bpf: Fix subprog names in stack traces.

The commit 7337224fc150 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
accidently made bpf_prog_ksym_set_name() conservative for bpf subprograms.
Fixed it so instead of "bpf_prog_tag_F" the stack traces print "bpf_prog_tag_full_subprog_name".

Fixes: 7337224fc150 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220714211637.17150-1-alexei.starovoitov@gmail.com

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 47fd6ef..c59c3df 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -13631,6 +13631,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
                /* Below members will be freed only at prog->aux */
                func[i]->aux->btf = prog->aux->btf;
                func[i]->aux->func_info = prog->aux->func_info;
+               func[i]->aux->func_info_cnt = prog->aux->func_info_cnt;
                func[i]->aux->poke_tab = prog->aux->poke_tab;
                func[i]->aux->size_poke_tab = prog->aux->size_poke_tab;
 
@@ -13643,9 +13644,6 @@ static int jit_subprogs(struct bpf_verifier_env *env)
                                poke->aux = func[i]->aux;
                }
 
-               /* Use bpf_prog_F_tag to indicate functions in stack traces.
-                * Long term would need debug info to populate names
-                */
                func[i]->aux->name[0] = 'F';
                func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
                func[i]->jit_requested = 1;