Messages in this thread Patch in this message | | | From | Andrew Jones <> | Subject | [PATCH v3 1/2] RISC-V: Fix /proc/cpuinfo cpumask warning | Date | Fri, 14 Oct 2022 17:58:44 +0200 |
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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 <ajones@ventanamicro.com> Cc: Yury Norov <yury.norov@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> --- arch/riscv/kernel/cpu.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 4d0dece5996c..5aa0ae8dd115 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -166,6 +166,9 @@ 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); -- 2.37.3
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