diff options
Diffstat (limited to 'gcc_plugin')
| -rw-r--r-- | gcc_plugin/Makefile | 6 | ||||
| -rw-r--r-- | gcc_plugin/afl-gcc-fast.c | 2 | ||||
| -rw-r--r-- | gcc_plugin/afl-gcc-rt.o.c | 100 |
3 files changed, 95 insertions, 13 deletions
diff --git a/gcc_plugin/Makefile b/gcc_plugin/Makefile index a603df78..287b6545 100644 --- a/gcc_plugin/Makefile +++ b/gcc_plugin/Makefile @@ -27,7 +27,7 @@ CFLAGS ?= -O3 -g -funroll-loops CFLAGS += -Wall -D_FORTIFY_SOURCE=2 -Wno-pointer-sign \ -DAFL_PATH=\"$(HELPER_PATH)\" -DBIN_PATH=\"$(BIN_PATH)\" \ -CXXFLAGS ?= -O3 -g -funroll-loops +CXXFLAGS ?= -O3 -g -funroll-loops CXXEFLAGS := $(CXXFLAGS) -Wall -D_FORTIFY_SOURCE=2 CC ?= gcc @@ -35,8 +35,6 @@ CXX ?= g++ PLUGIN_FLAGS = -fPIC -fno-rtti -I"$(shell $(CC) -print-file-name=plugin)/include" -PROGS = ../afl-gcc-fast ../afl-gcc-pass.so ../afl-gcc-rt.o - ifeq "$(shell echo '\#include <sys/ipc.h>@\#include <sys/shm.h>@int main() { int _id = shmget(IPC_PRIVATE, 65536, IPC_CREAT | IPC_EXCL | 0600); shmctl(_id, IPC_RMID, 0); return 0;}' | tr @ '\n' | $(CC) -x c - -o .test2 2>/dev/null && echo 1 || echo 0 )" "1" SHMAT_OK=1 else @@ -51,6 +49,8 @@ ifeq "$(TEST_MMAP)" "1" LDFLAGS += -lrt endif +PROGS = ../afl-gcc-fast ../afl-gcc-pass.so ../afl-gcc-rt.o + all: test_shm test_deps $(PROGS) afl-gcc-fast.8 test_build all_done diff --git a/gcc_plugin/afl-gcc-fast.c b/gcc_plugin/afl-gcc-fast.c index b0461584..093249a0 100644 --- a/gcc_plugin/afl-gcc-fast.c +++ b/gcc_plugin/afl-gcc-fast.c @@ -282,6 +282,8 @@ int main(int argc, char** argv) { "afl-gcc-fast" VERSION cRST " initially by <aseipp@pobox.com>, maintainer: hexcoder-\n" "\n" + "afl-gcc-fast [options]\n" + "\n" "This is a helper application for afl-fuzz. It serves as a drop-in " "replacement\n" "for gcc, letting you recompile third-party code with the required " diff --git a/gcc_plugin/afl-gcc-rt.o.c b/gcc_plugin/afl-gcc-rt.o.c index dd79a0ec..5b70a247 100644 --- a/gcc_plugin/afl-gcc-rt.o.c +++ b/gcc_plugin/afl-gcc-rt.o.c @@ -21,12 +21,16 @@ */ +#ifdef __ANDROID__ +#include "android-ashmem.h" +#endif #include "../config.h" #include "../types.h" #include <stdlib.h> #include <signal.h> #include <unistd.h> +#include <string.h> #include <assert.h> #include <sys/mman.h> @@ -34,29 +38,43 @@ #include <sys/wait.h> #include <sys/types.h> +#include <sys/mman.h> +#include <fcntl.h> + /* Globals needed by the injected instrumentation. The __afl_area_initial region is used for instrumentation output before __afl_map_shm() has a chance to run. It will end up as .comm, so it shouldn't be too wasteful. */ u8 __afl_area_initial[MAP_SIZE]; u8 *__afl_area_ptr = __afl_area_initial; -u32 __afl_prev_loc; -/* Running in persistent mode? */ - -static u8 is_persistent; +#ifdef __ANDROID__ +u32 __afl_prev_loc; +#else +__thread u32 __afl_prev_loc; +#endif /* Trace a basic block with some ID */ void __afl_trace(u32 x) { u32 l = __afl_prev_loc; - u32 n = l ^ x; - *(__afl_area_ptr + n) += 1; + +#if 0 /* enable for neverZero feature. By default disabled since too inefficient :-( */ + /* @Marc: avoid conditional jumps here */ + __afl_area_ptr[l ^ x] += 1 + (__afl_area_ptr[l ^ x] == (u8)~0); +#else + ++__afl_area_ptr[l ^ x]; +#endif + __afl_prev_loc = (x >> 1); return; } +/* Running in persistent mode? */ + +static u8 is_persistent; + /* SHM setup. */ static void __afl_map_shm(void) { @@ -69,9 +87,38 @@ static void __afl_map_shm(void) { if (id_str) { +#ifdef USEMMAP + const char* shm_file_path = id_str; + int shm_fd = -1; + unsigned char* shm_base = NULL; + + /* create the shared memory segment as if it was a file */ + shm_fd = shm_open(shm_file_path, O_RDWR, 0600); + if (shm_fd == -1) { + + printf("shm_open() failed\n"); + exit(1); + + } + + /* map the shared memory segment to the address space of the process */ + shm_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); + if (shm_base == MAP_FAILED) { + + close(shm_fd); + shm_fd = -1; + + printf("mmap() failed\n"); + exit(2); + + } + + __afl_area_ptr = shm_base; +#else u32 shm_id = atoi(id_str); __afl_area_ptr = shmat(shm_id, NULL, 0); +#endif /* Whooooops. */ @@ -95,6 +142,8 @@ static void __afl_start_forkserver(void) { u8 child_stopped = 0; + void (*old_sigchld_handler)(int) = signal(SIGCHLD, SIG_DFL); + /* Phone home and tell the parent that we're OK. If parent isn't there, assume we're not running in forkserver mode and just execute program. */ @@ -131,6 +180,8 @@ static void __afl_start_forkserver(void) { if (!child_pid) { + signal(SIGCHLD, old_sigchld_handler); + close(FORKSRV_FD); close(FORKSRV_FD + 1); return; @@ -176,18 +227,47 @@ int __afl_persistent_loop(unsigned int max_cnt) { if (first_pass) { + /* Make sure that every iteration of __AFL_LOOP() starts with a clean slate. + On subsequent calls, the parent will take care of that, but on the first + iteration, it's our job to erase any trace of whatever happened + before the loop. */ + + if (is_persistent) { + + memset(__afl_area_ptr, 0, MAP_SIZE); + __afl_area_ptr[0] = 1; + __afl_prev_loc = 0; + + } + cycle_cnt = max_cnt; first_pass = 0; return 1; } - if (is_persistent && --cycle_cnt) { + if (is_persistent) { - raise(SIGSTOP); - return 1; + if (--cycle_cnt) { - } else + raise(SIGSTOP); + + __afl_area_ptr[0] = 1; + __afl_prev_loc = 0; + + return 1; + + } else { + + /* When exiting __AFL_LOOP(), make sure that the subsequent code that + follows the loop is not traced. We do that by pivoting back to the + dummy output region. */ + + __afl_area_ptr = __afl_area_initial; + + } + + } return 0; |