Re: [PATCH v2] netfilter: Clean up tests if NULL returned on failure

From	SIMRAN SINGHAL <singhalsimran0@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2] netfilter: Clean up tests if NULL returned on failure
Date	2017-03-29 11:20 +0200
Message-ID	<tqhVM-4OF-11@gated-at.bofh.it> (permalink)
References	<tpZcu-88d-23@gated-at.bofh.it> <tpZYR-lk-5@gated-at.bofh.it> <tq2am-1Rr-7@gated-at.bofh.it> <tqfKh-3aT-5@gated-at.bofh.it> <tqhsJ-4jR-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Mar 29, 2017 at 2:19 PM, SIMRAN SINGHAL
<singhalsimran0@gmail.com> wrote:
> On Wed, Mar 29, 2017 at 12:25 PM, Jan Engelhardt <jengelh@inai.de> wrote:
>>
>> On Tuesday 2017-03-28 18:23, SIMRAN SINGHAL wrote:
>>>On Tue, Mar 28, 2017 at 7:24 PM, Jan Engelhardt <jengelh@inai.de> wrote:
>>>> On Tuesday 2017-03-28 15:13, simran singhal wrote:
>>>>
>>>>>Some functions like kmalloc/kzalloc return NULL on failure. When NULL
>>>>>represents failure, !x is commonly used.
>>>>>
>>>>>@@ -910,7 +910,7 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest,
>>>>>       }
>>>>>
>>>>>       dest = kzalloc(sizeof(struct ip_vs_dest), GFP_KERNEL);
>>>>>-      if (dest == NULL)
>>>>>+      if (!dest)
>>>>>               return -ENOMEM;
>>>>
>>>> This kind of transformation however is not cleanup anymore, it's really
>>>> bikeshedding and should be avoided. There are pro and cons for both
>>>> variants, and there is not really an overwhelming number of arguments
>>>> for either variant to justify the change.
>>>
>>>Sorry, but I didn't get what you are trying to convey. And particularly pros and
>>>cons of both variants.
>>
>> The ==NULL/!=NULL part sort of ensures that the left side is a pointer, which
>> is lost when just using the variable and have it implicitly convert to bool.
>
> Thanks for the explaination!!!!
>
> But, according to me we should prefer != NULL over ==NULL according to
> coding style.

Sorry their is typing mistake in above.

But, according to me we should prefer !var over ( var ==NULL ) according to the
coding style

Thread

[PATCH v2] netfilter: Clean up tests if NULL returned on failure simran singhal <singhalsimran0@gmail.com> - 2017-03-28 15:20 +0200
  Re: [PATCH v2] netfilter: Clean up tests if NULL returned on  failure Jan Engelhardt <jengelh@inai.de> - 2017-03-28 16:10 +0200
    Re: [PATCH v2] netfilter: Clean up tests if NULL returned on failure SIMRAN SINGHAL <singhalsimran0@gmail.com> - 2017-03-28 18:30 +0200
      Re: [PATCH v2] netfilter: Clean up tests if NULL returned on  failure Jan Engelhardt <jengelh@inai.de> - 2017-03-29 09:00 +0200
        Re: [PATCH v2] netfilter: Clean up tests if NULL returned on failure SIMRAN SINGHAL <singhalsimran0@gmail.com> - 2017-03-29 10:50 +0200
          Re: [PATCH v2] netfilter: Clean up tests if NULL returned on failure SIMRAN SINGHAL <singhalsimran0@gmail.com> - 2017-03-29 11:20 +0200
            Re: [PATCH v2] netfilter: Clean up tests if NULL returned on  failure Jan Engelhardt <jengelh@inai.de> - 2017-03-29 11:40 +0200

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