linux-kernel - RE: [PATCH] rtc: twl: optimize IRQ bit access

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] [day] [month] [year] [list]

Date:	Mon, 30 Jan 2012 08:47:59 +0530
From:	Venu Byravarasu <vbyravarasu@...dia.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	"a.zummo@...ertech.it" <a.zummo@...ertech.it>,
	"rtc-linux@...glegroups.com" <rtc-linux@...glegroups.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] rtc: twl: optimize IRQ bit access

> -----Original Message-----
> From: Andrew Morton [mailto:akpm@...ux-foundation.org]
> Sent: Saturday, January 28, 2012 6:09 AM
> To: Venu Byravarasu
> Cc: a.zummo@...ertech.it; rtc-linux@...glegroups.com; linux-
> kernel@...r.kernel.org
> Subject: Re: [PATCH] rtc: twl: optimize IRQ bit access
> 
> Are these functions called frequently enough to make this optimisation
> significant?
I did not check how frequent these functions are called.
However, as the values are cached any way, thought of using them before doing hardware access.
> 
> I can see no locking protecting rtc_irq_bits from concurrent updaters.
> Is this code as racy as it appears?
Yes, looks like it is. Will push a separate patch to fix this issue.

--
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/