The patch titled
bcm43xx: netlink deadlock fix
has been removed from the -mm tree. Its filename is
bcm43xx-netlink-deadlock-fix.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: bcm43xx: netlink deadlock fix
From: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Michael Buesch <mb@xxxxxxxxx>
Cc: "John W. Linville" <linville@xxxxxxxxxxxxx>
Cc: Jeff Garzik <jeff@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: jamal <hadi@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
net/netlink/af_netlink.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff -puN net/netlink/af_netlink.c~bcm43xx-netlink-deadlock-fix net/netlink/af_netlink.c
--- a/net/netlink/af_netlink.c~bcm43xx-netlink-deadlock-fix
+++ a/net/netlink/af_netlink.c
@@ -156,7 +156,7 @@ static void netlink_sock_destruct(struct
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);
}
_
Patches currently in -mm which might be from arjan@xxxxxxxxxxxxx are
origin.patch
debug-shared-irqs.patch
vdso-print-fatal-signals.patch
vdso-improve-print_fatal_signals-support-by-adding-memory-maps.patch
-
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