Re: 4.6.3 kernel panic on ppp interface termination (__tcf_hash_release / spinlock )

On 2016-07-05 01:02, Cong Wang wrote:

On Mon, Jul 4, 2016 at 12:07 PM,  [off-list ref] wrote:

quoted

A little bit more details:

 ~ # tc -s -d filter show dev ppp0 parent ffff:
filter protocol ip pref 100 u32
filter protocol ip pref 100 u32 fh 800: ht divisor 1
filter protocol ip pref 100 u32 fh 800::1 order 1 key ht 800 bkt 0 
flowid :1
(rule hit 156 success 156)
  match 00000000/00000000 at 12 (success 156 )
        action order 1:  police 0x1 rate 4024Kbit burst 503000b mtu 
2Kb
action drop overhead 0b linklayer unspec
ref 1 bind 1
        Action statistics:
        Sent 10564 bytes 156 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0


Panic occurs when i delete ingress qdisc

tc qdisc del dev ppp0 ingress

After reversing commits (and some related commits)
        1d4150c02c5709fdfd80f10368a31867de35e72e
        ddf97ccdd7cb7e00daba465a5c947b8d941dc2a4

Problem is not occurring.

I'm not certainly sure this commits are causing issue, it is very hard 
to
reverse patches on this particular system.

Can you check if the following commit helps?

commit a03e6fe569713fb3ff0714f8fd7c8785c0ca9e22
Author: WANG Cong [off-list ref]
Date:   Mon Jun 6 09:54:30 2016 -0700

    act_police: fix a crash during removal

Yes, it fixes issue, thanks.