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299 lines
7.6 KiB
299 lines
7.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#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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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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int vfs_utimes(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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if (times) { |
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if (!nsec_valid(times[0].tv_nsec) || |
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!nsec_valid(times[1].tv_nsec)) |
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return -EINVAL; |
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if (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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} |
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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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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 = times[0]; |
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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 = times[1]; |
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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(mnt_user_ns(path->mnt), path->dentry, &newattrs, |
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&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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static int do_utimes_path(int dfd, const char __user *filename, |
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struct timespec64 *times, int flags) |
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{ |
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struct path path; |
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int lookup_flags = 0, error; |
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if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) |
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return -EINVAL; |
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if (!(flags & AT_SYMLINK_NOFOLLOW)) |
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lookup_flags |= LOOKUP_FOLLOW; |
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if (flags & AT_EMPTY_PATH) |
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lookup_flags |= LOOKUP_EMPTY; |
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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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return error; |
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error = vfs_utimes(&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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return error; |
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} |
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static int do_utimes_fd(int fd, struct timespec64 *times, int flags) |
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{ |
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struct fd f; |
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int error; |
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if (flags) |
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return -EINVAL; |
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f = fdget(fd); |
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if (!f.file) |
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return -EBADF; |
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error = vfs_utimes(&f.file->f_path, times); |
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fdput(f); |
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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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if (filename == NULL && dfd != AT_FDCWD) |
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return do_utimes_fd(dfd, times, flags); |
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return do_utimes_path(dfd, filename, times, flags); |
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} |
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SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename, |
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struct __kernel_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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#ifdef __ARCH_WANT_SYS_UTIME |
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/* |
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* futimesat(), utimes() and utime() are older versions of utimensat() |
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* that are provided for compatibility with traditional C libraries. |
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* On modern architectures, we always use libc wrappers around |
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* utimensat() instead. |
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*/ |
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static long do_futimesat(int dfd, const char __user *filename, |
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struct __kernel_old_timeval __user *utimes) |
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{ |
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struct __kernel_old_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_DEFINE3(futimesat, int, dfd, const char __user *, filename, |
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struct __kernel_old_timeval __user *, utimes) |
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{ |
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return do_futimesat(dfd, filename, utimes); |
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} |
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SYSCALL_DEFINE2(utimes, char __user *, filename, |
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struct __kernel_old_timeval __user *, utimes) |
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{ |
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return do_futimesat(AT_FDCWD, filename, utimes); |
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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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#ifdef CONFIG_COMPAT_32BIT_TIME |
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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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#ifdef __ARCH_WANT_SYS_UTIME32 |
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SYSCALL_DEFINE2(utime32, const char __user *, filename, |
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struct old_utimbuf32 __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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#endif |
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SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __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 (get_old_timespec32(&tv[0], &t[0]) || |
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get_old_timespec32(&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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#ifdef __ARCH_WANT_SYS_UTIME32 |
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static long do_compat_futimesat(unsigned int dfd, const char __user *filename, |
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struct old_timeval32 __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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SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd, |
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const char __user *, filename, |
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struct old_timeval32 __user *, t) |
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{ |
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return do_compat_futimesat(dfd, filename, t); |
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} |
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SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t) |
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{ |
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return do_compat_futimesat(AT_FDCWD, filename, t); |
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} |
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#endif |
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#endif
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