* [PATCH] mISDN: Fix a sleep-in-atomic bug
@ 2017-05-31 7:08 Jia-Ju Bai
2017-06-01 18:50 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Jia-Ju Bai @ 2017-05-31 7:08 UTC (permalink / raw)
To: isdn, mingo, fweisbec, geliangtang, akpm, davem, yamada.masahiro
Cc: netdev, linux-kernel, Jia-Ju Bai
The driver may sleep under a read spin lock, and the function call path is:
send_socklist (acquire the lock by read_lock)
skb_copy(GFP_KERNEL) --> may sleep
To fix it, the "GFP_KERNEL" is replaced with "GFP_ATOMIC".
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
drivers/isdn/mISDN/stack.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/isdn/mISDN/stack.c b/drivers/isdn/mISDN/stack.c
index 8b7faea..422dced 100644
--- a/drivers/isdn/mISDN/stack.c
+++ b/drivers/isdn/mISDN/stack.c
@@ -75,7 +75,7 @@
if (sk->sk_state != MISDN_BOUND)
continue;
if (!cskb)
- cskb = skb_copy(skb, GFP_KERNEL);
+ cskb = skb_copy(skb, GFP_ATOMIC);
if (!cskb) {
printk(KERN_WARNING "%s no skb\n", __func__);
break;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] mISDN: Fix a sleep-in-atomic bug
2017-05-31 7:08 [PATCH] mISDN: Fix a sleep-in-atomic bug Jia-Ju Bai
@ 2017-06-01 18:50 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2017-06-01 18:50 UTC (permalink / raw)
To: baijiaju1990
Cc: isdn, mingo, fweisbec, geliangtang, akpm, yamada.masahiro, netdev,
linux-kernel
From: Jia-Ju Bai <baijiaju1990@163.com>
Date: Wed, 31 May 2017 15:08:25 +0800
> The driver may sleep under a read spin lock, and the function call path is:
> send_socklist (acquire the lock by read_lock)
> skb_copy(GFP_KERNEL) --> may sleep
>
> To fix it, the "GFP_KERNEL" is replaced with "GFP_ATOMIC".
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Just proves that nobody has ever run this code with lock debugging
enabled, if at all.
Applied, thanks.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-05-31 7:08 [PATCH] mISDN: Fix a sleep-in-atomic bug Jia-Ju Bai
2017-06-01 18:50 ` David Miller
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