Re: [RFC PATCH 0/4] kstrdup optimization

From: Andrzej Hajda
Date: Tue Dec 30 2014 - 02:16:47 EST

On 12/30/2014 07:45 AM, Andi Kleen wrote:
> Andrzej Hajda <a.hajda@xxxxxxxxxxx> 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.

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