Re: [PATCH] Use kzfree in tty buffer management to enforce data sanitization

From: Pekka Enberg
Date: Sun May 31 2009 - 02:27:21 EST

Hi Larry,

On Sat, 30 May 2009, Larry H. wrote:
>>> This patch doesn't affect fastpaths.

On 19:04 Sat 30 May, Linus Torvalds wrote:
>> This patch is ugly as hell.
>> You already know the size of the data to clear.
>> If we actually wanted this (and I am in _no_way_ saying we do), the only
>> sane thing to do is to just do
>>       memset(buf->data, 0, N_TTY_BUF_SIZE);
>>       if (PAGE_SIZE != N_TTY_BUF_SIZE)
>>               kfree(...)
>>       else
>>               free_page(...)

On Sun, May 31, 2009 at 5:35 AM, Larry H. <research@xxxxxxxxxxxxxx> wrote:
> It wasn't me who proposed using kzfree in these places. Ask Ingo and
> Peter or refer to the entire thread about my previous patches.

Nobody suggested using kzfree() in this _specific_place_. It's obvious
that memset() is a better solution here given the current constraints
of the code as demonstrated by Linus' patch.

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