diff mbox

mISDN: Fix wrong usage of flush_work_sync while holding locks

Message ID 1347546980-15923-1-git-send-email-keil@b1-systems.de
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Karsten Keil Sept. 13, 2012, 2:36 p.m. UTC
It is a bad idea to hold a spinlock and call flush_work_sync.
Move the workqueue cleanup outside the spinlock and use cancel_work_sync,
on closing the channel this seems to be the more correct function.
Remove the never used and constant return value of mISDN_freebchannel.

Signed-off-by: Karsten Keil <keil@b1-systems.de>
Cc: <stable@kernel.org>
---
 drivers/isdn/hardware/mISDN/avmfritz.c  |    3 ++-
 drivers/isdn/hardware/mISDN/mISDNipac.c |    3 ++-
 drivers/isdn/hardware/mISDN/mISDNisar.c |    3 ++-
 drivers/isdn/hardware/mISDN/netjet.c    |    3 ++-
 drivers/isdn/hardware/mISDN/w6692.c     |    3 ++-
 drivers/isdn/mISDN/hwchannel.c          |    9 ++++-----
 include/linux/mISDNhw.h                 |    2 +-
 7 files changed, 15 insertions(+), 11 deletions(-)

Comments

David Miller Sept. 13, 2012, 6:59 p.m. UTC | #1
From: Karsten Keil <keil@b1-systems.de>
Date: Thu, 13 Sep 2012 16:36:20 +0200

> It is a bad idea to hold a spinlock and call flush_work_sync.
> Move the workqueue cleanup outside the spinlock and use cancel_work_sync,
> on closing the channel this seems to be the more correct function.
> Remove the never used and constant return value of mISDN_freebchannel.
> 
> Signed-off-by: Karsten Keil <keil@b1-systems.de>
> Cc: <stable@kernel.org>

Applied, thanks.
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David Miller Sept. 13, 2012, 7:06 p.m. UTC | #2
From: David Miller <davem@davemloft.net>
Date: Thu, 13 Sep 2012 14:59:37 -0400 (EDT)

> From: Karsten Keil <keil@b1-systems.de>
> Date: Thu, 13 Sep 2012 16:36:20 +0200
> 
>> It is a bad idea to hold a spinlock and call flush_work_sync.
>> Move the workqueue cleanup outside the spinlock and use cancel_work_sync,
>> on closing the channel this seems to be the more correct function.
>> Remove the never used and constant return value of mISDN_freebchannel.
>> 
>> Signed-off-by: Karsten Keil <keil@b1-systems.de>
>> Cc: <stable@kernel.org>
> 
> Applied, thanks.

BTW, about -stable:

1) Even if it were appropriate to submit this directly to -stable,
   stable@kernel.org is not the correct email address and you must
   have seen the bounce produced by trying to send email there.

   Rather, stable@vger.kernel.org is the correct address.

2) I queue up and submit networking bug fixes for -stable myself so
   you should not submit them directly but rather make a request that
   I add your patch to my networking -stable queue.

Thanks.
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Karsten Keil Sept. 13, 2012, 7:50 p.m. UTC | #3
Am 13.09.2012 21:06, schrieb David Miller:
> From: David Miller <davem@davemloft.net>
> Date: Thu, 13 Sep 2012 14:59:37 -0400 (EDT)
> 
>> From: Karsten Keil <keil@b1-systems.de>
>> Date: Thu, 13 Sep 2012 16:36:20 +0200
>>
>>> It is a bad idea to hold a spinlock and call flush_work_sync.
>>> Move the workqueue cleanup outside the spinlock and use cancel_work_sync,
>>> on closing the channel this seems to be the more correct function.
>>> Remove the never used and constant return value of mISDN_freebchannel.
>>>
>>> Signed-off-by: Karsten Keil <keil@b1-systems.de>
>>> Cc: <stable@kernel.org>
>>
>> Applied, thanks.
> 
> BTW, about -stable:
> 
> 1) Even if it were appropriate to submit this directly to -stable,
>    stable@kernel.org is not the correct email address and you must
>    have seen the bounce produced by trying to send email there.
> 
>    Rather, stable@vger.kernel.org is the correct address.
> 
> 2) I queue up and submit networking bug fixes for -stable myself so
>    you should not submit them directly but rather make a request that
>    I add your patch to my networking -stable queue.
> 

OK, then I will put something like, "Should be considered for stable
too" in the comment and do not add the CC: stable@vger.kernel.org
for the next time.

Thanks.

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diff mbox

Patch

diff --git a/drivers/isdn/hardware/mISDN/avmfritz.c b/drivers/isdn/hardware/mISDN/avmfritz.c
index fa6ca47..dceaec8 100644
--- a/drivers/isdn/hardware/mISDN/avmfritz.c
+++ b/drivers/isdn/hardware/mISDN/avmfritz.c
@@ -857,8 +857,9 @@  avm_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	switch (cmd) {
 	case CLOSE_CHANNEL:
 		test_and_clear_bit(FLG_OPEN, &bch->Flags);
+		cancel_work_sync(&bch->workq);
 		spin_lock_irqsave(&fc->lock, flags);
-		mISDN_freebchannel(bch);
+		mISDN_clear_bchannel(bch);
 		modehdlc(bch, ISDN_P_NONE);
 		spin_unlock_irqrestore(&fc->lock, flags);
 		ch->protocol = ISDN_P_NONE;
diff --git a/drivers/isdn/hardware/mISDN/mISDNipac.c b/drivers/isdn/hardware/mISDN/mISDNipac.c
index 752e082..ccd7d85 100644
--- a/drivers/isdn/hardware/mISDN/mISDNipac.c
+++ b/drivers/isdn/hardware/mISDN/mISDNipac.c
@@ -1406,8 +1406,9 @@  hscx_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	switch (cmd) {
 	case CLOSE_CHANNEL:
 		test_and_clear_bit(FLG_OPEN, &bch->Flags);
+		cancel_work_sync(&bch->workq);
 		spin_lock_irqsave(hx->ip->hwlock, flags);
-		mISDN_freebchannel(bch);
+		mISDN_clear_bchannel(bch);
 		hscx_mode(hx, ISDN_P_NONE);
 		spin_unlock_irqrestore(hx->ip->hwlock, flags);
 		ch->protocol = ISDN_P_NONE;
diff --git a/drivers/isdn/hardware/mISDN/mISDNisar.c b/drivers/isdn/hardware/mISDN/mISDNisar.c
index be5973d..182ecf0 100644
--- a/drivers/isdn/hardware/mISDN/mISDNisar.c
+++ b/drivers/isdn/hardware/mISDN/mISDNisar.c
@@ -1588,8 +1588,9 @@  isar_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	switch (cmd) {
 	case CLOSE_CHANNEL:
 		test_and_clear_bit(FLG_OPEN, &bch->Flags);
+		cancel_work_sync(&bch->workq);
 		spin_lock_irqsave(ich->is->hwlock, flags);
-		mISDN_freebchannel(bch);
+		mISDN_clear_bchannel(bch);
 		modeisar(ich, ISDN_P_NONE);
 		spin_unlock_irqrestore(ich->is->hwlock, flags);
 		ch->protocol = ISDN_P_NONE;
diff --git a/drivers/isdn/hardware/mISDN/netjet.c b/drivers/isdn/hardware/mISDN/netjet.c
index c3e3e76..9bcade5 100644
--- a/drivers/isdn/hardware/mISDN/netjet.c
+++ b/drivers/isdn/hardware/mISDN/netjet.c
@@ -812,8 +812,9 @@  nj_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	switch (cmd) {
 	case CLOSE_CHANNEL:
 		test_and_clear_bit(FLG_OPEN, &bch->Flags);
+		cancel_work_sync(&bch->workq);
 		spin_lock_irqsave(&card->lock, flags);
-		mISDN_freebchannel(bch);
+		mISDN_clear_bchannel(bch);
 		mode_tiger(bc, ISDN_P_NONE);
 		spin_unlock_irqrestore(&card->lock, flags);
 		ch->protocol = ISDN_P_NONE;
diff --git a/drivers/isdn/hardware/mISDN/w6692.c b/drivers/isdn/hardware/mISDN/w6692.c
index 26a86b8..335fe64 100644
--- a/drivers/isdn/hardware/mISDN/w6692.c
+++ b/drivers/isdn/hardware/mISDN/w6692.c
@@ -1054,8 +1054,9 @@  w6692_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	switch (cmd) {
 	case CLOSE_CHANNEL:
 		test_and_clear_bit(FLG_OPEN, &bch->Flags);
+		cancel_work_sync(&bch->workq);
 		spin_lock_irqsave(&card->lock, flags);
-		mISDN_freebchannel(bch);
+		mISDN_clear_bchannel(bch);
 		w6692_mode(bc, ISDN_P_NONE);
 		spin_unlock_irqrestore(&card->lock, flags);
 		ch->protocol = ISDN_P_NONE;
diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c
index ef34fd4..2602be2 100644
--- a/drivers/isdn/mISDN/hwchannel.c
+++ b/drivers/isdn/mISDN/hwchannel.c
@@ -148,17 +148,16 @@  mISDN_clear_bchannel(struct bchannel *ch)
 	ch->next_minlen = ch->init_minlen;
 	ch->maxlen = ch->init_maxlen;
 	ch->next_maxlen = ch->init_maxlen;
+	skb_queue_purge(&ch->rqueue);
+	ch->rcount = 0;
 }
 EXPORT_SYMBOL(mISDN_clear_bchannel);
 
-int
+void
 mISDN_freebchannel(struct bchannel *ch)
 {
+	cancel_work_sync(&ch->workq);
 	mISDN_clear_bchannel(ch);
-	skb_queue_purge(&ch->rqueue);
-	ch->rcount = 0;
-	flush_work_sync(&ch->workq);
-	return 0;
 }
 EXPORT_SYMBOL(mISDN_freebchannel);
 
diff --git a/include/linux/mISDNhw.h b/include/linux/mISDNhw.h
index d0752ec..9d96d5d 100644
--- a/include/linux/mISDNhw.h
+++ b/include/linux/mISDNhw.h
@@ -183,7 +183,7 @@  extern int	mISDN_initbchannel(struct bchannel *, unsigned short,
 				   unsigned short);
 extern int	mISDN_freedchannel(struct dchannel *);
 extern void	mISDN_clear_bchannel(struct bchannel *);
-extern int	mISDN_freebchannel(struct bchannel *);
+extern void	mISDN_freebchannel(struct bchannel *);
 extern int	mISDN_ctrl_bchannel(struct bchannel *, struct mISDN_ctrl_req *);
 extern void	queue_ch_frame(struct mISDNchannel *, u_int,
 			int, struct sk_buff *);