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b=geYSyUoQgrGtwDbkkBwlXHTFNbhkeqzSW52AV3xgPmMnYLfnuh7bWTDf/yXqU3F0/ Uwp1PErTxxkS8aF8yIsAFIQ1nhA00DgrpkkCC7FiIsrXMH53H1wB36EDCWCPl02axG 28tMyiaQfMjN4uVROLQPgjZg0X5RcvRFC6U0tFe9mplLI5iAzo3pSuq09urihZoG+s NJw+Uih0fQ4fiBUQjBo9hNO6n41sCFUDB0nkmyrg9XfpgJxgSuXj5uT4keq74WaL8W xjG6EiPDB4+X8HzbnjU3aigdSmQzXkr3BZpA2vajjR8JZDNm0nzmY1+LNovKF3Zw4F DGM3/VWtbmnHg== Date: Wed, 28 Oct 2026 15:37:31 +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-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: B8A2D4000D X-Stat-Signature: nz5ip39fzxw5hcdzqn3ftwjhb1xwue7e X-Rspam-User: 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: 1793201854-798138 X-HE-Meta: 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 MwRL23ek 7hW1lMbFYdCY3HetAsBTQo8YQaCfMaCYnj4DlrGAvm3VUkMRfwmiST4nPdmf79RCw2kCZN4AYvt4e/xRsB5mmwu5gXGofYJ2AG/Cj0b0hkdSkOXuq8iClYJWKTHF8RcdQ0ejzFInYpmlIRGc/2ulfncG2LsSO9Xl/hTMkQBFIIplxAQYUBYVPjYls4wZzyZvx74lXlkJUhS4gTXfIXQ7tCAYrsgl6o1qxV5QgcGGDaZY/ajYcXqiAFAO1FCJ9BHKLL/6A 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 On Wed, Oct 28, 2026 at 11:27:37PM +0800, Chris Down wrote: > 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. There has been constant, steady efforts to add more and more hardening features over the last decade. So I'd say slab_hardening= is more future proof :-) Kees or Marco might have more insights on this. -- Cheers, Harry / Hyeonggon