diff options
Diffstat (limited to 'llvm_mode/afl-llvm-rt.o.c')
| -rw-r--r-- | llvm_mode/afl-llvm-rt.o.c | 287 |
1 files changed, 268 insertions, 19 deletions
diff --git a/llvm_mode/afl-llvm-rt.o.c b/llvm_mode/afl-llvm-rt.o.c index 5f9a5534..3ad9eab4 100644 --- a/llvm_mode/afl-llvm-rt.o.c +++ b/llvm_mode/afl-llvm-rt.o.c @@ -26,6 +26,7 @@ #include "config.h" #include "types.h" #include "cmplog.h" +#include "llvm-ngram-coverage.h" #include <stdio.h> #include <stdlib.h> @@ -41,15 +42,15 @@ #include <sys/wait.h> #include <sys/types.h> +#ifdef __linux__ +#include "snapshot-inl.h" +#endif + /* This is a somewhat ugly hack for the experimental 'trace-pc-guard' mode. Basically, we need to make sure that the forkserver is initialized after the LLVM-generated runtime initialization pass, not before. */ -#ifdef USE_TRACE_PC #define CONST_PRIO 5 -#else -#define CONST_PRIO 0 -#endif /* ^USE_TRACE_PC */ #include <sys/mman.h> #include <fcntl.h> @@ -60,17 +61,23 @@ u8 __afl_area_initial[MAP_SIZE]; u8 *__afl_area_ptr = __afl_area_initial; +u8 *__afl_dictionary; #ifdef __ANDROID__ -u32 __afl_prev_loc; -u32 __afl_final_loc; +PREV_LOC_T __afl_prev_loc[NGRAM_SIZE_MAX]; +u32 __afl_final_loc; +u32 __afl_prev_ctx; +u32 __afl_cmp_counter; +u32 __afl_dictionary_len; #else -__thread u32 __afl_prev_loc; -__thread u32 __afl_final_loc; +__thread PREV_LOC_T __afl_prev_loc[NGRAM_SIZE_MAX]; +__thread u32 __afl_final_loc; +__thread u32 __afl_prev_ctx; +__thread u32 __afl_cmp_counter; +__thread u32 __afl_dictionary_len; #endif struct cmp_map *__afl_cmp_map; -__thread u32 __afl_cmp_counter; /* Running in persistent mode? */ @@ -92,6 +99,10 @@ static void __afl_map_shm(void) { const char * shm_file_path = id_str; int shm_fd = -1; unsigned char *shm_base = NULL; + unsigned int map_size = MAP_SIZE + + if (__afl_final_loc > 1 && __afl_final_loc < MAP_SIZE) map_size = + __afl_final_loc; /* create the shared memory segment as if it was a file */ shm_fd = shm_open(shm_file_path, O_RDWR, 0600); @@ -103,7 +114,7 @@ static void __afl_map_shm(void) { } /* 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); + shm_base = mmap(0, map_size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); if (shm_base == MAP_FAILED) { close(shm_fd); @@ -176,30 +187,264 @@ static void __afl_map_shm(void) { } +#ifdef __linux__ +static void __afl_start_snapshots(void) { + + static u8 tmp[4] = {0, 0, 0, 0}; + s32 child_pid; + u32 status = 0; + u32 map_size = MAP_SIZE; + u32 already_read_first = 0; + u32 was_killed; + + if (__afl_final_loc > 1 && __afl_final_loc < MAP_SIZE) + map_size = __afl_final_loc; + + u8 child_stopped = 0; + + void (*old_sigchld_handler)(int) = 0; // = 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. */ + + status |= (FS_OPT_ENABLED | FS_OPT_SNAPSHOT); + if (map_size <= 0x800000) + status |= (FS_OPT_SET_MAPSIZE(map_size) | FS_OPT_MAPSIZE); + if (__afl_dictionary_len > 0 && __afl_dictionary) status |= FS_OPT_AUTODICT; + memcpy(tmp, &status, 4); + + if (write(FORKSRV_FD + 1, tmp, 4) != 4) return; + + if (__afl_dictionary_len > 0 && __afl_dictionary) { + + if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + + if ((was_killed & (FS_OPT_ENABLED | FS_OPT_AUTODICT)) == + (FS_OPT_ENABLED | FS_OPT_AUTODICT)) { + + // great lets pass the dictionary through the forkserver FD + u32 len = __afl_dictionary_len, offset = 0; + s32 ret; + + if (write(FORKSRV_FD + 1, &len, 4) != 4) { + + write(2, "Error: could not send dictionary len\n", + strlen("Error: could not send dictionary len\n")); + _exit(1); + + } + + while (len != 0) { + + ret = write(FORKSRV_FD + 1, __afl_dictionary + offset, len); + + if (ret < 1) { + + write(2, "Error: could not send dictionary\n", + strlen("Error: could not send dictionary\n")); + _exit(1); + + } + + len -= ret; + offset += ret; + + } + + } else { + + // uh this forkserver master does not understand extended option passing + // or does not want the dictionary + already_read_first = 1; + + } + + } + + while (1) { + + int status; + + if (already_read_first) { + + already_read_first = 0; + + } else { + + /* Wait for parent by reading from the pipe. Abort if read fails. */ + if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + + } + + /* If we stopped the child in persistent mode, but there was a race + condition and afl-fuzz already issued SIGKILL, write off the old + process. */ + + if (child_stopped && was_killed) { + + child_stopped = 0; + if (waitpid(child_pid, &status, 0) < 0) _exit(1); + + } + + if (!child_stopped) { + + /* Once woken up, create a clone of our process. */ + + child_pid = fork(); + if (child_pid < 0) _exit(1); + + /* In child process: close fds, resume execution. */ + + if (!child_pid) { + + signal(SIGCHLD, old_sigchld_handler); + + close(FORKSRV_FD); + close(FORKSRV_FD + 1); + + if (!afl_snapshot_do()) { raise(SIGSTOP); } + + __afl_area_ptr[0] = 1; + memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T)); + + return; + + } + + } else { + + /* Special handling for persistent mode: if the child is alive but + currently stopped, simply restart it with SIGCONT. */ + + kill(child_pid, SIGCONT); + child_stopped = 0; + + } + + /* In parent process: write PID to pipe, then wait for child. */ + + if (write(FORKSRV_FD + 1, &child_pid, 4) != 4) _exit(1); + + if (waitpid(child_pid, &status, WUNTRACED) < 0) _exit(1); + + /* In persistent mode, the child stops itself with SIGSTOP to indicate + a successful run. In this case, we want to wake it up without forking + again. */ + + if (WIFSTOPPED(status)) child_stopped = 1; + + /* Relay wait status to pipe, then loop back. */ + + if (write(FORKSRV_FD + 1, &status, 4) != 4) _exit(1); + + } + +} + +#endif + /* Fork server logic. */ static void __afl_start_forkserver(void) { - static u8 tmp[4]; - s32 child_pid; +#ifdef __linux__ + if (!is_persistent && !__afl_cmp_map && !getenv("AFL_NO_SNAPSHOT") && + afl_snapshot_init() >= 0) { + + __afl_start_snapshots(); + return; + + } + +#endif + + u8 tmp[4] = {0, 0, 0, 0}; + s32 child_pid; + u32 status = 0; + u32 map_size = MAP_SIZE; + u32 already_read_first = 0; + u32 was_killed; + + if (__afl_final_loc > 1 && __afl_final_loc < MAP_SIZE) + map_size = __afl_final_loc; u8 child_stopped = 0; void (*old_sigchld_handler)(int) = 0; // = signal(SIGCHLD, SIG_DFL); + if (map_size <= 0x800000) + status |= (FS_OPT_SET_MAPSIZE(map_size) | FS_OPT_MAPSIZE); + if (__afl_dictionary_len > 0 && __afl_dictionary) status |= FS_OPT_AUTODICT; + if (status) status |= (FS_OPT_ENABLED); + memcpy(tmp, &status, 4); + /* 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. */ if (write(FORKSRV_FD + 1, tmp, 4) != 4) return; + if (__afl_dictionary_len > 0 && __afl_dictionary) { + + if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + + if ((was_killed & (FS_OPT_ENABLED | FS_OPT_AUTODICT)) == + (FS_OPT_ENABLED | FS_OPT_AUTODICT)) { + + // great lets pass the dictionary through the forkserver FD + u32 len = __afl_dictionary_len, offset = 0; + s32 ret; + + if (write(FORKSRV_FD + 1, &len, 4) != 4) { + + write(2, "Error: could not send dictionary len\n", + strlen("Error: could not send dictionary len\n")); + _exit(1); + + } + + while (len != 0) { + + ret = write(FORKSRV_FD + 1, __afl_dictionary + offset, len); + + if (ret < 1) { + + write(2, "Error: could not send dictionary\n", + strlen("Error: could not send dictionary\n")); + _exit(1); + + } + + len -= ret; + offset += ret; + + } + + } else { + + // uh this forkserver master does not understand extended option passing + // or does not want the dictionary + already_read_first = 1; + + } + + } + while (1) { - u32 was_killed; int status; /* Wait for parent by reading from the pipe. Abort if read fails. */ - if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + if (already_read_first) { + + already_read_first = 0; + + } else { + + if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + + } /* If we stopped the child in persistent mode, but there was a race condition and afl-fuzz already issued SIGKILL, write off the old @@ -267,8 +512,12 @@ static void __afl_start_forkserver(void) { int __afl_persistent_loop(unsigned int max_cnt) { - static u8 first_pass = 1; - static u32 cycle_cnt; + static u8 first_pass = 1; + static u32 cycle_cnt; + unsigned int map_size = MAP_SIZE; + + if (__afl_final_loc > 1 && __afl_final_loc < MAP_SIZE) + map_size = __afl_final_loc; if (first_pass) { @@ -279,9 +528,9 @@ int __afl_persistent_loop(unsigned int max_cnt) { if (is_persistent) { - memset(__afl_area_ptr, 0, MAP_SIZE); + memset(__afl_area_ptr, 0, map_size); __afl_area_ptr[0] = 1; - __afl_prev_loc = 0; + memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T)); } @@ -298,7 +547,7 @@ int __afl_persistent_loop(unsigned int max_cnt) { raise(SIGSTOP); __afl_area_ptr[0] = 1; - __afl_prev_loc = 0; + memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T)); return 1; |