On Mon, Oct 26, 2020 at 12:37 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> There are thousands of warnings about one macro in a W=2 build:
>
> include/linux/filter.h:561:6: warning: declaration of 'ret' shadows a previous local [-Wshadow]
>
> Prefix all the locals in that macro with __ to avoid most of
> these warnings.
>
> Fixes: 492ecee892c2 ("bpf: enable program stats")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> include/linux/filter.h | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/filter.h b/include/linux/filter.h
> index 954f279fde01..20ba04583eaa 100644
> --- a/include/linux/filter.h
> +++ b/include/linux/filter.h
> @@ -558,21 +558,21 @@ struct sk_filter {
> DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
>
> #define __BPF_PROG_RUN(prog, ctx, dfunc) ({ \
> - u32 ret; \
> + u32 __ret; \
> cant_migrate(); \
> if (static_branch_unlikely(&bpf_stats_enabled_key)) { \
> - struct bpf_prog_stats *stats; \
> - u64 start = sched_clock(); \
> - ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \
> - stats = this_cpu_ptr(prog->aux->stats); \
> - u64_stats_update_begin(&stats->syncp); \
> - stats->cnt++; \
> - stats->nsecs += sched_clock() - start; \
> - u64_stats_update_end(&stats->syncp); \
> + struct bpf_prog_stats *__stats; \
> + u64 __start = sched_clock(); \
> + __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \
> + __stats = this_cpu_ptr(prog->aux->stats); \
> + u64_stats_update_begin(&__stats->syncp); \
> + __stats->cnt++; \
> + __stats->nsecs += sched_clock() - __start; \
> + u64_stats_update_end(&__stats->syncp); \
> } else { \
> - ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \
> + __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \
> } \
> - ret; })
> + __ret; })
>
> #define BPF_PROG_RUN(prog, ctx) \
> __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func)
> --
> 2.27.0
>
