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Diffstat (limited to 'gcc_plugin/afl-gcc-rt.o.c')
| -rw-r--r-- | gcc_plugin/afl-gcc-rt.o.c | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/gcc_plugin/afl-gcc-rt.o.c b/gcc_plugin/afl-gcc-rt.o.c deleted file mode 100644 index 4e238fa8..00000000 --- a/gcc_plugin/afl-gcc-rt.o.c +++ /dev/null @@ -1,224 +0,0 @@ -/* - american fuzzy lop - GCC plugin instrumentation bootstrap - --------------------------------------------------------- - - Written by Austin Seipp <aseipp@pobox.com> and - Laszlo Szekeres <lszekeres@google.com> and - Michal Zalewski <lcamtuf@google.com> - - GCC integration design is based on the LLVM design, which comes - from Laszlo Szekeres. - - Copyright 2015 Google Inc. All rights reserved. - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at: - - http://www.apache.org/licenses/LICENSE-2.0 - - This code is the rewrite of afl-as.h's main_payload. - -*/ - -#include "../config.h" -#include "../types.h" - -#include <stdlib.h> -#include <signal.h> -#include <unistd.h> -#include <assert.h> - -#include <sys/mman.h> -#include <sys/shm.h> -#include <sys/wait.h> -#include <sys/types.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; -u16 __afl_prev_loc; - - -/* Running in persistent mode? */ - -static u8 is_persistent; - -/* Trace a basic block with some ID */ -void __afl_trace(u16 x) { - u16 l = __afl_prev_loc; - u16 n = l ^ x; - *(__afl_area_ptr+n) += 1; - __afl_prev_loc = (x >> 1); - return; -} - -/* SHM setup. */ - -static void __afl_map_shm(void) { - - u8 *id_str = getenv(SHM_ENV_VAR); - - /* If we're running under AFL, attach to the appropriate region, replacing the - early-stage __afl_area_initial region that is needed to allow some really - hacky .init code to work correctly in projects such as OpenSSL. */ - - if (id_str) { - - u32 shm_id = atoi(id_str); - - __afl_area_ptr = shmat(shm_id, NULL, 0); - - /* Whooooops. */ - - if (__afl_area_ptr == (void *)-1) exit(1); - - /* Write something into the bitmap so that even with low AFL_INST_RATIO, - our parent doesn't give up on us. */ - - __afl_area_ptr[0] = 1; - - } - -} - - -/* Fork server logic. */ - -static void __afl_start_forkserver(void) { - - static u8 tmp[4]; - s32 child_pid; - - u8 child_stopped = 0; - - /* 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; - - 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 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) { - - close(FORKSRV_FD); - close(FORKSRV_FD + 1); - 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, is_persistent ? WUNTRACED : 0) < 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); - - } - -} - - -/* A simplified persistent mode handler, used as explained in README.llvm. */ - -int __afl_persistent_loop(unsigned int max_cnt) { - - static u8 first_pass = 1; - static u32 cycle_cnt; - - if (first_pass) { - - cycle_cnt = max_cnt; - first_pass = 0; - return 1; - - } - - if (is_persistent && --cycle_cnt) { - - raise(SIGSTOP); - return 1; - - } else return 0; - -} - - -/* This one can be called from user code when deferred forkserver mode - is enabled. */ - -void __afl_manual_init(void) { - - static u8 init_done; - - if (!init_done) { - - __afl_map_shm(); - __afl_start_forkserver(); - init_done = 1; - - } - -} - - -/* Proper initialization routine. */ - -__attribute__((constructor(101))) void __afl_auto_init(void) { - - is_persistent = !!getenv(PERSIST_ENV_VAR); - - if (getenv(DEFER_ENV_VAR)) return; - - __afl_manual_init(); - -} |