53 lines
2.4 KiB
Diff
53 lines
2.4 KiB
Diff
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From 19f0d787d8a3adfc16003456a2f6c30fb3852c8d Mon Sep 17 00:00:00 2001
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From: Grygorii Strashko <grygorii.strashko@ti.com>
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Date: Fri, 9 Oct 2015 09:25:49 -0500
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Subject: [PATCH 233/365] net/core/cpuhotplug: Drain input_pkt_queue lockless
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I can constantly see below error report with 4.1 RT-kernel on TI ARM dra7-evm
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if I'm trying to unplug cpu1:
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[ 57.737589] CPU1: shutdown
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[ 57.767537] BUG: spinlock bad magic on CPU#0, sh/137
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[ 57.767546] lock: 0xee994730, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
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[ 57.767552] CPU: 0 PID: 137 Comm: sh Not tainted 4.1.10-rt8-01700-g2c38702-dirty #55
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[ 57.767555] Hardware name: Generic DRA74X (Flattened Device Tree)
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[ 57.767568] [<c001acd0>] (unwind_backtrace) from [<c001534c>] (show_stack+0x20/0x24)
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[ 57.767579] [<c001534c>] (show_stack) from [<c075560c>] (dump_stack+0x84/0xa0)
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[ 57.767593] [<c075560c>] (dump_stack) from [<c00aca48>] (spin_dump+0x84/0xac)
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[ 57.767603] [<c00aca48>] (spin_dump) from [<c00acaa4>] (spin_bug+0x34/0x38)
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[ 57.767614] [<c00acaa4>] (spin_bug) from [<c00acc10>] (do_raw_spin_lock+0x168/0x1c0)
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[ 57.767624] [<c00acc10>] (do_raw_spin_lock) from [<c075b4cc>] (_raw_spin_lock+0x4c/0x54)
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[ 57.767631] [<c075b4cc>] (_raw_spin_lock) from [<c07599fc>] (rt_spin_lock_slowlock+0x5c/0x374)
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[ 57.767638] [<c07599fc>] (rt_spin_lock_slowlock) from [<c075bcf4>] (rt_spin_lock+0x38/0x70)
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[ 57.767649] [<c075bcf4>] (rt_spin_lock) from [<c06333c0>] (skb_dequeue+0x28/0x7c)
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[ 57.767662] [<c06333c0>] (skb_dequeue) from [<c06476ec>] (dev_cpu_callback+0x1b8/0x240)
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[ 57.767673] [<c06476ec>] (dev_cpu_callback) from [<c007566c>] (notifier_call_chain+0x3c/0xb4)
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The reason is that skb_dequeue is taking skb->lock, but RT changed the
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core code to use a raw spinlock. The non-raw lock is not initialized
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on purpose to catch exactly this kind of problem.
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Fixes: 91df05da13a6 'net: Use skbufhead with raw lock'
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Cc: stable-rt@vger.kernel.org
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---
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net/core/dev.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/net/core/dev.c b/net/core/dev.c
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index cc62279c2e1a..357d35cd2c54 100644
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--- a/net/core/dev.c
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+++ b/net/core/dev.c
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@@ -8135,7 +8135,7 @@ static int dev_cpu_callback(struct notifier_block *nfb,
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netif_rx_ni(skb);
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input_queue_head_incr(oldsd);
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}
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- while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
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+ while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
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netif_rx_ni(skb);
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input_queue_head_incr(oldsd);
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}
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--
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2.28.0
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