Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933322AbcK1PbI (ORCPT ); Mon, 28 Nov 2016 10:31:08 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:34190 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932357AbcK1PbC (ORCPT ); Mon, 28 Nov 2016 10:31:02 -0500 Subject: Re: [PATCH] of: Fix issue where code would fall through to error case. To: Rob Herring , Moritz Fischer References: <1479425157-6235-1-git-send-email-moritz.fischer@ettus.com> <582E3FFC.80305@gmail.com> <582E452E.3080909@gmail.com> <583A0110.4090603@gmail.com> Cc: Moritz Fischer , "linux-kernel@vger.kernel.org" , Pantelis Antoniou , moritz@pure-entropy.org, "devicetree@vger.kernel.org" From: Frank Rowand Message-ID: <583C4D83.6040800@gmail.com> Date: Mon, 28 Nov 2016 07:30:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <583A0110.4090603@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2616 Lines: 83 On 11/26/16 13:39, Frank Rowand wrote: > On 11/23/16 13:58, Rob Herring wrote: >> On Thu, Nov 17, 2016 at 6:10 PM, Moritz Fischer >> wrote: >>> On Thu, Nov 17, 2016 at 4:02 PM, Frank Rowand wrote: >>>> On 11/17/16 15:40, Frank Rowand wrote: >>>>> On 11/17/16 15:25, Moritz Fischer wrote: >>>>>> No longer fall through into the error case that prints out >>>>>> an error if no error (err = 0) occurred. >>>>>> >>>>>> Fixes d9181b20a83(of: Add back an error message, restructured) >>>>>> Signed-off-by: Moritz Fischer >>>>>> --- >>>>>> drivers/of/resolver.c | 6 +++++- >>>>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c >>>>>> index 783bd09..785076d 100644 >>>>>> --- a/drivers/of/resolver.c >>>>>> +++ b/drivers/of/resolver.c >>>>>> @@ -358,9 +358,13 @@ int of_resolve_phandles(struct device_node *overlay) >>>>>> >>>>>> err = update_usages_of_a_phandle_reference(overlay, prop, phandle); >>>>>> if (err) >>>>>> - break; >>>>>> + goto err_out; >>>>>> } >>>>>> >>>>>> + of_node_put(tree_symbols); >>>>>> + >>>>>> + return 0; >>>>>> + >>>>>> err_out: >>>>>> pr_err("overlay phandle fixup failed: %d\n", err); >>>>>> out: >>>>> >>>>> Thanks for catching that. >>>>> >>>>> Rob, please apply. >>>>> >>>>> Reviewed-by: Frank Rowand >>>>> >>>>> -Frank >>>> >>>> On second thought, isn't the common pattern when clean up is needed for >>>> both the no-error path and the error path something like: >>>> >>>> >>>> out: >>>> of_node_put(tree_symbols); >>>> return err; >>>> >>>> err_out: >>>> pr_err("overlay phandle fixup failed: %d\n", err); >>>> goto out; >>>> } >>>> >>>> >>>> I don't have a strong opinion, whatever Rob wants to take is fine with me. >>> >>> Same here. I tried to avoid the jumping back part, but if that's the >>> common pattern, >>> I can submit a v2 doing that instead. >> >> Both are ugly. Just do: >> >> if (err) >> pr_err(...); >> >> Rob > > Agreed. Thanks for the touch of sanity Rob. > > -Frank I succumbed to looking only at the few lines of code above and not the fuller context of the file that the patch applies to. The proposed patch was fixing the problem that a normal completion of the for loop was falling through into the err_out label. So what looks cleaner ("if (err) pr_err(...)") is actually not correct. -Frank