// 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>#include <linux/filelock.h>#include "internal.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 delegated_inode delegated_inode = { }; 	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(mnt_idmap(path->mnt), path->dentry, &newattrs,			      &delegated_inode);	inode_unlock(inode);	if (is_delegated(&delegated_inode)) {		error = break_deleg_wait(&delegated_inode);		if (!error)			goto retry_deleg;	} 	mnt_drop_write(path->mnt);out:	return error;}EXPORT_SYMBOL_GPL(vfs_utimes); 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; 	CLASS(filename_uflags, name)(filename, flags);retry:	error = filename_lookup(dfd, name, lookup_flags, &path, NULL);	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){	if (flags)		return -EINVAL; 	CLASS(fd, f)(fd);	if (fd_empty(f))		return -EBADF;	return vfs_utimes(&fd_file(f)->f_path, times);} /* * 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_UTIME32SYSCALL_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_UTIME32static 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