From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9A13221256C; Thu, 16 Apr 2026 12:30:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776342653; cv=none; b=BpLC0ibD52CUIy8KbC86N76NvLCW4umShQAcsp44UP6OODHNvLoy0MFi06L6nmNEy6QenxEV0PmCTY0VyLeG9krY1YUEXPYr2ab9KgqSmCtA6FVdLulH6sklAE09duHc311isI68hsXqE4wWz6E+d497/buXWYQhyf5u2mYc8mQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776342653; c=relaxed/simple; bh=0+upWZt1SQSfIz6OgmfLK1joGZgudnQ2lP+Bv+7s1DM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uY5j+eRGJwaUdgIOC2wLp7JJWLC8KQMerzLOZh5DMvxrB6t2JpmbgQo4UGJl3ZxmdQG9NKK0xe399S40n2RHiyoBpEp85ydqeSaOEqsvaCTpw1iILu6o9zQb2ZHR7YZXH1zQFt28BRMIAOSMt8WojY9cLwve3nXYQDHjoMWxcpY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aREs4pY9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aREs4pY9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB8D2C2BCAF; Thu, 16 Apr 2026 12:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776342653; bh=0+upWZt1SQSfIz6OgmfLK1joGZgudnQ2lP+Bv+7s1DM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=aREs4pY9AFWiyPis1yCUHi655kH6F2cmateO3OS3vwiWh4XGstegazkXh9fTeJRQW F7PNlGo+5uv4JS1ghUA7GmLt/nGdKTIiz0N3eNo0k9qdgxnlZ6UVo1xvuY/jm0Jsgz 6OXZlHvLM95FlzgQqthFFGhbIejPY5s4jQOos8SHiaMv+4GNWDNJ4NBjKmastJKLl9 B+kLcT7cwceOa9aKNihg3CZG+65E3BtgCcBvAVf5SIS4E47zAqVB8uUKfjkayyutdK 0Jj6v6r/4toyxe6BrveBQ3dEYq/LaiTL2nhXiDsBmOQK54Y4zcD7qDew9ISAzQHpha d9g1fsIICa3fA== Message-ID: <1fba96bd-124d-431d-8de8-78688c248600@kernel.org> Date: Thu, 16 Apr 2026 14:30:37 +0200 Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/61] Coccinelle: Prefer IS_ERR_OR_NULL over manual NULL check To: Philipp Hahn , amd-gfx@lists.freedesktop.org, apparmor@lists.ubuntu.com, bpf@vger.kernel.org, ceph-devel@vger.kernel.org, cocci@inria.fr, dm-devel@lists.linux.dev, dri-devel@lists.freedesktop.org, gfs2@lists.linux.dev, intel-gfx@lists.freedesktop.org, intel-wired-lan@lists.osuosl.org, iommu@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-clk@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, linux-omap@vger.kernel.org, linux-phy@lists.infradead.org, linux-pm@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-sctp@vger.kernel.org, linux-security-module@vger.kernel.org, linux-sh@vger.kernel.org, linux-sound@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-trace-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, samba-technical@lists.samba.org, sched-ext@lists.linux.dev, target-devel@vger.kernel.org, tipc-discussion@lists.sourceforge.net, v9fs@lists.linux.dev Cc: Julia Lawall , Nicolas Palix References: <20260310-b4-is_err_or_null-v1-0-bd63b656022d@avm.de> <20260310-b4-is_err_or_null-v1-1-bd63b656022d@avm.de> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/03/2026 12:48, Philipp Hahn wrote: > Find and convert uses of IS_ERR() plus NULL check to IS_ERR_OR_NULL(). > > There are several cases where `!ptr && WARN_ON[_ONCE](IS_ERR(ptr))` is > used: > - arch/x86/kernel/callthunks.c:215 WARN_ON_ONCE > - drivers/clk/clk.c:4561 WARN_ON_ONCE > - drivers/interconnect/core.c:793 WARN_ON > - drivers/reset/core.c:718 WARN_ON > The change is not 100% semantical equivalent as the warning will now > also happen when the pointer is NULL. > > To: Julia Lawall > To: Nicolas Palix > Cc: cocci@inria.fr > Cc: linux-kernel@vger.kernel.org > > --- > drivers/clocksource/mips-gic-timer.c:283 looks suspicious: ret != clk, > but Daniel Lezcano verified it as cottect. > > There are some cases where the checks are part of a larger expression: > - mm/kmemleak.c:1095 > - mm/kmemleak.c:1155 > - mm/kmemleak.c:1173 > - mm/kmemleak.c:1290 > - mm/kmemleak.c:1328 > - mm/kmemleak.c:1241 > - mm/kmemleak.c:1310 > - mm/kmemleak.c:1258 > - net/netlink/af_netlink.c:2670 > Thanks to Julia Lawall for the help to also handle them. > > Signed-off-by: Philipp Hahn > --- > scripts/coccinelle/api/is_err_or_null.cocci | 125 ++++++++++++++++++++++++++++ > 1 file changed, 125 insertions(+) > Neither this, nor try from 2011, nor any future try should be accepted, because it creates impression IS_ERR_OR_NULL is somehow okay. No, it is not okay, it is a discouraged pattern leading to less readable and maintainable code. We should not have therefore any tools suggesting usage of IS_ERR_OR_NULL, because people will be converting poor code into that, instead of fixing that poor code. Best regards, Krzysztof