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Commit 81993e81 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

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: default avatarH.J. Lu <hjl.tools@gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 5cb480f6

drivers/media/v4l2-core/v4l2-compat-ioctl32.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

fs/compat.c

+3 −3
Original line number Diff line number Diff line
@@ -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));

include/linux/compat.h

+10 −13
Original line number Diff line number Diff line
@@ -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;

ipc/compat.c

+3 −9
Original line number Diff line number Diff line
@@ -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))

	struct timespec __user *ts64;

	if (compat_convert_timespec(&ts64, timeout))

		return -EFAULT;

		if (copy_to_user(ts64, &ts, sizeof(ts)))

			return -EFAULT;

	}

	return sys_semtimedop(semid, tsems, nsops, ts64);

}

ipc/compat_mq.c

+3 −16
Original line number Diff line number Diff line
@@ -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,