[v0][PATCH 1/1] powerpc/book3e: disable interrupt after preempt_schedule_irq

Subsystems: linux for powerpc (32-bit and 64-bit), the rest

2 messages, 2 authors, 2013-01-24 · open the first message on its own page

[v0][PATCH 1/1] powerpc/book3e: disable interrupt after preempt_schedule_irq

From: Tiejun Chen <hidden>
Date: 2013-01-06 10:49:47

In preempt case current arch_local_irq_restore() from
preempt_schedule_irq() may enable hard interrupt but we really
should disable interrupts when we return from the interrupt,
and so that we don't get interrupted after loading SRR0/1.

Signed-off-by: Tiejun Chen <redacted>
---
 arch/powerpc/kernel/entry_64.S |   13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e9a906c..4e1de34 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -662,6 +662,19 @@ resume_kernel:
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
+
+	/*
+	 * arch_local_irq_restore() from preempt_schedule_irq above may
+	 * enable hard interrupt but we really should disable interrupts
+	 * when we return from the interrupt, and so that we don't get
+	 * interrupted after loading SRR0/1.
+	 */
+#ifdef CONFIG_PPC_BOOK3E
+	wrteei	0
+#else
+	ld	r10,PACAKMSR(r13) /* Get kernel MSR without EE */
+	mtmsrd	r10,1		  /* Update machine state */
+#endif /* CONFIG_PPC_BOOK3E */
 #endif /* CONFIG_PREEMPT */
 
 	.globl	fast_exc_return_irq
-- 
1.7.9.5

Re: [v0][PATCH 1/1] powerpc/book3e: disable interrupt after preempt_schedule_irq

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2013-01-24 04:03:02

On Sun, 2013-01-06 at 18:49 +0800, Tiejun Chen wrote:
In preempt case current arch_local_irq_restore() from
preempt_schedule_irq() may enable hard interrupt but we really
should disable interrupts when we return from the interrupt,
and so that we don't get interrupted after loading SRR0/1.
This is an excellent catch, thanks !

Cheers,
Ben.
quoted hunk
Signed-off-by: Tiejun Chen <redacted>
---
 arch/powerpc/kernel/entry_64.S |   13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e9a906c..4e1de34 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -662,6 +662,19 @@ resume_kernel:
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
+
+	/*
+	 * arch_local_irq_restore() from preempt_schedule_irq above may
+	 * enable hard interrupt but we really should disable interrupts
+	 * when we return from the interrupt, and so that we don't get
+	 * interrupted after loading SRR0/1.
+	 */
+#ifdef CONFIG_PPC_BOOK3E
+	wrteei	0
+#else
+	ld	r10,PACAKMSR(r13) /* Get kernel MSR without EE */
+	mtmsrd	r10,1		  /* Update machine state */
+#endif /* CONFIG_PPC_BOOK3E */
 #endif /* CONFIG_PREEMPT */
 
 	.globl	fast_exc_return_irq
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help