pkg/afl++

This commit is contained in:
Mitchell Hashimoto
2026-02-28 20:01:07 -08:00
parent adbb432930
commit 4e47c225b1
3 changed files with 120 additions and 0 deletions

85
pkg/afl++/afl.c Normal file
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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <limits.h>
#include <stdint.h>
/* Main entry point. */
/* To ensure checks are not optimized out it is recommended to disable
code optimization for the fuzzer harness main() */
#pragma clang optimize off
#pragma GCC optimize("O0")
// Zig integration
void zig_fuzz_init();
void zig_fuzz_test(unsigned char *, ssize_t);
// Linker-provided symbols marking the boundaries of the __sancov_guards section.
// These must be declared extern so the linker provides the actual section boundaries
// from the instrumented code, rather than creating new variables that shadow them.
extern uint32_t __start___sancov_guards;
extern uint32_t __stop___sancov_guards;
void __sanitizer_cov_trace_pc_guard_init(uint32_t*, uint32_t*);
// Symbols not defined by afl-compiler-rt
__attribute__((visibility("default"))) __attribute__((tls_model("initial-exec"))) _Thread_local uintptr_t __sancov_lowest_stack;
void __sanitizer_cov_trace_pc_indir () {}
void __sanitizer_cov_8bit_counters_init () {}
void __sanitizer_cov_pcs_init () {}
//__AFL_FUZZ_INIT()
int __afl_sharedmem_fuzzing = 1;
extern __attribute__((visibility("default"))) unsigned int *__afl_fuzz_len;
extern __attribute__((visibility("default"))) unsigned char *__afl_fuzz_ptr;
unsigned char __afl_fuzz_alt[1048576];
unsigned char *__afl_fuzz_alt_ptr = __afl_fuzz_alt;
int main(int argc, char **argv) {
__sanitizer_cov_trace_pc_guard_init(&__start___sancov_guards, &__stop___sancov_guards);
// __AFL_INIT();
static volatile const char *_A __attribute__((used,unused));
_A = (const char*)"##SIG_AFL_DEFER_FORKSRV##";
#ifdef __APPLE__
__attribute__((visibility("default")))
void _I(void) __asm__("___afl_manual_init");
#else
__attribute__((visibility("default")))
void _I(void) __asm__("__afl_manual_init");
#endif
_I();
zig_fuzz_init();
// unsigned char *buf = __AFL_FUZZ_TESTCASE_BUF;
unsigned char *buf = __afl_fuzz_ptr ? __afl_fuzz_ptr : __afl_fuzz_alt_ptr;
// while (__AFL_LOOP(UINT_MAX)) {
while (({ static volatile const char *_B __attribute__((used,unused)); _B = (const char*)"##SIG_AFL_PERSISTENT##"; extern __attribute__((visibility("default"))) int __afl_connected;
#ifdef __APPLE__
__attribute__((visibility("default"))) int _L(unsigned int) __asm__("___afl_persistent_loop");
#else
__attribute__((visibility("default"))) int _L(unsigned int) __asm__("__afl_persistent_loop");
#endif
_L(__afl_connected ? UINT_MAX : 1); })) {
// int len = __AFL_FUZZ_TESTCASE_LEN;
int len = __afl_fuzz_ptr ? *__afl_fuzz_len :
(*__afl_fuzz_len = read(0, __afl_fuzz_alt_ptr, 1048576)) == 0xffffffff ? 0 :
*__afl_fuzz_len;
zig_fuzz_test(buf, len);
}
return 0;
}

24
pkg/afl++/build.zig Normal file
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const std = @import("std");
pub fn addInstrumentedExe(
b: *std.Build,
obj: *std.Build.Step.Compile,
) ?std.Build.LazyPath {
const pkg = b.dependencyFromBuildZig(@This(), .{});
const run_afl_cc = b.addSystemCommand(&.{
b.findProgram(&.{"afl-cc"}, &.{}) catch
@panic("Could not find 'afl-cc', which is required to build"),
"-O3",
});
_ = obj.getEmittedBin(); // hack around build system bug
run_afl_cc.addArg("-o");
const fuzz_exe = run_afl_cc.addOutputFileArg(obj.name);
run_afl_cc.addFileArg(pkg.path("afl.c"));
run_afl_cc.addFileArg(obj.getEmittedLlvmBc());
return fuzz_exe;
}
pub fn build(b: *std.Build) !void {
_ = b;
}

11
pkg/afl++/build.zig.zon Normal file
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.{
.name = .afl_plus_plus,
.fingerprint = 0x465bc4bebb188f16,
.version = "0.1.0",
.dependencies = .{},
.paths = .{
"build.zig",
"build.zig.zon",
"afl.c",
},
}