bpf: Fix -Wshadow warnings

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@arndb.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201026162110.3710415-1-arnd@kernel.org

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 72d62cb..1b62397 100644 (file)
--- 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)