forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

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

Browse source 
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>
This commit is contained in:
H. Peter Anvin 2014-02-01 18:54:11 -08:00
parent 5cb480f6b4
commit 81993e81a9
7 changed files with 75 additions and 97 deletions
Download patch file Download diff file Expand all files Collapse all files

12
ipc/compat.c
View file

@ -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);
}

19
ipc/compat_mq.c
View file

@ -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,