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zld: fix finding pointers for rebasing

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This commit is contained in:
Jakub Konka
2021-06-22 10:29:58 +02:00
parent d1fcb99848
commit 0736365fa4
1 changed files with 33 additions and 10 deletions
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43
src/link/MachO/Zld.zig
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@@ -1948,29 +1948,52 @@ fn resolveRelocsAndWriteSections(self: *Zld) !void {
args.source_target_sect_addr = source_sect.inner.addr;
}
rebases: {
var hit: bool = false;
if (target_map.segment_id == self.data_segment_cmd_index.?) {
if (self.data_section_index) |index| {
if (index == target_map.section_id) hit = true;
const flags = @truncate(u8, target_sect.flags & 0xff);
const should_rebase = rebase: {
if (!unsigned.is_64bit) break :rebase false;
// TODO actually, a check similar to what dyld is doing, that is, verifying
// that the segment is writable should be enough here.
const is_right_segment = blk: {
if (self.data_segment_cmd_index) |idx| {
if (target_map.segment_id == idx) {
break :blk true;
}
}
if (self.data_const_segment_cmd_index) |idx| {
if (target_map.segment_id == idx) {
break :blk true;
}
}
break :blk false;
};
if (!is_right_segment) break :rebase false;
if (flags != macho.S_LITERAL_POINTERS and
flags != macho.S_REGULAR)
{
break :rebase false;
}
if (target_map.segment_id == self.data_const_segment_cmd_index.?) {
if (self.data_const_section_index) |index| {
if (index == target_map.section_id) hit = true;
if (rel.target == .symbol) {
const final = rel.target.symbol.getTopmostAlias();
if (final.cast(Symbol.Proxy)) |_| {
break :rebase false;
}
}
if (!hit) break :rebases;
break :rebase true;
};
if (should_rebase) {
try self.local_rebases.append(self.allocator, .{
.offset = source_addr - target_seg.inner.vmaddr,
.segment_id = target_map.segment_id,
});
}
// TLV is handled via a separate offset mechanism.
// Calculate the offset to the initializer.
if (target_sect.flags == macho.S_THREAD_LOCAL_VARIABLES) tlv: {
if (flags == macho.S_THREAD_LOCAL_VARIABLES) tlv: {
// TODO we don't want to save offset to tlv_bootstrap
if (mem.eql(u8, rel.target.symbol.name, "__tlv_bootstrap")) break :tlv;