* [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states
@ 2015-03-31 16:11 Jan Stancek
2015-04-01 2:40 ` Michael Ellerman
2015-04-01 9:37 ` Preeti U Murthy
0 siblings, 2 replies; 3+ messages in thread
From: Jan Stancek @ 2015-03-31 16:11 UTC (permalink / raw)
To: linuxppc-dev
Cc: linux-kernel, benh, paulus, mpe, mikey, jstancek, shreyas, preeti,
sbest
Space allocated for paca is based off nr_cpu_ids,
but pnv_alloc_idle_core_states() iterates paca with
cpu_nr_cores()*threads_per_core, which is using NR_CPUS.
This causes pnv_alloc_idle_core_states() to write over memory,
which is outside of paca array and may later lead to various panics.
Fixes: 7cba160ad789 (powernv/cpuidle: Redesign idle states management)
Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
arch/powerpc/include/asm/cputhreads.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
index 2bf8e93..4c8ad59 100644
--- a/arch/powerpc/include/asm/cputhreads.h
+++ b/arch/powerpc/include/asm/cputhreads.h
@@ -55,7 +55,7 @@ static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
static inline int cpu_nr_cores(void)
{
- return NR_CPUS >> threads_shift;
+ return nr_cpu_ids >> threads_shift;
}
static inline cpumask_t cpu_online_cores_map(void)
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states
2015-03-31 16:11 [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states Jan Stancek
@ 2015-04-01 2:40 ` Michael Ellerman
2015-04-01 9:37 ` Preeti U Murthy
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2015-04-01 2:40 UTC (permalink / raw)
To: Jan Stancek
Cc: linuxppc-dev, linux-kernel, benh, paulus, mikey, shreyas, preeti,
sbest
On Tue, 2015-03-31 at 18:11 +0200, Jan Stancek wrote:
> Space allocated for paca is based off nr_cpu_ids,
> but pnv_alloc_idle_core_states() iterates paca with
> cpu_nr_cores()*threads_per_core, which is using NR_CPUS.
>
> This causes pnv_alloc_idle_core_states() to write over memory,
> which is outside of paca array and may later lead to various panics.
>
> Fixes: 7cba160ad789 (powernv/cpuidle: Redesign idle states management)
> Signed-off-by: Jan Stancek <jstancek@redhat.com>
Thanks. I'll send that to Linus in the next day or two and mark it for stable
as well.
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states
2015-03-31 16:11 [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states Jan Stancek
2015-04-01 2:40 ` Michael Ellerman
@ 2015-04-01 9:37 ` Preeti U Murthy
1 sibling, 0 replies; 3+ messages in thread
From: Preeti U Murthy @ 2015-04-01 9:37 UTC (permalink / raw)
To: Jan Stancek, linuxppc-dev, mpe
Cc: linux-kernel, benh, paulus, mikey, shreyas, sbest
On 03/31/2015 09:41 PM, Jan Stancek wrote:
> Space allocated for paca is based off nr_cpu_ids,
> but pnv_alloc_idle_core_states() iterates paca with
> cpu_nr_cores()*threads_per_core, which is using NR_CPUS.
>
> This causes pnv_alloc_idle_core_states() to write over memory,
> which is outside of paca array and may later lead to various panics.
>
> Fixes: 7cba160ad789 (powernv/cpuidle: Redesign idle states management)
> Signed-off-by: Jan Stancek <jstancek@redhat.com>
> ---
> arch/powerpc/include/asm/cputhreads.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
> index 2bf8e93..4c8ad59 100644
> --- a/arch/powerpc/include/asm/cputhreads.h
> +++ b/arch/powerpc/include/asm/cputhreads.h
> @@ -55,7 +55,7 @@ static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
>
> static inline int cpu_nr_cores(void)
> {
> - return NR_CPUS >> threads_shift;
> + return nr_cpu_ids >> threads_shift;
> }
Thanks for the patch!
Reviewed-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
>
> static inline cpumask_t cpu_online_cores_map(void)
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-03-31 16:11 [PATCH] powerpc: fix memory corruption by pnv_alloc_idle_core_states Jan Stancek
2015-04-01 2:40 ` Michael Ellerman
2015-04-01 9:37 ` Preeti U Murthy
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