diff options
| author | Rodolfo Giometti <giometti@linux.it> | 2009-11-11 14:26:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-11-12 07:26:00 -0800 |
| commit | cbf83cc5a29dba480cf1ba1c5e3417a0d4a31410 (patch) | |
| tree | eb7757638e0a8e5509066eebec053a7bffe0138a | |
| parent | 69fd8d24673a8f4f8be5db7f84b5dc9e4ff354c8 (diff) | |
pps: locking scheme fix up for PPS_GETPARAMS
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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -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 fea17e7805e..ca5183bdad8 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; |