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 C031C1527B4 for ; Tue, 19 Aug 2025 11:22:58 +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=1755602578; cv=none; b=k6M8vb41Wz4B6ZutExI+WNSTi1HyTeBfu2cHKtJf5V8Y7Hw1PDryVSxCKBW4plHOuGjMy+jPuT02wDxxqVcfaA8yWWGuRHb5joqew42iw8ARvn5KcUIC2A03hS1woxg6aUGSmKbaDYWmrLU8ca1PgDbRbzAqvGEps3ylwbZ6ozo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755602578; c=relaxed/simple; bh=lx9i6RfMrgZPvRQQSqU1GeDKClYxgkVDFORTDq1kJPY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hm/fYmnlPqpVBMoEzbffV3QqKsBfA+Vm46ukDabzaEh7HdA2CgVTJgciuewjuFvtUUaE2DCxtD+KmvUBkIsZ+yCP6ksdq1GdiJd9uswQTu5Bkw1AvIAWSJG1FVsXWpmkdqegOGziPRCvMh3GMLNLWCO7rWLYk2VNbl/AvCIcqzM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vyHPvVsN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vyHPvVsN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF892C4CEF1; Tue, 19 Aug 2025 11:22:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755602578; bh=lx9i6RfMrgZPvRQQSqU1GeDKClYxgkVDFORTDq1kJPY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vyHPvVsN//mEC01avZBgD78qndXXtI1fpr4EeHGtuNnYfbWr9DDIMeXfM4UcBBC56 pcZ0e0xSPe3yb2azlw1hyS3jiEXMIb7/5dwN4DMuA51GyaBPAI5GrzWZlyHAA7chTF tiGH5bP1LtoWWSHEEwqc2pcpmmmiUREjfKlI/pDM= Date: Tue, 19 Aug 2025 13:22:55 +0200 From: Greg Kroah-Hartman To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: "Rafael J. Wysocki" , Danilo Krummrich , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/7] sysfs: attribute_group: allow registration of const attribute Message-ID: <2025081957-refueling-anteater-4720@gregkh> References: <20250811-sysfs-const-attr-prep-v3-0-0d973ff46afc@weissschuh.net> <20250811-sysfs-const-attr-prep-v3-1-0d973ff46afc@weissschuh.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250811-sysfs-const-attr-prep-v3-1-0d973ff46afc@weissschuh.net> On Mon, Aug 11, 2025 at 11:14:27AM +0200, Thomas Weißschuh wrote: > To be able to constify instances of struct attribute it has to be > possible to add them to struct attribute_group. > The current type of the attrs member however is not compatible with that. > Introduce a union that allows registration of both const and non-const > attributes to enable a piecewise transition. > As both union member types are compatible no logic needs to be adapted. > > Technically it is now possible register a const struct > attribute and receive it as mutable pointer in the callbacks. > This is a soundness issue. > But this same soundness issue already exists today in > sysfs_create_file(). > Also the struct definition and callback implementation are always > closely linked and are meant to be moved to const in lockstep. > > Similar to commit 906c508afdca ("sysfs: attribute_group: allow registration of const bin_attribute") > > Signed-off-by: Thomas Weißschuh > --- > include/linux/sysfs.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h > index f418aae4f1134f8126783d9e8eb575ba4278e927..a47092e837d9eb014894d1f7e49f0fd0f9a2e350 100644 > --- a/include/linux/sysfs.h > +++ b/include/linux/sysfs.h > @@ -105,7 +105,10 @@ struct attribute_group { > size_t (*bin_size)(struct kobject *, > const struct bin_attribute *, > int); > - struct attribute **attrs; > + union { > + struct attribute **attrs; > + const struct attribute *const *attrs_new; I know you will drop the "_new" prefix after a while, but "new" is relative, and not very descriptive. How about "_const"? > + }; > union { > const struct bin_attribute *const *bin_attrs; > const struct bin_attribute *const *bin_attrs_new; There is no bin_attrs_new anymore. Finally. sorry about that... greg k-h