[PATCH 5/7] libbpf: Return const btf_param from btf_params inline function

[Jiri Olsa]

I'm getting following errors when compiling with -Wcast-qual:

  bpf/btf.h: In function ‘btf_param* btf_params(const btf_type*)’:
  bpf/btf.h:291:35: warning: cast from type ‘const btf_type*’ to type
  ‘btf_param*’ casts away qualifiers [-Wcast-qual]
    291 |  return (struct btf_param *)(t + 1);
        |                                   ^

The argument is const so the cast to following struct btf_param
pointer should be const as well. Casting the const away in btf.c
call where it's correctly used without const in deduplication
code.

Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 tools/lib/bpf/btf.c | 6 +++---
 tools/lib/bpf/btf.h | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 560d1ae33675..b5121c79fd9f 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1487,7 +1487,7 @@ static int btf_for_each_str_off(struct btf_dedup *d, 
str_off_fn_t fn, void *ctx)
                        break;
                }
                case BTF_KIND_FUNC_PROTO: {
-                       struct btf_param *m = btf_params(t);
+                       struct btf_param *m = (struct btf_param *) 
btf_params(t);
                        __u16 vlen = btf_vlen(t);
 
                        for (j = 0; j < vlen; j++) {
@@ -2622,7 +2622,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 
type_id)
                t->type = ref_type_id;
 
                vlen = btf_vlen(t);
-               param = btf_params(t);
+               param = (struct btf_param *) btf_params(t);
                for (i = 0; i < vlen; i++) {
                        ref_type_id = btf_dedup_ref_type(d, param->type);
                        if (ref_type_id < 0)
@@ -2811,7 +2811,7 @@ static int btf_dedup_remap_type(struct btf_dedup *d, 
__u32 type_id)
        }
 
        case BTF_KIND_FUNC_PROTO: {
-               struct btf_param *param = btf_params(t);
+               struct btf_param *param = (struct btf_param *) btf_params(t);
                __u16 vlen = btf_vlen(t);
 
                r = btf_dedup_remap_type_id(d, t->type);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index cd1bd018ba8b..2817cf7ce2ee 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -286,9 +286,9 @@ static inline __u32 btf_member_bitfield_size(const struct 
btf_type *t,
        return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
 }
 
-static inline struct btf_param *btf_params(const struct btf_type *t)
+static inline const struct btf_param *btf_params(const struct btf_type *t)
 {
-       return (struct btf_param *)(t + 1);
+       return (const struct btf_param *)(t + 1);
 }
 
 static inline struct btf_var *btf_var(const struct btf_type *t)
-- 
2.21.0