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

fuzz: fix expected section start/end symbol name on MacOS when linking libfuzzer

Browse source 
Not only is the section name when adding the sancov variables different.

The linker symbol ending up in the binary is also different.

Reference: 60105ac6ba/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp (L1076-L1104)
This commit is contained in:
tjog 2025-04-21 17:44:31 +02:00 • committed by Alex Rønne Petersen
parent 69007f0961
commit 2e35fdd032
1 changed files with 26 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

37
lib/fuzzer.zig
View file

@ -468,27 +468,42 @@ export fn fuzzer_init(cache_dir_struct: Fuzzer.Slice) void {
// Linkers are expected to automatically add `__start_<section>` and // Linkers are expected to automatically add `__start_<section>` and
// `__stop_<section>` symbols when section names are valid C identifiers. // `__stop_<section>` symbols when section names are valid C identifiers.
const pc_counters_start = @extern([*]u8, .{ const ofmt = builtin.object_format;
.name = "__start___sancov_cntrs",
.linkage = .weak,
}) orelse fatal("missing __start___sancov_cntrs symbol", .{});
const pc_counters_end = @extern([*]u8, .{ const start_symbol_prefix: []const u8 = if (ofmt == .macho)
.name = "__stop___sancov_cntrs", "\x01section$start$__DATA$__"
else
"__start___";
const end_symbol_prefix: []const u8 = if (ofmt == .macho)
"\x01section$end$__DATA$__"
else
"__end___";
const pc_counters_start_name = start_symbol_prefix ++ "sancov_cntrs";
const pc_counters_start = @extern([*]u8, .{
.name = pc_counters_start_name,
.linkage = .weak, .linkage = .weak,
}) orelse fatal("missing __stop___sancov_cntrs symbol", .{}); }) orelse fatal("missing {s} symbol", .{pc_counters_start_name});
const pc_counters_end_name = end_symbol_prefix ++ "sancov_cntrs";
const pc_counters_end = @extern([*]u8, .{
.name = pc_counters_end_name,
.linkage = .weak,
}) orelse fatal("missing {s} symbol", .{pc_counters_end_name});
const pc_counters = pc_counters_start[0 .. pc_counters_end - pc_counters_start]; const pc_counters = pc_counters_start[0 .. pc_counters_end - pc_counters_start];
const pcs_start_name = start_symbol_prefix ++ "sancov_pcs1";
const pcs_start = @extern([*]usize, .{ const pcs_start = @extern([*]usize, .{
.name = "__start___sancov_pcs1", .name = pcs_start_name,
.linkage = .weak, .linkage = .weak,
}) orelse fatal("missing __start___sancov_pcs1 symbol", .{}); }) orelse fatal("missing {s} symbol", .{pcs_start_name});
const pcs_end_name = end_symbol_prefix ++ "sancov_pcs1";
const pcs_end = @extern([*]usize, .{ const pcs_end = @extern([*]usize, .{
.name = "__stop___sancov_pcs1", .name = pcs_end_name,
.linkage = .weak, .linkage = .weak,
}) orelse fatal("missing __stop___sancov_pcs1 symbol", .{}); }) orelse fatal("missing {s} symbol", .{pcs_end_name});
const pcs = pcs_start[0 .. pcs_end - pcs_start]; const pcs = pcs_start[0 .. pcs_end - pcs_start];