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

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Submitter Tiejun Chen
Date Jan. 6, 2013, 10:49 a.m.
Message ID <1357469374-25719-1-git-send-email-tiejun.chen@windriver.com>
Download mbox | patch
Permalink /patch/209736/
State Accepted, archived
Commit 572177d7c77db1981ba2563e01478126482c43bc
Headers show

Comments

Tiejun Chen - Jan. 6, 2013, 10:49 a.m.
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 <tiejun.chen@windriver.com>
---
 arch/powerpc/kernel/entry_64.S |   13 +++++++++++++
 1 file changed, 13 insertions(+)
Benjamin Herrenschmidt - Jan. 24, 2013, 4:02 a.m.
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.

> Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
> ---
>  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

Patch

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