linux-kernel - Re: [PATCH v2 1/7] s390/kdump: implement is_kdump

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: <20241014182054.10447-D-hca@linux.ibm.com>
Date: Mon, 14 Oct 2024 20:20:54 +0200
From: Heiko Carstens <hca@...ux.ibm.com>
To: David Hildenbrand <david@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-s390@...r.kernel.org, virtualization@...ts.linux.dev,
        linux-doc@...r.kernel.org, kvm@...r.kernel.org,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>, Thomas Huth <thuth@...hat.com>,
        Cornelia Huck <cohuck@...hat.com>,
        Janosch Frank <frankja@...ux.ibm.com>,
        Claudio Imbrenda <imbrenda@...ux.ibm.com>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Jason Wang <jasowang@...hat.com>,
        Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
        Eugenio Pérez <eperezma@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Jonathan Corbet <corbet@....net>, Mario Casquero <mcasquer@...hat.com>
Subject: Re: [PATCH v2 1/7] s390/kdump: implement is_kdump_kernel()

On Mon, Oct 14, 2024 at 04:46:13PM +0200, David Hildenbrand wrote:
> s390 currently always results in is_kdump_kernel() == false, because
> it sets "elfcorehdr_addr = ELFCORE_ADDR_MAX;" early during setup_arch to
> deactivate the elfcorehdr= kernel parameter.
> 
> Let's follow the powerpc example and implement our own logic.
> 
> This is required for virtio-mem to reliably identify a kdump
> environment to not try hotplugging memory.
> 
> Tested-by: Mario Casquero <mcasquer@...hat.com>
> Signed-off-by: David Hildenbrand <david@...hat.com>
> ---
>  arch/s390/include/asm/kexec.h | 4 ++++
>  arch/s390/kernel/crash_dump.c | 6 ++++++
>  2 files changed, 10 insertions(+)

Looks like this could work. But the comment in smp.c above
dump_available() needs to be updated.

Are you willing to do that, or should I provide an addon patch?