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h=Date:From:To:Cc:Subject:References:In-Reply-To; b=nSMN0kNUmbsSHdv9awMBVCH6qjwWaKvcGUVUjLsuOukkXyE8GaNWdnrlzGSOWPUxx nIsSj6zS3F7QsXpgAgCtNpKWs3qPXOfWQaHXjI7q8Xy8+AoZLdOW+kb2R2ariJ14KF kh39GIVq+tFgQWcEXC77GFJzfx3q8MIhkGL8UJIK+0HbuqXpIEj0zsOIpanmvlIs+I XY1CLvSbmqKiZpQM9NT3GWGDqEiJMlgHH68ERZ6/KUve1IBluVECVEYyQ6usMhvjLF 1k28ca39gz7anWHNTGkRQgyVUEHbN5YlUmHfrgIOGLQXh3xkTgFAB5SyTFIhCpCTuz s2VKrE5jIpz0Q== Date: Wed, 28 Oct 2026 15:06:19 +0000 From: Harry Yoo To: Chris Down 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 Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Queue-Id: 9657920014 X-Stat-Signature: ogp7b91zmeyorqs86t9bsq3zs4gxn1gp X-Rspamd-Server: rspam01 X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1793199982-754941 X-HE-Meta: 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 d67gaWsT vHow8DiAmuONueJkHY0X2Hwz7Hl/2hxdlBuTjhNb04FwvHphzmVrgdKuqp0qLhfDAG7zHs7m1VAwd8a2Zc3meq4MpDkiGsQ+NQf04kiGSDbozuefQbMAc+rraoU3QVuuhK3tWVDO86iAQPes3EkOzw4Kv446MIx16LHDD0llRArSKhhsNi7ReOdtSPozqiHi3UWVTvyd/wMG0b0KfBAcBByceWVzpl/a+6GyaLP9tMAGv2904ve4lrMDmWwwmWlGnhNvNl6x+ksKDOzOvLB/mPf31nw== 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 Chris! On Tue, Oct 27, 2026 at 03:35:16PM +0800, Chris Down wrote: > Slab hardening settings are currently all build time choices. This means > that, unfortunately, hosts with different requirements end up needing > separate kernel images. Let's allow those hosts to use one image and > select each policy at boot instead. > > This series adds four new boot parameters that default to their values > from CONFIG_*: > > slab_freelist_hardened= > slab_freelist_random= > slab_buckets= > kmalloc_partition= 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. -- Cheers, Harry / Hyeonggon