linux-kernel - Re: [PATCH 6/6] dma/imx-sdma: check whether event_id0 < 32 when set event

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]

Date:	Wed, 11 Jan 2012 21:09:11 +0800
From:	Richard Zhao <richard.zhao@...escale.com>
To:	Shawn Guo <shawn.guo@...aro.org>
CC:	Eric Miao <eric.miao@...aro.org>, <patches@...aro.org>,
	<vinod.koul@...el.com>, <linux-kernel@...r.kernel.org>,
	<kernel@...gutronix.de>, <dan.j.williams@...el.com>,
	Richard Zhao <richard.zhao@...aro.org>,
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 6/6] dma/imx-sdma: check whether event_id0 < 32 when set
 event_mask

On Wed, Jan 11, 2012 at 09:16:17PM +0800, Shawn Guo wrote:
> On Wed, Jan 11, 2012 at 02:37:08PM +0800, Eric Miao wrote:
> > I think Richard has made the issue quite clear here, the original
> 
> Yes, he has made it clear, but only after I asked for more comments,
> not with the empty commit message.
> 
> > code does seem to have some problems even to me, who do not
> > understand the very details of the SDMA:
> > 
> > -                       sdmac->event_mask0 = 1 << sdmac->event_id0;
> > -                       sdmac->event_mask1 = 1 << (sdmac->event_id0 - 32);
> > 
> > 1. if sdmac->event_id0 >= 32, which will cause event_mask0 to be incorrect
> > 2. if sdmac->event_id < 32, sdmac->event_mask1 will be incorrect
> > 
> My testing tells this is not the case.  The event_mask0 will be 0 in
> case 1) and event_mask1 will be 0 in case 2), which is quite what we
> expect.  And I do not believe you will see any functionality bug with
> the existing code.
Please see my mail mentioned "we shoud not let it depends on gcc's
behavior."
> 
> See, that's why we need verbose commit message to make the patch and
> the problem it's trying to address very clear.
I never doubt it.

Thanks
Richard
> 
> Regards,
> Shawn
> 

--
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/