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b=ElJMCl2ON+8u2jbqVFImaNpjKgvwsiEzdmTXkR15Xmg230hLoqmlSHXBv647f6r0W 7eCr/h4he7KLgGg4DeCFqFEFGW/wHLzleVbTRopXCWgaAxZjr1FZeUQonCHBMpyBsA Zn+gsWL6Y83Jjo3I8rTGS/kyNSXKBDu5aSdvL4Cg= Date: Thu, 27 Nov 2025 11:19:40 -0800 From: Andrew Morton To: Breno Leitao Cc: Alexander Potapenko , Marco Elver , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] mm/kfence: add reboot notifier to disable KFENCE on shutdown Message-Id: <20251127111940.8549bd7aa82cfae5e9be1b0e@linux-foundation.org> In-Reply-To: References: <20251126-kfence-v1-1-5a6e1d7c681c@debian.org> <20251126101453.3ba9b3184aa6dd3c718287e6@linux-foundation.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: A954FC000C X-Stat-Signature: nktipxzyh4smj7f6zx5uahsiyney9by6 X-Rspam-User: X-HE-Tag: 1764271182-24974 X-HE-Meta: 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 ANjHF3qk xSnE+y2puuyVcm9y0BGp58rzgWBs6Cy6Jgqn/1TOgzgbw7XyZKFkIGKDxxze6vWOABaqytAoRQE+SeLLC2ePLzRhxuq7WWnRnIDDl7hbefgbEA+Dzw1b06Utpy/jA2BfYiz2zIBLWkPuREhW4naXwK7UvjKciRvyAggFI1P1gqnuT+iSO0ZJ3nKuRiFdf0KDeZLje6Et+DSMyDbViABbo4z9DhcgwRGGxw4dT17+A8Z0ZaiUGMOMXf794DukIfCSZr46Kpj+pnvZ/BSEs70kR9u5rnEHSbqVsr5M0SeuEP8M2OH0= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 27 Nov 2025 03:12:10 -0800 Breno Leitao wrote: > > > This fixes a late kexec CSD lockup[1] when kfence is trying to IPI a CPU > > > that is busy in a IRQ-disabled context printing characters to the > > > console. > > > > > > Link: https://lore.kernel.org/all/sqwajvt7utnt463tzxgwu2yctyn5m6bjwrslsnupfexeml6hkd@v6sqmpbu3vvu/ [1] > > > > 6.13 kernels and earlier, so I assume we'll want a cc:stable on this. > > And I assume there's really no identifiable Fixes: target. > > This infrastructure showed up when kfence was created, so, a possible > Fixes: target would point to commit 0ce20dd84089 ("mm: add Kernel > Electric-Fence infrastructure") Great, thanks, I added that.