diff options
| author | Grygorii Strashko <grygorii.strashko@ti.com> | 2015-10-09 09:25:49 -0500 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-02-13 00:36:23 +0100 |
| commit | 0c0a810b74b499a564accfe6c30ab8c767b18262 (patch) | |
| tree | 9eae12497b107488ef8bc320775467e11cefc1d9 | |
| parent | f08162a016dad95303eef70b5ab9432ad082390e (diff) | |
| download | rt-linux-0c0a810b74b499a564accfe6c30ab8c767b18262.tar.gz | |
net/core/cpuhotplug: Drain input_pkt_queue lockless
I can constantly see below error report with 4.1 RT-kernel on TI ARM dra7-evm
if I'm trying to unplug cpu1:
[ 57.737589] CPU1: shutdown
[ 57.767537] BUG: spinlock bad magic on CPU#0, sh/137
[ 57.767546] lock: 0xee994730, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[ 57.767552] CPU: 0 PID: 137 Comm: sh Not tainted 4.1.10-rt8-01700-g2c38702-dirty #55
[ 57.767555] Hardware name: Generic DRA74X (Flattened Device Tree)
[ 57.767568] [<c001acd0>] (unwind_backtrace) from [<c001534c>] (show_stack+0x20/0x24)
[ 57.767579] [<c001534c>] (show_stack) from [<c075560c>] (dump_stack+0x84/0xa0)
[ 57.767593] [<c075560c>] (dump_stack) from [<c00aca48>] (spin_dump+0x84/0xac)
[ 57.767603] [<c00aca48>] (spin_dump) from [<c00acaa4>] (spin_bug+0x34/0x38)
[ 57.767614] [<c00acaa4>] (spin_bug) from [<c00acc10>] (do_raw_spin_lock+0x168/0x1c0)
[ 57.767624] [<c00acc10>] (do_raw_spin_lock) from [<c075b4cc>] (_raw_spin_lock+0x4c/0x54)
[ 57.767631] [<c075b4cc>] (_raw_spin_lock) from [<c07599fc>] (rt_spin_lock_slowlock+0x5c/0x374)
[ 57.767638] [<c07599fc>] (rt_spin_lock_slowlock) from [<c075bcf4>] (rt_spin_lock+0x38/0x70)
[ 57.767649] [<c075bcf4>] (rt_spin_lock) from [<c06333c0>] (skb_dequeue+0x28/0x7c)
[ 57.767662] [<c06333c0>] (skb_dequeue) from [<c06476ec>] (dev_cpu_callback+0x1b8/0x240)
[ 57.767673] [<c06476ec>] (dev_cpu_callback) from [<c007566c>] (notifier_call_chain+0x3c/0xb4)
The reason is that skb_dequeue is taking skb->lock, but RT changed the
core code to use a raw spinlock. The non-raw lock is not initialized
on purpose to catch exactly this kind of problem.
Fixes: 91df05da13a6 'net: Use skbufhead with raw lock'
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 95cd79cef65ae..c3246d24a3a5d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7468,7 +7468,7 @@ static int dev_cpu_callback(struct notifier_block *nfb, netif_rx_ni(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_ni(skb); input_queue_head_incr(oldsd); } |