ebpf: misc core cleanup

Besides others, move bpf_tail_call_proto to the remaining definitions
of other protos, improve comments a bit (i.e. remove some obvious ones,
where the code is already self-documenting, add objectives for others),
simplify bpf_prog_array_compatible() a bit.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index b3aaabd..7ad5d88 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -45,11 +45,11 @@
 }
 
 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
-	.func = bpf_map_lookup_elem,
-	.gpl_only = false,
-	.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
-	.arg1_type = ARG_CONST_MAP_PTR,
-	.arg2_type = ARG_PTR_TO_MAP_KEY,
+	.func		= bpf_map_lookup_elem,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
 };
 
 static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
@@ -64,13 +64,13 @@
 }
 
 const struct bpf_func_proto bpf_map_update_elem_proto = {
-	.func = bpf_map_update_elem,
-	.gpl_only = false,
-	.ret_type = RET_INTEGER,
-	.arg1_type = ARG_CONST_MAP_PTR,
-	.arg2_type = ARG_PTR_TO_MAP_KEY,
-	.arg3_type = ARG_PTR_TO_MAP_VALUE,
-	.arg4_type = ARG_ANYTHING,
+	.func		= bpf_map_update_elem,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE,
+	.arg4_type	= ARG_ANYTHING,
 };
 
 static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
@@ -84,11 +84,11 @@
 }
 
 const struct bpf_func_proto bpf_map_delete_elem_proto = {
-	.func = bpf_map_delete_elem,
-	.gpl_only = false,
-	.ret_type = RET_INTEGER,
-	.arg1_type = ARG_CONST_MAP_PTR,
-	.arg2_type = ARG_PTR_TO_MAP_KEY,
+	.func		= bpf_map_delete_elem,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
 };
 
 static u64 bpf_get_prandom_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)