powerpc: fix memory corruption by pnv_alloc_idle_core_states
authorJan Stancek <jstancek@redhat.com>
Tue, 31 Mar 2015 16:11:46 +0000 (18:11 +0200)
committerMichael Ellerman <mpe@ellerman.id.au>
Wed, 1 Apr 2015 01:05:44 +0000 (12:05 +1100)
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/include/asm/cputhreads.h

index 2bf8e9307be9833b5bf9af51defdfada8feae68d..4c8ad592ae3351d96f7e225411d9f551657c5bc7 100644 (file)
@@ -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)