1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
use crate::result::*;
pub mod rc;
#[derive(Copy, Clone)]
#[repr(C)]
pub struct ModuleStart {
pub reserved: u32,
pub magic_offset: u32,
}
pub fn relocate_with_dyn(base_address: *const u8, dynamic: *const elf::Dyn) -> Result<()> {
unsafe {
let rela_offset = (*dynamic).find_value(elf::Tag::RelaOffset)?;
let rela_size = (*dynamic).find_value(elf::Tag::RelaSize)?;
let rela_entry_size = (*dynamic).find_value(elf::Tag::RelaEntrySize)?;
let rela_count = (*dynamic).find_value(elf::Tag::RelaCount)?;
result_return_unless!(rela_size == rela_entry_size * rela_count, rc::ResultRelaSizeMismatch);
let rela_base = base_address.offset(rela_offset as isize) as *const elf::Rela;
for i in 0..rela_count {
let rela = rela_base.offset(i as isize);
match (*rela).info.symbol.relocation_type {
elf::RelocationType::AArch64Relative => {
if (*rela).info.symbol.symbol == 0 {
let relocation_offset = base_address.offset((*rela).offset as isize) as *mut *const u8;
*relocation_offset = base_address.offset((*rela).addend as isize);
}
},
_ => {}
}
}
}
Ok(())
}
pub fn relocate(base_address: *const u8) -> Result<()> {
unsafe {
let module_start = base_address as *const ModuleStart;
let mod_offset = (*module_start).magic_offset as isize;
let module = base_address.offset(mod_offset) as *const mod0::Header;
result_return_unless!((*module).magic == mod0::MAGIC, rc::ResultInvalidModuleMagic);
let dyn_offset = mod_offset + (*module).dynamic as isize;
let dynamic = base_address.offset(dyn_offset) as *const elf::Dyn;
relocate_with_dyn(base_address, dynamic)
}
}
pub mod elf;
pub mod mod0;