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dyld: streamline lib.rs

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Only riscv32 is supported anyway, no need to have excessive architecture check.
This commit is contained in:
occheung 2021-08-27 17:54:58 +08:00
parent 798774192d
commit d8ac429059
1 changed files with 20 additions and 25 deletions
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45
artiq/firmware/libdyld/lib.rs
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@ -84,7 +84,6 @@ pub enum Arch {
pub struct Library<'a> {
image_off: Elf32_Addr,
image_sz: usize,
arch: Arch,
strtab: &'a [u8],
symtab: &'a [Elf32_Sym],
pltrel: &'a [Elf32_Rela],
@ -140,9 +139,8 @@ impl<'a> Library<'a> {
// This is unsafe because it mutates global data (the PLT).
pub unsafe fn rebind(&self, name: &[u8], addr: Elf32_Word) -> Result<(), Error<'a>> {
for rela in self.pltrel.iter() {
match (ELF32_R_TYPE(rela.r_info), self.arch) {
(R_RISCV_32, Arch::RiscV) |
(R_RISCV_JUMP_SLOT, Arch::RiscV) => {
match ELF32_R_TYPE(rela.r_info) {
R_RISCV_32 | R_RISCV_JUMP_SLOT => {
let sym = self.symtab.get(ELF32_R_SYM(rela.r_info) as usize)
.ok_or("symbol out of bounds of symbol table")?;
let sym_name = self.name_starting_at(sym.st_name as usize)?;
@ -170,15 +168,14 @@ impl<'a> Library<'a> {
}
let value;
match (ELF32_R_TYPE(rela.r_info), self.arch) {
(R_RISCV_NONE, Arch::RiscV) =>
match ELF32_R_TYPE(rela.r_info) {
R_RISCV_NONE =>
return Ok(()),
(R_RISCV_RELATIVE, Arch::RiscV) =>
R_RISCV_RELATIVE =>
value = self.image_off + rela.r_addend as Elf32_Word,
(R_RISCV_32, Arch::RiscV) |
(R_RISCV_JUMP_SLOT, Arch::RiscV) => {
R_RISCV_32 | R_RISCV_JUMP_SLOT => {
let sym = sym.ok_or("relocation requires an associated symbol")?;
let sym_name = self.name_starting_at(sym.st_name as usize)?;
@ -211,7 +208,20 @@ impl<'a> Library<'a> {
let ehdr = read_unaligned::<Elf32_Ehdr>(data, 0)
.map_err(|()| "cannot read ELF header")?;
let arch = arch(&ehdr).ok_or("not a shared library for current architecture")?;
const IDENT: [u8; EI_NIDENT] = [
ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
ELFCLASS32, ELFDATA2LSB, EV_CURRENT, ELFOSABI_NONE,
/* ABI version */ 0, /* padding */ 0, 0, 0, 0, 0, 0, 0
];
#[cfg(target_arch = "riscv32")]
const ARCH: u16 = EM_RISCV;
#[cfg(not(target_arch = "riscv32"))]
const ARCH: u16 = EM_NONE;
if ehdr.e_ident != IDENT || ehdr.e_type != ET_DYN || ehdr.e_machine != ARCH {
return Err("not a shared library for current architecture")?
}
let mut dyn_off = None;
for i in 0..ehdr.e_phnum {
@ -310,7 +320,6 @@ impl<'a> Library<'a> {
let library = Library {
image_off: image.as_ptr() as Elf32_Word,
image_sz: image.len(),
arch: arch,
strtab: strtab,
symtab: symtab,
pltrel: pltrel,
@ -334,17 +343,3 @@ impl<'a> Library<'a> {
Ok(library)
}
}
fn arch(ehdr: &Elf32_Ehdr) -> Option<Arch> {
const IDENT_RISCV: [u8; EI_NIDENT] = [
ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
ELFCLASS32, ELFDATA2LSB, EV_CURRENT, ELFOSABI_NONE,
/* ABI version */ 0, /* padding */ 0, 0, 0, 0, 0, 0, 0
];
match (ehdr.e_ident, ehdr.e_machine) {
#[cfg(target_arch = "riscv32")]
(IDENT_RISCV, EM_RISCV) => Some(Arch::RiscV),
_ => None,
}
}