netdev - Re: [PATCH v3] s390/pci: Avoid deadlock between PCI error recovery and mlx5 crdump

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] [day] [month] [year] [list]

Message-ID: <20251021124721.26700C66-hca@linux.ibm.com>
Date: Tue, 21 Oct 2025 14:47:21 +0200
From: Heiko Carstens <hca@...ux.ibm.com>
To: Gerd Bayer <gbayer@...ux.ibm.com>
Cc: Niklas Schnelle <schnelle@...ux.ibm.com>,
        Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Shay Drori <shayd@...dia.com>, Jason Gunthorpe <jgg@...pe.ca>,
        Tariq Toukan <tariqt@...dia.com>, Saeed Mahameed <saeedm@...dia.com>,
        Leon Romanovsky <leon@...nel.org>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>,
        Pierre Morel <pmorel@...ux.ibm.com>,
        Matthew Rosato <mjrosato@...ux.ibm.com>, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        linux-rdma@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH v3] s390/pci: Avoid deadlock between PCI error recovery
 and mlx5 crdump

On Thu, Oct 16, 2025 at 11:27:03AM +0200, Gerd Bayer wrote:
> Do not block PCI config accesses through pci_cfg_access_lock() when
> executing the s390 variant of PCI error recovery: Acquire just
> device_lock() instead of pci_dev_lock() as powerpc's EEH and
> generig PCI AER processing do.
> 
> During error recovery testing a pair of tasks was reported to be hung:
> 
> mlx5_core 0000:00:00.1: mlx5_health_try_recover:338:(pid 5553): health recovery flow aborted, PCI reads still not working
> INFO: task kmcheck:72 blocked for more than 122 seconds.
>       Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1
> Cc: stable@...r.kernel.org
> Fixes: 4cdf2f4e24ff ("s390/pci: implement minimal PCI error recovery")
> Reviewed-by: Niklas Schnelle <schnelle@...ux.ibm.com>
> Signed-off-by: Gerd Bayer <gbayer@...ux.ibm.com>
> ---
> Hi Niklas, Shay, Jason,
> 
> by now I believe fixing this in s390/pci is the right way to go, since
> the other PCI error recovery implementations apparently don't require
> this strict blocking of accesses to the PCI config space.
>     
> Hi Alexander, Vasily, Heiko,
>     
> while I sent this to netdev since prior versions were discussed there,
> I assume this patch will go through the s390 tree, right?

Applied, thanks!