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Wed, 28 Oct 2026 08:27:42 -0700 (PDT) Received: from localhost ([116.86.153.182]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-71429e7b7basm1517856eaf.1.2026.10.28.08.27.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2026 08:27:41 -0700 (PDT) Date: Wed, 28 Oct 2026 23:27:37 +0800 From: Chris Down To: Harry Yoo Cc: Vlastimil Babka , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Kees Cook , Marco Elver , GONG Ruiqi , Jan Kiszka , Kieran Bingham , Jonathan Corbet , linux-mm@kvack.org, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH 0/8] mm/slab: Support selecting slab hardening features at boot Message-ID: References: X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.3.3 (9073d26d) (2026-06-12) X-Stat-Signature: swd3ks8ggco9boip349qs9xczkxgndpi X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: D0D2E140004 X-Rspam-User: X-HE-Tag: 1793201263-755684 X-HE-Meta: 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 d1I3IP8h 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hi Harry, Harry Yoo writes: >If we end up supporting boot-time parameters for hardening, >I think it should be all enabled (or disabled) by: > > slab_hardening=none|light|full > # please feel free to suggest bertter names > >none: "Turn of all of them to maximize performance" > >light: "I'm willying to sacrifice _some_ memory and CPU for security" > >full: "I'm willying to sacrifice more overhead for security > >IMHO more fine-grained knob for each feature doesn't make much sense. I think if we did the 4 knobs that is a good idea. Given now it's two, I think it seems reasonable to keep it as two separate knobs unless you object? Otherwise I think given it will only cover the latter two, it should be something like kmalloc_isolation= instead. Let me know what you think. Thanks!