From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D6D5D75BA8 for ; Thu, 21 Nov 2024 03:51:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8D2406B0085; Wed, 20 Nov 2024 22:51:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8815D6B0088; Wed, 20 Nov 2024 22:51:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 770086B0089; Wed, 20 Nov 2024 22:51:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 597AE6B0085 for ; Wed, 20 Nov 2024 22:51:43 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id C048340A3A for ; Thu, 21 Nov 2024 03:51:42 +0000 (UTC) X-FDA: 82808725692.08.113275A Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf22.hostedemail.com (Postfix) with ESMTP id C0BD0C0005 for ; Thu, 21 Nov 2024 03:50:35 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=GD10U7Vw; spf=none (imf22.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1732160950; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=2xeimqU1HjPVrZw0PVZ08j1Bp5dOdUnKVWuE8/Ca5ro=; b=Lyi3JcKEq9dDKbmHsQkqkUMC9wDFXR6DkEDBJWs+zruH1bI+mO6W22iACB+al2hR64Knc7 yirvfkb4qLnqFFce6kq17ALrNhzizoHUT7iKPUOOxcMtOffRh9WfFmo+h3sCCRCyJU0l19 mAgheA9Mvib1Rv9FmL2ch9lo+npF8Nk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1732160950; a=rsa-sha256; cv=none; b=C7YOI5jsfvdkAAmNcvgeRJf/W3Ewd2/8ryULabCKB7BzUjEEGGRGQTvXm7gpE/BmkIBZni Mg2+1ouqH+V/7KIB2yzCpcsB86dRajCe0xqVe2Z9q0bXiFCcXtMZGmIqP8lpMrk6MvObQ2 YAtIqd+PO5wMkrKos/y6ORF5H2s8dcM= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=GD10U7Vw; spf=none (imf22.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2xeimqU1HjPVrZw0PVZ08j1Bp5dOdUnKVWuE8/Ca5ro=; b=GD10U7VwxZlnhtNSLarPjIxu1t sgKN8SqpaWbZ77NYf/JMIe0v+Xw7f2qAZeHMHwEn9SNc+uLJ3Z4HG/y0i29QojXPMOirErOjiFUd5 VP+jMskl9qMqek6GOfAblAvzVw9OKLrpdzBqLHXT5WawqAmLPEmRGtc2wkI4gcfkdA6qSd5GTYDym zosyRM0PeH2fiIKx0IbAHl65oZX8f8XHy2+FmfP9Lg+sHV/GzHbUi4AcYuOUa0VtpKsxTD7laixsC b5UBcoBpcv1/Gh4wPEsV7UtA7YPwJ7y6Ll1eChn0kmKbZeM7D42aotv8OBgFVhoQB04Lpxt6Cvr+s Qiy4ZoIg==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tDyE8-00000005vhG-1rUX; Thu, 21 Nov 2024 03:51:32 +0000 Date: Thu, 21 Nov 2024 03:51:32 +0000 From: Matthew Wilcox To: "Christoph Lameter (Ampere)" Cc: Vlastimil Babka , Geert Uytterhoeven , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Jens Axboe , Pavel Begunkov , Mike Rapoport , Christian Brauner , Guenter Roeck , Kees Cook , Jann Horn , linux-mm@kvack.org, io-uring@vger.kernel.org, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] slab: Fix too strict alignment check in create_cache() Message-ID: References: <80c767a5d5927c099aea5178fbf2c897b459fa90.1732106544.git.geert@linux-m68k.org> <4f70f8d3-4ba5-43dc-af1c-f8e207d27e9f@suse.cz> <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: C0BD0C0005 X-Stat-Signature: wmdms1ze8xfzhxqdskrbjbuac49me4qt X-HE-Tag: 1732161035-542797 X-HE-Meta: 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 BQsQXVPN ZrFlMGPS2lhyodCs2AIJ4djOrI5iIZUpZvZ7FNBfOM943ixfX9jRqkvhE6vXlESGjJ3jlgvz1C8g8T1AW3q+cB8yx1A3uwYT7S1CW5g6PfoCez4vg0X1PwbMRuIIjqFMjeeJ/MFaVpl/y+DFxOUU4SThlAtKJgDrjMU8iXVuCLgRqC380JjQAw2Fs7uGfjPqHCwzx7b4y/j1RxfSmIGKUACPtG1yBdeYDvAEUAFPg1iPESWRu+ivM1VzRTmv9kydsHkmrL95bu2aDxgLpxCSCFP/9MK1sS/+7gEuNOqVxPTVWTqVBPRjds68+wPt5tLI5/9Si/zMH4Rp9JY2kS9FUWl29Yv1ZXzWwBkGHcCTMlKyDebHgPBAQrhdCgwdx5WC3zuCV0pKRszfqgAWYCk7RZr+gMk/Zgncivu6Vy9qqXiZc6tiDZBukhjK7r9QH4eWCVDAaofAudLX9Bkbx5h86shABKJmhveUQgl20O9FYbTDvi4k= 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 Wed, Nov 20, 2024 at 09:50:47AM -0800, Christoph Lameter (Ampere) wrote: > On Wed, 20 Nov 2024, Vlastimil Babka wrote: > > > > > > > Fixes: aaa736b186239b7d ("io_uring: specify freeptr usage for SLAB_TYPESAFE_BY_RCU io_kiocb cache") > > > Fixes: d345bd2e9834e2da ("mm: add kmem_cache_create_rcu()") > > > Reported-by: Guenter Roeck > > > Closes: https://lore.kernel.org/37c588d4-2c32-4aad-a19e-642961f200d7@roeck-us.net > > > Signed-off-by: Geert Uytterhoeven > > > > Thanks, will add it to slab pull for 6.13. > > Note that there are widespread assumptions in kernel code that the > alignment of scalars is the "natural alignment". Other portions of the > kernel may break. The compiler actually goes along with this?? u64s aren't aligned on x86-32. it's caused some problems over the years, but things work ok in general. > How do you deal with torn reads/writes in such a scenario? Is this UP > only? there were never a lot of smp m68k. not sure i can think of one, tbh. sun3 and hp300/400 seem like the obvious people who might have done an smp m68k, but neither did.