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android / platform / external / AFLplusplus / 9d4614ce / . / instrumentation / afl-compiler-rt.o.c
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/*
american fuzzy lop++ - instrumentation bootstrap
------------------------------------------------
Copyright 2015, 2016 Google Inc. All rights reserved.
Copyright 2019-2020 AFLplusplus Project. 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
*/
#ifdef __ANDROID__
#include "android-ashmem.h"
#endif
#include "config.h"
#include "types.h"
#include "cmplog.h"
#include "llvm-ngram-coverage.h"
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <stdint.h>
#include <stddef.h>
#include <limits.h>
#include <errno.h>
#include <sys/mman.h>
#ifndef __HAIKU__
#include <sys/shm.h>
#endif
#include <sys/wait.h>
#include <sys/types.h>
#if !__GNUC__
#include "llvm/Config/llvm-config.h"
#endif
#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. */
#ifndef MAP_FIXED_NOREPLACE
#ifdef MAP_EXCL
#define MAP_FIXED_NOREPLACE MAP_EXCL | MAP_FIXED
#else
#define MAP_FIXED_NOREPLACE MAP_FIXED
#endif
#endif
#define CTOR_PRIO 3
#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. */
#if MAP_SIZE <= 65536
#define MAP_INITIAL_SIZE 256000
#else
#define MAP_INITIAL_SIZE MAP_SIZE
#endif
u8 __afl_area_initial[MAP_INITIAL_SIZE];
u8 * __afl_area_ptr_dummy = __afl_area_initial;
u8 * __afl_area_ptr = __afl_area_initial;
u8 * __afl_area_ptr_backup = __afl_area_initial;
u8 * __afl_dictionary;
u8 * __afl_fuzz_ptr;
u32 __afl_fuzz_len_dummy;
u32 *__afl_fuzz_len = &__afl_fuzz_len_dummy;
u32 __afl_final_loc;
u32 __afl_map_size = MAP_SIZE;
u32 __afl_dictionary_len;
u64 __afl_map_addr;
// for the __AFL_COVERAGE_ON/__AFL_COVERAGE_OFF features to work:
int __afl_selective_coverage __attribute__((weak));
int __afl_selective_coverage_start_off __attribute__((weak));
int __afl_selective_coverage_temp = 1;
#if defined(__ANDROID__) || defined(__HAIKU__)
PREV_LOC_T __afl_prev_loc[NGRAM_SIZE_MAX];
u32 __afl_prev_ctx;
u32 __afl_cmp_counter;
#else
__thread PREV_LOC_T __afl_prev_loc[NGRAM_SIZE_MAX];
__thread u32 __afl_prev_ctx;
__thread u32 __afl_cmp_counter;
#endif
int __afl_sharedmem_fuzzing __attribute__((weak));
struct cmp_map *__afl_cmp_map;
struct cmp_map *__afl_cmp_map_backup;
/* Child pid? */
static s32 child_pid;
static void (*old_sigterm_handler)(int) = 0;
/* Running in persistent mode? */
static u8 is_persistent;
/* Are we in sancov mode? */
static u8 _is_sancov;
/* ensure we kill the child on termination */
void at_exit(int signal) {
if (child_pid > 0) { kill(child_pid, SIGKILL); }
}
/* Uninspired gcc plugin instrumentation */
void __afl_trace(const u32 x) {
PREV_LOC_T prev = __afl_prev_loc[0];
__afl_prev_loc[0] = (x >> 1);
u8 *p = &__afl_area_ptr[prev ^ x];
#if 1 /* enable for neverZero feature. */
#if __GNUC__
u8 c = __builtin_add_overflow(*p, 1, p);
*p += c;
#else
*p += 1 + ((u8)(1 + *p) == 0);
#endif
#else
++*p;
#endif
return;
}
/* Error reporting to forkserver controller */
void send_forkserver_error(int error) {
u32 status;
if (!error || error > 0xffff) return;
status = (FS_OPT_ERROR | FS_OPT_SET_ERROR(error));
if (write(FORKSRV_FD + 1, (char *)&status, 4) != 4) return;
}
/* SHM fuzzing setup. */
static void __afl_map_shm_fuzz() {
char *id_str = getenv(SHM_FUZZ_ENV_VAR);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "DEBUG: fuzzcase shmem %s\n", id_str ? id_str : "none");
}
if (id_str) {
u8 *map = NULL;
#ifdef USEMMAP
const char *shm_file_path = id_str;
int shm_fd = -1;
/* 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) {
fprintf(stderr, "shm_open() failed for fuzz\n");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
map =
(u8 *)mmap(0, MAX_FILE + sizeof(u32), PROT_READ, MAP_SHARED, shm_fd, 0);
#else
u32 shm_id = atoi(id_str);
map = (u8 *)shmat(shm_id, NULL, 0);
#endif
/* Whooooops. */
if (!map || map == (void *)-1) {
perror("Could not access fuzzing shared memory");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
__afl_fuzz_len = (u32 *)map;
__afl_fuzz_ptr = map + sizeof(u32);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "DEBUG: successfully got fuzzing shared memory\n");
}
} else {
fprintf(stderr, "Error: variable for fuzzing shared memory is not set\n");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
}
/* SHM setup. */
static void __afl_map_shm(void) {
// if we are not running in afl ensure the map exists
if (!__afl_area_ptr) { __afl_area_ptr = __afl_area_ptr_dummy; }
char *id_str = getenv(SHM_ENV_VAR);
if (__afl_final_loc) {
if (__afl_final_loc % 32)
__afl_final_loc = (((__afl_final_loc + 31) >> 5) << 5);
__afl_map_size = __afl_final_loc;
if (__afl_final_loc > MAP_SIZE) {
char *ptr;
u32 val = 0;
if ((ptr = getenv("AFL_MAP_SIZE")) != NULL) val = atoi(ptr);
if (val < __afl_final_loc) {
if (__afl_final_loc > FS_OPT_MAX_MAPSIZE) {
if (!getenv("AFL_QUIET"))
fprintf(stderr,
"Error: AFL++ tools *require* to set AFL_MAP_SIZE to %u "
"to be able to run this instrumented program!\n",
__afl_final_loc);
if (id_str) {
send_forkserver_error(FS_ERROR_MAP_SIZE);
exit(-1);
}
} else {
if (!getenv("AFL_QUIET"))
fprintf(stderr,
"Warning: AFL++ tools will need to set AFL_MAP_SIZE to %u "
"to be able to run this instrumented program!\n",
__afl_final_loc);
}
}
}
}
/* 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 (getenv("AFL_DEBUG"))
fprintf(stderr,
"DEBUG: id_str %s, __afl_area_ptr %p, __afl_area_initial %p, "
"__afl_map_addr 0x%llx, MAP_SIZE %u, __afl_final_loc %u, "
"max_size_forkserver %u/0x%x\n",
id_str == NULL ? "<null>" : id_str, __afl_area_ptr,
__afl_area_initial, __afl_map_addr, MAP_SIZE, __afl_final_loc,
FS_OPT_MAX_MAPSIZE, FS_OPT_MAX_MAPSIZE);
if (id_str) {
if (__afl_area_ptr && __afl_area_ptr != __afl_area_initial) {
if (__afl_map_addr) {
munmap((void *)__afl_map_addr, __afl_final_loc);
} else {
free(__afl_area_ptr);
}
__afl_area_ptr = __afl_area_ptr_dummy;
}
#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) {
fprintf(stderr, "shm_open() failed\n");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
/* map the shared memory segment to the address space of the process */
if (__afl_map_addr) {
shm_base =
mmap((void *)__afl_map_addr, __afl_map_size, PROT_READ | PROT_WRITE,
MAP_FIXED_NOREPLACE | MAP_SHARED, shm_fd, 0);
} else {
shm_base = mmap(0, __afl_map_size, PROT_READ | PROT_WRITE, MAP_SHARED,
shm_fd, 0);
}
if (shm_base == MAP_FAILED) {
close(shm_fd);
shm_fd = -1;
fprintf(stderr, "mmap() failed\n");
if (__afl_map_addr)
send_forkserver_error(FS_ERROR_MAP_ADDR);
else
send_forkserver_error(FS_ERROR_MMAP);
perror("mmap for map");
exit(2);
}
__afl_area_ptr = shm_base;
#else
u32 shm_id = atoi(id_str);
__afl_area_ptr = shmat(shm_id, (void *)__afl_map_addr, 0);
/* Whooooops. */
if (!__afl_area_ptr || __afl_area_ptr == (void *)-1) {
if (__afl_map_addr)
send_forkserver_error(FS_ERROR_MAP_ADDR);
else
send_forkserver_error(FS_ERROR_SHMAT);
perror("shmat for map");
_exit(1);
}
#endif
/* 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;
} else if ((!__afl_area_ptr || __afl_area_ptr == __afl_area_initial) &&
__afl_map_addr) {
__afl_area_ptr =
mmap((void *)__afl_map_addr, __afl_map_size, PROT_READ | PROT_WRITE,
MAP_FIXED_NOREPLACE | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if (__afl_area_ptr == MAP_FAILED) {
fprintf(stderr, "can not acquire mmap for address %p\n",
(void *)__afl_map_addr);
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
} else if (_is_sancov && __afl_area_ptr != __afl_area_initial) {
free(__afl_area_ptr);
__afl_area_ptr = NULL;
if (__afl_final_loc > MAP_INITIAL_SIZE) {
__afl_area_ptr = malloc(__afl_final_loc);
}
if (!__afl_area_ptr) { __afl_area_ptr = __afl_area_ptr_dummy; }
}
__afl_area_ptr_backup = __afl_area_ptr;
if (__afl_selective_coverage) {
if (__afl_map_size > MAP_INITIAL_SIZE) {
__afl_area_ptr_dummy = malloc(__afl_map_size);
if (__afl_area_ptr_dummy) {
if (__afl_selective_coverage_start_off) {
__afl_area_ptr = __afl_area_ptr_dummy;
}
} else {
fprintf(stderr, "Error: __afl_selective_coverage failed!\n");
__afl_selective_coverage = 0;
// continue;
}
}
}
id_str = getenv(CMPLOG_SHM_ENV_VAR);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "DEBUG: cmplog id_str %s\n",
id_str == NULL ? "<null>" : id_str);
}
if (id_str) {
#ifdef USEMMAP
const char * shm_file_path = id_str;
int shm_fd = -1;
struct cmp_map *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) {
perror("shm_open() failed\n");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(1);
}
/* map the shared memory segment to the address space of the process */
shm_base = mmap(0, sizeof(struct cmp_map), PROT_READ | PROT_WRITE,
MAP_SHARED, shm_fd, 0);
if (shm_base == MAP_FAILED) {
close(shm_fd);
shm_fd = -1;
fprintf(stderr, "mmap() failed\n");
send_forkserver_error(FS_ERROR_SHM_OPEN);
exit(2);
}
__afl_cmp_map = shm_base;
#else
u32 shm_id = atoi(id_str);
__afl_cmp_map = shmat(shm_id, NULL, 0);
#endif
__afl_cmp_map_backup = __afl_cmp_map;
if (!__afl_cmp_map || __afl_cmp_map == (void *)-1) {
perror("shmat for cmplog");
send_forkserver_error(FS_ERROR_SHM_OPEN);
_exit(1);
}
}
}
#ifdef __linux__
static void __afl_start_snapshots(void) {
static u8 tmp[4] = {0, 0, 0, 0};
u32 status = 0;
u32 already_read_first = 0;
u32 was_killed;
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 (__afl_sharedmem_fuzzing != 0) status |= FS_OPT_SHDMEM_FUZZ;
if (__afl_map_size <= FS_OPT_MAX_MAPSIZE)
status |= (FS_OPT_SET_MAPSIZE(__afl_map_size) | FS_OPT_MAPSIZE);
if (__afl_dictionary_len && __afl_dictionary) status |= FS_OPT_AUTODICT;
memcpy(tmp, &status, 4);
if (write(FORKSRV_FD + 1, tmp, 4) != 4) return;
if (__afl_sharedmem_fuzzing || (__afl_dictionary_len && __afl_dictionary)) {
if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "target forkserver recv: %08x\n", was_killed);
}
if ((was_killed & (FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ)) ==
(FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ)) {
__afl_map_shm_fuzz();
}
if ((was_killed & (FS_OPT_ENABLED | FS_OPT_AUTODICT)) ==
(FS_OPT_ENABLED | FS_OPT_AUTODICT) &&
__afl_dictionary_len && __afl_dictionary) {
// 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 does not understand extended option passing
// or does not want the dictionary
if (!__afl_fuzz_ptr) 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);
}
#ifdef _AFL_DOCUMENT_MUTATIONS
if (__afl_fuzz_ptr) {
static uint32_t counter = 0;
char fn[32];
sprintf(fn, "%09u:forkserver", counter);
s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (fd_doc >= 0) {
if (write(fd_doc, __afl_fuzz_ptr, *__afl_fuzz_len) != *__afl_fuzz_len) {
fprintf(stderr, "write of mutation file failed: %s\n", fn);
unlink(fn);
}
close(fd_doc);
}
counter++;
}
#endif
/* 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) {
//(void)nice(-20); // does not seem to improve
signal(SIGCHLD, old_sigchld_handler);
signal(SIGTERM, old_sigterm_handler);
close(FORKSRV_FD);
close(FORKSRV_FD + 1);
if (!afl_snapshot_take(AFL_SNAPSHOT_MMAP | AFL_SNAPSHOT_FDS |
AFL_SNAPSHOT_REGS | AFL_SNAPSHOT_EXIT)) {
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) {
struct sigaction orig_action;
sigaction(SIGTERM, NULL, &orig_action);
old_sigterm_handler = orig_action.sa_handler;
signal(SIGTERM, at_exit);
#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};
u32 status_for_fsrv = 0;
u32 already_read_first = 0;
u32 was_killed;
u8 child_stopped = 0;
void (*old_sigchld_handler)(int) = 0; // = signal(SIGCHLD, SIG_DFL);
if (__afl_map_size <= FS_OPT_MAX_MAPSIZE) {
status_for_fsrv |= (FS_OPT_SET_MAPSIZE(__afl_map_size) | FS_OPT_MAPSIZE);
}
if (__afl_dictionary_len && __afl_dictionary) {
status_for_fsrv |= FS_OPT_AUTODICT;
}
if (__afl_sharedmem_fuzzing != 0) { status_for_fsrv |= FS_OPT_SHDMEM_FUZZ; }
if (status_for_fsrv) { status_for_fsrv |= (FS_OPT_ENABLED); }
memcpy(tmp, &status_for_fsrv, 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_sharedmem_fuzzing || (__afl_dictionary_len && __afl_dictionary)) {
if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1);
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "target forkserver recv: %08x\n", was_killed);
}
if ((was_killed & (FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ)) ==
(FS_OPT_ENABLED | FS_OPT_SHDMEM_FUZZ)) {
__afl_map_shm_fuzz();
}
if ((was_killed & (FS_OPT_ENABLED | FS_OPT_AUTODICT)) ==
(FS_OPT_ENABLED | FS_OPT_AUTODICT) &&
__afl_dictionary_len && __afl_dictionary) {
// great lets pass the dictionary through the forkserver FD
u32 len = __afl_dictionary_len, offset = 0;
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) {
s32 ret;
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 does not understand extended option passing
// or does not want the dictionary
if (!__afl_fuzz_ptr) already_read_first = 1;
}
}
while (1) {
int status;
/* Wait for parent by reading from the pipe. Abort if read fails. */
if (already_read_first) {
already_read_first = 0;
} else {
if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1);
}
#ifdef _AFL_DOCUMENT_MUTATIONS
if (__afl_fuzz_ptr) {
static uint32_t counter = 0;
char fn[32];
sprintf(fn, "%09u:forkserver", counter);
s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (fd_doc >= 0) {
if (write(fd_doc, __afl_fuzz_ptr, *__afl_fuzz_len) != *__afl_fuzz_len) {
fprintf(stderr, "write of mutation file failed: %s\n", fn);
unlink(fn);
}
close(fd_doc);
}
counter++;
}
#endif
/* 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) {
//(void)nice(-20);
signal(SIGCHLD, old_sigchld_handler);
signal(SIGTERM, old_sigterm_handler);
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.md. */
int __afl_persistent_loop(unsigned int max_cnt) {
static u8 first_pass = 1;
static u32 cycle_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, __afl_map_size);
__afl_area_ptr[0] = 1;
memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T));
}
cycle_cnt = max_cnt;
first_pass = 0;
__afl_selective_coverage_temp = 1;
return 1;
}
if (is_persistent) {
if (--cycle_cnt) {
raise(SIGSTOP);
__afl_area_ptr[0] = 1;
memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T));
__afl_selective_coverage_temp = 1;
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_ptr_dummy;
}
}
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 (getenv("AFL_DISABLE_LLVM_INSTRUMENTATION")) {
init_done = 1;
is_persistent = 0;
__afl_sharedmem_fuzzing = 0;
if (__afl_area_ptr == NULL) __afl_area_ptr = __afl_area_ptr_dummy;
if (getenv("AFL_DEBUG"))
fprintf(stderr,
"DEBUG: disabled instrumentation because of "
"AFL_DISABLE_LLVM_INSTRUMENTATION\n");
}
if (!init_done) {
__afl_start_forkserver();
init_done = 1;
}
}
/* Initialization of the forkserver - latest possible */
__attribute__((constructor())) void __afl_auto_init(void) {
if (getenv("AFL_DISABLE_LLVM_INSTRUMENTATION")) return;
if (getenv(DEFER_ENV_VAR)) return;
__afl_manual_init();
}
/* Initialization of the shmem - earliest possible because of LTO fixed mem. */
__attribute__((constructor(CTOR_PRIO))) void __afl_auto_early(void) {
is_persistent = !!getenv(PERSIST_ENV_VAR);
if (getenv("AFL_DISABLE_LLVM_INSTRUMENTATION")) return;
__afl_map_shm();
}
/* preset __afl_area_ptr #2 */
__attribute__((constructor(1))) void __afl_auto_second(void) {
if (getenv("AFL_DISABLE_LLVM_INSTRUMENTATION")) return;
u8 *ptr;
if (__afl_final_loc) {
if (__afl_area_ptr && __afl_area_ptr != __afl_area_initial)
free(__afl_area_ptr);
if (__afl_map_addr)
ptr = (u8 *)mmap((void *)__afl_map_addr, __afl_final_loc,
PROT_READ | PROT_WRITE,
MAP_FIXED_NOREPLACE | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
else
ptr = (u8 *)malloc(__afl_final_loc);
if (ptr && (ssize_t)ptr != -1) {
__afl_area_ptr = ptr;
__afl_area_ptr_backup = __afl_area_ptr;
}
}
}
/* preset __afl_area_ptr #1 - at constructor level 0 global variables have
not been set */
__attribute__((constructor(0))) void __afl_auto_first(void) {
if (getenv("AFL_DISABLE_LLVM_INSTRUMENTATION")) return;
u8 *ptr;
ptr = (u8 *)malloc(1024000);
if (ptr && (ssize_t)ptr != -1) {
__afl_area_ptr = ptr;
__afl_area_ptr_backup = __afl_area_ptr;
}
}
/* The following stuff deals with supporting -fsanitize-coverage=trace-pc-guard.
It remains non-operational in the traditional, plugin-backed LLVM mode.
For more info about 'trace-pc-guard', see README.llvm.md.
The first function (__sanitizer_cov_trace_pc_guard) is called back on every
edge (as opposed to every basic block). */
void __sanitizer_cov_trace_pc_guard(uint32_t *guard) {
// For stability analysis, if you want to know to which function unstable
// edge IDs belong - uncomment, recompile+install llvm_mode, recompile
// the target. libunwind and libbacktrace are better solutions.
// Set AFL_DEBUG_CHILD=1 and run afl-fuzz with 2>file to capture
// the backtrace output
/*
uint32_t unstable[] = { ... unstable edge IDs };
uint32_t idx;
char bt[1024];
for (idx = 0; i < sizeof(unstable)/sizeof(uint32_t); i++) {
if (unstable[idx] == __afl_area_ptr[*guard]) {
int bt_size = backtrace(bt, 256);
if (bt_size > 0) {
char **bt_syms = backtrace_symbols(bt, bt_size);
if (bt_syms) {
fprintf(stderr, "DEBUG: edge=%u caller=%s\n", unstable[idx],
bt_syms[0]);
free(bt_syms);
}
}
}
}
*/
#if (LLVM_VERSION_MAJOR < 9)
__afl_area_ptr[*guard]++;
#else
__afl_area_ptr[*guard] =
__afl_area_ptr[*guard] + 1 + (__afl_area_ptr[*guard] == 255 ? 1 : 0);
#endif
}
/* Init callback. Populates instrumentation IDs. Note that we're using
ID of 0 as a special value to indicate non-instrumented bits. That may
still touch the bitmap, but in a fairly harmless way. */
void __sanitizer_cov_trace_pc_guard_init(uint32_t *start, uint32_t *stop) {
u32 inst_ratio = 100;
char *x;
_is_sancov = 1;
if (getenv("AFL_DEBUG")) {
fprintf(stderr, "Running __sanitizer_cov_trace_pc_guard_init: %p-%p\n",
start, stop);
}
if (start == stop || *start) return;
x = getenv("AFL_INST_RATIO");
if (x) inst_ratio = (u32)atoi(x);
if (!inst_ratio || inst_ratio > 100) {
fprintf(stderr, "[-] ERROR: Invalid AFL_INST_RATIO (must be 1-100).\n");
abort();
}
/* Make sure that the first element in the range is always set - we use that
to avoid duplicate calls (which can happen as an artifact of the underlying
implementation in LLVM). */
*(start++) = ++__afl_final_loc;
while (start < stop) {
if (R(100) < inst_ratio)
*start = ++__afl_final_loc;
else
*start = 0;
start++;
}
}
///// CmpLog instrumentation
void __cmplog_ins_hook1(uint8_t arg1, uint8_t arg2) {
if (unlikely(!__afl_cmp_map)) return;
uintptr_t k = (uintptr_t)__builtin_return_address(0);
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
// if (!__afl_cmp_map->headers[k].cnt)
// __afl_cmp_map->headers[k].cnt = __afl_cmp_counter++;
__afl_cmp_map->headers[k].shape = 0;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
void __cmplog_ins_hook2(uint16_t arg1, uint16_t arg2) {
if (unlikely(!__afl_cmp_map)) return;
uintptr_t k = (uintptr_t)__builtin_return_address(0);
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 1;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
void __cmplog_ins_hook4(uint32_t arg1, uint32_t arg2) {
if (unlikely(!__afl_cmp_map)) return;
uintptr_t k = (uintptr_t)__builtin_return_address(0);
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 3;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
void __cmplog_ins_hook8(uint64_t arg1, uint64_t arg2) {
if (unlikely(!__afl_cmp_map)) return;
uintptr_t k = (uintptr_t)__builtin_return_address(0);
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 7;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
#if defined(__APPLE__)
#pragma weak __sanitizer_cov_trace_const_cmp1 = __cmplog_ins_hook1
#pragma weak __sanitizer_cov_trace_const_cmp2 = __cmplog_ins_hook2
#pragma weak __sanitizer_cov_trace_const_cmp4 = __cmplog_ins_hook4
#pragma weak __sanitizer_cov_trace_const_cmp8 = __cmplog_ins_hook8
#pragma weak __sanitizer_cov_trace_cmp1 = __cmplog_ins_hook1
#pragma weak __sanitizer_cov_trace_cmp2 = __cmplog_ins_hook2
#pragma weak __sanitizer_cov_trace_cmp4 = __cmplog_ins_hook4
#pragma weak __sanitizer_cov_trace_cmp8 = __cmplog_ins_hook8
#else
void __sanitizer_cov_trace_const_cmp1(uint8_t arg1, uint8_t arg2)
__attribute__((alias("__cmplog_ins_hook1")));
void __sanitizer_cov_trace_const_cmp2(uint16_t arg1, uint16_t arg2)
__attribute__((alias("__cmplog_ins_hook2")));
void __sanitizer_cov_trace_const_cmp4(uint32_t arg1, uint32_t arg2)
__attribute__((alias("__cmplog_ins_hook4")));
void __sanitizer_cov_trace_const_cmp8(uint64_t arg1, uint64_t arg2)
__attribute__((alias("__cmplog_ins_hook8")));
void __sanitizer_cov_trace_cmp1(uint8_t arg1, uint8_t arg2)
__attribute__((alias("__cmplog_ins_hook1")));
void __sanitizer_cov_trace_cmp2(uint16_t arg1, uint16_t arg2)
__attribute__((alias("__cmplog_ins_hook2")));
void __sanitizer_cov_trace_cmp4(uint32_t arg1, uint32_t arg2)
__attribute__((alias("__cmplog_ins_hook4")));
void __sanitizer_cov_trace_cmp8(uint64_t arg1, uint64_t arg2)
__attribute__((alias("__cmplog_ins_hook8")));
#endif /* defined(__APPLE__) */
void __sanitizer_cov_trace_switch(uint64_t val, uint64_t *cases) {
if (unlikely(!__afl_cmp_map)) return;
for (uint64_t i = 0; i < cases[0]; i++) {
uintptr_t k = (uintptr_t)__builtin_return_address(0) + i;
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 7;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = val;
__afl_cmp_map->log[k][hits].v1 = cases[i + 2];
}
}
// POSIX shenanigan to see if an area is mapped.
// If it is mapped as X-only, we have a problem, so maybe we should add a check
// to avoid to call it on .text addresses
static int area_is_mapped(void *ptr, size_t len) {
char *p = ptr;
char *page = (char *)((uintptr_t)p & ~(sysconf(_SC_PAGE_SIZE) - 1));
int r = msync(page, (p - page) + len, MS_ASYNC);
if (r < 0) return errno != ENOMEM;
return 1;
}
void __cmplog_rtn_hook(u8 *ptr1, u8 *ptr2) {
if (unlikely(!__afl_cmp_map)) return;
if (!area_is_mapped(ptr1, 32) || !area_is_mapped(ptr2, 32)) return;
uintptr_t k = (uintptr_t)__builtin_return_address(0);
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_RTN;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 31;
hits &= CMP_MAP_RTN_H - 1;
__builtin_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v0,
ptr1, 32);
__builtin_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v1,
ptr2, 32);
}
/* COVERAGE manipulation features */
// this variable is then used in the shm setup to create an additional map
// if __afl_map_size > MAP_SIZE or cmplog is used.
// Especially with cmplog this would result in a ~260MB mem increase per
// target run.
// disable coverage from this point onwards until turned on again
void __afl_coverage_off() {
if (likely(__afl_selective_coverage)) {
__afl_area_ptr = __afl_area_ptr_dummy;
__afl_cmp_map = NULL;
}
}
// enable coverage
void __afl_coverage_on() {
if (likely(__afl_selective_coverage && __afl_selective_coverage_temp)) {
__afl_area_ptr = __afl_area_ptr_backup;
__afl_cmp_map = __afl_cmp_map_backup;
}
}
// discard all coverage up to this point
void __afl_coverage_discard() {
memset(__afl_area_ptr, 0, __afl_map_size);
__afl_area_ptr[0] = 1;
if (__afl_cmp_map) { memset(__afl_cmp_map, 0, sizeof(struct cmp_map)); }
}
// discard the testcase
void __afl_coverage_abort() {
__afl_coverage_discard();
if (likely(is_persistent && __afl_selective_coverage)) {
__afl_coverage_off();
__afl_selective_coverage_temp = 0;
} else {
exit(0);
}
}
// mark this area as especially interesting
void __afl_coverage_interesting(u32 id, u8 val) {
if (val) {
__afl_area_ptr[id] = val;
} else {
do {
__afl_area_ptr[id] = (u8)rand();
} while (!__afl_area_ptr[id]);
}
}