linux-kernel - Re: [BUG 4.15-rc7] IRQ matrix management errors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180117142440.GC7562@localhost.localdomain>
Date:   Wed, 17 Jan 2018 07:24:40 -0700
From:   Keith Busch <keith.busch@...el.com>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: Re: [BUG 4.15-rc7] IRQ matrix management errors

On Wed, Jan 17, 2018 at 10:32:12AM +0100, Thomas Gleixner wrote:
> On Wed, 17 Jan 2018, Thomas Gleixner wrote:
> > That doesn't sound right. The vectors should be spread evenly accross the
> > CPUs. So ENOSPC should never happen.
> > 
> > Can you please take snapshots of /sys/kernel/debug/irq/ between the
> > modprobe and modprobe -r steps?
> 
> The allocation fails because CPU1 has exhausted it's vector space here:
> 
> [002] d...   333.028216: irq_matrix_alloc_managed: bit=34 cpu=1 online=1 avl=0 alloc=202 managed=2 online_maps=112 global_avl=22085, global_rsvd=158, total_alloc=460
> 
> Now the interesting question is how that happens.

The trace with "trace_events=irq_matrix" kernel parameter is attached,
ended shortly after an allocation failure.

I'll have to get back to you on the debug/irq snapshots.

View attachment "irq-matrix-events" of type "text/plain" (491590 bytes)