[PATCH bpf-next v8 1/4] libbpf: Extract prog load type check from libbpf_probe_bpf_helper

Tao Chen
2025-02-21T16:36:09Z

Extract prog load type check part from libbpf_probe_bpf_helper
suggested by Andrii, which will be used in both
libbpf_probe_bpf_{helper, kfunc}.

Cc: Tao Chen <dylane.chen@didiglobal.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
---
tools/lib/bpf/libbpf_probes.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index 9dfbe7750f56..a48a557314f6 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -413,6 +413,23 @@ int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts)
return libbpf_err(ret);
}

+static bool can_probe_prog_type(enum bpf_prog_type prog_type)
+{
+ /* we can't successfully load all prog types to check for BPF helper
+ * and kfunc support.
+ */
+ switch (prog_type) {
+ case BPF_PROG_TYPE_TRACING:
+ case BPF_PROG_TYPE_EXT:
+ case BPF_PROG_TYPE_LSM:
+ case BPF_PROG_TYPE_STRUCT_OPS:
+ return false;
+ default:
+ break;
+ }
+ return true;
+}
+
int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id helper_id,
const void *opts)
{
@@ -427,18 +444,8 @@ int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id helpe
if (opts)
return libbpf_err(-EINVAL);

- /* we can't successfully load all prog types to check for BPF helper
- * support, so bail out with -EOPNOTSUPP error
- */
- switch (prog_type) {
- case BPF_PROG_TYPE_TRACING:
- case BPF_PROG_TYPE_EXT:
- case BPF_PROG_TYPE_LSM:
- case BPF_PROG_TYPE_STRUCT_OPS:
- return -EOPNOTSUPP;
- default:
- break;
- }
+ if (!can_probe_prog_type(prog_type))
+ return libbpf_err(-EOPNOTSUPP);

buf[0] = '\0';
ret = probe_prog_load(prog_type, insns, insn_cnt, buf, sizeof(buf));
--
2.43.0