linux-kernel - Re: [RFC PATCH 0/4] kstrdup optimization

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Date:	Tue, 30 Dec 2014 08:16:05 +0100
From:	Andrzej Hajda <a.hajda@...sung.com>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	linux-mm@...ck.org, Marek Szyprowski <m.szyprowski@...sung.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH 0/4] kstrdup optimization

On 12/30/2014 07:45 AM, Andi Kleen wrote:
> Andrzej Hajda <a.hajda@...sung.com> writes:
>
>> kstrdup if often used to duplicate strings where neither source neither
>> destination will be ever modified. In such case we can just reuse the source
>> instead of duplicating it. The problem is that we must be sure that
>> the source is non-modifiable and its life-time is long enough.
> What happens if someone is to kfree() these strings?
>
> -Andi
>
kstrdup_const must be accompanied by kfree_const, I did not mention it
in cover letter
but it is described in the 1st patch commit message.
Simpler alternative (but I am not sure if better) would be to add
similar check
(ie. if pointer is in .rodata) to kfree itself.

Regards
Andrzej
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