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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <54A25135.5030103@samsung.com>
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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/