linux-kernel - Re: [PATCH] coccinelle: api: add kzfree script

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Message-ID: <99e46d3d-b651-15a4-df94-1b4aa3719954@linux.com>
Date:   Mon, 15 Jun 2020 16:51:24 +0300
From:   Denis Efremov <efremov@...ux.com>
To:     Dan Carpenter <dan.carpenter@...cle.com>
Cc:     Joe Perches <joe@...ches.com>, Julia Lawall <Julia.Lawall@...6.fr>,
        cocci@...teme.lip6.fr, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] coccinelle: api: add kzfree script



On 6/15/20 3:03 PM, Dan Carpenter wrote:
> On Sun, Jun 14, 2020 at 10:42:54PM +0300, Denis Efremov wrote:
>> On 6/4/20 7:27 PM, Joe Perches wrote:
>>> On Thu, 2020-06-04 at 17:08 +0300, Denis Efremov wrote:
>>>> Check for memset() with 0 followed by kfree().
>>>
>>> Perhaps those uses should be memzero_explicit or kvfree_sensitive.
>>>
>>
>> Is it safe to suggest to use kzfree instead of memzero_explicit && kfree?
>> Or it would be better to use kvfree_sensitive in this case.
>>
>> kzfree uses memset(0) with no barrier_data.
> 
> Yeah.  That seems buggy.  It should have a barrier.  Also I thought I
> saw somewhere that Linus doesn't like the name and so that's why we have
> the _sensitive() name?
> 

Oh, there are already patches for renaming kzfree to kfree_sensitive.

https://lkml.org/lkml/2020/4/13/729

It seems they are not accepted despite multiple acks, through.

Thanks,
Denis