diff options
| author | Salah Triki | 2015-10-04 03:49:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2015-10-04 10:30:14 +0200 |
| commit | 51abf45c23872df0a43dbe849eb4439ebda6145f (patch) | |
| tree | b89016372e4bbc02e242fbe238181702fc29a2ca /drivers/staging/dgnc | |
| parent | staging: dgnc: remove dgnc_init_globals function (diff) | |
| download | kernel-qcow2-linux-51abf45c23872df0a43dbe849eb4439ebda6145f.tar.gz kernel-qcow2-linux-51abf45c23872df0a43dbe849eb4439ebda6145f.tar.xz kernel-qcow2-linux-51abf45c23872df0a43dbe849eb4439ebda6145f.zip | |
staging: dgnc: take a lock when storing value in dgnc_poll_tick
Reads of dgnc_poll_tick are protected by dgnc_poll_lock spinlock, but the write
to dgnc_poll_tick is not. It could theoretically race.
Signed-off-by: Salah Triki <salah.triki@acm.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/dgnc')
| -rw-r--r-- | drivers/staging/dgnc/dgnc_driver.c | 2 | ||||
| -rw-r--r-- | drivers/staging/dgnc/dgnc_driver.h | 1 | ||||
| -rw-r--r-- | drivers/staging/dgnc/dgnc_sysfs.c | 9 |
3 files changed, 10 insertions, 2 deletions
diff --git a/drivers/staging/dgnc/dgnc_driver.c b/drivers/staging/dgnc/dgnc_driver.c index ae81a8b1184e..ce2d1c7ed29e 100644 --- a/drivers/staging/dgnc/dgnc_driver.c +++ b/drivers/staging/dgnc/dgnc_driver.c @@ -63,6 +63,7 @@ static const struct file_operations dgnc_BoardFops = { uint dgnc_NumBoards; struct dgnc_board *dgnc_Board[MAXBOARDS]; DEFINE_SPINLOCK(dgnc_global_lock); +DEFINE_SPINLOCK(dgnc_poll_lock); /* Poll scheduling lock */ uint dgnc_Major; int dgnc_poll_tick = 20; /* Poll interval - 20 ms */ @@ -74,7 +75,6 @@ static struct class *dgnc_class; /* * Poller stuff */ -static DEFINE_SPINLOCK(dgnc_poll_lock); /* Poll scheduling lock */ static ulong dgnc_poll_time; /* Time of next poll */ static uint dgnc_poll_stop; /* Used to tell poller to stop */ static struct timer_list dgnc_poll_timer; diff --git a/drivers/staging/dgnc/dgnc_driver.h b/drivers/staging/dgnc/dgnc_driver.h index 06ece5151fe4..c61884c14777 100644 --- a/drivers/staging/dgnc/dgnc_driver.h +++ b/drivers/staging/dgnc/dgnc_driver.h @@ -390,6 +390,7 @@ struct channel_t { extern uint dgnc_Major; /* Our driver/mgmt major */ extern int dgnc_poll_tick; /* Poll interval - 20 ms */ extern spinlock_t dgnc_global_lock; /* Driver global spinlock */ +extern spinlock_t dgnc_poll_lock; /* Poll scheduling lock */ extern uint dgnc_NumBoards; /* Total number of boards */ extern struct dgnc_board *dgnc_Board[MAXBOARDS]; /* Array of board structs */ diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c index 44db8703eba4..48b605678c32 100644 --- a/drivers/staging/dgnc/dgnc_sysfs.c +++ b/drivers/staging/dgnc/dgnc_sysfs.c @@ -56,11 +56,18 @@ static ssize_t dgnc_driver_pollrate_show(struct device_driver *ddp, char *buf) static ssize_t dgnc_driver_pollrate_store(struct device_driver *ddp, const char *buf, size_t count) { + unsigned long flags; + int tick; int ret; - ret = sscanf(buf, "%d\n", &dgnc_poll_tick); + ret = sscanf(buf, "%d\n", &tick); if (ret != 1) return -EINVAL; + + spin_lock_irqsave(&dgnc_poll_lock, flags); + dgnc_poll_tick = tick; + spin_unlock_irqrestore(&dgnc_poll_lock, flags); + return count; } static DRIVER_ATTR(pollrate, (S_IRUSR | S_IWUSR), dgnc_driver_pollrate_show, |