From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BB4044CF2F; Fri, 9 Oct 2026 06:36:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791527771; cv=none; b=h/bOPwVE+3duCY9S0wZwr5mZmLpzu+BKC29HkbwxCwsdscYLzgXn6RTafHuvFWPO4RCJB/69MoPFIvOilFtKlu4Dsvd4dPvn7pyZIUzHAp1fe1ChHbPmQYIE60GCBEGIYhyNuV/Ytt8I5EBX8+FizHhczaWKi6jSjBCX7S6gSR4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791527771; c=relaxed/simple; bh=T/J4o4hDhA5TsOsEhsAJsZ6CJlOmR8oD1UmQSr37A/g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=L/XXsbZsaszgg/5u7axotxZ9XbXsy+fD2FZw8v24ijls2u+xyqthEH2anY5jIlPWkD3yChNu0vg9NQnjiZEMTv00ABjhYsxZupXbk1k6iS4eQzI39HvaRZW2FcbZXtrYD4CkRjCO9ALnxg/1rEJkmuIOQiqbEcGyvdzPqTKwUNk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=adm/PXte; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="adm/PXte" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E7D51F000FF; Fri, 9 Oct 2026 06:36:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791527770; bh=gDpTPyFrfxPK/Uf/lFR6lzmG1KtMFb1k0z6iyA57/Qk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=adm/PXteCoY9Ji6saNhj4L6Dqguia+KG2/3Nr+/ar0UHgfEYUz2BGq6wjJLDGi6F3 liU8vicxy2gTOqC4yZ0W5OeGkkJJC0uPn5qOX1/HqutbBsxs3TigwAPxmIwOJzmQ6t nJ9Sn5WzLPXhkmfTQBgZ7He7WVdlb0idBiQIE27jcKbGTZ9QE5yYOtgsUds+hBZGoK bGoPuCSWqujD6cXwPoHslFO++VzLMCWxK29x5mF0jrnvRXkWgGGVihOsEr+E4lhcXg 76j+4XTX5LIPQ0B539LHeDrjQVMAD9e+yoPSzyE0uAxVqGBjuhgxQ2a9XcsGNk7BLn iGbpxQ869yG5w== Date: Thu, 8 Oct 2026 23:36:09 -0700 From: Kees Cook To: Harry Yoo Cc: Vlastimil Babka , "David S. Miller" , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Pedro Falcato , Kuniyuki Iwashima , Christian Brauner , Jan Kara , Johannes Weiner , Michal Hocko , Shakeel Butt , Muchun Song , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Willem de Bruijn , Jason Xing , cgroups@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH net-next v6 0/8] net: skb: isolate skb data area allocations into a separate bucket Message-ID: <202610082331.853F0CBBA@keescook> References: <20261006092030.got.500-kees@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Oct 08, 2026 at 11:25:13PM +0200, Harry Yoo wrote: > On Tue, Oct 06, 2026 at 02:20:26AM -0700, Kees Cook wrote: > > Hi! > > Hi Kees! > > Was hoping to say hi to you at LPC but I missed the chance ;) > Maybe next time. Safe travels! Hi! Yes, I kept trying to find you and Vlastimil but it never worked out. LPC is a non-stop hallway track usually. :) I will try again next year! > > So v6 goes back to mirroring the kmalloc cache's alignment, > > I might be missing something, but why is that a problem? > > For kmem_buckets users, the reason* to specify alignment is because > they might need less strict alignment than kmalloc. > > (*Perhaps it's nice to document that in the comment) > > However, because kmem_buckets can fall back to kmalloc on e.g. kernels > w/o CONFIG_SLAB_BUCKETS, it should be fine to fall back. No? > > Creating kmem_buckets with more strict alignment than > kmalloc doesn't make sense. > > > and drops the ctor and flags arguments for the same reason. > > Uh, for ctor and flags, yes. We can't have them in kmem_buckets. Yeah, and given that these two, I'd just prefer to keep it a direct mirror for alignment too and not allow for any configurability here: they are supposed to be direct stand-ins for the general cache. > Going thorough slab/for-next sounds reasonable to me once it gets > some reviews. Thanks! -Kees -- Kees Cook