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authorArjan van de Ven <arjan@infradead.org>2006-07-03 00:24:07 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-03 15:26:58 -0700
commit6abd219c6eab92172038e4719e02905acb7b68d4 (patch)
treeb9ab0e856e1acf921f86baaebf14c5f34aa21371
parentb02454f43578b24bc8b8ab54a239156841f56f6d (diff)
[PATCH] bcm43xx: netlink deadlock fix
reported by Jure Repinc: > > http://bugzilla.kernel.org/show_bug.cgi?id=6773 > > checked out dmesg output and found the message > > > > ====================================================== > > [ BUG: hard-safe -> hard-unsafe lock order detected! ] > > ------------------------------------------------------ > > > > starting at line 660 of the dmesg.txt that I will attach. The patch below should fix the deadlock, albeit I suspect it's not the "right" fix; the right fix may well be to move the rx processing in bcm43xx to softirq context. [it's debatable, ipw2200 hit this exact same bug; at some point it's better to bite the bullet and move this to the common layer as my patch below does] Make the nl_table_lock irq-safe; it's taken for read in various netlink functions, including functions that several wireless drivers (ipw2200, bcm43xx) want to call from hardirq context. The deadlock was found by the lock validator. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: Michael Buesch <mb@bu3sch.de> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: Jeff Garzik <jeff@garzik.org> Acked-by: "David S. Miller" <davem@davemloft.net> Cc: jamal <hadi@cyberus.ca> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--net/netlink/af_netlink.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 70cee82a98b..55c0adc8f11 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -156,7 +156,7 @@ static void netlink_sock_destruct(struct sock *sk)
static void netlink_table_grab(void)
{
- write_lock_bh(&nl_table_lock);
+ write_lock_irq(&nl_table_lock);
if (atomic_read(&nl_table_users)) {
DECLARE_WAITQUEUE(wait, current);
@@ -166,9 +166,9 @@ static void netlink_table_grab(void)
set_current_state(TASK_UNINTERRUPTIBLE);
if (atomic_read(&nl_table_users) == 0)
break;
- write_unlock_bh(&nl_table_lock);
+ write_unlock_irq(&nl_table_lock);
schedule();
- write_lock_bh(&nl_table_lock);
+ write_lock_irq(&nl_table_lock);
}
__set_current_state(TASK_RUNNING);
@@ -178,7 +178,7 @@ static void netlink_table_grab(void)
static __inline__ void netlink_table_ungrab(void)
{
- write_unlock_bh(&nl_table_lock);
+ write_unlock_irq(&nl_table_lock);
wake_up(&nl_table_wait);
}