diff options
Diffstat (limited to 'utils/aflpp_driver')
| -rw-r--r-- | utils/aflpp_driver/GNUmakefile | 10 | ||||
| -rw-r--r-- | utils/aflpp_driver/README.md | 30 | ||||
| -rw-r--r-- | utils/aflpp_driver/aflpp_qemu_driver_hook.c | 21 |
3 files changed, 50 insertions, 11 deletions
diff --git a/utils/aflpp_driver/GNUmakefile b/utils/aflpp_driver/GNUmakefile index c1a087d7..8ac054a6 100644 --- a/utils/aflpp_driver/GNUmakefile +++ b/utils/aflpp_driver/GNUmakefile @@ -26,17 +26,17 @@ debug: ar ru libAFLDriver.a afl-performance.o aflpp_driver.o aflpp_qemu_driver.o: aflpp_qemu_driver.c - $(LLVM_BINDIR)clang $(CFLAGS) -O0 -funroll-loops -c aflpp_qemu_driver.c + -$(LLVM_BINDIR)clang $(CFLAGS) -O0 -funroll-loops -c aflpp_qemu_driver.c libAFLQemuDriver.a: aflpp_qemu_driver.o - ar ru libAFLQemuDriver.a aflpp_qemu_driver.o - cp -vf libAFLQemuDriver.a ../../ + -ar ru libAFLQemuDriver.a aflpp_qemu_driver.o + -cp -vf libAFLQemuDriver.a ../../ aflpp_qemu_driver_hook.so: aflpp_qemu_driver_hook.o - $(LLVM_BINDIR)clang -shared aflpp_qemu_driver_hook.o -o aflpp_qemu_driver_hook.so + -$(LLVM_BINDIR)clang -shared aflpp_qemu_driver_hook.o -o aflpp_qemu_driver_hook.so aflpp_qemu_driver_hook.o: aflpp_qemu_driver_hook.c - $(LLVM_BINDIR)clang -fPIC $(CFLAGS) -funroll-loops -c aflpp_qemu_driver_hook.c + -$(LLVM_BINDIR)clang -fPIC $(CFLAGS) -funroll-loops -c aflpp_qemu_driver_hook.c test: debug #clang -S -emit-llvm -D_DEBUG=\"1\" -I../../include -Wl,--allow-multiple-definition -funroll-loops -o aflpp_driver_test.ll aflpp_driver_test.c diff --git a/utils/aflpp_driver/README.md b/utils/aflpp_driver/README.md new file mode 100644 index 00000000..01bd10c0 --- /dev/null +++ b/utils/aflpp_driver/README.md @@ -0,0 +1,30 @@ +# afl++ drivers + +## aflpp_driver + +aflpp_driver is used to compile directly libfuzzer `LLVMFuzzerTestOneInput()` +targets. + +Just do `afl-clang-fast++ -o fuzz fuzzer_harness.cc libAFLDriver.a [plus required linking]`. + +You can also sneakily do this little trick: +If this is the clang compile command to build for libfuzzer: + `clang++ -o fuzz -fsanitize=fuzzer fuzzer_harness.cc -lfoo` +then just switch `clang++` with `afl-clang-fast++` and our compiler will +magically insert libAFLDriver.a :) + + +## aflpp_qemu_driver + +aflpp_qemu_driver is used for libfuzzer `LLVMFuzzerTestOneInput()` targets that +are to be fuzzed in qemu_mode. So we compile them with clang/clang++, without +-fsantize=fuzzer or afl-clang-fast, and link in libAFLQemuDriver.a: + +`clang++ -o fuzz fuzzer_harness.cc libAFLQemuDriver.a [plus required linking]`. + + +Then just do (where the name of the binary is `fuzz`): +``` +AFL_QEMU_PERSISTENT_ADDR=0x$(nm fuzz | grep "T LLVMFuzzerTestOneInput" | awk '{print $1}') +AFL_QEMU_PERSISTENT_HOOK=/path/to/aflpp_qemu_driver_hook.so afl-fuzz -Q ... -- ./fuzz` +``` diff --git a/utils/aflpp_driver/aflpp_qemu_driver_hook.c b/utils/aflpp_driver/aflpp_qemu_driver_hook.c index 823cc42d..d3dd98b0 100644 --- a/utils/aflpp_driver/aflpp_qemu_driver_hook.c +++ b/utils/aflpp_driver/aflpp_qemu_driver_hook.c @@ -1,21 +1,30 @@ +#include "../../qemu_mode/qemuafl/qemuafl/api.h" + #include <stdint.h> #include <string.h> +void afl_persistent_hook(struct x86_64_regs *regs, uint64_t guest_base, + uint8_t *input_buf, uint32_t input_buf_len) { + #define g2h(x) ((void *)((unsigned long)(x) + guest_base)) +#define h2g(x) ((uint64_t)(x)-guest_base) -#define REGS_RDI 7 -#define REGS_RSI 6 + // In this example the register RDI is pointing to the memory location + // of the target buffer, and the length of the input is in RSI. + // This can be seen with a debugger, e.g. gdb (and "disass main") -void afl_persistent_hook(uint64_t *regs, uint64_t guest_base, - uint8_t *input_buf, uint32_t input_len) { + memcpy(g2h(regs->rdi), input_buf, input_buf_len); + regs->rsi = input_buf_len; - memcpy(g2h(regs[REGS_RDI]), input_buf, input_len); - regs[REGS_RSI] = input_len; +#undef g2h +#undef h2g } int afl_persistent_hook_init(void) { + // 1 for shared memory input (faster), 0 for normal input (you have to use + // read(), input_buf will be NULL) return 1; } |