commit b2eee06bd67e720014809ade89b0b054865b0040 (tree)
parent 97bf880486c6bd0811f675c61d7675632fd1722d
Author: kcbanner <kcbanner@gmail.com>
Date: Fri, 5 Jun 2026 01:55:36 -0400
objdump: coff --tls
Diffstat:
2 files changed, 145 insertions(+), 15 deletions(-)
diff --git a/lib/compiler/objdump.zig b/lib/compiler/objdump.zig
@@ -535,15 +535,21 @@ const coff = struct {
opts.imports or
opts.tls;
- const data_dirs, const magic = if (header.size_of_optional_header > 0) optional_header: {
+ const ImageInfo = struct {
+ data_dirs: []const std.coff.ImageDataDirectory,
+ magic: std.coff.OptionalHeader.Magic,
+ image_base: u64,
+ };
+
+ const image_info: ?ImageInfo = if (header.size_of_optional_header > 0) image_info: {
if (!opts.file_headers and !needs_data_dirs) {
try fr.seekBy(header.size_of_optional_header);
- break :optional_header .{ &.{}, null };
+ break :image_info null;
}
if (opts.file_headers) try w.writeAll("COFF Optional Header:\n");
const magic: std.coff.OptionalHeader.Magic = @enumFromInt(try r.peekInt(u16, .little));
- const num_directory_entries = switch (magic) {
+ const num_directory_entries, const image_base = switch (magic) {
inline .PE32, .@"PE32+" => |v| num_data_dirs: {
const OptionalHeader = if (v == .PE32)
std.coff.OptionalHeader.PE32
@@ -593,7 +599,10 @@ const coff = struct {
try w.writeByte('\n');
}
- break :num_data_dirs optional_header.number_of_rva_and_sizes;
+ break :num_data_dirs .{
+ optional_header.number_of_rva_and_sizes,
+ optional_header.image_base,
+ };
},
else => return failParse(opts, "invalid optional header magic number: {x}", .{magic}),
};
@@ -614,10 +623,14 @@ const coff = struct {
}
if (opts.file_headers) try w.writeByte('\n');
- break :optional_header .{ known_dirs[0..@min(known_dirs.len, num_directory_entries)], magic };
+ break :image_info .{
+ .data_dirs = known_dirs[0..@min(known_dirs.len, num_directory_entries)],
+ .magic = magic,
+ .image_base = image_base,
+ };
} else if (is_image) {
return failParse(opts, "image did not contain an optional header", .{});
- } else .{ &.{}, null };
+ } else null;
// Section names in images don't use the string table, as they must fit inline in the header
const load_string_table = (opts.strings or !is_image) and header.pointer_to_symbol_table > 0;
@@ -1013,7 +1026,7 @@ const coff = struct {
defer gpa.free(rva_index);
if (opts.exports) {
- if (try seekToDataDirectory(opts, fr, w, rva_index, sections.items, data_dirs, .EXPORT)) |section_index| {
+ if (try seekToDataDirectory(opts, fr, w, rva_index, sections.items, image_info.?.data_dirs, .EXPORT)) |section_index| {
const export_dir = r.takeStruct(std.coff.ExportDirectoryTable, .little) catch |err|
return failParse(opts, "unable to read export directory: {t}", .{err});
@@ -1056,7 +1069,7 @@ const coff = struct {
// All the variable length fields should be contained within this directory.
// Read it entirely to avoid needing to seek per-name when iterating.
- const dir = data_dirs[@intFromEnum(DIRECTORY_ENTRY.EXPORT)];
+ const dir = image_info.?.data_dirs[@intFromEnum(DIRECTORY_ENTRY.EXPORT)];
const dir_end_rva = dir.virtual_address + dir.size;
const dir_loc = fr.logicalPos();
const dir_slice = try r.readAlloc(gpa, dir.size);
@@ -1097,7 +1110,15 @@ const coff = struct {
}
if (opts.imports) {
- if (try seekToDataDirectory(opts, fr, w, rva_index, sections.items, data_dirs, .IMPORT)) |_| {
+ if (try seekToDataDirectory(
+ opts,
+ fr,
+ w,
+ rva_index,
+ sections.items,
+ image_info.?.data_dirs,
+ .IMPORT,
+ )) |_| {
const Entry = std.coff.ImportDirectoryEntry;
var directory_entries: std.ArrayList(Entry) = .empty;
defer directory_entries.deinit(gpa);
@@ -1114,14 +1135,20 @@ const coff = struct {
}
for (directory_entries.items) |entry| {
- const name_section = sectionContainingRva(rva_index, sections.items, entry.name_rva) orelse
+ const name_section = sectionContainingRva(
+ rva_index,
+ sections.items,
+ entry.name_rva,
+ ) orelse
return failParse(
opts,
"import directory entry name rva 0x{x} was not found in any section",
.{entry.name_rva},
);
- const name_loc = sections.items[name_section].rvaFileOffset(entry.name_rva) catch unreachable;
+ const name_loc = sections.items[name_section].rvaFileOffset(
+ entry.name_rva,
+ ) catch unreachable;
fr.seekTo(name_loc) catch |err|
return failParse(
opts,
@@ -1161,7 +1188,7 @@ const coff = struct {
.{ ilt_loc, err },
);
- switch (magic.?) {
+ switch (image_info.?.magic) {
_ => try w.writeAll("(unknown magic)"),
inline else => |m| {
const TableEntry = std.coff.ImportLookupTableEntry(m);
@@ -1230,8 +1257,79 @@ const coff = struct {
}
if (opts.tls) {
- if (try seekToDataDirectory(opts, fr, w, rva_index, sections.items, data_dirs, .TLS)) |_| {
- // TODO
+ if (try seekToDataDirectory(
+ opts,
+ fr,
+ w,
+ rva_index,
+ sections.items,
+ image_info.?.data_dirs,
+ .TLS,
+ )) |_| {
+ switch (image_info.?.magic) {
+ _ => try w.writeAll("(unknown magic)"),
+ inline else => |m| {
+ const TlsDirectoryEntry = std.coff.TlsDirectoryEntry(m);
+ const tls_entry = r.takeStruct(TlsDirectoryEntry, .little) catch |err|
+ return failParse(opts, "unable to read tls directory: {t}", .{err});
+
+ try w.writeAll("TLS Directory:\n");
+ try dumpHeader(w, TlsDirectoryEntry, &tls_entry, struct {});
+
+ try w.writeAll(" | ");
+ if (tls_entry.characteristics.alignment == .NONE) {
+ try w.writeAll("Alignment not specified");
+ } else {
+ try w.print(
+ "Alignment: {d}",
+ .{tls_entry.characteristics.alignment.toByteUnits().?},
+ );
+ }
+
+ try w.writeAll(
+ \\
+ \\
+ \\TLS Callbacks:
+ \\ Address
+ \\
+ );
+
+ const callbacks_rva: u32 = @intCast(tls_entry.callbacks_va - image_info.?.image_base);
+ const section_index = sectionContainingRva(
+ rva_index,
+ sections.items,
+ callbacks_rva,
+ ) orelse
+ return failParse(
+ opts,
+ "tls callbacks rva 0x{x} was not found in any section",
+ .{callbacks_rva},
+ );
+
+ const callbacks_loc = sections.items[section_index]
+ .rvaFileOffset(callbacks_rva) catch unreachable;
+
+ fr.seekTo(callbacks_loc) catch |err|
+ return failParse(
+ opts,
+ "unable to seek to tls callbacks array at offset 0x{x}: {t}",
+ .{ callbacks_loc, err },
+ );
+
+ while (true) {
+ const callback_va = r.takeInt(@FieldType(TlsDirectoryEntry, "callbacks_va"), .little) catch |err|
+ return failParse(
+ opts,
+ "unable to read tls callbacks array: {t}",
+ .{err},
+ );
+
+ try w.print("{x: >16} \n", .{callback_va});
+ if (callback_va == 0) break;
+ }
+ try w.writeByte('\n');
+ },
+ }
}
}
}
@@ -1245,8 +1343,10 @@ const coff = struct {
data_dirs: []const std.coff.ImageDataDirectory,
entry: DIRECTORY_ENTRY,
) !?u16 {
- if (@intFromEnum(entry) < data_dirs.len) {
+ if (@intFromEnum(entry) < data_dirs.len) blk: {
const rva = data_dirs[@intFromEnum(entry)].virtual_address;
+ if (rva == 0) break :blk;
+
const section_index = sectionContainingRva(rva_index, sections, rva) orelse
return failParse(
opts,
diff --git a/lib/std/coff.zig b/lib/std/coff.zig
@@ -373,6 +373,36 @@ pub const DebugType = enum(u32) {
_,
};
+pub fn TlsDirectoryEntry(comptime magic: std.coff.OptionalHeader.Magic) type {
+ return switch (magic) {
+ _ => comptime unreachable,
+ .PE32 => extern struct {
+ raw_data_start_va: u32,
+ raw_data_end_va: u32,
+ tls_index_va: u32,
+ callbacks_va: u32,
+ size_of_zero_fill: u32,
+ characteristics: packed struct(u32) {
+ _reserved_0: u19,
+ alignment: SectionHeader.Flags.Align,
+ _reserved_1: u9,
+ },
+ },
+ .@"PE32+" => extern struct {
+ raw_data_start_va: u64,
+ raw_data_end_va: u64,
+ tls_index_va: u64,
+ callbacks_va: u64,
+ size_of_zero_fill: u32,
+ characteristics: packed struct(u32) {
+ _reserved_0: u19,
+ alignment: SectionHeader.Flags.Align,
+ _reserved_1: u9,
+ },
+ },
+ };
+}
+
pub const ImportDirectoryEntry = extern struct {
/// The RVA of the import lookup table.
/// This table contains a name or ordinal for each import.
