bpf: move arg:ctx type enforcement check inside the main logic loop

Now that bpf and bpf-next trees converged and we don't run the risk of
merge conflicts, move btf_validate_prog_ctx_type() into its most logical
place inside the main logic loop.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240125205510.3642094-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index edef96ceffa397eac6448710368677f1e6f8c050..9ec08cfb2967c61e5a27401f8a1a2aa680d8ad6a 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -7112,6 +7112,10 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
                                bpf_log(log, "arg#%d has invalid combination of tags\n", i);
                                return -EINVAL;
                        }
+                       if ((tags & ARG_TAG_CTX) &&
+                           btf_validate_prog_ctx_type(log, btf, t, i, prog_type,
+                                                      prog->expected_attach_type))
+                               return -EINVAL;
                        sub->args[i].arg_type = ARG_PTR_TO_CTX;
                        continue;
                }
@@ -7156,23 +7160,6 @@ skip_pointer:
                return -EINVAL;
        }
 
-       for (i = 0; i < nargs; i++) {
-               const char *tag;
-
-               if (sub->args[i].arg_type != ARG_PTR_TO_CTX)
-                       continue;
-
-               /* check if arg has "arg:ctx" tag */
-               t = btf_type_by_id(btf, args[i].type);
-               tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:");
-               if (IS_ERR_OR_NULL(tag) || strcmp(tag, "ctx") != 0)
-                       continue;
-
-               if (btf_validate_prog_ctx_type(log, btf, t, i, prog_type,
-                                              prog->expected_attach_type))
-                       return -EINVAL;
-       }
-
        sub->arg_cnt = nargs;
        sub->args_cached = true;