Re: [PATCH] net: Fixup netif_attrmask_next_and warning

[Guo Ren]

On Fri, Oct 14, 2022 at 12:39 AM <guoren@xxxxxxxxxx> wrote:
>
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> Don't pass nr_bits as arg1, cpu_max_bits_warn would cause warning
> now.
>
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 1 at include/linux/cpumask.h:110 __netif_set_xps_queue+0x14e/0x770
> Modules linked in:
> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc4-00018-g854701ba4c39 #324
> Hardware name: riscv-virtio,qemu (DT)
> epc : __netif_set_xps_queue+0x14e/0x770
>  ra : __netif_set_xps_queue+0x552/0x770
> epc : ffffffff806fe448 ra : ffffffff806fe84c sp : ff600000023279d0
>  gp : ffffffff815fff88 tp : ff600000023a0000 t0 : ff6000000308ab40
>  t1 : 0000000000000003 t2 : 0000000000000000 s0 : ff60000002327a90
>  s1 : 0000000000000000 a0 : ff6000000308ab00 a1 : ff6000000308ab00
>  a2 : ff6000000308a8e8 a3 : 0000000000000004 a4 : 0000000000000000
>  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
>  s2 : 0000000000000000 s3 : 0000000000000000 s4 : ff60000002327aa0
>  s5 : ffffffff816031c8 s6 : 0000000000000000 s7 : 0000000000000001
>  s8 : 0000000000000000 s9 : 0000000000000004 s10: ff6000000308a8c0
>  s11: 0000000000000004 t3 : 0000000000000000 t4 : 0000000000000014
>  t5 : 0000000000000000 t6 : 0000000000000000
> status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003
> [<ffffffff805e5824>] virtnet_set_affinity+0x14a/0x1c0
> [<ffffffff805e7b04>] virtnet_probe+0x7fc/0xee2
> [<ffffffff8050e120>] virtio_dev_probe+0x164/0x2de
> [<ffffffff8055b69e>] really_probe+0x82/0x224
> [<ffffffff8055b89a>] __driver_probe_device+0x5a/0xaa
> [<ffffffff8055b916>] driver_probe_device+0x2c/0xb8
> [<ffffffff8055bf34>] __driver_attach+0x76/0x108
> [<ffffffff805597c0>] bus_for_each_dev+0x4a/0x8e
> [<ffffffff8055b072>] driver_attach+0x1a/0x28
> [<ffffffff8055ab8c>] bus_add_driver+0x13c/0x1a6
> [<ffffffff8055c722>] driver_register+0x4a/0xfc
> [<ffffffff8050dc34>] register_virtio_driver+0x1c/0x2c
> [<ffffffff80a2bae4>] virtio_net_driver_init+0x7a/0xb0
> [<ffffffff80002840>] do_one_initcall+0x66/0x2e4
> [<ffffffff80a01212>] kernel_init_freeable+0x28a/0x304
> [<ffffffff808b21e2>] kernel_init+0x1e/0x110
> [<ffffffff80003c46>] ret_from_exception+0x0/0x10
> ---[ end trace 0000000000000000 ]---
>
> Fixes: 944c417daeb6 ("net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}")

Sorry, the Fixes commit is 854701ba4c39.
----
commit 854701ba4c39afae2362ba19a580c461cb183e4f
Author: Yury Norov <yury.norov@xxxxxxxxx>
Date:   Mon Sep 19 14:05:54 2022 -0700

    net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}

    The functions require to be passed with a cpu index prior to one that is
    the first to start search, so the valid input range is [-1, nr_cpu_ids-1).
    However, the code checks against [-1, nr_cpu_ids).

    Acked-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>


> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
> ---
>  net/core/dev.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index fa53830d0683..9ec8b10ae329 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2589,8 +2589,8 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
>                 copy = true;
>
>         /* allocate memory for queue storage */
> -       for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
> -            j < nr_ids;) {
> +       for (j = -1; j < nr_ids;
> +            j = netif_attrmask_next_and(j, online_mask, mask, nr_ids)) {
>                 if (!new_dev_maps) {
>                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
>                         if (!new_dev_maps) {
> --
> 2.36.1
>


-- 
Best Regards
 Guo Ren