Re: [PATCH] bpf/core.c - silence warning messages

From: Daniel Borkmann
Date: Wed Jun 12 2019 - 11:00:56 EST


On 06/07/2019 04:39 AM, Valdis KlÄtnieks wrote:
> Compiling kernel/bpf/core.c with W=1 causes a flood of warnings:
>
> kernel/bpf/core.c:1198:65: warning: initialized field overwritten [-Woverride-init]
> 1198 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
> | ^~~~
> kernel/bpf/core.c:1087:2: note: in expansion of macro 'BPF_INSN_3_TBL'
> 1087 | INSN_3(ALU, ADD, X), \
> | ^~~~~~
> kernel/bpf/core.c:1202:3: note: in expansion of macro 'BPF_INSN_MAP'
> 1202 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
> | ^~~~~~~~~~~~
> kernel/bpf/core.c:1198:65: note: (near initialization for 'public_insntable[12]')
> 1198 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
> | ^~~~
> kernel/bpf/core.c:1087:2: note: in expansion of macro 'BPF_INSN_3_TBL'
> 1087 | INSN_3(ALU, ADD, X), \
> | ^~~~~~
> kernel/bpf/core.c:1202:3: note: in expansion of macro 'BPF_INSN_MAP'
> 1202 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
> | ^~~~~~~~~~~~
>
> 98 copies of the above.
>
> The attached patch silences the warnings, because we *know* we're overwriting
> the default initializer. That leaves bpf/core.c with only 6 other warnings,
> which become more visible in comparison.
>
> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@xxxxxx>

Makes sense, applied!