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authorKarsten Keil <kkeil@suse.de>2007-10-18 03:04:31 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-11-16 09:30:23 -0800
commit4b3c198a4b5d083eb84abb89fe30e32f562b2771 (patch)
tree43f70b917448ad5bdfb02f7b6d176f5bacb9b284
parentdd0775720aa07a7b1c6a59bdd0f5d04a773395a7 (diff)
downloadlwn-4b3c198a4b5d083eb84abb89fe30e32f562b2771.tar.gz
lwn-4b3c198a4b5d083eb84abb89fe30e32f562b2771.zip
i4l: fix random freezes with AVM B1 drivers
patch 9713d9e650045f7f2afd81d58a068827be306993 in mainline. This fix the same issue which was debbuged for the C4 controller for the B1 versions. The capilib_ function modify or traverse a linked list without locking. This patch extends the existing locking to the calls of these function to prevent access to a list which is in the middle of a modification. Signed-off-by: Karsten Keil <kkeil@suse.de> 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>
-rw-r--r--drivers/isdn/hardware/avm/b1.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/isdn/hardware/avm/b1.c b/drivers/isdn/hardware/avm/b1.c
index 7a69a18d07e2..4484a6417235 100644
--- a/drivers/isdn/hardware/avm/b1.c
+++ b/drivers/isdn/hardware/avm/b1.c
@@ -321,12 +321,15 @@ void b1_reset_ctr(struct capi_ctr *ctrl)
avmctrl_info *cinfo = (avmctrl_info *)(ctrl->driverdata);
avmcard *card = cinfo->card;
unsigned int port = card->port;
+ unsigned long flags;
b1_reset(port);
b1_reset(port);
memset(cinfo->version, 0, sizeof(cinfo->version));
+ spin_lock_irqsave(&card->lock, flags);
capilib_release(&cinfo->ncci_head);
+ spin_unlock_irqrestore(&card->lock, flags);
capi_ctr_reseted(ctrl);
}
@@ -361,9 +364,8 @@ void b1_release_appl(struct capi_ctr *ctrl, u16 appl)
unsigned int port = card->port;
unsigned long flags;
- capilib_release_appl(&cinfo->ncci_head, appl);
-
spin_lock_irqsave(&card->lock, flags);
+ capilib_release_appl(&cinfo->ncci_head, appl);
b1_put_byte(port, SEND_RELEASE);
b1_put_word(port, appl);
spin_unlock_irqrestore(&card->lock, flags);
@@ -380,27 +382,27 @@ u16 b1_send_message(struct capi_ctr *ctrl, struct sk_buff *skb)
u8 subcmd = CAPIMSG_SUBCOMMAND(skb->data);
u16 dlen, retval;
+ spin_lock_irqsave(&card->lock, flags);
if (CAPICMD(cmd, subcmd) == CAPI_DATA_B3_REQ) {
retval = capilib_data_b3_req(&cinfo->ncci_head,
CAPIMSG_APPID(skb->data),
CAPIMSG_NCCI(skb->data),
CAPIMSG_MSGID(skb->data));
- if (retval != CAPI_NOERROR)
+ if (retval != CAPI_NOERROR) {
+ spin_unlock_irqrestore(&card->lock, flags);
return retval;
+ }
dlen = CAPIMSG_DATALEN(skb->data);
- spin_lock_irqsave(&card->lock, flags);
b1_put_byte(port, SEND_DATA_B3_REQ);
b1_put_slice(port, skb->data, len);
b1_put_slice(port, skb->data + len, dlen);
- spin_unlock_irqrestore(&card->lock, flags);
} else {
- spin_lock_irqsave(&card->lock, flags);
b1_put_byte(port, SEND_MESSAGE);
b1_put_slice(port, skb->data, len);
- spin_unlock_irqrestore(&card->lock, flags);
}
+ spin_unlock_irqrestore(&card->lock, flags);
dev_kfree_skb_any(skb);
return CAPI_NOERROR;
@@ -534,17 +536,17 @@ irqreturn_t b1_interrupt(int interrupt, void *devptr)
ApplId = (unsigned) b1_get_word(card->port);
MsgLen = b1_get_slice(card->port, card->msgbuf);
- spin_unlock_irqrestore(&card->lock, flags);
if (!(skb = alloc_skb(MsgLen, GFP_ATOMIC))) {
printk(KERN_ERR "%s: incoming packet dropped\n",
card->name);
+ spin_unlock_irqrestore(&card->lock, flags);
} else {
memcpy(skb_put(skb, MsgLen), card->msgbuf, MsgLen);
if (CAPIMSG_CMD(skb->data) == CAPI_DATA_B3_CONF)
capilib_data_b3_conf(&cinfo->ncci_head, ApplId,
CAPIMSG_NCCI(skb->data),
CAPIMSG_MSGID(skb->data));
-
+ spin_unlock_irqrestore(&card->lock, flags);
capi_ctr_handle_message(ctrl, ApplId, skb);
}
break;
@@ -554,21 +556,17 @@ irqreturn_t b1_interrupt(int interrupt, void *devptr)
ApplId = b1_get_word(card->port);
NCCI = b1_get_word(card->port);
WindowSize = b1_get_word(card->port);
- spin_unlock_irqrestore(&card->lock, flags);
-
capilib_new_ncci(&cinfo->ncci_head, ApplId, NCCI, WindowSize);
-
+ spin_unlock_irqrestore(&card->lock, flags);
break;
case RECEIVE_FREE_NCCI:
ApplId = b1_get_word(card->port);
NCCI = b1_get_word(card->port);
- spin_unlock_irqrestore(&card->lock, flags);
-
if (NCCI != 0xffffffff)
capilib_free_ncci(&cinfo->ncci_head, ApplId, NCCI);
-
+ spin_unlock_irqrestore(&card->lock, flags);
break;
case RECEIVE_START: