From: Cong Wang
Date: Thu, 21 Dec 2017 16:03:30 -0800
> __skb_array_empty() is only safe if array is never resized.
> pfifo_fast_dequeue() is called in TX BH context and without
> qdisc lock, so even after we disable BH on ->reset() path
> we can still race with other CPU's.
>
> Fixes: c5ad119fb
On 12/27/2017 10:29 AM, Cong Wang wrote:
> On Sat, Dec 23, 2017 at 10:57 PM, John Fastabend
> wrote:
>> On 12/22/2017 12:31 PM, Cong Wang wrote:
>>> I understand why you had it, but it is just not safe. You don't want
>>> to achieve performance gain by crashing system, right?
>>
>> huh? So my poin
On Sat, Dec 23, 2017 at 10:57 PM, John Fastabend
wrote:
> On 12/22/2017 12:31 PM, Cong Wang wrote:
>> I understand why you had it, but it is just not safe. You don't want
>> to achieve performance gain by crashing system, right?
>
> huh? So my point is the patch you submit here is not a
> real fix
On 12/22/2017 12:31 PM, Cong Wang wrote:
> On Thu, Dec 21, 2017 at 7:06 PM, John Fastabend
> wrote:
>> On 12/21/2017 04:03 PM, Cong Wang wrote:
>>> __skb_array_empty() is only safe if array is never resized.
>>> pfifo_fast_dequeue() is called in TX BH context and without
>>> qdisc lock, so even af
On Thu, Dec 21, 2017 at 7:06 PM, John Fastabend
wrote:
> On 12/21/2017 04:03 PM, Cong Wang wrote:
>> __skb_array_empty() is only safe if array is never resized.
>> pfifo_fast_dequeue() is called in TX BH context and without
>> qdisc lock, so even after we disable BH on ->reset() path
>> we can sti
On 12/21/2017 04:03 PM, Cong Wang wrote:
> __skb_array_empty() is only safe if array is never resized.
> pfifo_fast_dequeue() is called in TX BH context and without
> qdisc lock, so even after we disable BH on ->reset() path
> we can still race with other CPU's.
>
> Fixes: c5ad119fb6c0 ("net: sche
__skb_array_empty() is only safe if array is never resized.
pfifo_fast_dequeue() is called in TX BH context and without
qdisc lock, so even after we disable BH on ->reset() path
we can still race with other CPU's.
Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array")
Reported-by: Jakub Kici
