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 A456C12B71 for ; Fri, 12 Jul 2024 07:19:06 +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=1720768746; cv=none; b=aoy/D5Ti07q8Rufq1DQa/JyP6lph1CpIEtcU8B0BI3+RYuVxj0lJibsE0uBoCRbyFjagPNlelYjjLQJOYbVl8b29rrcpsY4N5zDI9L7n0aSuKWHHNr6UfZ6tuAZMvYmx67R0L9H7mel6ax8HUY96MBeUxZW+O4cMQlFObqoiIk0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720768746; c=relaxed/simple; bh=DN0yhcGErt3ZK+10gBvOnzNHZaDv6LP6/yELSW7NStg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cI+dS95hT6/bfo3hr+ZQ60L3jtCUxYweGvTsIOaUD4/Y0NAbpt2UMCCPOBzAV2JlpTWEEdvqYyNaJg+NX5hwexfE87XMgUidx2VJvqrn70Yjj9ufMowfACwrbtKGpeYNKcwWNI1gq5fu2fk3uOiNrk3zr9iwRLBRwRkbFvur5N8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vXc01ofO; 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="vXc01ofO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96A83C3277B; Fri, 12 Jul 2024 07:19:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720768746; bh=DN0yhcGErt3ZK+10gBvOnzNHZaDv6LP6/yELSW7NStg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vXc01ofOEyUbSoMQq+IcU99xYjn1nbTe8ExG9YPOTjbfSQMxwy2gqgbj9v/+cLPSq B898SebhVs1sGjtyubhP1TmYmaXC8AGbcmM2OP3BoH3m2iUnb96kLmmK1ftYdxacYq VE7X3rIcDEGUMJYoY+J0m+UtnATzD5jG3Fy9hXxY= Date: Fri, 12 Jul 2024 09:19:02 +0200 From: Greg Kroah-Hartman To: Leesoo Ahn Cc: Carlos Llamas , Leesoo Ahn , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Suren Baghdasaryan , linux-kernel@vger.kernel.org Subject: Re: [PATCH] android: binder: print error message on failure of creating proc file Message-ID: <2024071241-entail-icing-58cf@gregkh> References: <20240712032140.4012667-1-lsahn@wewakecorp.com> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 12, 2024 at 03:52:32PM +0900, Leesoo Ahn wrote: > 2024년 7월 12일 (금) 오후 1:01, Carlos Llamas 님이 작성: > > > > On Fri, Jul 12, 2024 at 12:21:40PM +0900, Leesoo Ahn wrote: > > > It better prints out an error message to give more information if > > > calling debugfs_create_file() is failure and the return value has an > > > error code. > > > > > > Signed-off-by: Leesoo Ahn > > > --- > > > > What are you trying to fix? My understanding is that users of the > > debugfs API can safely ignore any errors and move on. IMO it doesn't > > make sense to add this without a real reason. > > What I was trying to say, users would predict that a file under > debugfs will be created while they are opening a binder device. But if > it failed for some reason without any debug message, they would get > confused that the file doesn't exist and have no clue what happened > without a message. And that's fine, again, the kernel does not care if debugfs is working or not. It's just a debugging help, it does not affect the normal operation of a system at all, and as such, userspace can't rely on it being present for any functionality other than debugging issues that might happen at times. thanks, greg k-h