[PATCH SRU Bionic 2/3] sched/topology: Fix sched_domain_topology_level alloc in sched_init_numa()

[dann frazier]

From: Dietmar Eggemann <dietmar.eggemann at arm.com>

BugLink: https://bugs.launchpad.net/bugs/1951289

commit 71e5f6644fb2f3304fcb310145ded234a37e7cc1 upstream.

Commit "sched/topology: Make sched_init_numa() use a set for the
deduplicating sort" allocates 'i + nr_levels (level)' instead of
'i + nr_levels + 1' sched_domain_topology_level.

This led to an Oops (on Arm64 juno with CONFIG_SCHED_DEBUG):

sched_init_domains
  build_sched_domains()
    __free_domain_allocs()
      __sdt_free() {
	...
        for_each_sd_topology(tl)
	  ...
          sd = *per_cpu_ptr(sdd->sd, j); <--
	  ...
      }

Signed-off-by: Dietmar Eggemann <dietmar.eggemann at arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Tested-by: Vincent Guittot <vincent.guittot at linaro.org>
Tested-by: Barry Song <song.bao.hua at hisilicon.com>
Link: https://lkml.kernel.org/r/6000e39e-7d28-c360-9cd6-8798fd22a9bf@arm.com
Signed-off-by: dann frazier <dann.frazier at canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit 6d93ffef8ccdc1f3da616c71ef1fe580c7a4a3af linux-4.19.y)
Signed-off-by: dann frazier <dann.frazier at canonical.com>
---
 kernel/sched/topology.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 2f94a02b45f9..4f49b941be34 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1433,7 +1433,7 @@ void sched_init_numa(void)
 	/* Compute default topology size */
 	for (i = 0; sched_domain_topology[i].mask; i++);
 
-	tl = kzalloc((i + nr_levels) *
+	tl = kzalloc((i + nr_levels + 1) *
 			sizeof(struct sched_domain_topology_level), GFP_KERNEL);
 	if (!tl)
 		return;
-- 
2.36.0