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Re: [PATCH] Fix buffer overflow in SH expand_cbranchdi4 (PR target/79462)
- From: Oleg Endo <oleg dot endo at t-online dot de>
- To: Jakub Jelinek <jakub at redhat dot com>, Alexandre Oliva <aoliva at redhat dot com>, Kaz Kojima <kkojima at gcc dot gnu dot org>, Oleg Endo <olegendo at gcc dot gnu dot org>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 14 Feb 2017 17:41:35 +0900
- Subject: Re: [PATCH] Fix buffer overflow in SH expand_cbranchdi4 (PR target/79462)
- Authentication-results: sourceware.org; auth=none
- References: <20170214082237.GS1849@tucnak>
On Tue, 2017-02-14 at 09:22 +0100, Jakub Jelinek wrote:
> Hi!
>
> The following patch fixes a buffer overflow in the SH backend.
> r235698 removed an operand (clobber of match_scratch) from the
> various
> cbranch pattersn that called expand_cbranchdi4 as well as all but
> one references to operands[4] in that code. Now that the insn only
> has 4 operands, clearing operands[4] is a buffer overflow.
>
> Tested by Kaz (thanks).
> In the PR Oleg asked for a comment, but I'm not sure how useful is
> it to document that something used to be cleared and is not anymore,
> because it doesn't exist.
>
> Ok for trunk (or suggested wording for a comment)?
>
Sorry, I haven't checked the code in a while. If it's the last
reference, then of course a comment would be just confusing like you've
said. Thanks for figuring it out. OK as it is for trunk and the other
branches.
Cheers,
Oleg