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![Deepa Dinamani](/assets/img/avatar_default.png)
struct timespec is not y2038 safe on 32 bit machines. Replace timespec with y2038 safe struct timespec64. Note that the patch only changes the internals without modifying the syscall interfaces. This will be part of a separate series. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
278 lines
7.1 KiB
C
278 lines
7.1 KiB
C
#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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#include <linux/utime.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <linux/compat.h>
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#include <asm/unistd.h>
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#ifdef __ARCH_WANT_SYS_UTIME
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/*
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* sys_utime() can be implemented in user-level using sys_utimes().
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* Is this for backwards compatibility? If so, why not move it
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* into the appropriate arch directory (for those architectures that
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* need it).
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*/
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/* If times==NULL, set access and modification to current time,
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* must be owner or have write permission.
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* Else, update from *times, must be owner or super user.
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*/
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SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
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{
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struct timespec64 tv[2];
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if (times) {
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if (get_user(tv[0].tv_sec, ×->actime) ||
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get_user(tv[1].tv_sec, ×->modtime))
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return -EFAULT;
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tv[0].tv_nsec = 0;
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tv[1].tv_nsec = 0;
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}
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return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
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}
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#endif
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static bool nsec_valid(long nsec)
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{
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if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
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return true;
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return nsec >= 0 && nsec <= 999999999;
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}
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static int utimes_common(const struct path *path, struct timespec64 *times)
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{
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int error;
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struct iattr newattrs;
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struct inode *inode = path->dentry->d_inode;
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struct inode *delegated_inode = NULL;
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error = mnt_want_write(path->mnt);
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if (error)
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goto out;
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if (times && times[0].tv_nsec == UTIME_NOW &&
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times[1].tv_nsec == UTIME_NOW)
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times = NULL;
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newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
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if (times) {
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if (times[0].tv_nsec == UTIME_OMIT)
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newattrs.ia_valid &= ~ATTR_ATIME;
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else if (times[0].tv_nsec != UTIME_NOW) {
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newattrs.ia_atime.tv_sec = times[0].tv_sec;
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newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
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newattrs.ia_valid |= ATTR_ATIME_SET;
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}
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if (times[1].tv_nsec == UTIME_OMIT)
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newattrs.ia_valid &= ~ATTR_MTIME;
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else if (times[1].tv_nsec != UTIME_NOW) {
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newattrs.ia_mtime.tv_sec = times[1].tv_sec;
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newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
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newattrs.ia_valid |= ATTR_MTIME_SET;
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}
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/*
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* Tell setattr_prepare(), that this is an explicit time
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* update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
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* were used.
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*/
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newattrs.ia_valid |= ATTR_TIMES_SET;
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} else {
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newattrs.ia_valid |= ATTR_TOUCH;
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}
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retry_deleg:
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inode_lock(inode);
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error = notify_change(path->dentry, &newattrs, &delegated_inode);
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inode_unlock(inode);
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if (delegated_inode) {
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error = break_deleg_wait(&delegated_inode);
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if (!error)
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goto retry_deleg;
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}
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mnt_drop_write(path->mnt);
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out:
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return error;
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}
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/*
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* do_utimes - change times on filename or file descriptor
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* @dfd: open file descriptor, -1 or AT_FDCWD
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* @filename: path name or NULL
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* @times: new times or NULL
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* @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
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*
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* If filename is NULL and dfd refers to an open file, then operate on
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* the file. Otherwise look up filename, possibly using dfd as a
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* starting point.
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*
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* If times==NULL, set access and modification to current time,
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* must be owner or have write permission.
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* Else, update from *times, must be owner or super user.
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*/
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long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
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int flags)
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{
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int error = -EINVAL;
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if (times && (!nsec_valid(times[0].tv_nsec) ||
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!nsec_valid(times[1].tv_nsec))) {
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goto out;
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}
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if (flags & ~AT_SYMLINK_NOFOLLOW)
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goto out;
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if (filename == NULL && dfd != AT_FDCWD) {
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struct fd f;
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if (flags & AT_SYMLINK_NOFOLLOW)
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goto out;
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f = fdget(dfd);
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error = -EBADF;
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if (!f.file)
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goto out;
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error = utimes_common(&f.file->f_path, times);
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fdput(f);
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} else {
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struct path path;
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int lookup_flags = 0;
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if (!(flags & AT_SYMLINK_NOFOLLOW))
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lookup_flags |= LOOKUP_FOLLOW;
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retry:
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error = user_path_at(dfd, filename, lookup_flags, &path);
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if (error)
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goto out;
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error = utimes_common(&path, times);
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path_put(&path);
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if (retry_estale(error, lookup_flags)) {
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lookup_flags |= LOOKUP_REVAL;
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goto retry;
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}
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}
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out:
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return error;
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}
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SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
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struct timespec __user *, utimes, int, flags)
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{
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struct timespec64 tstimes[2];
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if (utimes) {
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if ((get_timespec64(&tstimes[0], &utimes[0]) ||
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get_timespec64(&tstimes[1], &utimes[1])))
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return -EFAULT;
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/* Nothing to do, we must not even check the path. */
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if (tstimes[0].tv_nsec == UTIME_OMIT &&
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tstimes[1].tv_nsec == UTIME_OMIT)
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return 0;
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}
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return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
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}
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SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
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struct timeval __user *, utimes)
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{
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struct timeval times[2];
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struct timespec64 tstimes[2];
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if (utimes) {
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if (copy_from_user(×, utimes, sizeof(times)))
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return -EFAULT;
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/* This test is needed to catch all invalid values. If we
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would test only in do_utimes we would miss those invalid
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values truncated by the multiplication with 1000. Note
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that we also catch UTIME_{NOW,OMIT} here which are only
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valid for utimensat. */
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if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
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times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
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return -EINVAL;
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tstimes[0].tv_sec = times[0].tv_sec;
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tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
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tstimes[1].tv_sec = times[1].tv_sec;
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tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
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}
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return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
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}
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SYSCALL_DEFINE2(utimes, char __user *, filename,
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struct timeval __user *, utimes)
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{
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return sys_futimesat(AT_FDCWD, filename, utimes);
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}
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#ifdef CONFIG_COMPAT
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/*
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* Not all architectures have sys_utime, so implement this in terms
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* of sys_utimes.
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*/
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COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
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struct compat_utimbuf __user *, t)
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{
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struct timespec64 tv[2];
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if (t) {
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if (get_user(tv[0].tv_sec, &t->actime) ||
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get_user(tv[1].tv_sec, &t->modtime))
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return -EFAULT;
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tv[0].tv_nsec = 0;
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tv[1].tv_nsec = 0;
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}
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return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
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}
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COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filename, struct compat_timespec __user *, t, int, flags)
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{
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struct timespec64 tv[2];
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if (t) {
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if (compat_get_timespec64(&tv[0], &t[0]) ||
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compat_get_timespec64(&tv[1], &t[1]))
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return -EFAULT;
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if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
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return 0;
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}
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return do_utimes(dfd, filename, t ? tv : NULL, flags);
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}
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COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd, const char __user *, filename, struct compat_timeval __user *, t)
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{
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struct timespec64 tv[2];
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if (t) {
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if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
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get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
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get_user(tv[1].tv_sec, &t[1].tv_sec) ||
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get_user(tv[1].tv_nsec, &t[1].tv_usec))
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return -EFAULT;
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if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
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tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
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return -EINVAL;
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tv[0].tv_nsec *= 1000;
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tv[1].tv_nsec *= 1000;
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}
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return do_utimes(dfd, filename, t ? tv : NULL, 0);
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}
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COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct compat_timeval __user *, t)
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{
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return compat_sys_futimesat(AT_FDCWD, filename, t);
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}
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#endif
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