The patch titled
fix soft lockup when removing netconsole module
has been added to the -mm tree. Its filename is
fix-soft-lockup-when-removing-netconsole-module.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: fix soft lockup when removing netconsole module
From: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
The netpoll_cleanup handler can hang the kernel if there is no work in the
work queue because a call to cancel_rearming_delayed_work() with no work
goes into an infinite loop.
The typical case where this is a problem is on removing a kernel module
such as the netconsole driver or kgdboe.
To maintain 80 column code, the function had to have one level of braces
dropped.
Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Cc: Stephen Hemminger <shemminger@xxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
net/core/netpoll.c | 36 +++++++++++++++++++-----------------
1 files changed, 19 insertions(+), 17 deletions(-)
diff -puN net/core/netpoll.c~fix-soft-lockup-when-removing-netconsole-module net/core/netpoll.c
--- a/net/core/netpoll.c~fix-soft-lockup-when-removing-netconsole-module
+++ a/net/core/netpoll.c
@@ -771,30 +771,32 @@ void netpoll_cleanup(struct netpoll *np)
struct netpoll_info *npinfo;
unsigned long flags;
- if (np->dev) {
- npinfo = np->dev->npinfo;
- if (npinfo) {
- if (npinfo->rx_np == np) {
- spin_lock_irqsave(&npinfo->rx_lock, flags);
- npinfo->rx_np = NULL;
- npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
- spin_unlock_irqrestore(&npinfo->rx_lock, flags);
- }
+ if (!np->dev)
+ return;
+
+ npinfo = np->dev->npinfo;
+ if (npinfo) {
+ if (npinfo->rx_np == np) {
+ spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_np = NULL;
+ npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
+ spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ }
- np->dev->npinfo = NULL;
- if (atomic_dec_and_test(&npinfo->refcnt)) {
- skb_queue_purge(&npinfo->arp_tx);
- skb_queue_purge(&npinfo->txq);
+ np->dev->npinfo = NULL;
+ if (atomic_dec_and_test(&npinfo->refcnt)) {
+ skb_queue_purge(&npinfo->arp_tx);
+ skb_queue_purge(&npinfo->txq);
+ if (delayed_work_pending(&npinfo->tx_work)) {
cancel_rearming_delayed_work(&npinfo->tx_work);
flush_scheduled_work();
-
- kfree(npinfo);
}
- }
- dev_put(np->dev);
+ kfree(npinfo);
+ }
}
+ dev_put(np->dev);
np->dev = NULL;
}
_
Patches currently in -mm which might be from jason.wessel@xxxxxxxxxxxxx are
fix-soft-lockup-when-removing-netconsole-module.patch
-
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