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diff --git a/docs/fuzzing.md b/docs/fuzzing.md index b173847a..23b24ad0 100644 --- a/docs/fuzzing.md +++ b/docs/fuzzing.md @@ -51,9 +51,9 @@ anything below 9 is not recommended. Clickable README links for the chosen compiler: - * [LTO mode - afl-clang-lto](instrumentation/README.lto.md) - * [LLVM mode - afl-clang-fast](instrumentation/README.llvm.md) - * [GCC_PLUGIN mode - afl-gcc-fast](instrumentation/README.gcc_plugin.md) + * [LTO mode - afl-clang-lto](../instrumentation/README.lto.md) + * [LLVM mode - afl-clang-fast](../instrumentation/README.llvm.md) + * [GCC_PLUGIN mode - afl-gcc-fast](../instrumentation/README.gcc_plugin.md) * GCC/CLANG modes (afl-gcc/afl-clang) have no README as they have no own features You can select the mode for the afl-cc compiler by: @@ -79,7 +79,7 @@ The following options are available when you instrument with LTO mode (afl-clang and large input corpus. This technique is called laf-intel or COMPCOV. To use this set the following environment variable before compiling the target: `export AFL_LLVM_LAF_ALL=1` - You can read more about this in [instrumentation/README.laf-intel.md](instrumentation/README.laf-intel.md) + You can read more about this in [instrumentation/README.laf-intel.md](../instrumentation/README.laf-intel.md) * A different technique (and usually a better one than laf-intel) is to instrument the target so that any compare values in the target are sent to AFL++ which then tries to put these values into the fuzzing data at different @@ -91,7 +91,7 @@ The following options are available when you instrument with LTO mode (afl-clang via the `-c` parameter. Note that you can compile also just a cmplog binary and use that for both however there will be a performance penality. - You can read more about this in [instrumentation/README.cmplog.md](instrumentation/README.cmplog.md) + You can read more about this in [instrumentation/README.cmplog.md](../instrumentation/README.cmplog.md) If you use LTO, LLVM or GCC_PLUGIN mode (afl-clang-fast/afl-clang-lto/afl-gcc-fast) you have the option to selectively only instrument parts of the target that you @@ -108,16 +108,16 @@ are interested in: default to instrument unless noted (DENYLIST) or not perform instrumentation unless requested (ALLOWLIST). **NOTE:** During optimization functions might be inlined and then would not match! - See [instrumentation/README.instrument_list.md](instrumentation/README.instrument_list.md) + See [instrumentation/README.instrument_list.md](../instrumentation/README.instrument_list.md) There are many more options and modes available however these are most of the time less effective. See: - * [instrumentation/README.ctx.md](instrumentation/README.ctx.md) - * [instrumentation/README.ngram.md](instrumentation/README.ngram.md) + * [instrumentation/README.ctx.md](../instrumentation/README.ctx.md) + * [instrumentation/README.ngram.md](../instrumentation/README.ngram.md) AFL++ performs "never zero" counting in its bitmap. You can read more about this here: - * [instrumentation/README.neverzero.md](instrumentation/README.neverzero.md) + * [instrumentation/README.neverzero.md](../instrumentation/README.neverzero.md) #### c) Sanitizers @@ -225,7 +225,7 @@ For `configure` build systems this is usually done by: Note that if you are using the (better) afl-clang-lto compiler you also have to set AR to llvm-ar[-VERSION] and RANLIB to llvm-ranlib[-VERSION] - as is -described in [instrumentation/README.lto.md](instrumentation/README.lto.md). +described in [instrumentation/README.lto.md](../instrumentation/README.lto.md). ##### cmake @@ -234,7 +234,7 @@ For `cmake` build systems this is usually done by: Note that if you are using the (better) afl-clang-lto compiler you also have to set AR to llvm-ar[-VERSION] and RANLIB to llvm-ranlib[-VERSION] - as is -described in [instrumentation/README.lto.md](instrumentation/README.lto.md). +described in [instrumentation/README.lto.md](../instrumentation/README.lto.md). ##### meson @@ -260,7 +260,7 @@ This variant requires the usage of afl-clang-lto, afl-clang-fast or afl-gcc-fast It is the so-called `persistent mode`, which is much, much faster but requires that you code a source file that is specifically calling the target functions that you want to fuzz, plus a few specific AFL++ functions around -it. See [instrumentation/README.persistent_mode.md](instrumentation/README.persistent_mode.md) for details. +it. See [instrumentation/README.persistent_mode.md](../instrumentation/README.persistent_mode.md) for details. Basically if you do not fuzz a target in persistent mode then you are just doing it for a hobby and not professionally :-). @@ -281,7 +281,7 @@ The generated binary is fuzzed with afl-fuzz like any other fuzz target. Bonus: the target is already optimized for fuzzing due to persistent mode and shared-memory testcases and hence gives you the fastest speed possible. -For more information see [utils/aflpp_driver/README.md](utils/aflpp_driver/README.md) +For more information see [utils/aflpp_driver/README.md](../utils/aflpp_driver/README.md) ### 2. Preparing the fuzzing campaign @@ -394,12 +394,12 @@ out of memory. You can decrease the memory with the `-m` option, the value is in MB. If this is too small for the target, you can usually see this by afl-fuzz bailing with the message that it could not connect to the forkserver. -Adding a dictionary is helpful. See the directory [dictionaries/](dictionaries/) if +Adding a dictionary is helpful. See the directory [dictionaries/](../dictionaries/) if something is already included for your data format, and tell afl-fuzz to load that dictionary by adding `-x dictionaries/FORMAT.dict`. With afl-clang-lto you have an autodictionary generation for which you need to do nothing except to use afl-clang-lto as the compiler. You also have the option to generate -a dictionary yourself, see [utils/libtokencap/README.md](utils/libtokencap/README.md). +a dictionary yourself, see [utils/libtokencap/README.md](../utils/libtokencap/README.md). afl-fuzz has a variety of options that help to workaround target quirks like specific locations for the input file (`-f`), performing deterministic @@ -604,7 +604,7 @@ switch or honggfuzz. #### h) Improve the speed! - * Use [persistent mode](instrumentation/README.persistent_mode.md) (x2-x20 speed increase) + * Use [persistent mode](../instrumentation/README.persistent_mode.md) (x2-x20 speed increase) * If you do not use shmem persistent mode, use `AFL_TMPDIR` to point the input file on a tempfs location, see [env_variables.md](env_variables.md) * Linux: Improve kernel performance: modify `/etc/default/grub`, set `GRUB_CMDLINE_LINUX_DEFAULT="ibpb=off ibrs=off kpti=off l1tf=off mds=off mitigations=off no_stf_barrier noibpb noibrs nopcid nopti nospec_store_bypass_disable nospectre_v1 nospectre_v2 pcid=off pti=off spec_store_bypass_disable=off spectre_v2=off stf_barrier=off"`; then `update-grub` and `reboot` (warning: makes the system more insecure) - you can also just run `sudo afl-persistent-config` * Linux: Running on an `ext2` filesystem with `noatime` mount option will be a bit faster than on any other journaling filesystem |