diff options
| author | Rodolfo Giometti <giometti@linux.it> | 2009-11-11 14:26:52 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-08 10:21:18 -0800 |
| commit | 073493a20768a109ed1e6e744a2fe88e8bbd2fab (patch) | |
| tree | d391fccb7734d75862eb11c0d586e1546a5b4cda /drivers | |
| parent | f1d8f4d0822df5c5f06021d221658fe2ad25c0cb (diff) | |
pps: locking scheme fix up for PPS_GETPARAMS
commit cbf83cc5a29dba480cf1ba1c5e3417a0d4a31410 upstream.
Userland programs may read/write PPS parameters at same time and these
operations may corrupt PPS data.
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Tested-by: Reg Clemens <clemens@dwf.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pps/pps.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index fea17e7805e9..ca5183bdad85 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -71,9 +71,14 @@ static long pps_cdev_ioctl(struct file *file, case PPS_GETPARAMS: pr_debug("PPS_GETPARAMS: source %d\n", pps->id); - /* Return current parameters */ - err = copy_to_user(uarg, &pps->params, - sizeof(struct pps_kparams)); + spin_lock_irq(&pps->lock); + + /* Get the current parameters */ + params = pps->params; + + spin_unlock_irq(&pps->lock); + + err = copy_to_user(uarg, ¶ms, sizeof(struct pps_kparams)); if (err) return -EFAULT; |