[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 = timestamp_truncate(times[0], inode);
			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 = timestamp_truncate(times[1], inode);
			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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1c710c89	2	#include <linux/file.h>
74f9fdfa	3	#include <linux/mount.h>
82b0547c AD	4	#include <linux/namei.h>
82b0547c AD	5	#include <linux/utime.h>
12c2ab5e	6	#include <linux/syscalls.h>
7c0f6ba6	7	#include <linux/uaccess.h>
1a060ba3	8	#include <linux/compat.h>
82b0547c AD	9	#include <asm/unistd.h>
82b0547c AD	10
043f46f6 MS	11	static bool nsec_valid(long nsec)
043f46f6 MS	12	{
4cca9226	13	if (nsec == UTIME_OMIT \|\| nsec == UTIME_NOW)
043f46f6 MS	14	return true;
	15
	16	return nsec >= 0 && nsec <= 999999999;
	17	}
	18
aaed2dd8	19	static int utimes_common(const struct path path, struct timespec64 times)
82b0547c AD	20	{
82b0547c AD	21	int error;
82b0547c	22	struct iattr newattrs;
e9b76fed	23	struct inode *inode = path->dentry->d_inode;
27ac0ffe	24	struct inode *delegated_inode = NULL;
82b0547c	25
e9b76fed	26	error = mnt_want_write(path->mnt);
74f9fdfa	27	if (error)
e9b76fed	28	goto out;
82b0547c	29
12fd0d30 MK	30	if (times && times[0].tv_nsec == UTIME_NOW &&
	31	times[1].tv_nsec == UTIME_NOW)
	32	times = NULL;
	33
82b0547c AD	34	newattrs.ia_valid = ATTR_CTIME \| ATTR_MTIME \| ATTR_ATIME;
82b0547c AD	35	if (times) {
1c710c89 UD	36	if (times[0].tv_nsec == UTIME_OMIT)
	37	newattrs.ia_valid &= ~ATTR_ATIME;
	38	else if (times[0].tv_nsec != UTIME_NOW) {
42e729b9	39	newattrs.ia_atime = timestamp_truncate(times[0], inode);
1c710c89 UD	40	newattrs.ia_valid \|= ATTR_ATIME_SET;
	41	}
	42
	43	if (times[1].tv_nsec == UTIME_OMIT)
	44	newattrs.ia_valid &= ~ATTR_MTIME;
	45	else if (times[1].tv_nsec != UTIME_NOW) {
42e729b9	46	newattrs.ia_mtime = timestamp_truncate(times[1], inode);
1c710c89 UD	47	newattrs.ia_valid \|= ATTR_MTIME_SET;
1c710c89 UD	48	}
4cca9226	49	/*
31051c85	50	* Tell setattr_prepare(), that this is an explicit time
9767d749 MS	51	* update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
9767d749 MS	52	* were used.
4cca9226	53	*/
9767d749	54	newattrs.ia_valid \|= ATTR_TIMES_SET;
4cca9226	55	} else {
f2b20f6e	56	newattrs.ia_valid \|= ATTR_TOUCH;
82b0547c	57	}
27ac0ffe	58	retry_deleg:
5955102c	59	inode_lock(inode);
27ac0ffe	60	error = notify_change(path->dentry, &newattrs, &delegated_inode);
5955102c	61	inode_unlock(inode);
27ac0ffe BF	62	if (delegated_inode) {
	63	error = break_deleg_wait(&delegated_inode);
	64	if (!error)
	65	goto retry_deleg;
	66	}
e9b76fed	67
e9b76fed MS	68	mnt_drop_write(path->mnt);
	69	out:
	70	return error;
	71	}
	72
	73	/*
	74	* do_utimes - change times on filename or file descriptor
	75	* @dfd: open file descriptor, -1 or AT_FDCWD
	76	* @filename: path name or NULL
	77	* @times: new times or NULL
	78	* @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
	79	*
	80	* If filename is NULL and dfd refers to an open file, then operate on
	81	* the file. Otherwise look up filename, possibly using dfd as a
	82	* starting point.
	83	*
	84	* If times==NULL, set access and modification to current time,
	85	* must be owner or have write permission.
	86	* Else, update from *times, must be owner or super user.
	87	*/
aaed2dd8	88	long do_utimes(int dfd, const char __user filename, struct timespec64 times,
c7887325	89	int flags)
e9b76fed MS	90	{
	91	int error = -EINVAL;
	92
	93	if (times && (!nsec_valid(times[0].tv_nsec) \|\|
	94	!nsec_valid(times[1].tv_nsec))) {
	95	goto out;
	96	}
	97
	98	if (flags & ~AT_SYMLINK_NOFOLLOW)
	99	goto out;
	100
	101	if (filename == NULL && dfd != AT_FDCWD) {
2903ff01	102	struct fd f;
e9b76fed MS	103
	104	if (flags & AT_SYMLINK_NOFOLLOW)
	105	goto out;
	106
2903ff01	107	f = fdget(dfd);
e9b76fed	108	error = -EBADF;
2903ff01	109	if (!f.file)
e9b76fed MS	110	goto out;
e9b76fed MS	111
2903ff01 AV	112	error = utimes_common(&f.file->f_path, times);
2903ff01 AV	113	fdput(f);
e9b76fed	114	} else {
2d8f3038	115	struct path path;
e9b76fed MS	116	int lookup_flags = 0;
	117
	118	if (!(flags & AT_SYMLINK_NOFOLLOW))
	119	lookup_flags \|= LOOKUP_FOLLOW;
a69201d6	120	retry:
2d8f3038	121	error = user_path_at(dfd, filename, lookup_flags, &path);
e9b76fed MS	122	if (error)
	123	goto out;
	124
2d8f3038 AV	125	error = utimes_common(&path, times);
2d8f3038 AV	126	path_put(&path);
a69201d6 JL	127	if (retry_estale(error, lookup_flags)) {
	128	lookup_flags \|= LOOKUP_REVAL;
	129	goto retry;
	130	}
e9b76fed MS	131	}
e9b76fed MS	132
82b0547c AD	133	out:
	134	return error;
	135	}
	136
c7887325	137	SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
a4f7a300	138	struct __kernel_timespec __user *, utimes, int, flags)
1c710c89	139	{
aaed2dd8	140	struct timespec64 tstimes[2];
1c710c89 UD	141
1c710c89 UD	142	if (utimes) {
aaed2dd8 DD	143	if ((get_timespec64(&tstimes[0], &utimes[0]) \|\|
aaed2dd8 DD	144	get_timespec64(&tstimes[1], &utimes[1])))
1c710c89	145	return -EFAULT;
1c710c89 UD	146
	147	/* Nothing to do, we must not even check the path. */
	148	if (tstimes[0].tv_nsec == UTIME_OMIT &&
	149	tstimes[1].tv_nsec == UTIME_OMIT)
	150	return 0;
	151	}
	152
	153	return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
	154	}
	155
185cfaf7 AB	156	#ifdef __ARCH_WANT_SYS_UTIME
	157	/*
	158	* futimesat(), utimes() and utime() are older versions of utimensat()
	159	* that are provided for compatibility with traditional C libraries.
	160	* On modern architectures, we always use libc wrappers around
	161	* utimensat() instead.
	162	*/
f1390358 DB	163	static long do_futimesat(int dfd, const char __user *filename,
f1390358 DB	164	struct timeval __user *utimes)
82b0547c AD	165	{
82b0547c AD	166	struct timeval times[2];
aaed2dd8	167	struct timespec64 tstimes[2];
1c710c89 UD	168
	169	if (utimes) {
	170	if (copy_from_user(&times, utimes, sizeof(times)))
	171	return -EFAULT;
	172
	173	/* This test is needed to catch all invalid values. If we
	174	would test only in do_utimes we would miss those invalid
	175	values truncated by the multiplication with 1000. Note
	176	that we also catch UTIME_{NOW,OMIT} here which are only
	177	valid for utimensat. */
	178	if (times[0].tv_usec >= 1000000 \|\| times[0].tv_usec < 0 \|\|
	179	times[1].tv_usec >= 1000000 \|\| times[1].tv_usec < 0)
	180	return -EINVAL;
	181
	182	tstimes[0].tv_sec = times[0].tv_sec;
	183	tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
	184	tstimes[1].tv_sec = times[1].tv_sec;
	185	tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
	186	}
82b0547c	187
1c710c89	188	return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
82b0547c AD	189	}
82b0547c AD	190
f1390358 DB	191
	192	SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
	193	struct timeval __user *, utimes)
	194	{
	195	return do_futimesat(dfd, filename, utimes);
	196	}
	197
003d7ab4 HC	198	SYSCALL_DEFINE2(utimes, char __user *, filename,
003d7ab4 HC	199	struct timeval __user *, utimes)
82b0547c	200	{
f1390358	201	return do_futimesat(AT_FDCWD, filename, utimes);
82b0547c	202	}
1a060ba3	203
185cfaf7 AB	204	SYSCALL_DEFINE2(utime, char __user , filename, struct utimbuf __user , times)
	205	{
	206	struct timespec64 tv[2];
	207
	208	if (times) {
	209	if (get_user(tv[0].tv_sec, &times->actime) \|\|
	210	get_user(tv[1].tv_sec, &times->modtime))
	211	return -EFAULT;
	212	tv[0].tv_nsec = 0;
	213	tv[1].tv_nsec = 0;
	214	}
	215	return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
	216	}
	217	#endif
	218
4faea239	219	#ifdef CONFIG_COMPAT_32BIT_TIME
1a060ba3 AV	220	/*
	221	* Not all architectures have sys_utime, so implement this in terms
	222	* of sys_utimes.
	223	*/
4faea239	224	#ifdef __ARCH_WANT_SYS_UTIME32
8dabe724 AB	225	SYSCALL_DEFINE2(utime32, const char __user *, filename,
8dabe724 AB	226	struct old_utimbuf32 __user *, t)
1a060ba3	227	{
aaed2dd8	228	struct timespec64 tv[2];
1a060ba3 AV	229
	230	if (t) {
	231	if (get_user(tv[0].tv_sec, &t->actime) \|\|
	232	get_user(tv[1].tv_sec, &t->modtime))
	233	return -EFAULT;
	234	tv[0].tv_nsec = 0;
	235	tv[1].tv_nsec = 0;
	236	}
	237	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
	238	}
4faea239	239	#endif
1a060ba3	240
8dabe724	241	SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user , filename, struct old_timespec32 __user , t, int, flags)
1a060ba3	242	{
aaed2dd8	243	struct timespec64 tv[2];
1a060ba3 AV	244
1a060ba3 AV	245	if (t) {
9afc5eee AB	246	if (get_old_timespec32(&tv[0], &t[0]) \|\|
9afc5eee AB	247	get_old_timespec32(&tv[1], &t[1]))
1a060ba3 AV	248	return -EFAULT;
	249
	250	if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
	251	return 0;
	252	}
	253	return do_utimes(dfd, filename, t ? tv : NULL, flags);
	254	}
	255
4faea239	256	#ifdef __ARCH_WANT_SYS_UTIME32
ab641afa	257	static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
9afc5eee	258	struct old_timeval32 __user *t)
1a060ba3	259	{
aaed2dd8	260	struct timespec64 tv[2];
1a060ba3 AV	261
	262	if (t) {
	263	if (get_user(tv[0].tv_sec, &t[0].tv_sec) \|\|
	264	get_user(tv[0].tv_nsec, &t[0].tv_usec) \|\|
	265	get_user(tv[1].tv_sec, &t[1].tv_sec) \|\|
	266	get_user(tv[1].tv_nsec, &t[1].tv_usec))
	267	return -EFAULT;
	268	if (tv[0].tv_nsec >= 1000000 \|\| tv[0].tv_nsec < 0 \|\|
	269	tv[1].tv_nsec >= 1000000 \|\| tv[1].tv_nsec < 0)
	270	return -EINVAL;
	271	tv[0].tv_nsec *= 1000;
	272	tv[1].tv_nsec *= 1000;
	273	}
	274	return do_utimes(dfd, filename, t ? tv : NULL, 0);
	275	}
	276
8dabe724	277	SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
ab641afa	278	const char __user *, filename,
9afc5eee	279	struct old_timeval32 __user *, t)
ab641afa DB	280	{
	281	return do_compat_futimesat(dfd, filename, t);
	282	}
	283
8dabe724	284	SYSCALL_DEFINE2(utimes_time32, const char __user , filename, struct old_timeval32 __user , t)
1a060ba3	285	{
ab641afa	286	return do_compat_futimesat(AT_FDCWD, filename, t);
1a060ba3 AV	287	}
1a060ba3 AV	288	#endif
4faea239	289	#endif