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 255EB1A9FAC; Sat, 29 Nov 2025 15:25:33 +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=1764429934; cv=none; b=MPdxZj2mUqDa6Gm3NVFfBpRDE0Wr+dYD8SQRNSQlyDXntaO9XNpMPbZkXjisaqrS4AKSpqVpRNnirrpm+k4iJz8PftesQioxA2N91165ZDaq1XhNCh8dtxcZA+ngnFWpypEk98u7TQz70tl92GT//Zr4MBKu8tGFXZdedFkpPac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764429934; c=relaxed/simple; bh=FDfNfdjZAK1CRX+PZryTBYkcC38g8MKCrpLm485korQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aS8jeRw0FWN8v/PMCkiBLENsAQEVLnh9zv2m7KgF4m7XudlXSh2YNB1u/6zkyLq6IxGEgY5yHBZ7wbjSOdP1xNidnyoIDfBj3A+AAvS6b3VNJTqqb/ltOMz24McK9jE11MNDIMuG/UkHgd4Y2DiRdyJhLfxxGISVBaUp5Lv1rF0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GBmpQYWr; 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="GBmpQYWr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8849C4CEF7; Sat, 29 Nov 2025 15:25:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764429933; bh=FDfNfdjZAK1CRX+PZryTBYkcC38g8MKCrpLm485korQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=GBmpQYWr80Ajy6bRs3lLVE2ZsOP+GszaDMDxdeUyZVzD8z0yQ960oPHxMqUIzd+FG upVxMvjKHMt6TAq2lXL4Xmw0MZng5Ax/I0/0CB12Czndo4NqnvxSvoS9chZrHtVU9L yR/K4P99KsMcnLxbaYmkKZNNzqykxebdpKj7XLPsd69bd72ATNtV5K0MQQFtve1I3x dROQ6HnlG1NzjqoD6Ol2tw/YBbb3n4c59a7pgUOcbQO74eLJMQfMdlOh5YdncdwPrv ANTwFEuB+C3phNjh7LGu6Tcaculmb1wP5Qup0q5KeW6a786kW+fjeYzuM66TAWPs4G RQxuXOxvYrg8w== Message-ID: <58ccca49-f30c-4461-b4aa-4985f72c89fb@kernel.org> Date: Sat, 29 Nov 2025 16:25:28 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/4] syscon: Wire up has-inaccessible-regs To: Richard Weinberger , linux-kernel@vger.kernel.org Cc: linux-omap@vger.kernel.org, devicetree@vger.kernel.org, arnd@arndb.de, lee@kernel.org, dakr@kernel.org, rafael@kernel.org, gregkh@linuxfoundation.org, broonie@kernel.org, tony@atomide.com, rogerq@kernel.org, khilman@baylibre.com, andreas@kemnade.info, aaro.koskinen@iki.fi, conor+dt@kernel.org, krzk+dt@kernel.org, robh@kernel.org References: <20251129142042.344359-1-richard@nod.at> <20251129142042.344359-4-richard@nod.at> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 29/11/2025 15:20, Richard Weinberger wrote: > Evaluate the has-inaccessible-regs device tree property to disable > debugfs access if a register map contains dangerous/harmful registers. > > Signed-off-by: Richard Weinberger > --- > drivers/mfd/syscon.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index ae71a2710bed8..73fff0df3f42f 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -70,6 +70,16 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) > else if (of_property_read_bool(np, "native-endian")) > syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE; > > + > + /* > + * Disable debugfs access if a register map has various inaccessible > + * registers. > + * In such a case the device driver has to know exactly how and when > + * access is allowed but general access via userspace can cause harm. > + */ > + if (of_property_read_bool(np, "has-inaccessible-regs")) > + syscon_config.debugfs_disable = true; So you mark ENTIRE device like that? Then you don't need the property. Your compatible already tells you that (IOW, this is fully deducible from the compatible). Best regards, Krzysztof