mirrors/zig
1
0
Fork 0
mirror of https://codeberg.org/ziglang/zig.git synced 2025-12-06 13:54:21 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

macho: don't scan all eh_frame entries, instead follow the offset from the __unwind_info directly

Browse source
This commit is contained in:
kcbanner 2023-07-17 10:22:01 -04:00
parent 774dc2fdb7
commit 97bda56306
3 changed files with 29 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
lib/std/debug.zig
View file

@ -642,7 +642,7 @@ pub const StackIterator = struct {
// __unwind_info is a requirement for unwinding on Darwin. It may fall back to DWARF, but unwinding
// via DWARF before attempting to use the compact unwind info will produce incorrect results.
if (module.unwind_info) |unwind_info| {
if (macho.unwindFrame(&unwind_state.dwarf_context, unwind_info, module.base_address)) |return_address| {
if (macho.unwindFrame(&unwind_state.dwarf_context, unwind_info, module.eh_frame, module.base_address)) |return_address| {
return return_address;
} else |err| {
if (err != error.RequiresDWARFUnwind) return err;
@ -2026,10 +2026,6 @@ pub const ModuleDebugInfo = switch (native_os) {
};
try DW.openDwarfDebugInfo(&di, allocator);
// TODO: Don't actually scan everything, search on demand
di.scanAllUnwindInfo(allocator, self.base_address) catch {};
var info = OFileInfo{
.di = di,
.addr_table = addr_table,

9
lib/std/dwarf.zig
View file

@ -686,7 +686,8 @@ pub const DwarfInfo = struct {
pub const null_section_array = [_]?Section{null} ** num_sections;
endian: std.builtin.Endian,
sections: SectionArray,
sections: SectionArray = null_section_array,
is_macho: bool,
// Filled later by the initializer
abbrev_table_list: std.ArrayListUnmanaged(AbbrevTableHeader) = .{},
@ -699,8 +700,6 @@ pub const DwarfInfo = struct {
// Sorted by start_pc
fde_list: std.ArrayListUnmanaged(FrameDescriptionEntry) = .{},
is_macho: bool,
pub fn section(di: DwarfInfo, dwarf_section: DwarfSection) ?[]const u8 {
return if (di.sections[@intFromEnum(dwarf_section)]) |s| s.data else null;
}
@ -1672,6 +1671,8 @@ pub const DwarfInfo = struct {
if (fde_offset >= frame_section.len) return error.MissingFDE;
var stream = io.fixedBufferStream(frame_section);
try stream.seekTo(fde_offset);
const fde_entry_header = try EntryHeader.read(&stream, dwarf_section, di.endian);
if (fde_entry_header.type != .fde) return error.MissingFDE;
@ -1701,8 +1702,6 @@ pub const DwarfInfo = struct {
builtin.cpu.arch.endian(),
);
} else if (di.eh_frame_hdr) |header| {
std.debug.print("EH_FRAME_HDR\n", .{});
const eh_frame_len = if (di.section(.eh_frame)) |eh_frame| eh_frame.len else null;
try header.findEntry(
context.isValidMemory,

29
lib/std/macho.zig
View file

@ -2142,7 +2142,7 @@ fn dwarfRegNumber(unwind_reg_number: u3) !u8 {
const dwarf = std.dwarf;
const abi = dwarf.abi;
pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, module_base_address: usize) !usize {
pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, eh_frame: ?[]const u8, module_base_address: usize) !usize {
const header = mem.bytesAsValue(
unwind_info_section_header,
unwind_info[0..@sizeOf(unwind_info_section_header)],
@ -2396,7 +2396,9 @@ pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, modul
break :blk new_ip;
},
.DWARF => return error.RequiresDWARFUnwind,
.DWARF => {
return unwindFrameDwarf(context, eh_frame orelse return error.MissingEhFrame, @intCast(encoding.value.x86_64.dwarf));
},
},
.aarch64 => switch (encoding.mode.arm64) {
.OLD => return error.UnimplementedUnwindEncoding,
@ -2408,8 +2410,10 @@ pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, modul
(try abi.regValueNative(usize, context.thread_context, abi.spRegNum(reg_context), reg_context)).* = new_sp;
break :blk new_ip;
},
.DWARF => return error.RequiresDWARFUnwind,
.FRAME => {
.DWARF => {
return unwindFrameDwarf(context, eh_frame orelse return error.MissingEhFrame, @intCast(encoding.value.arm64.dwarf));
},
.FRAME => blk: {
const fp = (try abi.regValueNative(usize, context.thread_context, abi.fpRegNum(reg_context), reg_context)).*;
const new_sp = fp + 16;
const ip_ptr = fp + @sizeOf(usize);
@ -2453,7 +2457,7 @@ pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, modul
(try abi.regValueNative(usize, context.thread_context, abi.fpRegNum(reg_context), reg_context)).* = new_fp;
(try abi.regValueNative(usize, context.thread_context, abi.ipRegNum(), reg_context)).* = new_ip;
return error.UnimplementedUnwindEncoding;
break :blk new_ip;
},
},
else => return error.UnimplementedArch,
@ -2463,3 +2467,18 @@ pub fn unwindFrame(context: *dwarf.UnwindContext, unwind_info: []const u8, modul
if (context.pc > 0) context.pc -= 1;
return new_ip;
}
fn unwindFrameDwarf(context: *dwarf.UnwindContext, eh_frame: []const u8, fde_offset: usize) !usize {
var di = dwarf.DwarfInfo{
.endian = builtin.cpu.arch.endian(),
.is_macho = true,
};
defer di.deinit(context.allocator);
di.sections[@intFromEnum(dwarf.DwarfSection.eh_frame)] = .{
.data = eh_frame,
.owned = false,
};
return di.unwindFrame(context, fde_offset);
}