[PATCH] v3: utimensat implementation

Ulrich Drepper
2007-04-27T03:08:42Z

One comment I got suggested to clean up the overflow tests. There
is no reason to not perform the full micro-second overflow test
in those two places. The four conditions are reduced by the compiler
to just two tests so there's no problems with performance.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>

diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 796df69..12611c8 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -714,9 +714,10 @@ ia32_sys_call_table:
.quad compat_sys_get_robust_list
.quad sys_splice
.quad sys_sync_file_range
- .quad sys_tee
+ .quad sys_tee /* 315 */
.quad compat_sys_vmsplice
.quad compat_sys_move_pages
.quad sys_getcpu
.quad sys_epoll_pwait
+ .quad compat_sys_utimensat /* 320 */
ia32_syscall_end:
diff --git a/fs/compat.c b/fs/compat.c
index 040a8be..d8a8cb5 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -79,28 +79,55 @@ int compat_printk(const char *fmt, ...)
*/
asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __user *t)
{
- struct timeval tv[2];
+ struct timespec 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_usec = 0;
- tv[1].tv_usec = 0;
+ tv[0].tv_nsec = 0;
+ tv[1].tv_nsec = 0;
}
return do_utimes(AT_FDCWD, filename, t ? tv : NULL);
}

+asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, struct compat_timespec __user *t)
+{
+ struct timespec tv[2];
+
+ if (t) {
+ if (get_compat_timespec(&tv[0], &t[0]) ||
+ get_compat_timespec(&tv[1], &t[1]))
+ return -EFAULT;
+
+ if ((tv[0].tv_nsec == UTIME_OMIT || tv[0].tv_nsec == UTIME_NOW)
+ && tv[0].tv_sec != 0)
+ return -EINVAL;
+ if ((tv[1].tv_nsec == UTIME_OMIT || tv[1].tv_nsec == UTIME_NOW)
+ && tv[1].tv_sec != 0)
+ return -EINVAL;
+
+ if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
+ return 0;
+ }
+ return do_utimes(dfd, filename, t ? tv : NULL);
+}
+
asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, struct compat_timeval __user *t)
{
- struct timeval tv[2];
+ struct timespec tv[2];

if (t) {
if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
- get_user(tv[0].tv_usec, &t[0].tv_usec) ||
+ 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_usec, &t[1].tv_usec))
+ 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);
}
diff --git a/fs/utimes.c b/fs/utimes.c
index 99cf2cb..d854af7 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -3,6 +3,7 @@
#include <linux/linkage.h>
#include <linux/namei.h>
#include <linux/sched.h>
+#include <linux/stat.h>
#include <linux/utime.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -76,7 +77,7 @@ out:
* must be owner or have write permission.
* Else, update from *times, must be owner or super user.
*/
-long do_utimes(int dfd, char __user *filename, struct timeval *times)
+long do_utimes(int dfd, char __user *filename, struct timespec *times)
{
int error;
struct nameidata nd;
@@ -100,11 +101,21 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times)
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
goto dput_and_out;

- newattrs.ia_atime.tv_sec = times[0].tv_sec;
- newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000;
- newattrs.ia_mtime.tv_sec = times[1].tv_sec;
- newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000;
- newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
+ if (times[0].tv_nsec == UTIME_OMIT)
+ newattrs.ia_valid &= ~ATTR_ATIME;
+ else if (times[0].tv_nsec != UTIME_NOW) {
+ newattrs.ia_atime.tv_sec = times[0].tv_sec;
+ newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
+ 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.tv_sec = times[1].tv_sec;
+ newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
+ newattrs.ia_valid |= ATTR_MTIME_SET;
+ }
} else {
error = -EACCES;
if (IS_IMMUTABLE(inode))
@@ -123,13 +134,55 @@ out:
return error;
}

+asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes)
+{
+ struct timespec tstimes[2];
+ if (utimes) {
+ if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
+ return -EFAULT;
+ if ((tstimes[0].tv_nsec == UTIME_OMIT ||
+ tstimes[0].tv_nsec == UTIME_NOW) &&
+ tstimes[0].tv_sec != 0)
+ return -EINVAL;
+ if ((tstimes[1].tv_nsec == UTIME_OMIT ||
+ tstimes[1].tv_nsec == UTIME_NOW) &&
+ tstimes[1].tv_sec != 0)
+ return -EINVAL;
+
+ /* 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);
+}
+
asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes)
{
struct timeval times[2];
+ struct timespec 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;
+ }

- if (utimes && copy_from_user(&times, utimes, sizeof(times)))
- return -EFAULT;
- return do_utimes(dfd, filename, utimes ? times : NULL);
+ return do_utimes(dfd, filename, utimes ? tstimes : NULL);
}

asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes)
diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index 833fa17..17a9d5a 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -325,6 +325,7 @@
#define __NR_move_pages 317
#define __NR_getcpu 318
#define __NR_epoll_pwait 319
+#define __NR_utimensat 320

#ifdef __KERNEL__

diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index c5f596e..0aae2ae 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -619,8 +619,10 @@ __SYSCALL(__NR_sync_file_range, sys_sync_file_range)
__SYSCALL(__NR_vmsplice, sys_vmsplice)
#define __NR_move_pages 279
__SYSCALL(__NR_move_pages, sys_move_pages)
+#define __NR_utimensat 280
+__SYSCALL(__NR_utimensat, sys_utimensat)

-#define __NR_syscall_max __NR_move_pages
+#define __NR_syscall_max __NR_utimensat

#ifndef __NO_STUBS
#define __ARCH_WANT_OLD_READDIR
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 679ef0d..611c398 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -53,6 +53,9 @@
#define S_IWUGO (S_IWUSR|S_IWGRP|S_IWOTH)
#define S_IXUGO (S_IXUSR|S_IXGRP|S_IXOTH)

+#define UTIME_NOW ((1l << 30) - 1l)
+#define UTIME_OMIT ((1l << 30) - 2l)
+
#include <linux/types.h>
#include <linux/time.h>

diff --git a/include/linux/time.h b/include/linux/time.h
index 8ea8dea..936b21b 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -109,7 +109,7 @@ extern void do_gettimeofday(struct timeval *tv);
extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
-extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
+extern long do_utimes(int dfd, char __user *filename, struct timespec *times);
struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
struct itimerval *ovalue);