[PATCH] RISC-V: Fix /proc/cpuinfo cpumask warning

From: Andrew Jones
Date: Tue Oct 11 2022 - 13:50:52 EST


Upcoming cpumask changes will start issuing warnings[*] when cpu
indices equal to nr_cpu_ids are passed to cpumask_next* functions.
Ensure we don't generate a warning when reading /proc/cpuinfo by
validating the cpu index before calling cpumask_next().

[*] Warnings will only appear with DEBUG_PER_CPU_MAPS enabled.

Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Cc: Yury Norov <yury.norov@xxxxxxxxx>
---
arch/riscv/kernel/cpu.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 4aa8cd749441..592ff065e09f 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -166,9 +166,12 @@ static void print_mmu(struct seq_file *f)

static void *c_start(struct seq_file *m, loff_t *pos)
{
- *pos = cpumask_next(*pos - 1, cpu_online_mask);
- if ((*pos) < nr_cpu_ids)
- return (void *)(uintptr_t)(1 + *pos);
+ if (*pos < nr_cpu_ids) {
+ *pos = cpumask_next(*pos - 1, cpu_online_mask);
+ if (*pos < nr_cpu_ids)
+ return (void *)(uintptr_t)(1 + *pos);
+ }
+
return NULL;
}

--
2.37.3