[PATCHv4 05/14] bpf: Allow return values 0 and 1 for uprobe/kprobe session

[Jiri Olsa]

The uprobe and kprobe session program can return only 0 or 1,
instruct verifier to check for that.

Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 kernel/bpf/verifier.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d8520095ca03..988858fc37e5 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -15668,6 +15668,16 @@ static int check_return_code(struct bpf_verifier_env 
*env, int regno, const char
                        return -ENOTSUPP;
                }
                break;
+       case BPF_PROG_TYPE_KPROBE:
+               switch (env->prog->expected_attach_type) {
+               case BPF_TRACE_KPROBE_SESSION:
+               case BPF_TRACE_UPROBE_SESSION:
+                       range = retval_range(0, 1);
+                       break;
+               default:
+                       return 0;
+               }
+               break;
        case BPF_PROG_TYPE_SK_LOOKUP:
                range = retval_range(SK_DROP, SK_PASS);
                break;
-- 
2.46.0