linux-kernel - Re: [PATCH] clear irq pending when bypassing it

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:	Thu, 30 Apr 2009 14:00:12 -0400
From:	Joe Korty <joe.korty@...r.com>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	"venkatesh.pallipadi@...el.com" <venkatesh.pallipadi@...el.com>,
	"mingo@...e.hu" <mingo@...e.hu>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] clear irq pending when bypassing it

On Thu, Apr 30, 2009 at 12:49:39PM -0400, Eric W. Biederman wrote:
> Joe Korty <jak@...hoon.ccur.com> writes:
> 
> > IRQ_MOVE_PENDING must be cleared whenever it is bypassed.
> >
> > Otherwise, we risk an old, pending affinity change
> > overtaking and erasing a more recent affinity change that
> > had been directly applied (eg, IRQ_MOVE_PCNTXT mode).
> 
> When can this happen?

Probably doesn't happen.  AFAIK, each IRQ is either fully MSI
or non-MSI.  The MSI IRQs will always use IRQ_MOVE_PCNTXT and
the non-MSI's will never use IRQ_MOVE_PCNTXT.  Thus no collision.

It could only happen if it was possible for a MSI and non-MSI
device to share an IRQ.

Joe
--
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/