From: Kiryl Shutsemau <kas@kernel.org>
To: Usama Arif <usama.arif@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>, Marc Zyngier <maz@kernel.org>,
Doug Anderson <dianders@chromium.org>,
Breno Leitao <leitao@debian.org>, Dawei Li <dawei.li@linux.dev>,
mrigendrachaubey <mrigendra.chaubey@gmail.com>,
kernel-team@meta.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/2] arm64: sdei: Run the event handler on the kernel vectors
Date: Thu, 5 Nov 2026 11:38:08 +0000 [thread overview]
Message-ID: <auxqaslfm5t3FAPL@thinkstation> (raw)
In-Reply-To: <20261104182842.3436759-1-usama.arif@linux.dev>
On Wed, Nov 04, 2026 at 10:28:41AM -0800, Usama Arif wrote:
> Would doing the swap in __sdei_handler(), around the whole NMI
> entry and exit pair, close that window?
Yes. The WARNs you point at only fire when context tracking is already
broken, but the same window has tracepoints: trace_hardirqs_off_finish()
fires irq_disable exactly when the event lands in user space, and a BPF
program attached there can fault.
It applies to 2/2 too: anything that traps in irqentry_nmi_enter()
overwrites ELR, ESR and FAR before do_sdei_event() saves them.
I'll move both into __sdei_handler(), around irqentry_nmi_enter() and
irqentry_nmi_exit(), in v2. do_sdei_event() still needs the interrupted
VBAR for the IRQ-like resume, so it will get it as an argument.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2026-11-05 11:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-04 18:09 [PATCH 0/2] arm64: sdei: Handle exceptions taken inside the event handler Kiryl Shutsemau (Meta)
2026-11-04 18:09 ` [PATCH 1/2] arm64: sdei: Run the event handler on the kernel vectors Kiryl Shutsemau (Meta)
2026-11-04 18:28 ` Usama Arif
2026-11-05 11:38 ` Kiryl Shutsemau [this message]
2026-11-04 18:09 ` [PATCH 2/2] arm64: sdei: Preserve the interrupted context's exception registers Kiryl Shutsemau (Meta)
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=auxqaslfm5t3FAPL@thinkstation \
--to=kas@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=dawei.li@linux.dev \
--cc=dianders@chromium.org \
--cc=james.morse@arm.com \
--cc=kernel-team@meta.com \
--cc=leitao@debian.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
--cc=mrigendra.chaubey@gmail.com \
--cc=stable@vger.kernel.org \
--cc=usama.arif@linux.dev \
--cc=will@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
all inboxes | Powered by JetHome®