libdyld: add riscv support

This commit is contained in:
occheung 2021-08-06 10:52:14 +08:00
parent ad3037d0f6
commit bfddd8a30f
2 changed files with 101 additions and 20 deletions

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@ -131,6 +131,7 @@ pub const EM_TILEPRO: u16 = 188;
pub const EM_MICROBLAZE: u16 = 189; pub const EM_MICROBLAZE: u16 = 189;
pub const EM_TILEGX: u16 = 191; pub const EM_TILEGX: u16 = 191;
pub const EM_NUM: u16 = 192; pub const EM_NUM: u16 = 192;
pub const EM_RISCV: u16 = 243;
pub const EM_ALPHA: u16 = 36902; pub const EM_ALPHA: u16 = 36902;
pub const EV_NONE: u8 = 0; pub const EV_NONE: u8 = 0;
pub const EV_CURRENT: u8 = 1; pub const EV_CURRENT: u8 = 1;
@ -2229,6 +2230,61 @@ pub const R_OR1K_TLS_TPOFF: u8 = 32;
pub const R_OR1K_TLS_DTPOFF: u8 = 33; pub const R_OR1K_TLS_DTPOFF: u8 = 33;
pub const R_OR1K_TLS_DTPMOD: u8 = 34; pub const R_OR1K_TLS_DTPMOD: u8 = 34;
pub const R_OR1K_NUM: u8 = 35; pub const R_OR1K_NUM: u8 = 35;
pub const R_RISCV_NONE: u8 = 0;
pub const R_RISCV_32: u8 = 1;
pub const R_RISCV_64: u8 = 2;
pub const R_RISCV_RELATIVE: u8 = 3;
pub const R_RISCV_COPY: u8 = 4;
pub const R_RISCV_JUMP_SLOT: u8 = 5;
pub const R_RISCV_TLS_DTPMOD32: u8 = 6;
pub const R_RISCV_TLS_DTPMOD64: u8 = 7;
pub const R_RISCV_TLS_DTPREL32: u8 = 8;
pub const R_RISCV_TLS_DTPREL64: u8 = 9;
pub const R_RISCV_TLS_TPREL32: u8 = 10;
pub const R_RISCV_TLS_TPREL64: u8 = 11;
pub const R_RISCV_BRANCH: u8 = 16;
pub const R_RISCV_JAL: u8 = 17;
pub const R_RISCV_CALL: u8 = 18;
pub const R_RISCV_CALL_PLT: u8 = 19;
pub const R_RISCV_GOT_HI20: u8 = 20;
pub const R_RISCV_TLS_GOT_HI20: u8 = 21;
pub const R_RISCV_TLS_GD_HI20: u8 = 22;
pub const R_RISCV_PCREL_HI20: u8 = 23;
pub const R_RISCV_PCREL_LO12_I: u8 = 24;
pub const R_RISCV_PCREL_LO12_S: u8 = 25;
pub const R_RISCV_HI20: u8 = 26;
pub const R_RISCV_LO12_I: u8 = 27;
pub const R_RISCV_LO12_S: u8 = 28;
pub const R_RISCV_TPREL_HI20: u8 = 29;
pub const R_RISCV_TPREL_LO12_I: u8 = 30;
pub const R_RISCV_TPREL_LO12_S: u8 = 31;
pub const R_RISCV_TPREL_ADD: u8 = 32;
pub const R_RISCV_ADD8: u8 = 33;
pub const R_RISCV_ADD16: u8 = 34;
pub const R_RISCV_ADD32: u8 = 35;
pub const R_RISCV_ADD64: u8 = 36;
pub const R_RISCV_SUB8: u8 = 37;
pub const R_RISCV_SUB16: u8 = 38;
pub const R_RISCV_SUB32: u8 = 39;
pub const R_RISCV_SUB64: u8 = 40;
pub const R_RISCV_GNU_VTINHERIT: u8 = 41;
pub const R_RISCV_GNU_VTENTRY: u8 = 42;
pub const R_RISCV_ALIGN: u8 = 43;
pub const R_RISCV_RVC_BRANCH: u8 = 44;
pub const R_RISCV_RVC_JUMP: u8 = 45;
pub const R_RISCV_RVC_LUI: u8 = 46;
pub const R_RISCV_GPREL_I: u8 = 47;
pub const R_RISCV_GPREL_S: u8 = 48;
pub const R_RISCV_TPREL_I: u8 = 49;
pub const R_RISCV_TPREL_S: u8 = 50;
pub const R_RISCV_RELAX: u8 = 51;
pub const R_RISCV_SUB6: u8 = 52;
pub const R_RISCV_SET6: u8 = 53;
pub const R_RISCV_SET8: u8 = 54;
pub const R_RISCV_SET16: u8 = 55;
pub const R_RISCV_SET32: u8 = 56;
pub const R_RISCV_32_PCREL: u8 = 57;
pub const R_RISCV_NUM: u8 = 58;
pub type Elf32_Half = u16; pub type Elf32_Half = u16;
pub type Elf64_Half = u16; pub type Elf64_Half = u16;

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@ -75,9 +75,16 @@ impl<'a> fmt::Display for Error<'a> {
} }
} }
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Arch {
RiscV,
OpenRisc,
}
pub struct Library<'a> { pub struct Library<'a> {
image_off: Elf32_Addr, image_off: Elf32_Addr,
image_sz: usize, image_sz: usize,
arch: Arch,
strtab: &'a [u8], strtab: &'a [u8],
symtab: &'a [Elf32_Sym], symtab: &'a [Elf32_Sym],
pltrel: &'a [Elf32_Rela], pltrel: &'a [Elf32_Rela],
@ -133,8 +140,12 @@ impl<'a> Library<'a> {
// This is unsafe because it mutates global data (the PLT). // This is unsafe because it mutates global data (the PLT).
pub unsafe fn rebind(&self, name: &[u8], addr: Elf32_Word) -> Result<(), Error<'a>> { pub unsafe fn rebind(&self, name: &[u8], addr: Elf32_Word) -> Result<(), Error<'a>> {
for rela in self.pltrel.iter() { for rela in self.pltrel.iter() {
match ELF32_R_TYPE(rela.r_info) { match (ELF32_R_TYPE(rela.r_info), self.arch) {
R_OR1K_32 | R_OR1K_GLOB_DAT | R_OR1K_JMP_SLOT => { (R_OR1K_32, Arch::OpenRisc) |
(R_OR1K_GLOB_DAT, Arch::OpenRisc) |
(R_OR1K_JMP_SLOT, Arch::OpenRisc) |
(R_RISCV_32, Arch::RiscV) |
(R_RISCV_JUMP_SLOT, Arch::RiscV) => {
let sym = self.symtab.get(ELF32_R_SYM(rela.r_info) as usize) let sym = self.symtab.get(ELF32_R_SYM(rela.r_info) as usize)
.ok_or("symbol out of bounds of symbol table")?; .ok_or("symbol out of bounds of symbol table")?;
let sym_name = self.name_starting_at(sym.st_name as usize)?; let sym_name = self.name_starting_at(sym.st_name as usize)?;
@ -162,14 +173,18 @@ impl<'a> Library<'a> {
} }
let value; let value;
match ELF32_R_TYPE(rela.r_info) { match (ELF32_R_TYPE(rela.r_info), self.arch) {
R_OR1K_NONE => (R_OR1K_NONE, Arch::OpenRisc) | (R_RISCV_NONE, Arch::RiscV) =>
return Ok(()), return Ok(()),
R_OR1K_RELATIVE => (R_OR1K_RELATIVE, Arch::OpenRisc) | (R_RISCV_RELATIVE, Arch::RiscV) =>
value = self.image_off + rela.r_addend as Elf32_Word, value = self.image_off + rela.r_addend as Elf32_Word,
R_OR1K_32 | R_OR1K_GLOB_DAT | R_OR1K_JMP_SLOT => { (R_OR1K_32, Arch::OpenRisc) |
(R_OR1K_GLOB_DAT, Arch::OpenRisc) |
(R_OR1K_JMP_SLOT, Arch::OpenRisc) |
(R_RISCV_32, Arch::RiscV) |
(R_RISCV_JUMP_SLOT, Arch::RiscV) => {
let sym = sym.ok_or("relocation requires an associated symbol")?; let sym = sym.ok_or("relocation requires an associated symbol")?;
let sym_name = self.name_starting_at(sym.st_name as usize)?; let sym_name = self.name_starting_at(sym.st_name as usize)?;
@ -202,20 +217,7 @@ impl<'a> Library<'a> {
let ehdr = read_unaligned::<Elf32_Ehdr>(data, 0) let ehdr = read_unaligned::<Elf32_Ehdr>(data, 0)
.map_err(|()| "cannot read ELF header")?; .map_err(|()| "cannot read ELF header")?;
const IDENT: [u8; EI_NIDENT] = [ let arch = arch(&ehdr).ok_or("not a shared library for current architecture")?;
ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
ELFCLASS32, ELFDATA2MSB, EV_CURRENT, ELFOSABI_NONE,
/* ABI version */ 0, /* padding */ 0, 0, 0, 0, 0, 0, 0
];
#[cfg(target_arch = "or1k")]
const ARCH: u16 = EM_OPENRISC;
#[cfg(not(target_arch = "or1k"))]
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; let mut dyn_off = None;
for i in 0..ehdr.e_phnum { for i in 0..ehdr.e_phnum {
@ -314,6 +316,7 @@ impl<'a> Library<'a> {
let library = Library { let library = Library {
image_off: image.as_ptr() as Elf32_Word, image_off: image.as_ptr() as Elf32_Word,
image_sz: image.len(), image_sz: image.len(),
arch: arch,
strtab: strtab, strtab: strtab,
symtab: symtab, symtab: symtab,
pltrel: pltrel, pltrel: pltrel,
@ -337,3 +340,25 @@ impl<'a> Library<'a> {
Ok(library) Ok(library)
} }
} }
fn arch(ehdr: &Elf32_Ehdr) -> Option<Arch> {
const IDENT_OPENRISC: [u8; EI_NIDENT] = [
ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
ELFCLASS32, ELFDATA2MSB, EV_CURRENT, ELFOSABI_NONE,
/* ABI version */ 0, /* padding */ 0, 0, 0, 0, 0, 0, 0
];
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),
#[cfg(target_arch = "or1k")]
(IDENT_OPENRISC, EM_OPENRISC) => Some(Arch::OpenRisc),
_ => None,
}
}