From: Helge Deller <deller@gmx.de>
Date: Tue, 19 Sep 2023 13:26:35 +0000 (+0200)
Subject: parisc: Fix crash with nr_cpus=1 option
X-Git-Tag: v6.6-rc5~4^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d3b3c637e4eb8d3bbe53e5692aee66add72f9851;p=thirdparty%2Fkernel%2Flinux.git

parisc: Fix crash with nr_cpus=1 option

John David Anglin reported that giving "nr_cpus=1" on the command
line causes a crash, while "maxcpus=1" works.

Reported-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.18+
---

diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 4098f9a0964b9..2019c1f04bd03 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -440,7 +440,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 	if (cpu_online(cpu))
 		return 0;
 
-	if (num_online_cpus() < setup_max_cpus && smp_boot_one_cpu(cpu, tidle))
+	if (num_online_cpus() < nr_cpu_ids &&
+		num_online_cpus() < setup_max_cpus &&
+		smp_boot_one_cpu(cpu, tidle))
 		return -EIO;
 
 	return cpu_online(cpu) ? 0 : -EIO;