3.18.27-rt26-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Grygorii Strashko <grygorii.strashko@xxxxxx> 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@xxxxxxxxxxxxx> Cc: stable-rt@xxxxxxxxxxxxxxx Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 48872718d8e2..39d2a0ba38ed 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7065,7 +7065,7 @@ static int dev_cpu_callback(struct notifier_block *nfb, netif_rx_internal(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_internal(skb); input_queue_head_incr(oldsd); } -- 2.7.0 -- To unsubscribe from this list: send the line "unsubscribe stable-rt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html