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 0FF2DD75BCD for ; Thu, 21 Nov 2024 08:15:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 80C1F6B0083; Thu, 21 Nov 2024 03:15:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7BBAB6B0088; Thu, 21 Nov 2024 03:15:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 683106B0089; Thu, 21 Nov 2024 03:15:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 452D56B0083 for ; Thu, 21 Nov 2024 03:15:56 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E48A3AE6E7 for ; Thu, 21 Nov 2024 08:15:55 +0000 (UTC) X-FDA: 82809391518.19.BFF6A60 Received: from mail-yb1-f179.google.com (mail-yb1-f179.google.com [209.85.219.179]) by imf09.hostedemail.com (Postfix) with ESMTP id 8DDA9140002 for ; Thu, 21 Nov 2024 08:15:17 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf09.hostedemail.com: domain of geert.uytterhoeven@gmail.com designates 209.85.219.179 as permitted sender) smtp.mailfrom=geert.uytterhoeven@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1732176803; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Fa1bafhgnf4UjyHiSsOg5v1diyDhD3E0RXZDuNixLkQ=; b=Gr0Pa1n5GVBSptKV4qBuZyoCHsCLPlRVSBk5qz3a5+b0Umfahq3cgNK3TSCGQJ3uCH6GFs hHQ+L+VgU5mw3kCXDM2t3/AW+HfIWX6CHF1ZAUdMp/rOZUemioAjizJ0gvoY7zB/RaiIJE sUcWcQzXdqjuE1rxlkRah2d0alHeiyY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1732176803; a=rsa-sha256; cv=none; b=IbrWtjT1eft2dvvCX4MUZaSccvXqaYRAXYK3DsdzRpzgdFezW7U+9WEUm/mnHBfOC1tfha FbsgFkvvXNnhnBHQ/9dWVdx4Ywj/cEWfEUa/cmyizTID+UhcZjd7Vg+e6wHINrJ32O7qvT cjTO+W697HxEuZqXE7GdQ2icvc8Zutw= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf09.hostedemail.com: domain of geert.uytterhoeven@gmail.com designates 209.85.219.179 as permitted sender) smtp.mailfrom=geert.uytterhoeven@gmail.com Received: by mail-yb1-f179.google.com with SMTP id 3f1490d57ef6-e388e1fd582so577109276.2 for ; Thu, 21 Nov 2024 00:15:53 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732176952; x=1732781752; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Fa1bafhgnf4UjyHiSsOg5v1diyDhD3E0RXZDuNixLkQ=; b=dzyzHdDVRUQE6NSlW7pjDzC1+L7lkf6Ssilie9NutOhFHVwIElJl+nIxBAX6Bo0lPo el11j6jP0ogIhC8Y0dd0xEITCxgNoKLp/iAH2s/u+faGGtKIwAh9/0na7oRxHkCy1bk7 KPN29qRf6Kx6srXJz77JE1Bhoa3lZKbn/WpouPd8KpAXATonNn6sEVErDh2MryJMw4ey NIAe/B+MzTi78Utn2/R5c9GZK9Vun8pcQwBnAngMTJzJindl1aNttrTjj52Fchx1KAak 6nbpX/yG1cJHzTtByyI5mTw+hPrWoEWoiJzaERLywJDVEn3MIcjp9/T36TTX+6RSACAg AV+A== X-Forwarded-Encrypted: i=1; AJvYcCXpTD9Rfoo0Ab5gRzV/TbnLdQ0Fgik3mTCr4e8bens2t19Ym4SI4I90wxAhMhU0TpbDmvPP7bXumQ==@kvack.org X-Gm-Message-State: AOJu0YxzJNXoJMhptwOe49onGTf6qyWxVfEceL1FGhxwfb2CFpNCDqDj UNSgJ6hj9CZug8kgm/9aw7yGEa4WfgN3TPozPVW0njLEK1slBereLrpjftjY X-Google-Smtp-Source: AGHT+IEsykrg2lrc7mB2ZHfB1ZuXv8X/TE321hMIUACwn53Sf6U0pMBHFS5mBX68X1Lr/0taswF/7g== X-Received: by 2002:a05:6902:724:b0:e38:a15d:40ad with SMTP id 3f1490d57ef6-e38cb54e1d5mr5159065276.7.1732176952520; Thu, 21 Nov 2024 00:15:52 -0800 (PST) Received: from mail-yw1-f182.google.com (mail-yw1-f182.google.com. [209.85.128.182]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e387e754a34sm3680789276.24.2024.11.21.00.15.49 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Nov 2024 00:15:50 -0800 (PST) Received: by mail-yw1-f182.google.com with SMTP id 00721157ae682-6ee994218d9so5477937b3.0 for ; Thu, 21 Nov 2024 00:15:49 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCUoWqR3eE8JLkR2Ko1GqbPckqZZz4ngFUaH623TunHILgwDD58g8Q9kBeW8xvG5qwKEmhBza3u5eQ==@kvack.org X-Received: by 2002:a05:690c:7209:b0:6e2:fcb5:52ea with SMTP id 00721157ae682-6eebd2ae56emr67688777b3.29.1732176948950; Thu, 21 Nov 2024 00:15:48 -0800 (PST) MIME-Version: 1.0 References: <80c767a5d5927c099aea5178fbf2c897b459fa90.1732106544.git.geert@linux-m68k.org> <4f70f8d3-4ba5-43dc-af1c-f8e207d27e9f@suse.cz> <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> In-Reply-To: <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> From: Geert Uytterhoeven Date: Thu, 21 Nov 2024 09:15:37 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] slab: Fix too strict alignment check in create_cache() To: "Christoph Lameter (Ampere)" Cc: Vlastimil Babka , 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 8DDA9140002 X-Stat-Signature: 6oq4wx64g9x9toe8jzmtkyqhzgbnepkm X-HE-Tag: 1732176917-419823 X-HE-Meta: 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 hGPyu0bv 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 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: Hi Christoph, On Wed, Nov 20, 2024 at 6:50=E2=80=AFPM Christoph Lameter (Ampere) wrote: > On Wed, 20 Nov 2024, Vlastimil Babka wrote: > > > Fixes: aaa736b186239b7d ("io_uring: specify freeptr usage for SLAB_TY= PESAFE_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?? Linux has supported m68k since last century. Any new such assumptions are fixed quickly (at least in the kernel). If you need a specific alignment, make sure to use __aligned and/or appropriate padding in structures. And yes, the compiler knows, and provides __alignof__. > How do you deal with torn reads/writes in such a scenario? Is this UP > only? Linux does not support (rate) SMP m68k machines. Gr{oetje,eeting}s, Geert --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds