From: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> [ Upstream commit 872f27103874a73783aeff2aac2b41a489f67d7c ] /proc/cpuinfo should not print information about CPU 0 when it is offline. Fixes: 281eaa8cb67c ("s390/cpuinfo: simplify locking and skip offline cpus early") Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> Reviewed-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> [heiko.carstens@xxxxxxxxxx: shortened commit message] Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/s390/kernel/processor.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c index d856263fd7687..737e22cf09728 100644 --- a/arch/s390/kernel/processor.c +++ b/arch/s390/kernel/processor.c @@ -139,8 +139,9 @@ static void show_cpu_mhz(struct seq_file *m, unsigned long n) static int show_cpuinfo(struct seq_file *m, void *v) { unsigned long n = (unsigned long) v - 1; + unsigned long first = cpumask_first(cpu_online_mask); - if (!n) + if (n == first) show_cpu_summary(m, v); if (!machine_has_cpu_mhz) return 0; @@ -153,6 +154,8 @@ static inline void *c_update(loff_t *pos) { if (*pos) *pos = cpumask_next(*pos - 1, cpu_online_mask); + else + *pos = cpumask_first(cpu_online_mask); return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL; } -- 2.20.1