blob: 9763cdc85e4e6ba8eb4e1071a894465976f00359 [file] [log] [blame]
// KMSAN: uninit-value in smsc75xx_bind
// https://syzkaller.appspot.com/bug?id=45ee70ca00699d61239bbf9ebc790e33f83add6a
// status:open
// autogenerated by syzkaller (https://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <linux/usb/ch9.h>
unsigned long long procid;
static void sleep_ms(uint64_t ms)
{
usleep(ms * 1000);
}
static uint64_t current_time_ms(void)
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts))
exit(1);
return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}
static void use_temporary_dir(void)
{
char tmpdir_template[] = "./syzkaller.XXXXXX";
char* tmpdir = mkdtemp(tmpdir_template);
if (!tmpdir)
exit(1);
if (chmod(tmpdir, 0777))
exit(1);
if (chdir(tmpdir))
exit(1);
}
static bool write_file(const char* file, const char* what, ...)
{
char buf[1024];
va_list args;
va_start(args, what);
vsnprintf(buf, sizeof(buf), what, args);
va_end(args);
buf[sizeof(buf) - 1] = 0;
int len = strlen(buf);
int fd = open(file, O_WRONLY | O_CLOEXEC);
if (fd == -1)
return false;
if (write(fd, buf, len) != len) {
int err = errno;
close(fd);
errno = err;
return false;
}
close(fd);
return true;
}
#define USB_DEBUG 0
#define USB_MAX_EP_NUM 32
struct usb_device_index {
struct usb_device_descriptor* dev;
struct usb_config_descriptor* config;
unsigned config_length;
struct usb_interface_descriptor* iface;
struct usb_endpoint_descriptor* eps[USB_MAX_EP_NUM];
unsigned eps_num;
};
static bool parse_usb_descriptor(char* buffer, size_t length,
struct usb_device_index* index)
{
if (length <
sizeof(*index->dev) + sizeof(*index->config) + sizeof(*index->iface))
return false;
index->dev = (struct usb_device_descriptor*)buffer;
index->config = (struct usb_config_descriptor*)(buffer + sizeof(*index->dev));
index->config_length = length - sizeof(*index->dev);
index->iface =
(struct usb_interface_descriptor*)(buffer + sizeof(*index->dev) +
sizeof(*index->config));
index->eps_num = 0;
size_t offset = 0;
while (true) {
if (offset + 1 >= length)
break;
uint8_t desc_length = buffer[offset];
uint8_t desc_type = buffer[offset + 1];
if (desc_length <= 2)
break;
if (offset + desc_length > length)
break;
if (desc_type == USB_DT_ENDPOINT) {
index->eps[index->eps_num] =
(struct usb_endpoint_descriptor*)(buffer + offset);
index->eps_num++;
}
if (index->eps_num == USB_MAX_EP_NUM)
break;
offset += desc_length;
}
return true;
}
enum usb_fuzzer_event_type {
USB_FUZZER_EVENT_INVALID,
USB_FUZZER_EVENT_CONNECT,
USB_FUZZER_EVENT_DISCONNECT,
USB_FUZZER_EVENT_SUSPEND,
USB_FUZZER_EVENT_RESUME,
USB_FUZZER_EVENT_CONTROL,
};
struct usb_fuzzer_event {
uint32_t type;
uint32_t length;
char data[0];
};
struct usb_fuzzer_init {
uint64_t speed;
const char* driver_name;
const char* device_name;
};
struct usb_fuzzer_ep_io {
uint16_t ep;
uint16_t flags;
uint32_t length;
char data[0];
};
#define USB_FUZZER_IOCTL_INIT _IOW('U', 0, struct usb_fuzzer_init)
#define USB_FUZZER_IOCTL_RUN _IO('U', 1)
#define USB_FUZZER_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_fuzzer_event)
#define USB_FUZZER_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP0_READ _IOWR('U', 4, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor)
#define USB_FUZZER_IOCTL_EP_WRITE _IOW('U', 7, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_READ _IOWR('U', 8, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_CONFIGURE _IO('U', 9)
#define USB_FUZZER_IOCTL_VBUS_DRAW _IOW('U', 10, uint32_t)
int usb_fuzzer_open()
{
return open("/sys/kernel/debug/usb-fuzzer", O_RDWR);
}
int usb_fuzzer_init(int fd, uint32_t speed, const char* driver,
const char* device)
{
struct usb_fuzzer_init arg;
arg.speed = speed;
arg.driver_name = driver;
arg.device_name = device;
return ioctl(fd, USB_FUZZER_IOCTL_INIT, &arg);
}
int usb_fuzzer_run(int fd)
{
return ioctl(fd, USB_FUZZER_IOCTL_RUN, 0);
}
int usb_fuzzer_event_fetch(int fd, struct usb_fuzzer_event* event)
{
return ioctl(fd, USB_FUZZER_IOCTL_EVENT_FETCH, event);
}
int usb_fuzzer_ep0_write(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP0_WRITE, io);
}
int usb_fuzzer_ep0_read(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP0_READ, io);
}
int usb_fuzzer_ep_write(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_WRITE, io);
}
int usb_fuzzer_ep_read(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_READ, io);
}
int usb_fuzzer_ep_enable(int fd, struct usb_endpoint_descriptor* desc)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_ENABLE, desc);
}
int usb_fuzzer_configure(int fd)
{
return ioctl(fd, USB_FUZZER_IOCTL_CONFIGURE, 0);
}
int usb_fuzzer_vbus_draw(int fd, uint32_t power)
{
return ioctl(fd, USB_FUZZER_IOCTL_VBUS_DRAW, power);
}
#define USB_MAX_PACKET_SIZE 1024
struct usb_fuzzer_control_event {
struct usb_fuzzer_event inner;
struct usb_ctrlrequest ctrl;
char data[USB_MAX_PACKET_SIZE];
};
struct usb_fuzzer_ep_io_data {
struct usb_fuzzer_ep_io inner;
char data[USB_MAX_PACKET_SIZE];
};
struct vusb_connect_string_descriptor {
uint32_t len;
char* str;
} __attribute__((packed));
struct vusb_connect_descriptors {
uint32_t qual_len;
char* qual;
uint32_t bos_len;
char* bos;
uint32_t strs_len;
struct vusb_connect_string_descriptor strs[0];
} __attribute__((packed));
static const char* default_string = "syzkaller";
static bool lookup_connect_response(struct vusb_connect_descriptors* descs,
struct usb_device_index* index,
struct usb_ctrlrequest* ctrl,
char** response_data,
uint32_t* response_length)
{
uint8_t str_idx;
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
switch (ctrl->bRequest) {
case USB_REQ_GET_DESCRIPTOR:
switch (ctrl->wValue >> 8) {
case USB_DT_DEVICE:
*response_data = (char*)index->dev;
*response_length = sizeof(*index->dev);
return true;
case USB_DT_CONFIG:
*response_data = (char*)index->config;
*response_length = index->config_length;
return true;
case USB_DT_STRING:
str_idx = (uint8_t)ctrl->wValue;
if (str_idx >= descs->strs_len) {
*response_data = (char*)default_string;
*response_length = strlen(default_string);
} else {
*response_data = descs->strs[str_idx].str;
*response_length = descs->strs[str_idx].len;
}
return true;
case USB_DT_BOS:
*response_data = descs->bos;
*response_length = descs->bos_len;
return true;
case USB_DT_DEVICE_QUALIFIER:
*response_data = descs->qual;
*response_length = descs->qual_len;
return true;
default:
exit(1);
return false;
}
break;
default:
exit(1);
return false;
}
break;
default:
exit(1);
return false;
}
return false;
}
static volatile long syz_usb_connect(volatile long a0, volatile long a1,
volatile long a2, volatile long a3)
{
uint64_t speed = a0;
uint64_t dev_len = a1;
char* dev = (char*)a2;
struct vusb_connect_descriptors* descs = (struct vusb_connect_descriptors*)a3;
if (!dev) {
return -1;
}
struct usb_device_index index;
memset(&index, 0, sizeof(index));
int rv = 0;
rv = parse_usb_descriptor(dev, dev_len, &index);
if (!rv) {
return rv;
}
int fd = usb_fuzzer_open();
if (fd < 0) {
return fd;
}
char device[32];
sprintf(&device[0], "dummy_udc.%llu", procid);
rv = usb_fuzzer_init(fd, speed, "dummy_udc", &device[0]);
if (rv < 0) {
return rv;
}
rv = usb_fuzzer_run(fd);
if (rv < 0) {
return rv;
}
bool done = false;
while (!done) {
struct usb_fuzzer_control_event event;
event.inner.type = 0;
event.inner.length = sizeof(event.ctrl);
rv = usb_fuzzer_event_fetch(fd, (struct usb_fuzzer_event*)&event);
if (rv < 0) {
return rv;
}
if (event.inner.type != USB_FUZZER_EVENT_CONTROL)
continue;
bool response_found = false;
char* response_data = NULL;
uint32_t response_length = 0;
if (event.ctrl.bRequestType & USB_DIR_IN) {
response_found = lookup_connect_response(
descs, &index, &event.ctrl, &response_data, &response_length);
if (!response_found) {
return -1;
}
} else {
if ((event.ctrl.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD ||
event.ctrl.bRequest != USB_REQ_SET_CONFIGURATION) {
exit(1);
return -1;
}
done = true;
}
if (done) {
rv = usb_fuzzer_vbus_draw(fd, index.config->bMaxPower);
if (rv < 0) {
return rv;
}
rv = usb_fuzzer_configure(fd);
if (rv < 0) {
return rv;
}
unsigned ep;
for (ep = 0; ep < index.eps_num; ep++) {
rv = usb_fuzzer_ep_enable(fd, index.eps[ep]);
if (rv < 0) {
} else {
}
}
}
struct usb_fuzzer_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if (event.ctrl.bRequestType & USB_DIR_IN)
rv = usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response);
else
rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_ep_io*)&response);
if (rv < 0) {
return rv;
}
}
sleep_ms(200);
return fd;
}
struct vusb_descriptor {
uint8_t req_type;
uint8_t desc_type;
uint32_t len;
char data[0];
} __attribute__((packed));
struct vusb_descriptors {
uint32_t len;
struct vusb_descriptor* generic;
struct vusb_descriptor* descs[0];
} __attribute__((packed));
struct vusb_response {
uint8_t type;
uint8_t req;
uint32_t len;
char data[0];
} __attribute__((packed));
struct vusb_responses {
uint32_t len;
struct vusb_response* generic;
struct vusb_response* resps[0];
} __attribute__((packed));
static bool lookup_control_response(struct vusb_descriptors* descs,
struct vusb_responses* resps,
struct usb_ctrlrequest* ctrl,
char** response_data,
uint32_t* response_length)
{
int descs_num = (descs->len - offsetof(struct vusb_descriptors, descs)) /
sizeof(descs->descs[0]);
int resps_num = (resps->len - offsetof(struct vusb_responses, resps)) /
sizeof(resps->resps[0]);
uint8_t req = ctrl->bRequest;
uint8_t req_type = ctrl->bRequestType & USB_TYPE_MASK;
uint8_t desc_type = ctrl->wValue >> 8;
if (req == USB_REQ_GET_DESCRIPTOR) {
int i;
for (i = 0; i < descs_num; i++) {
struct vusb_descriptor* desc = descs->descs[i];
if (!desc)
continue;
if (desc->req_type == req_type && desc->desc_type == desc_type) {
*response_length = desc->len;
if (*response_length != 0)
*response_data = &desc->data[0];
else
*response_data = NULL;
return true;
}
}
if (descs->generic) {
*response_data = &descs->generic->data[0];
*response_length = descs->generic->len;
return true;
}
} else {
int i;
for (i = 0; i < resps_num; i++) {
struct vusb_response* resp = resps->resps[i];
if (!resp)
continue;
if (resp->type == req_type && resp->req == req) {
*response_length = resp->len;
if (*response_length != 0)
*response_data = &resp->data[0];
else
*response_data = NULL;
return true;
}
}
if (resps->generic) {
*response_data = &resps->generic->data[0];
*response_length = resps->generic->len;
return true;
}
}
return false;
}
static volatile long syz_usb_control_io(volatile long a0, volatile long a1,
volatile long a2)
{
int fd = a0;
struct vusb_descriptors* descs = (struct vusb_descriptors*)a1;
struct vusb_responses* resps = (struct vusb_responses*)a2;
struct usb_fuzzer_control_event event;
event.inner.type = 0;
event.inner.length = USB_MAX_PACKET_SIZE;
int rv = usb_fuzzer_event_fetch(fd, (struct usb_fuzzer_event*)&event);
if (rv < 0) {
return rv;
}
if (event.inner.type != USB_FUZZER_EVENT_CONTROL) {
return -1;
}
bool response_found = false;
char* response_data = NULL;
uint32_t response_length = 0;
if (event.ctrl.bRequestType & USB_DIR_IN) {
response_found = lookup_control_response(descs, resps, &event.ctrl,
&response_data, &response_length);
if (!response_found) {
return -1;
}
} else {
response_length = event.ctrl.wLength;
}
struct usb_fuzzer_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if (event.ctrl.bRequestType & USB_DIR_IN) {
rv = usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response);
} else {
rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_ep_io*)&response);
}
if (rv < 0) {
return rv;
}
sleep_ms(200);
return 0;
}
#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
DIR* dp;
struct dirent* ep;
int iter = 0;
retry:
while (umount2(dir, MNT_DETACH) == 0) {
}
dp = opendir(dir);
if (dp == NULL) {
if (errno == EMFILE) {
exit(1);
}
exit(1);
}
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);
while (umount2(filename, MNT_DETACH) == 0) {
}
struct stat st;
if (lstat(filename, &st))
exit(1);
if (S_ISDIR(st.st_mode)) {
remove_dir(filename);
continue;
}
int i;
for (i = 0;; i++) {
if (unlink(filename) == 0)
break;
if (errno == EPERM) {
int fd = open(filename, O_RDONLY);
if (fd != -1) {
long flags = 0;
if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
close(fd);
continue;
}
}
if (errno == EROFS) {
break;
}
if (errno != EBUSY || i > 100)
exit(1);
if (umount2(filename, MNT_DETACH))
exit(1);
}
}
closedir(dp);
int i;
for (i = 0;; i++) {
if (rmdir(dir) == 0)
break;
if (i < 100) {
if (errno == EPERM) {
int fd = open(dir, O_RDONLY);
if (fd != -1) {
long flags = 0;
if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
close(fd);
continue;
}
}
if (errno == EROFS) {
break;
}
if (errno == EBUSY) {
if (umount2(dir, MNT_DETACH))
exit(1);
continue;
}
if (errno == ENOTEMPTY) {
if (iter < 100) {
iter++;
goto retry;
}
}
}
exit(1);
}
}
static void kill_and_wait(int pid, int* status)
{
kill(-pid, SIGKILL);
kill(pid, SIGKILL);
int i;
for (i = 0; i < 100; i++) {
if (waitpid(-1, status, WNOHANG | __WALL) == pid)
return;
usleep(1000);
}
DIR* dir = opendir("/sys/fs/fuse/connections");
if (dir) {
for (;;) {
struct dirent* ent = readdir(dir);
if (!ent)
break;
if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
continue;
char abort[300];
snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
ent->d_name);
int fd = open(abort, O_WRONLY);
if (fd == -1) {
continue;
}
if (write(fd, abort, 1) < 0) {
}
close(fd);
}
closedir(dir);
} else {
}
while (waitpid(-1, status, __WALL) != pid) {
}
}
static void setup_test()
{
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
setpgrp();
write_file("/proc/self/oom_score_adj", "1000");
}
static void execute_one(void);
#define WAIT_FLAGS __WALL
static void loop(void)
{
int iter;
for (iter = 0;; iter++) {
char cwdbuf[32];
sprintf(cwdbuf, "./%d", iter);
if (mkdir(cwdbuf, 0777))
exit(1);
int pid = fork();
if (pid < 0)
exit(1);
if (pid == 0) {
if (chdir(cwdbuf))
exit(1);
setup_test();
execute_one();
exit(0);
}
int status = 0;
uint64_t start = current_time_ms();
for (;;) {
if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
break;
sleep_ms(1);
if (current_time_ms() - start < 5 * 1000)
continue;
kill_and_wait(pid, &status);
break;
}
remove_dir(cwdbuf);
}
}
uint64_t r[1] = {0xffffffffffffffff};
void execute_one(void)
{
intptr_t res = 0;
*(uint8_t*)0x200008c0 = 0x12;
*(uint8_t*)0x200008c1 = 1;
*(uint16_t*)0x200008c2 = 0;
*(uint8_t*)0x200008c4 = 0xcc;
*(uint8_t*)0x200008c5 = 0xa0;
*(uint8_t*)0x200008c6 = 0xed;
*(uint8_t*)0x200008c7 = 8;
*(uint16_t*)0x200008c8 = 0x424;
*(uint16_t*)0x200008ca = 0x7500;
*(uint16_t*)0x200008cc = 0x8212;
*(uint8_t*)0x200008ce = 0;
*(uint8_t*)0x200008cf = 0;
*(uint8_t*)0x200008d0 = 0;
*(uint8_t*)0x200008d1 = 1;
*(uint8_t*)0x200008d2 = 9;
*(uint8_t*)0x200008d3 = 2;
*(uint16_t*)0x200008d4 = 0x24;
*(uint8_t*)0x200008d6 = 1;
*(uint8_t*)0x200008d7 = 0;
*(uint8_t*)0x200008d8 = 0;
*(uint8_t*)0x200008d9 = 0;
*(uint8_t*)0x200008da = 0;
*(uint8_t*)0x200008db = 9;
*(uint8_t*)0x200008dc = 4;
*(uint8_t*)0x200008dd = 0xba;
*(uint8_t*)0x200008de = 0;
*(uint8_t*)0x200008df = 2;
*(uint8_t*)0x200008e0 = 0xf2;
*(uint8_t*)0x200008e1 = 0x23;
*(uint8_t*)0x200008e2 = 0x6b;
*(uint8_t*)0x200008e3 = 0;
*(uint8_t*)0x200008e4 = 9;
*(uint8_t*)0x200008e5 = 5;
*(uint8_t*)0x200008e6 = 0xb;
*(uint8_t*)0x200008e7 = 2;
*(uint16_t*)0x200008e8 = 0;
*(uint8_t*)0x200008ea = 0;
*(uint8_t*)0x200008eb = 0;
*(uint8_t*)0x200008ec = 0;
*(uint8_t*)0x200008ed = 9;
*(uint8_t*)0x200008ee = 5;
*(uint8_t*)0x200008ef = 0x8a;
*(uint8_t*)0x200008f0 = 2;
*(uint16_t*)0x200008f1 = 0;
*(uint8_t*)0x200008f3 = 0;
*(uint8_t*)0x200008f4 = 0;
*(uint8_t*)0x200008f5 = 0;
res = syz_usb_connect(0, 0x36, 0x200008c0, 0);
if (res != -1)
r[0] = res;
*(uint32_t*)0x20000fc0 = 0x34;
*(uint64_t*)0x20000fc4 = 0;
*(uint64_t*)0x20000fcc = 0;
*(uint64_t*)0x20000fd4 = 0;
*(uint64_t*)0x20000fdc = 0;
*(uint64_t*)0x20000fe4 = 0;
*(uint64_t*)0x20000fec = 0;
*(uint32_t*)0x20001980 = 0xcc;
*(uint64_t*)0x20001984 = 0x20001000;
*(uint8_t*)0x20001000 = 0;
*(uint8_t*)0x20001001 = 0;
*(uint32_t*)0x20001002 = 0;
*(uint64_t*)0x2000198c = 0;
*(uint64_t*)0x20001994 = 0;
*(uint64_t*)0x2000199c = 0;
*(uint64_t*)0x200019a4 = 0;
*(uint64_t*)0x200019ac = 0;
*(uint64_t*)0x200019b4 = 0;
*(uint64_t*)0x200019bc = 0;
*(uint64_t*)0x200019c4 = 0;
*(uint64_t*)0x200019cc = 0;
*(uint64_t*)0x200019d4 = 0;
*(uint64_t*)0x200019dc = 0;
*(uint64_t*)0x200019e4 = 0;
*(uint64_t*)0x200019ec = 0;
*(uint64_t*)0x200019f4 = 0;
*(uint64_t*)0x200019fc = 0;
*(uint64_t*)0x20001a04 = 0;
*(uint64_t*)0x20001a0c = 0;
*(uint64_t*)0x20001a14 = 0;
*(uint64_t*)0x20001a1c = 0;
*(uint64_t*)0x20001a24 = 0;
*(uint64_t*)0x20001a2c = 0;
*(uint64_t*)0x20001a34 = 0;
*(uint64_t*)0x20001a3c = 0;
*(uint64_t*)0x20001a44 = 0;
syz_usb_control_io(r[0], 0x20000fc0, 0x20001980);
}
int main(void)
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
for (procid = 0; procid < 6; procid++) {
if (fork() == 0) {
use_temporary_dir();
loop();
}
}
sleep(1000000);
return 0;
}