From: pkluba@dension•com (Patrik, Kluba)
To: linux-arm-kernel@lists•infradead.org
Subject: Fw: [PATCH 01/01] arm: fix a preempt_count() corruption for CONFIG_PREEMPT=n
Date: Sat, 15 Dec 2012 08:51:29 +0100 [thread overview]
Message-ID: <20121215085129.71d203b2.pkluba@dension.com> (raw)
Hi All,
Maybe this list is a better place for the following request.
I've checked, and this bug is also present in the linux-next tree.
Regards,
Patrik
Begin forwarded message:
Date: Fri, 14 Dec 2012 15:13:57 +0100
From: "Patrik, Kluba" <pkluba@dension•com>
To: linux-kernel at vger.kernel.org
Subject: [PATCH 01/01] arm: fix a preempt_count() corruption for
CONFIG_PREEMPT=n
Hi All,
After a hard days' work, I've managed to track down a ghost causing
sporadic kernel warnings and system crashes. The patch applies for the
HEAD of linux-stable. I don't know how to create and submit patches
correctly, and hope that somebody will pick it up...
Regards,
Patrik
---
>From 4dd31e88a2715389e5ac198dcf00b48b4f148ea6 Mon Sep 17 00:00:00 2001
From: Patrik Kluba <pkluba@dension•com>
Date: Fri, 14 Dec 2012 14:36:27 +0100
Subject: [PATCH] arm: fix a preempt_count() corruption for
CONFIG_PREEMPT=n
All the preempt-disabling assembly code is under CONFIG_PREEMPT,
while VFP_bounce calls preempt_enable() uncoditionally, leading to
a preempt_count() corruption (gets set to 0xffffffff). Fix the
imbalance by adding #ifdef CONFIG_PREEMPT before preempt_enable().
---
arch/arm/vfp/vfpmodule.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 3b44e0d..2184f7e 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -428,7 +428,10 @@ void VFP_bounce(u32 trigger, u32 fpexc, struct
pt_regs *regs) if (exceptions)
vfp_raise_exceptions(exceptions, trigger, orig_fpscr,
regs); exit:
+#ifdef CONFIG_PREEMPT
preempt_enable();
+#endif
+ return;
}
static void vfp_enable(void *unused)
--
1.7.10.4
--
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next reply other threads:[~2012-12-15 7:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-15 7:51 Patrik, Kluba [this message]
2012-12-18 23:54 ` Fw: [PATCH 01/01] arm: fix a preempt_count() corruption for CONFIG_PREEMPT=n Stephen Boyd
2012-12-19 0:01 ` Russell King - ARM Linux
2013-01-03 0:41 ` Stephen Boyd
2013-01-04 7:48 ` Patrik, Kluba
2013-01-04 22:21 ` Stephen Boyd
2013-01-08 11:51 ` Patrik, Kluba
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