[linux-2.6-block.git] / fs / utimes.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/utime.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/compat.h>
#include <asm/unistd.h>

static bool nsec_valid(long nsec)
{
	if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
		return true;

	return nsec >= 0 && nsec <= 999999999;
}

static int utimes_common(const struct path *path, struct timespec64 *times)
{
	int error;
	struct iattr newattrs;
	struct inode *inode = path->dentry->d_inode;
	struct inode *delegated_inode = NULL;

	error = mnt_want_write(path->mnt);
	if (error)
		goto out;

	if (times && times[0].tv_nsec == UTIME_NOW &&
		     times[1].tv_nsec == UTIME_NOW)
		times = NULL;

	newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
	if (times) {
		if (times[0].tv_nsec == UTIME_OMIT)
			newattrs.ia_valid &= ~ATTR_ATIME;
		else if (times[0].tv_nsec != UTIME_NOW) {
			newattrs.ia_atime.tv_sec = times[0].tv_sec;
			newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
			newattrs.ia_valid |= ATTR_ATIME_SET;
		}

		if (times[1].tv_nsec == UTIME_OMIT)
			newattrs.ia_valid &= ~ATTR_MTIME;
		else if (times[1].tv_nsec != UTIME_NOW) {
			newattrs.ia_mtime.tv_sec = times[1].tv_sec;
			newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
			newattrs.ia_valid |= ATTR_MTIME_SET;
		}
		/*
		 * Tell setattr_prepare(), that this is an explicit time
		 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
		 * were used.
		 */
		newattrs.ia_valid |= ATTR_TIMES_SET;
	} else {
		newattrs.ia_valid |= ATTR_TOUCH;
	}
retry_deleg:
	inode_lock(inode);
	error = notify_change(path->dentry, &newattrs, &delegated_inode);
	inode_unlock(inode);
	if (delegated_inode) {
		error = break_deleg_wait(&delegated_inode);
		if (!error)
			goto retry_deleg;
	}

	mnt_drop_write(path->mnt);
out:
	return error;
}

/*
 * do_utimes - change times on filename or file descriptor
 * @dfd: open file descriptor, -1 or AT_FDCWD
 * @filename: path name or NULL
 * @times: new times or NULL
 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
 *
 * If filename is NULL and dfd refers to an open file, then operate on
 * the file.  Otherwise look up filename, possibly using dfd as a
 * starting point.
 *
 * If times==NULL, set access and modification to current time,
 * must be owner or have write permission.
 * Else, update from *times, must be owner or super user.
 */
long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
	       int flags)
{
	int error = -EINVAL;

	if (times && (!nsec_valid(times[0].tv_nsec) ||
		      !nsec_valid(times[1].tv_nsec))) {
		goto out;
	}

	if (flags & ~AT_SYMLINK_NOFOLLOW)
		goto out;

	if (filename == NULL && dfd != AT_FDCWD) {
		struct fd f;

		if (flags & AT_SYMLINK_NOFOLLOW)
			goto out;

		f = fdget(dfd);
		error = -EBADF;
		if (!f.file)
			goto out;

		error = utimes_common(&f.file->f_path, times);
		fdput(f);
	} else {
		struct path path;
		int lookup_flags = 0;

		if (!(flags & AT_SYMLINK_NOFOLLOW))
			lookup_flags |= LOOKUP_FOLLOW;
retry:
		error = user_path_at(dfd, filename, lookup_flags, &path);
		if (error)
			goto out;

		error = utimes_common(&path, times);
		path_put(&path);
		if (retry_estale(error, lookup_flags)) {
			lookup_flags |= LOOKUP_REVAL;
			goto retry;
		}
	}

out:
	return error;
}

SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
		struct __kernel_timespec __user *, utimes, int, flags)
{
	struct timespec64 tstimes[2];

	if (utimes) {
		if ((get_timespec64(&tstimes[0], &utimes[0]) ||
			get_timespec64(&tstimes[1], &utimes[1])))
			return -EFAULT;

		/* Nothing to do, we must not even check the path.  */
		if (tstimes[0].tv_nsec == UTIME_OMIT &&
		    tstimes[1].tv_nsec == UTIME_OMIT)
			return 0;
	}

	return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
}

#ifdef __ARCH_WANT_SYS_UTIME
/*
 * futimesat(), utimes() and utime() are older versions of utimensat()
 * that are provided for compatibility with traditional C libraries.
 * On modern architectures, we always use libc wrappers around
 * utimensat() instead.
 */
static long do_futimesat(int dfd, const char __user *filename,
			 struct timeval __user *utimes)
{
	struct timeval times[2];
	struct timespec64 tstimes[2];

	if (utimes) {
		if (copy_from_user(&times, utimes, sizeof(times)))
			return -EFAULT;

		/* This test is needed to catch all invalid values.  If we
		   would test only in do_utimes we would miss those invalid
		   values truncated by the multiplication with 1000.  Note
		   that we also catch UTIME_{NOW,OMIT} here which are only
		   valid for utimensat.  */
		if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
		    times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
			return -EINVAL;

		tstimes[0].tv_sec = times[0].tv_sec;
		tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
		tstimes[1].tv_sec = times[1].tv_sec;
		tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
	}

	return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
}


SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
		struct timeval __user *, utimes)
{
	return do_futimesat(dfd, filename, utimes);
}

SYSCALL_DEFINE2(utimes, char __user *, filename,
		struct timeval __user *, utimes)
{
	return do_futimesat(AT_FDCWD, filename, utimes);
}

SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
{
	struct timespec64 tv[2];

	if (times) {
		if (get_user(tv[0].tv_sec, &times->actime) ||
		    get_user(tv[1].tv_sec, &times->modtime))
			return -EFAULT;
		tv[0].tv_nsec = 0;
		tv[1].tv_nsec = 0;
	}
	return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
}
#endif

#ifdef CONFIG_COMPAT_32BIT_TIME
/*
 * Not all architectures have sys_utime, so implement this in terms
 * of sys_utimes.
 */
#ifdef __ARCH_WANT_SYS_UTIME32
SYSCALL_DEFINE2(utime32, const char __user *, filename,
		struct old_utimbuf32 __user *, t)
{
	struct timespec64 tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t->actime) ||
		    get_user(tv[1].tv_sec, &t->modtime))
			return -EFAULT;
		tv[0].tv_nsec = 0;
		tv[1].tv_nsec = 0;
	}
	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
}
#endif

SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
{
	struct timespec64 tv[2];

	if  (t) {
		if (get_old_timespec32(&tv[0], &t[0]) ||
		    get_old_timespec32(&tv[1], &t[1]))
			return -EFAULT;

		if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
			return 0;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, flags);
}

#ifdef __ARCH_WANT_SYS_UTIME32
static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
				struct old_timeval32 __user *t)
{
	struct timespec64 tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
		    get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
		    get_user(tv[1].tv_sec, &t[1].tv_sec) ||
		    get_user(tv[1].tv_nsec, &t[1].tv_usec))
			return -EFAULT;
		if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
		    tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
			return -EINVAL;
		tv[0].tv_nsec *= 1000;
		tv[1].tv_nsec *= 1000;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, 0);
}

SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
		       const char __user *, filename,
		       struct old_timeval32 __user *, t)
{
	return do_compat_futimesat(dfd, filename, t);
}

SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t)
{
	return do_compat_futimesat(AT_FDCWD, filename, t);
}
#endif
#endif
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	#include <linux/file.h>
	3	#include <linux/mount.h>
	4	#include <linux/namei.h>
	5	#include <linux/utime.h>
	6	#include <linux/syscalls.h>
	7	#include <linux/uaccess.h>
	8	#include <linux/compat.h>
	9	#include <asm/unistd.h>
	10
	11	static bool nsec_valid(long nsec)
	12	{
	13	if (nsec == UTIME_OMIT \|\| nsec == UTIME_NOW)
	14	return true;
	15
	16	return nsec >= 0 && nsec <= 999999999;
	17	}
	18
	19	static int utimes_common(const struct path path, struct timespec64 times)
	20	{
	21	int error;
	22	struct iattr newattrs;
	23	struct inode *inode = path->dentry->d_inode;
	24	struct inode *delegated_inode = NULL;
	25
	26	error = mnt_want_write(path->mnt);
	27	if (error)
	28	goto out;
	29
	30	if (times && times[0].tv_nsec == UTIME_NOW &&
	31	times[1].tv_nsec == UTIME_NOW)
	32	times = NULL;
	33
	34	newattrs.ia_valid = ATTR_CTIME \| ATTR_MTIME \| ATTR_ATIME;
	35	if (times) {
	36	if (times[0].tv_nsec == UTIME_OMIT)
	37	newattrs.ia_valid &= ~ATTR_ATIME;
	38	else if (times[0].tv_nsec != UTIME_NOW) {
	39	newattrs.ia_atime.tv_sec = times[0].tv_sec;
	40	newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
	41	newattrs.ia_valid \|= ATTR_ATIME_SET;
	42	}
	43
	44	if (times[1].tv_nsec == UTIME_OMIT)
	45	newattrs.ia_valid &= ~ATTR_MTIME;
	46	else if (times[1].tv_nsec != UTIME_NOW) {
	47	newattrs.ia_mtime.tv_sec = times[1].tv_sec;
	48	newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
	49	newattrs.ia_valid \|= ATTR_MTIME_SET;
	50	}
	51	/*
	52	* Tell setattr_prepare(), that this is an explicit time
	53	* update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
	54	* were used.
	55	*/
	56	newattrs.ia_valid \|= ATTR_TIMES_SET;
	57	} else {
	58	newattrs.ia_valid \|= ATTR_TOUCH;
	59	}
	60	retry_deleg:
	61	inode_lock(inode);
	62	error = notify_change(path->dentry, &newattrs, &delegated_inode);
	63	inode_unlock(inode);
	64	if (delegated_inode) {
	65	error = break_deleg_wait(&delegated_inode);
	66	if (!error)
	67	goto retry_deleg;
	68	}
	69
	70	mnt_drop_write(path->mnt);
	71	out:
	72	return error;
	73	}
	74
	75	/*
	76	* do_utimes - change times on filename or file descriptor
	77	* @dfd: open file descriptor, -1 or AT_FDCWD
	78	* @filename: path name or NULL
	79	* @times: new times or NULL
	80	* @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
	81	*
	82	* If filename is NULL and dfd refers to an open file, then operate on
	83	* the file. Otherwise look up filename, possibly using dfd as a
	84	* starting point.
	85	*
	86	* If times==NULL, set access and modification to current time,
	87	* must be owner or have write permission.
	88	* Else, update from *times, must be owner or super user.
	89	*/
	90	long do_utimes(int dfd, const char __user filename, struct timespec64 times,
	91	int flags)
	92	{
	93	int error = -EINVAL;
	94
	95	if (times && (!nsec_valid(times[0].tv_nsec) \|\|
	96	!nsec_valid(times[1].tv_nsec))) {
	97	goto out;
	98	}
	99
	100	if (flags & ~AT_SYMLINK_NOFOLLOW)
	101	goto out;
	102
	103	if (filename == NULL && dfd != AT_FDCWD) {
	104	struct fd f;
	105
	106	if (flags & AT_SYMLINK_NOFOLLOW)
	107	goto out;
	108
	109	f = fdget(dfd);
	110	error = -EBADF;
	111	if (!f.file)
	112	goto out;
	113
	114	error = utimes_common(&f.file->f_path, times);
	115	fdput(f);
	116	} else {
	117	struct path path;
	118	int lookup_flags = 0;
	119
	120	if (!(flags & AT_SYMLINK_NOFOLLOW))
	121	lookup_flags \|= LOOKUP_FOLLOW;
	122	retry:
	123	error = user_path_at(dfd, filename, lookup_flags, &path);
	124	if (error)
	125	goto out;
	126
	127	error = utimes_common(&path, times);
	128	path_put(&path);
	129	if (retry_estale(error, lookup_flags)) {
	130	lookup_flags \|= LOOKUP_REVAL;
	131	goto retry;
	132	}
	133	}
	134
	135	out:
	136	return error;
	137	}
	138
	139	SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
	140	struct __kernel_timespec __user *, utimes, int, flags)
	141	{
	142	struct timespec64 tstimes[2];
	143
	144	if (utimes) {
	145	if ((get_timespec64(&tstimes[0], &utimes[0]) \|\|
	146	get_timespec64(&tstimes[1], &utimes[1])))
	147	return -EFAULT;
	148
	149	/* Nothing to do, we must not even check the path. */
	150	if (tstimes[0].tv_nsec == UTIME_OMIT &&
	151	tstimes[1].tv_nsec == UTIME_OMIT)
	152	return 0;
	153	}
	154
	155	return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
	156	}
	157
	158	#ifdef __ARCH_WANT_SYS_UTIME
	159	/*
	160	* futimesat(), utimes() and utime() are older versions of utimensat()
	161	* that are provided for compatibility with traditional C libraries.
	162	* On modern architectures, we always use libc wrappers around
	163	* utimensat() instead.
	164	*/
	165	static long do_futimesat(int dfd, const char __user *filename,
	166	struct timeval __user *utimes)
	167	{
	168	struct timeval times[2];
	169	struct timespec64 tstimes[2];
	170
	171	if (utimes) {
	172	if (copy_from_user(&times, utimes, sizeof(times)))
	173	return -EFAULT;
	174
	175	/* This test is needed to catch all invalid values. If we
	176	would test only in do_utimes we would miss those invalid
	177	values truncated by the multiplication with 1000. Note
	178	that we also catch UTIME_{NOW,OMIT} here which are only
	179	valid for utimensat. */
	180	if (times[0].tv_usec >= 1000000 \|\| times[0].tv_usec < 0 \|\|
	181	times[1].tv_usec >= 1000000 \|\| times[1].tv_usec < 0)
	182	return -EINVAL;
	183
	184	tstimes[0].tv_sec = times[0].tv_sec;
	185	tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
	186	tstimes[1].tv_sec = times[1].tv_sec;
	187	tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
	188	}
	189
	190	return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
	191	}
	192
	193
	194	SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
	195	struct timeval __user *, utimes)
	196	{
	197	return do_futimesat(dfd, filename, utimes);
	198	}
	199
	200	SYSCALL_DEFINE2(utimes, char __user *, filename,
	201	struct timeval __user *, utimes)
	202	{
	203	return do_futimesat(AT_FDCWD, filename, utimes);
	204	}
	205
	206	SYSCALL_DEFINE2(utime, char __user , filename, struct utimbuf __user , times)
	207	{
	208	struct timespec64 tv[2];
	209
	210	if (times) {
	211	if (get_user(tv[0].tv_sec, &times->actime) \|\|
	212	get_user(tv[1].tv_sec, &times->modtime))
	213	return -EFAULT;
	214	tv[0].tv_nsec = 0;
	215	tv[1].tv_nsec = 0;
	216	}
	217	return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
	218	}
	219	#endif
	220
	221	#ifdef CONFIG_COMPAT_32BIT_TIME
	222	/*
	223	* Not all architectures have sys_utime, so implement this in terms
	224	* of sys_utimes.
	225	*/
	226	#ifdef __ARCH_WANT_SYS_UTIME32
	227	SYSCALL_DEFINE2(utime32, const char __user *, filename,
	228	struct old_utimbuf32 __user *, t)
	229	{
	230	struct timespec64 tv[2];
	231
	232	if (t) {
	233	if (get_user(tv[0].tv_sec, &t->actime) \|\|
	234	get_user(tv[1].tv_sec, &t->modtime))
	235	return -EFAULT;
	236	tv[0].tv_nsec = 0;
	237	tv[1].tv_nsec = 0;
	238	}
	239	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
	240	}
	241	#endif
	242
	243	SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user , filename, struct old_timespec32 __user , t, int, flags)
	244	{
	245	struct timespec64 tv[2];
	246
	247	if (t) {
	248	if (get_old_timespec32(&tv[0], &t[0]) \|\|
	249	get_old_timespec32(&tv[1], &t[1]))
	250	return -EFAULT;
	251
	252	if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
	253	return 0;
	254	}
	255	return do_utimes(dfd, filename, t ? tv : NULL, flags);
	256	}
	257
	258	#ifdef __ARCH_WANT_SYS_UTIME32
	259	static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
	260	struct old_timeval32 __user *t)
	261	{
	262	struct timespec64 tv[2];
	263
	264	if (t) {
	265	if (get_user(tv[0].tv_sec, &t[0].tv_sec) \|\|
	266	get_user(tv[0].tv_nsec, &t[0].tv_usec) \|\|
	267	get_user(tv[1].tv_sec, &t[1].tv_sec) \|\|
	268	get_user(tv[1].tv_nsec, &t[1].tv_usec))
	269	return -EFAULT;
	270	if (tv[0].tv_nsec >= 1000000 \|\| tv[0].tv_nsec < 0 \|\|
	271	tv[1].tv_nsec >= 1000000 \|\| tv[1].tv_nsec < 0)
	272	return -EINVAL;
	273	tv[0].tv_nsec *= 1000;
	274	tv[1].tv_nsec *= 1000;
	275	}
	276	return do_utimes(dfd, filename, t ? tv : NULL, 0);
	277	}
	278
	279	SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
	280	const char __user *, filename,
	281	struct old_timeval32 __user *, t)
	282	{
	283	return do_compat_futimesat(dfd, filename, t);
	284	}
	285
	286	SYSCALL_DEFINE2(utimes_time32, const char __user , filename, struct old_timeval32 __user , t)
	287	{
	288	return do_compat_futimesat(AT_FDCWD, filename, t);
	289	}
	290	#endif
	291	#endif