From: Thomas Gleixner <tglx@linutronix.de>
To: Waiman Long <llong@redhat.com>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v2] x86/nmi: Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()
Date: Wed, 04 Dec 2024 19:03:08 +0100 [thread overview]
Message-ID: <87zflbqqar.ffs@tglx> (raw)
In-Reply-To: <7aa93137-4b5e-474f-a99c-47acffdf71a3@redhat.com>
On Wed, Dec 04 2024 at 12:23, Waiman Long wrote:
> On 12/4/24 8:10 AM, Thomas Gleixner wrote:
>> On Tue, Dec 03 2024 at 10:07, Waiman Long wrote:
>>> + /*
>>> + * Call the emergency handler first, if set
>>> + * Emergency handler is not traced or checked by nmi_check_duration().
>>> + */
>>> + ehandler = READ_ONCE(desc->emerg_handler);
>>> + if (ehandler)
>>> + handled = ehandler(type, regs);
>> Shouldn't this just stop processing right here?
>
> Yes in the case of crash_nmi_callback(). I suppose it is a no-return
> call. As the emergency handler is supposed to be a general mechanism in
> design, I don't want to make too many assumptions of what will happen
> when the handler is invoked.
I'm not convinced that this should be used as a general mechanism. It's
for emergency situations and that's where it stops. If the thing
returns, it's a bug IMO.
Thanks,
tglx
next prev parent reply other threads:[~2024-12-04 18:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-03 15:07 [PATCH v2] x86/nmi: Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus() Waiman Long
2024-12-04 1:00 ` Rik van Riel
2024-12-04 1:39 ` Waiman Long
2024-12-04 7:58 ` kernel test robot
2024-12-04 13:10 ` Thomas Gleixner
2024-12-04 17:23 ` Waiman Long
2024-12-04 18:03 ` Thomas Gleixner [this message]
2024-12-04 19:28 ` Waiman Long
2024-12-05 4:01 ` Waiman Long
2024-12-05 13:12 ` Thomas Gleixner
[not found] ` <1166fd72-8a4a-489f-9de5-7c06b70b0ad4@redhat.com>
2024-12-05 18:17 ` Thomas Gleixner
2024-12-06 4:16 ` Waiman Long
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87zflbqqar.ffs@tglx \
--to=tglx@linutronix.de \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=llong@redhat.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox