motiejus/zig
1
Fork 0
Code Releases Activity

std.os.linux.start_pie: Add support for the new RELR relocation format.

Browse Source
This commit is contained in:
Alex Rønne Petersen
2024-07-26 01:07:34 +02:00
committed by Andrew Kelley
parent 61dac74128
commit 8161e61548
1 changed files with 24 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
lib/std/os/linux/start_pie.zig
View File

@@ -277,4 +277,28 @@ pub fn relocate(phdrs: []elf.Phdr) void {
@as(*usize, @ptrFromInt(base_addr + r.r_offset)).* = base_addr + @as(usize, @bitCast(r.r_addend));
}
}
const relr = sorted_dynv[elf.DT_RELR];
if (relr != 0) {
const relrs = @call(.always_inline, std.mem.bytesAsSlice, .{
elf.Relr,
@as([*]u8, @ptrFromInt(base_addr + relr))[0..sorted_dynv[elf.DT_RELRSZ]],
});
var current: [*]usize = undefined;
for (relrs) |r| {
if ((r & 1) == 0) {
current = @ptrFromInt(base_addr + r);
current[0] += base_addr;
current += 1;
} else {
// Skip the first bit; there are 63 locations in the bitmap.
var i: if (@sizeOf(usize) == 8) u6 else u5 = 1;
while (i < @bitSizeOf(elf.Relr)) : (i += 1) {
if (((r >> i) & 1) != 0) current[i] += base_addr;
}
current += @bitSizeOf(elf.Relr) - 1;
}
}
}
}