` (handled in [`Self::lazy_relocate`]) due to the lack of a
|
|
/// standard unfortunately.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `reloc.kind` is not `RelocationKind::TLSDESC`.
|
|
fn do_tlsdesc_reloc(&self, reloc: Relocation, ptr: *mut usize, global_scope: &Scope) {
|
|
assert!(reloc.kind == RelocationKind::TLSDESC);
|
|
let (sym, tls_module_id, tls_offset) = if reloc.sym != SymbolIndex(0) {
|
|
let sym_name = self.dynamic.symbol_name(reloc.sym).unwrap();
|
|
let (sym, _, obj) = resolve_sym(sym_name, &[global_scope, self.scope()]).unwrap();
|
|
(sym.value, obj.tls_module_id, obj.tls_offset)
|
|
} else {
|
|
(0, self.tls_module_id, self.tls_offset)
|
|
};
|
|
|
|
let resolver = unsafe { &mut *ptr };
|
|
let descriptor = unsafe { &mut *ptr.add(1) };
|
|
|
|
if self.dlopened {
|
|
#[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
|
|
{
|
|
unimplemented!("`TLSDESC` relocations are not yet implemented for riscv64 and x86");
|
|
}
|
|
|
|
let mut tls_index = crate::header::dl_tls::dl_tls_index {
|
|
ti_module: tls_module_id,
|
|
ti_offset: reloc.addend.unwrap_or_default(),
|
|
};
|
|
|
|
// Ensure the DTV entry is initialised.
|
|
unsafe { __tls_get_addr(&raw mut tls_index) };
|
|
|
|
*resolver = __tlsdesc_dynamic as *const () as usize;
|
|
*descriptor = Box::into_raw(Box::new(TlsDescriptor {
|
|
module_id: tls_module_id - 1,
|
|
addend: sym + reloc.addend.unwrap_or_default(),
|
|
})) as usize;
|
|
} else {
|
|
*resolver = __tlsdesc_static as *const () as usize;
|
|
*descriptor = sym + tls_offset + reloc.addend.unwrap_or_default();
|
|
}
|
|
}
|
|
|
|
fn static_relocate(&self, global_scope: &Scope, reloc: Relocation) -> object::Result<()> {
|
|
let b = self.mmap.as_ptr() as usize;
|
|
|
|
let (sym, my_sym) = if reloc.sym != STN_UNDEF {
|
|
let name = self.dynamic.symbol_name(reloc.sym).unwrap();
|
|
|
|
let lookup_scopes = [global_scope, self.scope()];
|
|
let sym = if matches!(reloc.kind, RelocationKind::COPY) {
|
|
lookup_scopes
|
|
.iter()
|
|
.find_map(|scope| scope._get_sym(name, 1))
|
|
} else {
|
|
resolve_sym(name, &lookup_scopes)
|
|
}
|
|
.map(|(sym, _, obj)| (sym, obj));
|
|
|
|
(sym, self.dynamic.symbol(reloc.sym))
|
|
} else {
|
|
(None, None)
|
|
};
|
|
|
|
let (s, tls_obj) = sym
|
|
.as_ref()
|
|
.map(|(sym, obj)| (sym.as_ptr() as usize, obj.as_ref()))
|
|
// (1) According to the System V gABI (Chapter 4, "Relocation"): if
|
|
// the symbol index (`reloc.sym`) is undefined, the symbol value
|
|
// (`s`) is defined as 0.
|
|
//
|
|
// (2) According to Drepper's ELF Handling For Thread-Local Storage
|
|
// (Section 4.2, "Local Dynamic TLS Model"): a relocation with
|
|
// undefined symbol index implies a reference to the current module
|
|
// itself. Hence we resolve the object to `self`.
|
|
.unwrap_or((0, self));
|
|
|
|
let ptr = if self.pie {
|
|
(b + reloc.offset) as *mut u8
|
|
} else {
|
|
reloc.offset as *mut u8
|
|
};
|
|
let p = ptr as usize;
|
|
let a = match reloc.addend {
|
|
Some(some) => some,
|
|
None => match reloc.kind {
|
|
RelocationKind::COPY | RelocationKind::GOT | RelocationKind::PLT => 0,
|
|
_ => unsafe { *ptr.cast::<usize>() },
|
|
},
|
|
};
|
|
|
|
// TODO: support different sizes?
|
|
let set_usize = |value| unsafe {
|
|
*ptr.cast::<usize>() = value;
|
|
};
|
|
|
|
match reloc.kind {
|
|
RelocationKind::DTPMOD => set_usize(tls_obj.tls_module_id),
|
|
// TODO: Subtract DTP_OFFSET, which is 0x800 on riscv64, 0 on x86?
|
|
RelocationKind::DTPOFF => {
|
|
if reloc.sym.0 > 0 {
|
|
let (sym, _) = sym
|
|
.as_ref()
|
|
.expect("RelocationKind::DTPOFF called without valid symbol");
|
|
set_usize(sym.value + a);
|
|
} else {
|
|
set_usize(a);
|
|
}
|
|
}
|
|
RelocationKind::GOT => set_usize(s),
|
|
RelocationKind::OFFSET => set_usize((s + a).wrapping_sub(p)),
|
|
RelocationKind::RELATIVE => set_usize(b + a),
|
|
RelocationKind::SYMBOLIC => set_usize(s + a),
|
|
RelocationKind::TPOFF => {
|
|
assert!(
|
|
!tls_obj.dlopened,
|
|
"The {{local/initial}}-exec access model is used for symbol '{}' in '{}', which requires a static TLS block. However, the definition in '{}' resides in the dynamic TLS block because the object was loaded via dlopen(2).",
|
|
reloc.sym, self.name, tls_obj.name
|
|
);
|
|
if reloc.sym.0 > 0 {
|
|
let (sym, _) = sym
|
|
.as_ref()
|
|
.expect("RelocationKind::TPOFF called without valid symbol");
|
|
set_usize((sym.value + a).wrapping_sub(tls_obj.tls_offset));
|
|
} else {
|
|
set_usize(a.wrapping_sub(tls_obj.tls_offset));
|
|
}
|
|
}
|
|
RelocationKind::IRELATIVE => unsafe {
|
|
let f: unsafe extern "C" fn() -> usize = core::mem::transmute(b + a);
|
|
set_usize(f());
|
|
},
|
|
RelocationKind::COPY => unsafe {
|
|
let (sym, obj) = sym
|
|
.as_ref()
|
|
.expect("RelocationKind::COPY called without valid symbol");
|
|
let my_sym = my_sym.expect("RelocationKind::COPY called without valid symbol");
|
|
assert!(
|
|
sym.size == my_sym.st_size(NativeEndian) as usize,
|
|
"RelocationKind::COPY failed: I was trying to use the symbol {} from {} for {} but they had different sizes. Please consider relinking.",
|
|
sym.name,
|
|
obj.name,
|
|
self.name
|
|
);
|
|
// SAFETY: Both the source and destination have the same size.
|
|
ptr::copy_nonoverlapping(sym.as_ptr() as *const u8, ptr, sym.size);
|
|
},
|
|
RelocationKind::TLSDESC => {
|
|
self.do_tlsdesc_reloc(reloc, ptr.cast::<usize>(), global_scope)
|
|
}
|
|
_ => unimplemented!("relocation type {:?}", reloc.kind),
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn lazy_relocate(&self, global_scope: &Scope, resolve: Resolve) -> object::Result<()> {
|
|
let Some(got) = self.got() else {
|
|
assert_eq!(self.dynamic.jmprel, 0);
|
|
return Ok(());
|
|
};
|
|
|
|
let object_base_addr = self.mmap.as_ptr() as usize;
|
|
let jmprel = self.dynamic.jmprel;
|
|
let pltrelsz = self.dynamic.pltrelsz;
|
|
|
|
unsafe {
|
|
got.add(1).write(core::ptr::addr_of!(*self) as usize);
|
|
got.add(2)
|
|
.write(__plt_resolve_trampoline as *const () as usize);
|
|
}
|
|
|
|
let relsz = if self.dynamic.explicit_addend {
|
|
size_of::<Rela>()
|
|
} else {
|
|
size_of::<Rel>()
|
|
};
|
|
|
|
for addr in (jmprel..(jmprel + pltrelsz)).step_by(relsz) {
|
|
let reloc: Relocation = if self.dynamic.explicit_addend {
|
|
unsafe { &*(addr as *const Rela) }.into()
|
|
} else {
|
|
unsafe { &*(addr as *const Rel) }.into()
|
|
};
|
|
|
|
let ptr = if self.pie {
|
|
(object_base_addr + reloc.offset) as *mut usize
|
|
} else {
|
|
reloc.offset as *mut usize
|
|
};
|
|
|
|
match (reloc.kind, resolve) {
|
|
(RelocationKind::PLT, Resolve::Lazy) if self.pie => unsafe {
|
|
*ptr += object_base_addr;
|
|
},
|
|
|
|
(RelocationKind::PLT, Resolve::Lazy) => {
|
|
// NOP.
|
|
}
|
|
|
|
(RelocationKind::PLT, Resolve::Now) => {
|
|
let name = self.dynamic.symbol_name(reloc.sym).unwrap();
|
|
|
|
let resolved = resolve_sym(name, &[global_scope, self.scope()])
|
|
.map(|(sym, _, _)| sym.as_ptr() as usize)
|
|
.unwrap_or_else(|| {
|
|
panic!(
|
|
"unresolved symbol: {name} for soname {:?}",
|
|
self.dynamic.soname
|
|
)
|
|
});
|
|
|
|
unsafe {
|
|
*ptr = resolved + reloc.addend.unwrap_or(0);
|
|
}
|
|
}
|
|
|
|
(RelocationKind::TLSDESC, Resolve::Now) => {
|
|
self.do_tlsdesc_reloc(reloc, ptr, global_scope);
|
|
}
|
|
(RelocationKind::TLSDESC, Resolve::Lazy) => {
|
|
unreachable!("TLSDESC cannot be lazily resolved")
|
|
}
|
|
|
|
_ => {
|
|
unimplemented!(
|
|
"relocation type {:?} with resolve {:?}",
|
|
reloc.kind,
|
|
resolve
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
pub fn relocate(&self, ph: &[ProgramHeader], resolve: Resolve) -> object::Result<()> {
|
|
let global_scope = GLOBAL_SCOPE.read();
|
|
let base = self.mmap.as_ptr();
|
|
|
|
unsafe {
|
|
apply_relr(base, self.dynamic.relr);
|
|
}
|
|
|
|
self.dynamic
|
|
.static_relocations()
|
|
.try_for_each(|reloc| self.static_relocate(&global_scope, reloc))?;
|
|
|
|
self.lazy_relocate(&global_scope, resolve)?;
|
|
|
|
// Protect pages
|
|
for ph in ph
|
|
.iter()
|
|
.filter(|ph| ph.p_type(NativeEndian) == elf::PT_LOAD)
|
|
{
|
|
let voff = ph.p_vaddr(NativeEndian) % ph.p_align(NativeEndian);
|
|
let vaddr = (ph.p_vaddr(NativeEndian) - voff) as usize;
|
|
let vsize = ((ph.p_memsz(NativeEndian) + voff) as usize)
|
|
.next_multiple_of(ph.p_align(NativeEndian) as usize);
|
|
|
|
let mut prot = 0;
|
|
if ph.p_flags(NativeEndian) & elf::PF_R == elf::PF_R {
|
|
prot |= sys_mman::PROT_READ;
|
|
}
|
|
|
|
// W ^ X. If it is executable, do not allow it to be writable, even if requested
|
|
if ph.p_flags(NativeEndian) & elf::PF_X == elf::PF_X {
|
|
prot |= sys_mman::PROT_EXEC;
|
|
} else if ph.p_flags(NativeEndian) & elf::PF_W == elf::PF_W {
|
|
prot |= sys_mman::PROT_WRITE;
|
|
}
|
|
|
|
unsafe {
|
|
let ptr = if self.pie {
|
|
self.mmap.as_ptr().add(vaddr)
|
|
} else {
|
|
vaddr as *const u8
|
|
};
|
|
log::trace!(" prot {:#x}, {:#x}: {:p}, {:#x}", vaddr, vsize, ptr, prot);
|
|
Sys::mprotect(ptr as *mut c_void, vsize, prot).expect("[ld.so]: mprotect failed");
|
|
}
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl Drop for DSO {
|
|
fn drop(&mut self) {
|
|
if self.is_ready.load(Ordering::SeqCst) {
|
|
// `run_fini` should not be called if we are being prematurely
|
|
// dropped (e.g. failed to satisfy dependencies).
|
|
self.run_fini();
|
|
}
|
|
unsafe { Sys::munmap(self.mmap.as_ptr() as *mut c_void, self.mmap.len()).unwrap() };
|
|
}
|
|
}
|
|
|
|
fn is_pie_enabled(elf: &ElfFile) -> bool {
|
|
elf.elf_header().e_type.get(elf.endian()) == elf::ET_DYN
|
|
}
|
|
|
|
fn basename(path: &str) -> String {
|
|
path.split("/").last().unwrap_or(path).to_string()
|
|
}
|
|
|
|
fn dirname(path: &str) -> String {
|
|
let mut parts: Vec<&str> = path.split("/").collect();
|
|
parts.truncate(parts.len() - 1);
|
|
parts.join("/")
|
|
}
|
|
|
|
pub fn resolve_sym<'a>(
|
|
name: &'a str,
|
|
scopes: &[&'a Scope],
|
|
) -> Option<(Symbol<'a>, SymbolBinding, Arc<DSO>)> {
|
|
scopes.iter().find_map(|scope| scope.get_sym(name))
|
|
}
|
|
|
|
#[repr(C)]
|
|
struct TlsDescriptor {
|
|
module_id: usize,
|
|
addend: usize,
|
|
}
|
|
|
|
#[cfg(target_arch = "x86_64")]
|
|
#[unsafe(naked)]
|
|
unsafe extern "C" fn __tlsdesc_static() {
|
|
core::arch::naked_asm!("mov rax, [rax + 8]", "ret")
|
|
}
|
|
|
|
#[cfg(target_arch = "x86")]
|
|
#[unsafe(naked)]
|
|
unsafe extern "C" fn __tlsdesc_static() {
|
|
core::arch::naked_asm!("mov eax, [eax + 4]", "ret")
|
|
}
|
|
|
|
#[cfg(target_arch = "aarch64")]
|
|
#[unsafe(naked)]
|
|
unsafe extern "C" fn __tlsdesc_static() {
|
|
core::arch::naked_asm!("ldr x0, [x0, #8]", "ret")
|
|
}
|
|
|
|
#[cfg(target_arch = "riscv64")]
|
|
#[unsafe(naked)]
|
|
unsafe extern "C" fn __tlsdesc_static() {
|
|
core::arch::naked_asm!("ld a0, 8(a0)", "ret");
|
|
}
|
|
|
|
unsafe extern "C" {
|
|
fn __tlsdesc_dynamic();
|
|
}
|
|
|
|
#[cfg(target_arch = "x86_64")]
|
|
core::arch::global_asm!(
|
|
"
|
|
.global __tlsdesc_dynamic
|
|
.hidden __tlsdesc_dynamic
|
|
__tlsdesc_dynamic:
|
|
push rbx
|
|
push rcx
|
|
|
|
mov rax, [rax + 8] // TLS descriptor
|
|
mov rbx, [rax + {TLS_DESCRIPTOR_MODULE_ID_OFF}] // tls_descriptor.module_id
|
|
mov rcx, [rax + {TLS_DESCRIPTOR_ADDEND_OFF}] // tls_descriptor.addend
|
|
mov rax, qword ptr fs:[{DTV_PTR_OFF}] // tcb.dtv_ptr
|
|
|
|
// tcb.dtv_ptr[tls_descriptor.module_id] + tls_descriptor.addend
|
|
mov rax, [rax + rbx * 8]
|
|
add rax, rcx
|
|
sub rax, qword ptr fs:[{TCB_SELF_PTR_OFF}]
|
|
|
|
pop rcx
|
|
pop rbx
|
|
|
|
ret
|
|
",
|
|
TLS_DESCRIPTOR_MODULE_ID_OFF = const offset_of!(TlsDescriptor, module_id),
|
|
TLS_DESCRIPTOR_ADDEND_OFF = const offset_of!(TlsDescriptor, addend),
|
|
DTV_PTR_OFF = const offset_of!(Tcb, dtv_ptr),
|
|
TCB_SELF_PTR_OFF = const offset_of!(Tcb, generic.tcb_ptr),
|
|
);
|
|
|
|
#[cfg(target_arch = "x86")]
|
|
core::arch::global_asm!(
|
|
"
|
|
.global __tlsdesc_dynamic
|
|
.hidden __tlsdesc_dynamic
|
|
__tlsdesc_dynamic:
|
|
ud2
|
|
"
|
|
);
|
|
|
|
#[cfg(target_arch = "aarch64")]
|
|
core::arch::global_asm!(
|
|
"
|
|
.global __tlsdesc_dynamic
|
|
.hidden __tlsdesc_dynamic
|
|
__tlsdesc_dynamic:
|
|
stp x1, x2, [sp, #-16]!
|
|
|
|
ldr x0, [x0, #8] // TLS descriptor
|
|
|
|
// x0 := tls_descriptor.module_id
|
|
// x1 := tls_descriptor.addend
|
|
ldp x0, x1, [x0]
|
|
|
|
mrs x2, tpidr_el0 // ABI ptr
|
|
ldr x2, [x2] // TCB ptr
|
|
|
|
sub x1, x1, x2 // tls_descriptor.addend -= tcb
|
|
|
|
ldr x2, [x2, {DTV_PTR_OFF}] // tcb.dtv_ptr
|
|
ldr x2, [x2, x0, lsl #3] // tcb.dtv_ptr[tls_descriptor.module_id]
|
|
add x0, x2, x1 // tcb.dtv_ptr[tls_descriptor.module_id] + tls_descriptor.addend
|
|
|
|
ldp x1, x2, [sp], #16
|
|
ret
|
|
",
|
|
DTV_PTR_OFF = const offset_of!(Tcb, dtv_ptr),
|
|
);
|
|
|
|
#[cfg(target_arch = "riscv64")]
|
|
core::arch::global_asm!(
|
|
"
|
|
.global __tlsdesc_dynamic
|
|
.hidden __tlsdesc_dynamic
|
|
__tlsdesc_dynamic:
|
|
unimp
|
|
"
|
|
);
|
|
|
|
/// Applies [`DT_RELR`] relative relocations.
|
|
pub unsafe fn apply_relr(base: *const u8, relr: &[Relr]) {
|
|
let mut addr = ptr::null_mut();
|
|
for &entry in relr {
|
|
if entry & 1 == 0 {
|
|
// An even entry sets up `addr` for subsequent odd entries.
|
|
unsafe {
|
|
addr = base.add(entry) as *mut usize;
|
|
*addr += base as usize;
|
|
addr = addr.add(1);
|
|
}
|
|
} else {
|
|
// An odd entry indicates a bitmap describing at maximum 63
|
|
// (for 64-bit) or 31 (for 32-bit) locations following `addr`.
|
|
// Odd entries can be chained.
|
|
let mut entry = entry >> 1;
|
|
let mut i = 0;
|
|
while entry != 0 {
|
|
if entry & 1 != 0 {
|
|
unsafe {
|
|
*addr.add(i) += base as usize;
|
|
}
|
|
}
|
|
entry >>= 1;
|
|
i += 1;
|
|
}
|
|
|
|
addr = unsafe { addr.add(CHAR_BITS * size_of::<Relr>() - 1) };
|
|
}
|
|
}
|
|
}
|