compat: Get rid of (get|put)_compat_time(val|spec)

We have two APIs for compatiblity timespec/val, with confusingly
similar names.  compat_(get|put)_time(val|spec) *do* handle the case
where COMPAT_USE_64BIT_TIME is set, whereas
(get|put)_compat_time(val|spec) do not.  This is an accident waiting
to happen.

Clean it up by favoring the full-service version; the limited version
is replaced with double-underscore versions static to kernel/compat.c.

A common pattern is to convert a struct timespec to kernel format in
an allocation on the user stack.  Unfortunately it is open-coded in
several places.  Since this allocation isn't actually needed if
COMPAT_USE_64BIT_TIME is true (since user format == kernel format)
encapsulate that whole pattern into the function
compat_convert_timespec().  An equivalent function should be written
for struct timeval if it is needed in the future.

Finally, get rid of compat_(get|put)_timeval_convert(): each was only
used once, and the latter was not even doing what the function said
(no conversion actually was being done.)  Moving the conversion into
compat_sys_settimeofday() itself makes the code much more similar to
sys_settimeofday() itself.

v3: Remove unused compat_convert_timeval().

v2: Drop bogus "const" in the destination argument for
    compat_convert_time*().

Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Tested-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 8f7a6a454a4ca72460ac7e3c793a8115c94ea66d..6191968db8fa6c0458996ce394e324ba2427c4f6 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -733,7 +733,7 @@ static int put_v4l2_event32(struct v4l2_event *kp, struct v4l2_event32 __user *u
                copy_to_user(&up->u, &kp->u, sizeof(kp->u)) ||
                put_user(kp->pending, &up->pending) ||
                put_user(kp->sequence, &up->sequence) ||
-               put_compat_timespec(&kp->timestamp, &up->timestamp) ||
+               compat_put_timespec(&kp->timestamp, &up->timestamp) ||
                put_user(kp->id, &up->id) ||
                copy_to_user(up->reserved, kp->reserved, 8 * sizeof(__u32)))
                        return -EFAULT;

diff --git a/fs/compat.c b/fs/compat.c
index 6af20de2c1a3c29d5cc7c251d8fb3fa2182de445..62092f43375905d15cbdd84eb81387db13e3f8e4 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -92,8 +92,8 @@ asmlinkage long compat_sys_utimensat(unsigned int dfd, const char __user *filena
        struct timespec tv[2];
 
        if  (t) {
-               if (get_compat_timespec(&tv[0], &t[0]) ||
-                   get_compat_timespec(&tv[1], &t[1]))
+               if (compat_get_timespec(&tv[0], &t[0]) ||
+                   compat_get_timespec(&tv[1], &t[1]))
                        return -EFAULT;
 
                if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
@@ -512,7 +512,7 @@ compat_sys_io_getevents(aio_context_t ctx_id,
                                nr * sizeof(struct io_event))))
                goto out;
        if (timeout) {
-               if (get_compat_timespec(&t, timeout))
+               if (compat_get_timespec(&t, timeout))
                        goto out;
 
                ut = compat_alloc_user_space(sizeof(*ut));

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 3f448c65511b525ae9d92c38d7201f087b568334..f7d5bc0a239fd1c5d1e21320e9c3dec7cf44da6d 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -140,27 +140,24 @@ struct compat_sigaction {
        compat_sigset_t                 sa_mask __packed;
 };
 
-/*
- * These functions operate strictly on struct compat_time*
- */
-extern int get_compat_timespec(struct timespec *,
-                              const struct compat_timespec __user *);
-extern int put_compat_timespec(const struct timespec *,
-                              struct compat_timespec __user *);
-extern int get_compat_timeval(struct timeval *,
-                             const struct compat_timeval __user *);
-extern int put_compat_timeval(const struct timeval *,
-                             struct compat_timeval __user *);
 /*
  * These functions operate on 32- or 64-bit specs depending on
- * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments and the
- * naming as compat_get/put_ rather than get/put_compat_.
+ * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments.
  */
 extern int compat_get_timespec(struct timespec *, const void __user *);
 extern int compat_put_timespec(const struct timespec *, void __user *);
 extern int compat_get_timeval(struct timeval *, const void __user *);
 extern int compat_put_timeval(const struct timeval *, void __user *);
 
+/*
+ * This function convert a timespec if necessary and returns a *user
+ * space* pointer.  If no conversion is necessary, it returns the
+ * initial pointer.  NULL is a legitimate argument and will always
+ * output NULL.
+ */
+extern int compat_convert_timespec(struct timespec __user **,
+                                  const void __user *);
+
 struct compat_iovec {
        compat_uptr_t   iov_base;
        compat_size_t   iov_len;

diff --git a/ipc/compat.c b/ipc/compat.c
index f486b0096a67f32fe453cca13b40ad6268a76d45..1048522479e556b421be164b96a18f9370464764 100644 (file)
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -752,14 +752,8 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
 long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
                unsigned nsops, const struct compat_timespec __user *timeout)
 {
-       struct timespec __user *ts64 = NULL;
-       if (timeout) {
-               struct timespec ts;
-               ts64 = compat_alloc_user_space(sizeof(*ts64));
-               if (get_compat_timespec(&ts, timeout))
-                       return -EFAULT;
-               if (copy_to_user(ts64, &ts, sizeof(ts)))
-                       return -EFAULT;
-       }
+       struct timespec __user *ts64;
+       if (compat_convert_timespec(&ts64, timeout))
+               return -EFAULT;
        return sys_semtimedop(semid, tsems, nsops, ts64);
 }

diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c
index 63d7c6de335bd3b4878f8f2cf65d1d9e3f7e9474..a9cf16378d7a6438e685fe6473daf879b88ba35d 100644 (file)
--- a/ipc/compat_mq.c
+++ b/ipc/compat_mq.c
@@ -64,20 +64,6 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name,
        return sys_mq_open(u_name, oflag, mode, p);
 }
 
-static int compat_prepare_timeout(struct timespec __user **p,
-                                 const struct compat_timespec __user *u)
-{
-       struct timespec ts;
-       if (!u) {
-               *p = NULL;
-               return 0;
-       }
-       *p = compat_alloc_user_space(sizeof(ts));
-       if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
-               return -EFAULT;
-       return 0;
-}
-
 asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
                        const char __user *u_msg_ptr,
                        size_t msg_len, unsigned int msg_prio,
@@ -85,7 +71,7 @@ asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
 {
        struct timespec __user *u_ts;
 
-       if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+       if (compat_convert_timespec(&u_ts, u_abs_timeout))
                return -EFAULT;
 
        return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
@@ -98,7 +84,8 @@ asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
                        const struct compat_timespec __user *u_abs_timeout)
 {
        struct timespec __user *u_ts;
-       if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+
+       if (compat_convert_timespec(&u_ts, u_abs_timeout))
                return -EFAULT;
 
        return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,

diff --git a/kernel/compat.c b/kernel/compat.c
index 0a09e481b70b6e97519841f2eebf57da2e02d851..3afc524a57ad301e3391d35db9205af8825611d8 100644 (file)
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -30,28 +30,6 @@
 
 #include <asm/uaccess.h>
 
-/*
- * Get/set struct timeval with struct timespec on the native side
- */
-static int compat_get_timeval_convert(struct timespec *o,
-                                     struct compat_timeval __user *i)
-{
-       long usec;
-
-       if (get_user(o->tv_sec, &i->tv_sec) ||
-           get_user(usec, &i->tv_usec))
-               return -EFAULT;
-       o->tv_nsec = usec * 1000;
-       return 0;
-}
-
-static int compat_put_timeval_convert(struct compat_timeval __user *o,
-                                     struct timeval *i)
-{
-       return (put_user(i->tv_sec, &o->tv_sec) ||
-               put_user(i->tv_usec, &o->tv_usec)) ? -EFAULT : 0;
-}
-
 static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp)
 {
        memset(txc, 0, sizeof(struct timex));
@@ -116,7 +94,7 @@ asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv,
        if (tv) {
                struct timeval ktv;
                do_gettimeofday(&ktv);
-               if (compat_put_timeval_convert(tv, &ktv))
+               if (compat_put_timeval(&ktv, tv))
                        return -EFAULT;
        }
        if (tz) {
@@ -130,59 +108,58 @@ asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv,
 asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv,
                struct timezone __user *tz)
 {
-       struct timespec kts;
-       struct timezone ktz;
+       struct timeval user_tv;
+       struct timespec new_ts;
+       struct timezone new_tz;
 
        if (tv) {
-               if (compat_get_timeval_convert(&kts, tv))
+               if (compat_get_timeval(&user_tv, tv))
                        return -EFAULT;
+               new_ts.tv_sec = user_tv.tv_sec;
+               new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
        }
        if (tz) {
-               if (copy_from_user(&ktz, tz, sizeof(ktz)))
+               if (copy_from_user(&new_tz, tz, sizeof(*tz)))
                        return -EFAULT;
        }
 
-       return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
+       return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
 }
 
-int get_compat_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
+static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
 {
        return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
                        __get_user(tv->tv_sec, &ctv->tv_sec) ||
                        __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
 }
-EXPORT_SYMBOL_GPL(get_compat_timeval);
 
-int put_compat_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
+static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
 {
        return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
                        __put_user(tv->tv_sec, &ctv->tv_sec) ||
                        __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
 }
-EXPORT_SYMBOL_GPL(put_compat_timeval);
 
-int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
+static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
 {
        return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
                        __get_user(ts->tv_sec, &cts->tv_sec) ||
                        __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
 }
-EXPORT_SYMBOL_GPL(get_compat_timespec);
 
-int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
+static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
 {
        return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
                        __put_user(ts->tv_sec, &cts->tv_sec) ||
                        __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
 }
-EXPORT_SYMBOL_GPL(put_compat_timespec);
 
 int compat_get_timeval(struct timeval *tv, const void __user *utv)
 {
        if (COMPAT_USE_64BIT_TIME)
                return copy_from_user(tv, utv, sizeof *tv) ? -EFAULT : 0;
        else
-               return get_compat_timeval(tv, utv);
+               return __compat_get_timeval(tv, utv);
 }
 EXPORT_SYMBOL_GPL(compat_get_timeval);
 
@@ -191,7 +168,7 @@ int compat_put_timeval(const struct timeval *tv, void __user *utv)
        if (COMPAT_USE_64BIT_TIME)
                return copy_to_user(utv, tv, sizeof *tv) ? -EFAULT : 0;
        else
-               return put_compat_timeval(tv, utv);
+               return __compat_put_timeval(tv, utv);
 }
 EXPORT_SYMBOL_GPL(compat_put_timeval);
 
@@ -200,7 +177,7 @@ int compat_get_timespec(struct timespec *ts, const void __user *uts)
        if (COMPAT_USE_64BIT_TIME)
                return copy_from_user(ts, uts, sizeof *ts) ? -EFAULT : 0;
        else
-               return get_compat_timespec(ts, uts);
+               return __compat_get_timespec(ts, uts);
 }
 EXPORT_SYMBOL_GPL(compat_get_timespec);
 
@@ -209,10 +186,33 @@ int compat_put_timespec(const struct timespec *ts, void __user *uts)
        if (COMPAT_USE_64BIT_TIME)
                return copy_to_user(uts, ts, sizeof *ts) ? -EFAULT : 0;
        else
-               return put_compat_timespec(ts, uts);
+               return __compat_put_timespec(ts, uts);
 }
 EXPORT_SYMBOL_GPL(compat_put_timespec);
 
+int compat_convert_timespec(struct timespec __user **kts,
+                           const void __user *cts)
+{
+       struct timespec ts;
+       struct timespec __user *uts;
+
+       if (!cts || COMPAT_USE_64BIT_TIME) {
+               *kts = (struct timespec __user *)cts;
+               return 0;
+       }
+
+       uts = compat_alloc_user_space(sizeof(ts));
+       if (!uts)
+               return -EFAULT;
+       if (compat_get_timespec(&ts, cts))
+               return -EFAULT;
+       if (copy_to_user(uts, &ts, sizeof(ts)))
+               return -EFAULT;
+
+       *kts = uts;
+       return 0;
+}
+
 static long compat_nanosleep_restart(struct restart_block *restart)
 {
        struct compat_timespec __user *rmtp;
@@ -229,7 +229,7 @@ static long compat_nanosleep_restart(struct restart_block *restart)
        if (ret) {
                rmtp = restart->nanosleep.compat_rmtp;
 
-               if (rmtp && put_compat_timespec(&rmt, rmtp))
+               if (rmtp && compat_put_timespec(&rmt, rmtp))
                        return -EFAULT;
        }
 
@@ -243,7 +243,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
        mm_segment_t oldfs;
        long ret;
 
-       if (get_compat_timespec(&tu, rqtp))
+       if (compat_get_timespec(&tu, rqtp))
                return -EFAULT;
 
        if (!timespec_valid(&tu))
@@ -263,7 +263,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
                restart->fn = compat_nanosleep_restart;
                restart->nanosleep.compat_rmtp = rmtp;
 
-               if (rmtp && put_compat_timespec(&rmt, rmtp))
+               if (rmtp && compat_put_timespec(&rmt, rmtp))
                        return -EFAULT;
        }
 
@@ -647,8 +647,8 @@ asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
 int get_compat_itimerspec(struct itimerspec *dst,
                          const struct compat_itimerspec __user *src)
 {
-       if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
-           get_compat_timespec(&dst->it_value, &src->it_value))
+       if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
+           __compat_get_timespec(&dst->it_value, &src->it_value))
                return -EFAULT;
        return 0;
 }
@@ -656,8 +656,8 @@ int get_compat_itimerspec(struct itimerspec *dst,
 int put_compat_itimerspec(struct compat_itimerspec __user *dst,
                          const struct itimerspec *src)
 {
-       if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
-           put_compat_timespec(&src->it_value, &dst->it_value))
+       if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
+           __compat_put_timespec(&src->it_value, &dst->it_value))
                return -EFAULT;
        return 0;
 }
@@ -727,7 +727,7 @@ long compat_sys_clock_settime(clockid_t which_clock,
        mm_segment_t oldfs;
        struct timespec ts;
 
-       if (get_compat_timespec(&ts, tp))
+       if (compat_get_timespec(&ts, tp))
                return -EFAULT;
        oldfs = get_fs();
        set_fs(KERNEL_DS);
@@ -749,7 +749,7 @@ long compat_sys_clock_gettime(clockid_t which_clock,
        err = sys_clock_gettime(which_clock,
                                (struct timespec __user *) &ts);
        set_fs(oldfs);
-       if (!err && put_compat_timespec(&ts, tp))
+       if (!err && compat_put_timespec(&ts, tp))
                return -EFAULT;
        return err;
 }
@@ -789,7 +789,7 @@ long compat_sys_clock_getres(clockid_t which_clock,
        err = sys_clock_getres(which_clock,
                               (struct timespec __user *) &ts);
        set_fs(oldfs);
-       if (!err && tp && put_compat_timespec(&ts, tp))
+       if (!err && tp && compat_put_timespec(&ts, tp))
                return -EFAULT;
        return err;
 }
@@ -808,7 +808,7 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart)
        set_fs(oldfs);
 
        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
-           put_compat_timespec(&tu, rmtp))
+           compat_put_timespec(&tu, rmtp))
                return -EFAULT;
 
        if (err == -ERESTART_RESTARTBLOCK) {
@@ -827,7 +827,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
        struct timespec in, out;
        struct restart_block *restart;
 
-       if (get_compat_timespec(&in, rqtp))
+       if (compat_get_timespec(&in, rqtp))
                return -EFAULT;
 
        oldfs = get_fs();
@@ -838,7 +838,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
        set_fs(oldfs);
 
        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
-           put_compat_timespec(&out, rmtp))
+           compat_put_timespec(&out, rmtp))
                return -EFAULT;
 
        if (err == -ERESTART_RESTARTBLOCK) {
@@ -1130,7 +1130,7 @@ COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
        set_fs(KERNEL_DS);
        ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
        set_fs(old_fs);
-       if (put_compat_timespec(&t, interval))
+       if (compat_put_timespec(&t, interval))
                return -EFAULT;
        return ret;
 }

diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index f9f44fd4d34d443b1d7f28c3d5f3428b06aec614..55c8c9349cfe6db49b9443c7b4aefb378c6f0249 100644 (file)
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -183,7 +183,7 @@ COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
        if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
                      cmd == FUTEX_WAIT_BITSET ||
                      cmd == FUTEX_WAIT_REQUEUE_PI)) {
-               if (get_compat_timespec(&ts, utime))
+               if (compat_get_timespec(&ts, utime))
                        return -EFAULT;
                if (!timespec_valid(&ts))
                        return -EINVAL;