linux-kernel - Re: [PATCH 01/22] powerpc: convert idle_loop to use hard_irq

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: <17762.9524.67555.778549@cargo.ozlabs.ibm.com>
Date:	Tue, 21 Nov 2006 08:59:16 +1100
From:	Paul Mackerras <paulus@...ba.org>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	cbe-oss-dev@...abs.org, linuxppc-dev@...abs.org,
	linux-kernel@...r.kernel.org,
	Arnd Bergmann <arnd.bergmann@...ibm.com>
Subject: Re: [PATCH 01/22] powerpc: convert idle_loop to use hard_irq_disable()

Arnd Bergmann writes:

> I got a bug report that I believe might be fixed by this
> patch. The problem seems to be that with soft-disabled
> interrupts in power_save, we can still get external exceptions
> on Cell, even if we are in pause(0) a.k.a. sleep state.

[snip]

> -				local_irq_disable();
> +				hard_irq_disable();

This would mean that any platform-specific power_save function that
wants to re-enable interrupts (as the pseries ones do) would have to
do hard_irq_enable instead of local_irq_enable.  Also, I don't think
this change will be good on iSeries.

What we want is an irq-disable function that is like local_irq_disable
but also clears MSR_EE and the hard irq enabled flag (provided we
aren't running on iSeries).

Paul.
-
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/