Subject: linux-next: build failure after merge of the kspp tree

From: Stephen Rothwell <[email-masked]>
Date: Mon, 31 Jan 2022 10:09:54 +1100

Hi all,

After merging the kspp tree, today's linux-next build (x86_64
allmodconfig) failed like this:

In file included from include/linux/string.h:253,
                 from include/linux/bitmap.h:11,
                 from include/linux/cpumask.h:12,
                 from arch/x86/include/asm/cpumask.h:5,
                 from arch/x86/include/asm/msr.h:11,
                 from arch/x86/include/asm/processor.h:22,
                 from arch/x86/include/asm/timex.h:5,
                 from include/linux/timex.h:65,
                 from include/linux/time32.h:13,
                 from include/linux/time.h:60,
                 from include/linux/skbuff.h:15,
                 from include/linux/tcp.h:17,
                 from drivers/net/ethernet/mellanox/mlx5/core/en_tx.c:33:
In function 'fortify_memcpy_chk',
    inlined from 'mlx5e_insert_vlan' at drivers/net/ethernet/mellanox/mlx5/core/en_tx.c:211:2,
    inlined from 'mlx5e_sq_xmit_wqe' at drivers/net/ethernet/mellanox/mlx5/core/en_tx.c:496:4:
include/linux/fortify-string.h:325:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  325 |                         __write_overflow_field(p_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from include/linux/string.h:253,
                 from include/linux/bitmap.h:11,
                 from include/linux/cpumask.h:12,
                 from arch/x86/include/asm/cpumask.h:5,
                 from arch/x86/include/asm/msr.h:11,
                 from arch/x86/include/asm/processor.h:22,
                 from arch/x86/include/asm/timex.h:5,
                 from include/linux/timex.h:65,
                 from include/linux/time32.h:13,
                 from include/linux/time.h:60,
                 from include/linux/ktime.h:24,
                 from include/linux/timer.h:6,
                 from include/linux/netdevice.h:24,
                 from include/trace/events/xdp.h:8,
                 from include/linux/bpf_trace.h:5,
                 from drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c:33:
In function 'fortify_memcpy_chk',
    inlined from 'mlx5e_xmit_xdp_frame' at drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c:344:3:
include/linux/fortify-string.h:325:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  325 |                         __write_overflow_field(p_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Caused by various commits in the mlx5 driver interacting with the new
memcpy checking.

I have disabled CONFIG_MLX5_CORE_EN for today while this gets sorted
out properly.

-- 
Cheers,
Stephen Rothwell