bpf: Silence coverity false positive warning.

Coverity issued the following warning:
6685            cands = bpf_core_add_cands(cands, main_btf, 1);
6686            if (IS_ERR(cands))
>>>     CID 1510300:    (RETURN_LOCAL)
>>>     Returning pointer "cands" which points to local variable "local_cand".
6687                    return cands;

It's a false positive.
Add ERR_CAST() to silence it.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index baa90f3..6523104 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6656,7 +6656,7 @@ bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id)
 
        main_btf = bpf_get_btf_vmlinux();
        if (IS_ERR(main_btf))
-               return (void *)main_btf;
+               return ERR_CAST(main_btf);
 
        local_type = btf_type_by_id(local_btf, local_type_id);
        if (!local_type)
@@ -6683,14 +6683,14 @@ bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id)
        /* Attempt to find target candidates in vmlinux BTF first */
        cands = bpf_core_add_cands(cands, main_btf, 1);
        if (IS_ERR(cands))
-               return cands;
+               return ERR_CAST(cands);
 
        /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */
 
        /* populate cache even when cands->cnt == 0 */
        cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
        if (IS_ERR(cc))
-               return cc;
+               return ERR_CAST(cc);
 
        /* if vmlinux BTF has any candidate, don't go for module BTFs */
        if (cc->cnt)
@@ -6716,7 +6716,7 @@ check_modules:
                cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf));
                if (IS_ERR(cands)) {
                        btf_put(mod_btf);
-                       return cands;
+                       return ERR_CAST(cands);
                }
                spin_lock_bh(&btf_idr_lock);
                btf_put(mod_btf);