[PATCH bpf-next v4 02/14] bpf: save subprogram name in bpf_subprog_info

[Eduard Zingerman <eddyz87@gmail.com>]

Subprogram name can be computed from function info and BTF, but it is
convenient to have the name readily available for logging purposes.
Update comment saying that bpf_subprog_info->start has to be the first
field, this is no longer true, relevant sites access .start field
by it's name.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
---
 include/linux/bpf_verifier.h | 2 +-
 kernel/bpf/verifier.c        | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 15f7f9f35be9..cec6054d6333 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -664,7 +664,7 @@ enum priv_stack_mode {
 };
 
 struct bpf_subprog_info {
-	/* 'start' has to be the first field otherwise find_subprog() won't work */
+	const char *name; /* name extracted from BTF */
 	u32 start; /* insn idx of function entry point */
 	u32 linfo_idx; /* The idx to the main_prog->aux->linfo */
 	u32 postorder_start; /* The idx to the env->cfg.insn_postorder */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index dd81cfbad680..cd2a56308e59 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19682,6 +19682,7 @@ static int check_btf_func(struct bpf_verifier_env *env,
 			goto err_free;
 		}
 
+		env->subprog_info[i].name = btf_name_by_offset(btf, type->name_off);
 		bpfptr_add(&urecord, urec_size);
 	}
 

-- 
2.53.0