diff options
| -rw-r--r-- | README.md | 4 | ||||
| -rw-r--r-- | gcc_plugin/afl-gcc-rt.o.c | 9 |
2 files changed, 8 insertions, 5 deletions
diff --git a/README.md b/README.md index d58b49e2..de012e62 100644 --- a/README.md +++ b/README.md @@ -55,12 +55,14 @@ | Feature/Instrumentation | AFL-GCC | LLVM_MODE | GCC_PLUGIN | QEMU_MODE | Unicorn | | ----------------------- |:-------:|:---------:|:----------:|:---------:|:-------:| | laf-intel / CompCov | | x | | x | x | - | NeverZero | X | x(1) | X | x | x | + | NeverZero | X | x(1) | (2) | x | x | | Persistent mode | | x | X | x | | | Whitelist | | x | X | | | | InsTrim | | x | | | | + neverZero: (1) only in LLVM >= 9.0 due to a bug in llvm in previous versions + (2) gcc create non-performant code, hence it is disabled in gcc_plugin So all in all this is the best-of AFL that is currently out there :-) diff --git a/gcc_plugin/afl-gcc-rt.o.c b/gcc_plugin/afl-gcc-rt.o.c index 1dfca9e3..47049167 100644 --- a/gcc_plugin/afl-gcc-rt.o.c +++ b/gcc_plugin/afl-gcc-rt.o.c @@ -58,10 +58,11 @@ __thread u32 __afl_prev_loc; void __afl_trace(u32 x) { u32 l = __afl_prev_loc; - const u32 n = l ^ x; - u8 *const bitmap_ptr = __afl_area_ptr + n; - *bitmap_ptr += 1 + (*bitmap_ptr == (u8)~0); /* neverZero */ - + __afl_area_ptr[l ^ x]++; + /* // neverZero is disable as gcc creates non-performant code. shame on you gcc + if (__afl_area_ptr[l ^ x] == 0) + __afl_area_ptr[l ^ x]++; + */ __afl_prev_loc = (x >> 1); return; |