From: Jan Stancek <jstancek@xxxxxxxxxx> commit d52356e7f48e400ca258c6763a232a92fa82ff68 upstream 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. Bugzilla: https://bugzilla.linux.ibm.com/show_bug.cgi?id=123238 Fixes: 7cba160ad789 (powernv/cpuidle: Redesign idle states management) Signed-off-by: Jan Stancek <jstancek@xxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Preet U. Murthy <preeti@xxxxxxxxxxxxxxxxxx> --- This fix is intended for 3.19 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) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html