* [PATCH] netconsole: don't call __netpoll_cleanup() while atomic
@ 2013-03-11 10:21 Veaceslav Falico
2013-03-11 11:38 ` Neil Horman
0 siblings, 1 reply; 3+ messages in thread
From: Veaceslav Falico @ 2013-03-11 10:21 UTC (permalink / raw)
To: netdev; +Cc: amwang, davem, vfalico, nhorman
__netpoll_cleanup() is called in netconsole_netdev_event() while holding a
spinlock. Release/acquire the spinlock before/after it and restart the
loop. Also, disable the netconsole completely, because we won't have chance
after the restart of the loop, and might end up in a situation where
nt->enabled == 1 and nt->np.dev == NULL.
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
---
drivers/net/netconsole.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 37add21..59ac143 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -666,6 +666,7 @@ static int netconsole_netdev_event(struct notifier_block *this,
goto done;
spin_lock_irqsave(&target_list_lock, flags);
+restart:
list_for_each_entry(nt, &target_list, list) {
netconsole_target_get(nt);
if (nt->np.dev == dev) {
@@ -678,15 +679,17 @@ static int netconsole_netdev_event(struct notifier_block *this,
case NETDEV_UNREGISTER:
/*
* rtnl_lock already held
+ * we might sleep in __netpoll_cleanup()
*/
- if (nt->np.dev) {
- __netpoll_cleanup(&nt->np);
- dev_put(nt->np.dev);
- nt->np.dev = NULL;
- }
+ spin_unlock_irqrestore(&target_list_lock, flags);
+ __netpoll_cleanup(&nt->np);
+ spin_lock_irqsave(&target_list_lock, flags);
+ dev_put(nt->np.dev);
+ nt->np.dev = NULL;
nt->enabled = 0;
stopped = true;
- break;
+ netconsole_target_put(nt);
+ goto restart;
}
}
netconsole_target_put(nt);
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] netconsole: don't call __netpoll_cleanup() while atomic
2013-03-11 10:21 [PATCH] netconsole: don't call __netpoll_cleanup() while atomic Veaceslav Falico
@ 2013-03-11 11:38 ` Neil Horman
2013-03-12 10:59 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Neil Horman @ 2013-03-11 11:38 UTC (permalink / raw)
To: Veaceslav Falico; +Cc: netdev, amwang, davem
On Mon, Mar 11, 2013 at 11:21:48AM +0100, Veaceslav Falico wrote:
> __netpoll_cleanup() is called in netconsole_netdev_event() while holding a
> spinlock. Release/acquire the spinlock before/after it and restart the
> loop. Also, disable the netconsole completely, because we won't have chance
> after the restart of the loop, and might end up in a situation where
> nt->enabled == 1 and nt->np.dev == NULL.
>
> Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
> ---
> drivers/net/netconsole.c | 15 +++++++++------
> 1 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index 37add21..59ac143 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -666,6 +666,7 @@ static int netconsole_netdev_event(struct notifier_block *this,
> goto done;
>
> spin_lock_irqsave(&target_list_lock, flags);
> +restart:
> list_for_each_entry(nt, &target_list, list) {
> netconsole_target_get(nt);
> if (nt->np.dev == dev) {
> @@ -678,15 +679,17 @@ static int netconsole_netdev_event(struct notifier_block *this,
> case NETDEV_UNREGISTER:
> /*
> * rtnl_lock already held
> + * we might sleep in __netpoll_cleanup()
> */
> - if (nt->np.dev) {
> - __netpoll_cleanup(&nt->np);
> - dev_put(nt->np.dev);
> - nt->np.dev = NULL;
> - }
> + spin_unlock_irqrestore(&target_list_lock, flags);
> + __netpoll_cleanup(&nt->np);
> + spin_lock_irqsave(&target_list_lock, flags);
> + dev_put(nt->np.dev);
> + nt->np.dev = NULL;
> nt->enabled = 0;
> stopped = true;
> - break;
> + netconsole_target_put(nt);
> + goto restart;
> }
> }
> netconsole_target_put(nt);
> --
> 1.7.1
>
>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] netconsole: don't call __netpoll_cleanup() while atomic
2013-03-11 11:38 ` Neil Horman
@ 2013-03-12 10:59 ` David Miller
0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2013-03-12 10:59 UTC (permalink / raw)
To: nhorman; +Cc: vfalico, netdev, amwang
From: Neil Horman <nhorman@tuxdriver.com>
Date: Mon, 11 Mar 2013 07:38:56 -0400
> On Mon, Mar 11, 2013 at 11:21:48AM +0100, Veaceslav Falico wrote:
>> __netpoll_cleanup() is called in netconsole_netdev_event() while holding a
>> spinlock. Release/acquire the spinlock before/after it and restart the
>> loop. Also, disable the netconsole completely, because we won't have chance
>> after the restart of the loop, and might end up in a situation where
>> nt->enabled == 1 and nt->np.dev == NULL.
>>
>> Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
...
> Acked-by: Neil Horman <nhorman@tuxdriver.com>
Applied.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-03-12 10:59 UTC | newest]
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2013-03-11 10:21 [PATCH] netconsole: don't call __netpoll_cleanup() while atomic Veaceslav Falico
2013-03-11 11:38 ` Neil Horman
2013-03-12 10:59 ` David Miller
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