[linux.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;
}

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

	if (times) {
		if (!nsec_valid(times[0].tv_nsec) ||
		    !nsec_valid(times[1].tv_nsec))
			return -EINVAL;
		if (times[0].tv_nsec == UTIME_NOW &&
		    times[1].tv_nsec == UTIME_NOW)
			times = NULL;
	}

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

	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 = times[0];
			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 = times[1];
			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;
}

static int do_utimes_path(int dfd, const char __user *filename,
		struct timespec64 *times, int flags)
{
	struct path path;
	int lookup_flags = 0, error;

	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
		return -EINVAL;

	if (!(flags & AT_SYMLINK_NOFOLLOW))
		lookup_flags |= LOOKUP_FOLLOW;
	if (flags & AT_EMPTY_PATH)
		lookup_flags |= LOOKUP_EMPTY;

retry:
	error = user_path_at(dfd, filename, lookup_flags, &path);
	if (error)
		return error;

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

	return error;
}

static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
{
	struct fd f;
	int error;

	if (flags)
		return -EINVAL;

	f = fdget(fd);
	if (!f.file)
		return -EBADF;
	error = vfs_utimes(&f.file->f_path, times);
	fdput(f);
	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)
{
	if (filename == NULL && dfd != AT_FDCWD)
		return do_utimes_fd(dfd, times, flags);
	return do_utimes_path(dfd, filename, times, flags);
}

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 __kernel_old_timeval __user *utimes)
{
	struct __kernel_old_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 __kernel_old_timeval __user *, utimes)
{
	return do_futimesat(dfd, filename, utimes);
}

SYSCALL_DEFINE2(utimes, char __user *, filename,
		struct __kernel_old_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
fd5ad30c	19	int vfs_utimes(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
27eb11c9 CH	26	if (times) {
	27	if (!nsec_valid(times[0].tv_nsec) \|\|
	28	!nsec_valid(times[1].tv_nsec))
	29	return -EINVAL;
	30	if (times[0].tv_nsec == UTIME_NOW &&
	31	times[1].tv_nsec == UTIME_NOW)
	32	times = NULL;
	33	}
	34
e9b76fed	35	error = mnt_want_write(path->mnt);
74f9fdfa	36	if (error)
e9b76fed	37	goto out;
82b0547c	38
82b0547c AD	39	newattrs.ia_valid = ATTR_CTIME \| ATTR_MTIME \| ATTR_ATIME;
82b0547c AD	40	if (times) {
1c710c89 UD	41	if (times[0].tv_nsec == UTIME_OMIT)
	42	newattrs.ia_valid &= ~ATTR_ATIME;
	43	else if (times[0].tv_nsec != UTIME_NOW) {
eb31e2f6	44	newattrs.ia_atime = times[0];
1c710c89 UD	45	newattrs.ia_valid \|= ATTR_ATIME_SET;
	46	}
	47
	48	if (times[1].tv_nsec == UTIME_OMIT)
	49	newattrs.ia_valid &= ~ATTR_MTIME;
	50	else if (times[1].tv_nsec != UTIME_NOW) {
eb31e2f6	51	newattrs.ia_mtime = times[1];
1c710c89 UD	52	newattrs.ia_valid \|= ATTR_MTIME_SET;
1c710c89 UD	53	}
4cca9226	54	/*
31051c85	55	* Tell setattr_prepare(), that this is an explicit time
9767d749 MS	56	* update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
9767d749 MS	57	* were used.
4cca9226	58	*/
9767d749	59	newattrs.ia_valid \|= ATTR_TIMES_SET;
4cca9226	60	} else {
f2b20f6e	61	newattrs.ia_valid \|= ATTR_TOUCH;
82b0547c	62	}
27ac0ffe	63	retry_deleg:
5955102c	64	inode_lock(inode);
27ac0ffe	65	error = notify_change(path->dentry, &newattrs, &delegated_inode);
5955102c	66	inode_unlock(inode);
27ac0ffe BF	67	if (delegated_inode) {
	68	error = break_deleg_wait(&delegated_inode);
	69	if (!error)
	70	goto retry_deleg;
	71	}
e9b76fed	72
e9b76fed MS	73	mnt_drop_write(path->mnt);
	74	out:
	75	return error;
	76	}
	77
9d4b74ae CH	78	static int do_utimes_path(int dfd, const char __user *filename,
	79	struct timespec64 *times, int flags)
	80	{
	81	struct path path;
	82	int lookup_flags = 0, error;
	83
9d4b74ae CH	84	if (flags & ~(AT_SYMLINK_NOFOLLOW \| AT_EMPTY_PATH))
	85	return -EINVAL;
	86
	87	if (!(flags & AT_SYMLINK_NOFOLLOW))
	88	lookup_flags \|= LOOKUP_FOLLOW;
	89	if (flags & AT_EMPTY_PATH)
	90	lookup_flags \|= LOOKUP_EMPTY;
	91
	92	retry:
	93	error = user_path_at(dfd, filename, lookup_flags, &path);
	94	if (error)
	95	return error;
	96
fd5ad30c	97	error = vfs_utimes(&path, times);
9d4b74ae CH	98	path_put(&path);
	99	if (retry_estale(error, lookup_flags)) {
	100	lookup_flags \|= LOOKUP_REVAL;
	101	goto retry;
	102	}
	103
	104	return error;
	105	}
	106
	107	static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
	108	{
	109	struct fd f;
	110	int error;
	111
9d4b74ae CH	112	if (flags)
	113	return -EINVAL;
	114
	115	f = fdget(fd);
	116	if (!f.file)
	117	return -EBADF;
fd5ad30c	118	error = vfs_utimes(&f.file->f_path, times);
9d4b74ae CH	119	fdput(f);
	120	return error;
	121	}
	122
e9b76fed MS	123	/*
	124	* do_utimes - change times on filename or file descriptor
	125	* @dfd: open file descriptor, -1 or AT_FDCWD
	126	* @filename: path name or NULL
	127	* @times: new times or NULL
	128	* @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
	129	*
	130	* If filename is NULL and dfd refers to an open file, then operate on
	131	* the file. Otherwise look up filename, possibly using dfd as a
	132	* starting point.
	133	*
	134	* If times==NULL, set access and modification to current time,
	135	* must be owner or have write permission.
	136	* Else, update from *times, must be owner or super user.
	137	*/
aaed2dd8	138	long do_utimes(int dfd, const char __user filename, struct timespec64 times,
c7887325	139	int flags)
e9b76fed	140	{
9d4b74ae CH	141	if (filename == NULL && dfd != AT_FDCWD)
	142	return do_utimes_fd(dfd, times, flags);
	143	return do_utimes_path(dfd, filename, times, flags);
82b0547c AD	144	}
82b0547c AD	145
c7887325	146	SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
a4f7a300	147	struct __kernel_timespec __user *, utimes, int, flags)
1c710c89	148	{
aaed2dd8	149	struct timespec64 tstimes[2];
1c710c89 UD	150
1c710c89 UD	151	if (utimes) {
aaed2dd8 DD	152	if ((get_timespec64(&tstimes[0], &utimes[0]) \|\|
aaed2dd8 DD	153	get_timespec64(&tstimes[1], &utimes[1])))
1c710c89	154	return -EFAULT;
1c710c89 UD	155
	156	/* Nothing to do, we must not even check the path. */
	157	if (tstimes[0].tv_nsec == UTIME_OMIT &&
	158	tstimes[1].tv_nsec == UTIME_OMIT)
	159	return 0;
	160	}
	161
	162	return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
	163	}
	164
185cfaf7 AB	165	#ifdef __ARCH_WANT_SYS_UTIME
	166	/*
	167	* futimesat(), utimes() and utime() are older versions of utimensat()
	168	* that are provided for compatibility with traditional C libraries.
	169	* On modern architectures, we always use libc wrappers around
	170	* utimensat() instead.
	171	*/
f1390358	172	static long do_futimesat(int dfd, const char __user *filename,
75d319c0	173	struct __kernel_old_timeval __user *utimes)
82b0547c	174	{
75d319c0	175	struct __kernel_old_timeval times[2];
aaed2dd8	176	struct timespec64 tstimes[2];
1c710c89 UD	177
	178	if (utimes) {
	179	if (copy_from_user(&times, utimes, sizeof(times)))
	180	return -EFAULT;
	181
	182	/* This test is needed to catch all invalid values. If we
	183	would test only in do_utimes we would miss those invalid
	184	values truncated by the multiplication with 1000. Note
	185	that we also catch UTIME_{NOW,OMIT} here which are only
	186	valid for utimensat. */
	187	if (times[0].tv_usec >= 1000000 \|\| times[0].tv_usec < 0 \|\|
	188	times[1].tv_usec >= 1000000 \|\| times[1].tv_usec < 0)
	189	return -EINVAL;
	190
	191	tstimes[0].tv_sec = times[0].tv_sec;
	192	tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
	193	tstimes[1].tv_sec = times[1].tv_sec;
	194	tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
	195	}
82b0547c	196
1c710c89	197	return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
82b0547c AD	198	}
82b0547c AD	199
f1390358 DB	200
f1390358 DB	201	SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
75d319c0	202	struct __kernel_old_timeval __user *, utimes)
f1390358 DB	203	{
	204	return do_futimesat(dfd, filename, utimes);
	205	}
	206
003d7ab4	207	SYSCALL_DEFINE2(utimes, char __user *, filename,
75d319c0	208	struct __kernel_old_timeval __user *, utimes)
82b0547c	209	{
f1390358	210	return do_futimesat(AT_FDCWD, filename, utimes);
82b0547c	211	}
1a060ba3	212
185cfaf7 AB	213	SYSCALL_DEFINE2(utime, char __user , filename, struct utimbuf __user , times)
	214	{
	215	struct timespec64 tv[2];
	216
	217	if (times) {
	218	if (get_user(tv[0].tv_sec, &times->actime) \|\|
	219	get_user(tv[1].tv_sec, &times->modtime))
	220	return -EFAULT;
	221	tv[0].tv_nsec = 0;
	222	tv[1].tv_nsec = 0;
	223	}
	224	return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
	225	}
	226	#endif
	227
4faea239	228	#ifdef CONFIG_COMPAT_32BIT_TIME
1a060ba3 AV	229	/*
	230	* Not all architectures have sys_utime, so implement this in terms
	231	* of sys_utimes.
	232	*/
4faea239	233	#ifdef __ARCH_WANT_SYS_UTIME32
8dabe724 AB	234	SYSCALL_DEFINE2(utime32, const char __user *, filename,
8dabe724 AB	235	struct old_utimbuf32 __user *, t)
1a060ba3	236	{
aaed2dd8	237	struct timespec64 tv[2];
1a060ba3 AV	238
	239	if (t) {
	240	if (get_user(tv[0].tv_sec, &t->actime) \|\|
	241	get_user(tv[1].tv_sec, &t->modtime))
	242	return -EFAULT;
	243	tv[0].tv_nsec = 0;
	244	tv[1].tv_nsec = 0;
	245	}
	246	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
	247	}
4faea239	248	#endif
1a060ba3	249
8dabe724	250	SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user , filename, struct old_timespec32 __user , t, int, flags)
1a060ba3	251	{
aaed2dd8	252	struct timespec64 tv[2];
1a060ba3 AV	253
1a060ba3 AV	254	if (t) {
9afc5eee AB	255	if (get_old_timespec32(&tv[0], &t[0]) \|\|
9afc5eee AB	256	get_old_timespec32(&tv[1], &t[1]))
1a060ba3 AV	257	return -EFAULT;
	258
	259	if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
	260	return 0;
	261	}
	262	return do_utimes(dfd, filename, t ? tv : NULL, flags);
	263	}
	264
4faea239	265	#ifdef __ARCH_WANT_SYS_UTIME32
ab641afa	266	static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
9afc5eee	267	struct old_timeval32 __user *t)
1a060ba3	268	{
aaed2dd8	269	struct timespec64 tv[2];
1a060ba3 AV	270
	271	if (t) {
	272	if (get_user(tv[0].tv_sec, &t[0].tv_sec) \|\|
	273	get_user(tv[0].tv_nsec, &t[0].tv_usec) \|\|
	274	get_user(tv[1].tv_sec, &t[1].tv_sec) \|\|
	275	get_user(tv[1].tv_nsec, &t[1].tv_usec))
	276	return -EFAULT;
	277	if (tv[0].tv_nsec >= 1000000 \|\| tv[0].tv_nsec < 0 \|\|
	278	tv[1].tv_nsec >= 1000000 \|\| tv[1].tv_nsec < 0)
	279	return -EINVAL;
	280	tv[0].tv_nsec *= 1000;
	281	tv[1].tv_nsec *= 1000;
	282	}
	283	return do_utimes(dfd, filename, t ? tv : NULL, 0);
	284	}
	285
8dabe724	286	SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
ab641afa	287	const char __user *, filename,
9afc5eee	288	struct old_timeval32 __user *, t)
ab641afa DB	289	{
	290	return do_compat_futimesat(dfd, filename, t);
	291	}
	292
8dabe724	293	SYSCALL_DEFINE2(utimes_time32, const char __user , filename, struct old_timeval32 __user , t)
1a060ba3	294	{
ab641afa	295	return do_compat_futimesat(AT_FDCWD, filename, t);
1a060ba3 AV	296	}
1a060ba3 AV	297	#endif
4faea239	298	#endif