From d14e99bf95510fa2d6affc371ad68161afc1dc8e Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Fri, 14 Oct 2022 17:58:44 +0200 Subject: RISC-V: Fix /proc/cpuinfo cpumask warning Commit 78e5a3399421 ("cpumask: fix checking valid cpu range") has started issuing warnings[*] when cpu indices equal to nr_cpu_ids - 1 are passed to cpumask_next* functions. seq_read_iter() and cpuinfo's start and next seq operations implement a pattern like n = cpumask_next(n - 1, mask); show(n); while (1) { ++n; n = cpumask_next(n - 1, mask); if (n >= nr_cpu_ids) break; show(n); } which will issue the warning when reading /proc/cpuinfo. Ensure no warning is generated by validating the cpu index before calling cpumask_next(). [*] Warnings will only appear with DEBUG_PER_CPU_MAPS enabled. Signed-off-by: Andrew Jones Reviewed-by: Anup Patel Reviewed-by: Conor Dooley Tested-by: Conor Dooley Acked-by: Yury Norov Link: https://lore.kernel.org/r/20221014155845.1986223-2-ajones@ventanamicro.com/ Fixes: 78e5a3399421 ("cpumask: fix checking valid cpu range") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index fa427bdcf773..852ecccd8920 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -213,6 +213,9 @@ static void print_mmu(struct seq_file *f) static void *c_start(struct seq_file *m, loff_t *pos) { + if (*pos == nr_cpu_ids) + return NULL; + *pos = cpumask_next(*pos - 1, cpu_online_mask); if ((*pos) < nr_cpu_ids) return (void *)(uintptr_t)(1 + *pos); -- cgit v1.2.3