Fix slight deviation from spec in handling Elf*_Rela relative relocations

`Elf*_Rela` relocations store their argument in `r_addend`, including for `R_*_RELATIVE` relocations.  Unlike `Elf*_Rel` relocations, they are not applied as a delta to the destination virtual address.  Instead, they are computed from `base_address + r_addend` directly.
This commit is contained in:
Shane Peelar 2024-06-06 20:04:16 -04:00 committed by Andrew Kelley
parent 7ae9d8089d
commit ec337051a9

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@ -113,7 +113,7 @@ pub fn relocate(phdrs: []elf.Phdr) void {
const rela = std.mem.bytesAsSlice(elf.Rela, @as([*]u8, @ptrFromInt(rela_addr))[0..rela_size]); const rela = std.mem.bytesAsSlice(elf.Rela, @as([*]u8, @ptrFromInt(rela_addr))[0..rela_size]);
for (rela) |r| { for (rela) |r| {
if (r.r_type() != R_RELATIVE) continue; if (r.r_type() != R_RELATIVE) continue;
@as(*usize, @ptrFromInt(base_addr + r.r_offset)).* += base_addr + @as(usize, @bitCast(r.r_addend)); @as(*usize, @ptrFromInt(base_addr + r.r_offset)).* = base_addr + @as(usize, @bitCast(r.r_addend));
} }
} }
} }