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// Copyright 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
// This file is shared between executor and csource package.
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <sys/syscall.h>
#include <unistd.h>
#if defined(SYZ_EXECUTOR) || defined(SYZ_THREADED) || defined(SYZ_COLLIDE)
#include <pthread.h>
#include <stdlib.h>
#endif
#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT))
#include <errno.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#endif
#if defined(SYZ_EXECUTOR) || defined(SYZ_HANDLE_SEGV)
#include <parlib/parlib.h>
#include <setjmp.h>
#include <signal.h>
#endif
#if defined(SYZ_EXECUTOR) || defined(SYZ_USE_TMP_DIR)
#include <stdlib.h>
#include <sys/stat.h>
#endif
#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT) && defined(SYZ_USE_TMP_DIR))
#include <dirent.h>
#endif
#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT)) || \
defined(SYZ_USE_TMP_DIR) || defined(SYZ_HANDLE_SEGV) || defined(SYZ_TUN_ENABLE) || \
defined(SYZ_SANDBOX_NAMESPACE) || defined(SYZ_SANDBOX_SETUID) || \
defined(SYZ_SANDBOX_NONE) || defined(SYZ_FAULT_INJECTION) || defined(__NR_syz_kvm_setup_cpu)
__attribute__((noreturn)) static void doexit(int status)
{
_exit(status);
for (;;) {
}
}
#endif
#include "common.h"
#if defined(SYZ_EXECUTOR) || defined(SYZ_HANDLE_SEGV)
static __thread int skip_segv;
static __thread jmp_buf segv_env;
static void recover()
{
_longjmp(segv_env, 1);
}
static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
// Generated programs can contain bad (unmapped/protected) addresses,
// which cause SIGSEGVs during copyin/copyout.
// This handler ignores such crashes to allow the program to proceed.
// We additionally opportunistically check that the faulty address
// is not within executable data region, because such accesses can corrupt
// output region and then fuzzer will fail on corrupted data.
uintptr_t addr = (uintptr_t)info->si_addr;
const uintptr_t prog_start = 1 << 20;
const uintptr_t prog_end = 100 << 20;
if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) {
debug("SIGSEGV on 0x%lx, skipping\n", addr);
struct user_context* uctx = (struct user_context*)ctx;
uctx->tf.hw_tf.tf_rip = (long)(void*)recover;
return;
}
debug("SIGSEGV on 0x%lx, exiting\n", addr);
doexit(sig);
for (;;) {
}
}
static void install_segv_handler()
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = segv_handler;
sa.sa_flags = SA_NODEFER | SA_SIGINFO;
sigemptyset(&sa.sa_mask);
sigaction(SIGSEGV, &sa, NULL);
sigaction(SIGBUS, &sa, NULL);
}
#define NONFAILING(...) \
{ \
__atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \
if (_setjmp(segv_env) == 0) { \
__VA_ARGS__; \
} \
__atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \
}
#endif
#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT))
static uint64 current_time_ms()
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts))
fail("clock_gettime failed");
return (uint64)ts.tv_sec * 1000 + (uint64)ts.tv_nsec / 1000000;
}
#endif
#if defined(SYZ_EXECUTOR) || defined(SYZ_USE_TMP_DIR)
static void use_temporary_dir()
{
char tmpdir_template[] = "./syzkaller.XXXXXX";
char* tmpdir = mkdtemp(tmpdir_template);
if (!tmpdir)
fail("failed to mkdtemp");
if (chmod(tmpdir, 0777))
fail("failed to chmod");
if (chdir(tmpdir))
fail("failed to chdir");
}
#endif
#if defined(SYZ_EXECUTOR)
static void sleep_ms(uint64 ms)
{
usleep(ms * 1000);
}
#endif
#if defined(SYZ_EXECUTOR) || defined(SYZ_FAULT_INJECTION)
static int inject_fault(int nth)
{
return 0;
}
static int fault_injected(int fail_fd)
{
return 0;
}
#endif
#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT) && defined(SYZ_USE_TMP_DIR))
static void remove_dir(const char* dir)
{
DIR* dp;
struct dirent* ep;
dp = opendir(dir);
if (dp == NULL)
exitf("opendir(%s) failed", dir);
while ((ep = readdir(dp))) {
if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
continue;
char filename[FILENAME_MAX];
snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
struct stat st;
if (lstat(filename, &st))
exitf("lstat(%s) failed", filename);
if (S_ISDIR(st.st_mode)) {
remove_dir(filename);
continue;
}
if (unlink(filename))
exitf("unlink(%s) failed", filename);
}
closedir(dp);
if (rmdir(dir))
exitf("rmdir(%s) failed", dir);
}
#endif
#if defined(SYZ_SANDBOX_NONE)
static void loop();
static int do_sandbox_none(void)
{
loop();
doexit(0);
fail("doexit returned");
return 0;
}
#endif
#if defined(SYZ_REPEAT)
static void execute_one();
#if defined(SYZ_WAIT_REPEAT)
void loop()
{
int iter;
for (iter = 0;; iter++) {
#ifdef SYZ_USE_TMP_DIR
char cwdbuf[256];
sprintf(cwdbuf, "./%d", iter);
if (mkdir(cwdbuf, 0777))
fail("failed to mkdir");
#endif
int pid = fork();
if (pid < 0)
fail("clone failed");
if (pid == 0) {
#ifdef SYZ_USE_TMP_DIR
if (chdir(cwdbuf))
fail("failed to chdir");
#endif
execute_one();
doexit(0);
}
int status = 0;
uint64 start = current_time_ms();
for (;;) {
int res = waitpid(-1, &status, WNOHANG);
if (res == pid)
break;
usleep(1000);
if (current_time_ms() - start > 5 * 1000) {
kill(pid, SIGKILL);
while (waitpid(-1, &status, 0) != pid) {
}
break;
}
}
#ifdef SYZ_USE_TMP_DIR
remove_dir(cwdbuf);
#endif
}
}
#else
void loop()
{
while (1) {
execute_one();
}
}
#endif
#endif
#if defined(SYZ_THREADED)
struct thread_t {
int created, running, call;
pthread_t th;
};
static struct thread_t threads[16];
static void execute_call(int call);
static int running;
#if defined(SYZ_COLLIDE)
static int collide;
#endif
static void* thr(void* arg)
{
struct thread_t* th = (struct thread_t*)arg;
for (;;) {
while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
usleep(200);
execute_call(th->call);
__atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
__atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
}
return 0;
}
static void execute(int num_calls)
{
int i, call, thread;
running = 0;
for (call = 0; call < num_calls; call++) {
for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
struct thread_t* th = &threads[thread];
if (!th->created) {
th->created = 1;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 128 << 10);
pthread_create(&th->th, &attr, thr, th);
}
if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
th->call = call;
__atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
__atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
#if defined(SYZ_COLLIDE)
if (collide && call % 2)
break;
#endif
for (i = 0; i < 100; i++) {
if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
break;
usleep(200);
}
if (__atomic_load_n(&running, __ATOMIC_RELAXED))
usleep((call == num_calls - 1) ? 10000 : 1000);
break;
}
}
}
}
#endif
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