[PATCH RESEND] smp: Fix a potential usage of stale nr_cpus

From: Muchun Song
Date: Thu Jul 16 2020 - 03:05:11 EST


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>
---
kernel/smp.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index 472c2b274c65..2a9a04acf123 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;
--
2.11.0