From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 524313BBFBA; Mon, 15 Jun 2026 09:54:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781517248; cv=none; b=HF7iEsFmEpeuheEEJH0U+141NpOrokd0g/Z4ZxUJ1t4vwiToLQX+RwyWwHYJ+ivHB7zkziK74n2FwaeNMsacaJXMm4tziAfGDyNTbGHcHFdMJOwHSa791KyHmDZ5xT2FXRxIWutW9a0tNJvK9etKNYlqOl8UpqKsonn8wyO68Pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781517248; c=relaxed/simple; bh=peZm/dA/V1NACXdcWFNQYDztQuC0ZGTliMu9Rdw8CFM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RvbZiG7iEZc4q/F6+X/cgU7wa4/8W31XE0SA/efuFwdDT29wUss1xTBeZY8RtPF2PwnfkTkDV4s83zvIws/KpZMvTs3havAsccKeS4mQJuDXPwW/qALmfrLzMhNZUMz0z7gW65Bat4u8bU3KyhtImKzxmEFi6Dd3VZvfC9L05kc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CfUH64ji; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CfUH64ji" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91ACB1F000E9; Mon, 15 Jun 2026 09:54:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781517246; bh=sFHjNnWDW/UEjcBAZ8oTGaGh+/904qdh9hRt8q+m+2k=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=CfUH64ji4H9oGcYm1b7GpH9cq745QX3p0TW/wSYa43ibNjqvpx+Hd/McMrmvC3RZP fKKlFUWBKd8fCSQFcEue74uZcbpsIOc5vPi0r5bkB+XtlnaNE/sAJMnYoUHWBu3Ue4 Gwj0UV4h9AXhSDoIYQ8BTwcMYtwUEy3k/tkPsuHphxDwhr+gcHH5NqS0cL+O7fKu47 f5NHy1XgHmuF1GnLMgvoVNZbyt+41qW5X+KM4SlpHWXN4np1I4Y2bo4CSQPJLCWO9j ujnzgkkZ50RhQ551DWVvzeN0I9g6Rtmj3BRfzZ8cEmRdMX34R67dwkB0c/3W5T0COd WgiMNfuhfwb9g== Message-ID: Date: Mon, 15 Jun 2026 11:54:01 +0200 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] of: property: Fix of_fwnode_get_reference_args() with negative index To: Alban Bedel Cc: devicetree@vger.kernel.org, Rob Herring , Saravana Kannan , driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, Tommaso Merciai References: <20260611102806.2643869-1-alban.bedel@lht.dlh.de> <20260615-obedient-axolotl-of-argument-fb55ef@quoll> <20260615113330.11406fbd@OMT-CWNXR4TFW5-LHT> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 15/06/2026 11:33, Alban Bedel wrote: > On Mon, 15 Jun 2026 08:33:32 +0200 > Krzysztof Kozlowski wrote: > >> On Thu, Jun 11, 2026 at 12:28:06PM +0200, Alban Bedel wrote: >>> fwnode_property_get_reference_args() should return -ENOENT when an out >>> of bound index is passed. An issue arised with the OF backend because >>> the OF API use signed indexes while the fwnode API use unsigned ones. >>> When an index value greater the INT_MAX was passed to the OF backend >>> it got casted to a negative value and it returned -EINVAL instead of >> >> INT_MAX is not out of bound for this function. It is invalid value, >> because OF code expects signed. > > But this is fwnode code, it use the OF API but it should implement the > fwnode API which, unlike the OF API, use unsigned index. >>> -ENOENT. This patch add a check to of_fwnode_get_reference_args() to >>> catch negative index before they are passed to the OF API and return >>> -ENOENT right away. >> >> I do not understand why are you fixing this issue that way. For this >> API, the INT_MAX is correct value, but you claim that it is wrong and >> should be ENOENT (even if there is entry). >> >> Fine, if this is not a correct value, then EINVAL. > > Indices larger than INT_MAX are valid in the fwnode API, so returning > -EINVAL is not appropriate here. > Then neither ENOENT are. But really, EINVAL is correct here. This is OF implementation, so this implementation decides what is EINVAL and what is right. Not fwnode API. >> But more important I think this should be just fixed in different way - >> why index in OF calls is signed in the first place? All indices are >> supposed to be unsigned in general, because that is both logical and >> readable when accessing arrays. > > I agree that would be the better fix in the long run. But that would > impact a lot more code and I found it difficult to ensure it would not > potentially break some of its users. I don't see how this fixes anything. You basically replace correct return value to a different one. Best regards, Krzysztof