Hello!
On 08/03/2017 02:33 PM, Anton Volkov wrote:
The synchronization type that was used earlier to guard the loop that
deletes unused log buffers may lead to a situation that prevents any
thread from going through the loop.
The patch deletes previously used synchronization mechanism and moves
the loop under the spin_lock so the similar cases won't be feasible in
the future.
Found by by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Anton Volkov <avol...@ispras.ru>
---
drivers/isdn/hysdn/hysdn_proclog.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/drivers/isdn/hysdn/hysdn_proclog.c
b/drivers/isdn/hysdn/hysdn_proclog.c
index 7b5fd8f..b152c6c 100644
--- a/drivers/isdn/hysdn/hysdn_proclog.c
+++ b/drivers/isdn/hysdn/hysdn_proclog.c
[...]
else
pd->log_tail->next = ib; /* follows existing messages */
pd->log_tail = ib; /* new tail */
- i = pd->del_lock++; /* get lock state */
- spin_unlock_irqrestore(&card->hysdn_lock, flags);
/* delete old entrys */
- if (!i)
- while (pd->log_head->next) {
- if ((pd->log_head->usage_cnt <= 0) &&
- (pd->log_head->next->usage_cnt <= 0)) {
- ib = pd->log_head;
- pd->log_head = pd->log_head->next;
- kfree(ib);
- } else
- break;
- } /* pd->log_head->next */
- pd->del_lock--; /* release lock level */
+ while (pd->log_head->next) {
+ if ((pd->log_head->usage_cnt <= 0) &&
+ (pd->log_head->next->usage_cnt <= 0)) {
+ ib = pd->log_head;
+ pd->log_head = pd->log_head->next;
+ kfree(ib);
+ } else
+ break;
+ } /* pd->log_head->next */
Need {} in the *else* branch as *if* had them.
[...]
MBR, Sergei
