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Message-ID: <0b82952a6e0b4a05c93f4d18b3d0b2f43b61ab98.camel@perches.com>
Subject: Re: [PATCH] xdp_rxq_info_user: Replace malloc/memset w/calloc
From:   Joe Perches <joe@perches.com>
To:     Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc:     Gaurav Singh <gaurav1086@gmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>,
        KP Singh <kpsingh@chromium.org>,
        "open list:XDP (eXpress Data Path)" <netdev@vger.kernel.org>,
        "open list:XDP (eXpress Data Path)" <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Date:   Fri, 12 Jun 2020 08:19:10 -0700
In-Reply-To: <20200612140520.1e3c0461@carbon>
References: <20200611150221.15665-1-gaurav1086@gmail.com>
         <20200612003640.16248-1-gaurav1086@gmail.com>
         <20200612084244.4ab4f6c6@carbon>
         <427be84b1154978342ef861f1f4634c914d03a94.camel@perches.com>
         <20200612140520.1e3c0461@carbon>
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On Fri, 2020-06-12 at 14:05 +0200, Jesper Dangaard Brouer wrote:
> On Fri, 12 Jun 2020 03:14:58 -0700
> Joe Perches <joe@perches.com> wrote:
> 
> > On Fri, 2020-06-12 at 08:42 +0200, Jesper Dangaard Brouer wrote:
> > > On Thu, 11 Jun 2020 20:36:40 -0400
> > > Gaurav Singh <gaurav1086@gmail.com> wrote:
> > >   
> > > > Replace malloc/memset with calloc
> > > > 
> > > > Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info")
> > > > Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>  
> > > 
> > > Above is the correct use of Fixes + Signed-off-by.
> > > 
> > > Now you need to update/improve the description, to also
> > > mention/describe that this also solves the bug you found.  
> > 
> > This is not a fix, it's a conversion of one
> > correct code to a shorter one.
> 
> Read the code again Joe.  There is a bug in the code that gets removed,
> as it runs memset on the memory before checking if it was NULL.
> 
> IHMO this proves why is it is necessary to mention in the commit
> message, as you didn't notice the bug in your code review.

I didn't review the code at all, just the commit message,

It's important to have commit messages that describe the
defect being corrected too.

Otherwise, a simple malloc/memset(0) vs zalloc equivalent
is not actually a defect.