The following commit has been merged into the sched/core branch of tip: Commit-ID: 589343569d7b58a64ec2446e6686c8e79aea7fcf Gitweb: https://git.kernel.org/tip/589343569d7b58a64ec2446e6686c8e79aea7fcf Author: Muchun Song <songmuchun@xxxxxxxxxxxxx> AuthorDate: Thu, 16 Jul 2020 15:04:57 +08:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Wed, 22 Jul 2020 10:22:04 +02:00 smp: Fix a potential usage of stale nr_cpus The get_option() maybe return 0, it means that the nr_cpus is not initialized. Then we will use the stale nr_cpus to initialize the nr_cpu_ids. So fix it. Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200716070457.53255-1-songmuchun@xxxxxxxxxxxxx --- kernel/smp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/smp.c b/kernel/smp.c index aa17eed..d0ae8eb 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -634,8 +634,7 @@ static int __init nrcpus(char *str) { int nr_cpus; - get_option(&str, &nr_cpus); - if (nr_cpus > 0 && nr_cpus < nr_cpu_ids) + if (get_option(&str, &nr_cpus) && nr_cpus > 0 && nr_cpus < nr_cpu_ids) nr_cpu_ids = nr_cpus; return 0;