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-next>] [day] [month] [year] [list]
Message-Id: <1244141989.27006.10369.camel@localhost.localdomain>
Date:	Thu, 04 Jun 2009 11:59:49 -0700
From:	Suresh Siddha <suresh.b.siddha@...el.com>
To:	mingo@...e.hu, hpa@...or.com, tglx@...utronix.de
Cc:	linux-kernel@...r.kernel.org, ebiederm@...ssion.com,
	andi@...ux.intel.com, travis@....com, steiner@....com
Subject: [patch] x64: Avoid irq_chip mask/unmask in fixup_irqs for
 interrupt-remapping

From: Suresh Siddha <suresh.b.siddha@...el.com>
Subject: x64: Avoid irq_chip mask/unmask in fixup_irqs for interrupt-remapping

In the presence of interrupt-remapping, irqs will be migrated in the
process context and we don't do (and there is no need to) irq_chip mask/unmask
while migrating the interrupt.

Similarly fix the fixup_irqs() that get called during cpu offline and avoid
calling irq_chip mask/unmask for irqs that are ok to be migrated in the
process context.

While we didn't observe any race condition with the existing code,
this change takes complete advantage of interrupt-remapping in
the newer generation platforms and avoids any potential HW lockup's
(that often worry Eric :)

Signed-off-by: Suresh Siddha <suresh.b.siddha@...el.com>
Cc: Eric W. Biederman <ebiederm@...ssion.com>
---

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 977d8b4..82265a5 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -95,7 +95,7 @@ void fixup_irqs(void)
 			affinity = cpu_all_mask;
 		}
 
-		if (desc->chip->mask)
+		if (!(desc->status & IRQ_MOVE_PCNTXT) && desc->chip->mask)
 			desc->chip->mask(irq);
 
 		if (desc->chip->set_affinity)
@@ -103,7 +103,7 @@ void fixup_irqs(void)
 		else if (!(warned++))
 			set_affinity = 0;
 
-		if (desc->chip->unmask)
+		if (!(desc->status & IRQ_MOVE_PCNTXT) && desc->chip->unmask)
 			desc->chip->unmask(irq);
 
 		spin_unlock(&desc->lock);


--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ