Re: List corruption on epoll_ctl(EPOLL_CTL_DEL) an AF_UNIX socket

Mathias Krause [off-list ref] writes:

On 30 September 2015 at 15:25, Rainer Weikusat
[off-list ref] wrote:

quoted

Mathias Krause [off-list ref] writes:

quoted

On 30 September 2015 at 12:56, Rainer Weikusat [off-list ref] wrote:

quoted

In case you want some information on this: This is a kernel warning I
could trigger (more than once) on the single day I could so far spend
looking into this (3.2.54 kernel):

Sep 15 19:37:19 doppelsaurus kernel: WARNING: at lib/list_debug.c:53 list_del+0x9/0x30()
Sep 15 19:37:19 doppelsaurus kernel: Hardware name: 500-330nam
Sep 15 19:37:19 doppelsaurus kernel: list_del corruption. prev->next should be ffff88022c38f078, but was dead000000100100
[snip]

Is that with Jason's patch or a vanilla v3.2.54?

That's a kernel warning which occurred repeatedly (among other "link
pointer disorganization" warnings) when I tested the "program with
unknown behaviour" you wrote with the kernel I'm currently supporting a
while ago (as I already wrote in the original mail).

So I assume Jason's patch is not included in your kernel.  Then those
messages are expected; expected even on kernels as old as v2.6.27.
Can you re-try with Jason's patch applied?

If something needs to be unregistered here (which I don't claim to
know but someone should), the corresponding code would need to be added
to the unix_dgram_disconnected function (as was already pointed
out).