Thread (10 messages) 10 messages, 2 authors, 2021-10-20

Re: [PATCH bpf-next v2 4/5] bpf: hook .test_run for struct_ops program

From: Martin KaFai Lau <hidden>
Date: 2021-10-20 05:24:40
Also in: netdev

On Sat, Oct 16, 2021 at 08:48:05PM +0800, Hou Tao wrote:
quoted hunk ↗ jump to hunk
bpf_struct_ops_test_run() will be used to run struct_ops program
from bpf_dummy_ops and now its main purpose is to test the handling
of return value and multiple arguments.

Signed-off-by: Hou Tao <redacted>
---
 kernel/bpf/bpf_struct_ops.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 44be101f2562..ceedc9f0f786 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -11,6 +11,9 @@
 #include <linux/refcount.h>
 #include <linux/mutex.h>
 
+static int bpf_struct_ops_test_run(struct bpf_prog *prog,
+				   const union bpf_attr *kattr,
+				   union bpf_attr __user *uattr);
 enum bpf_struct_ops_state {
 	BPF_STRUCT_OPS_STATE_INIT,
 	BPF_STRUCT_OPS_STATE_INUSE,
@@ -93,6 +96,7 @@ const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
 };
 
 const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
+	.test_run = bpf_struct_ops_test_run,
 };
 
 static const struct btf_type *module_type;
@@ -667,3 +671,16 @@ void bpf_struct_ops_put(const void *kdata)
 		call_rcu(&st_map->rcu, bpf_struct_ops_put_rcu);
 	}
 }
+
+static int bpf_struct_ops_test_run(struct bpf_prog *prog,
+				   const union bpf_attr *kattr,
+				   union bpf_attr __user *uattr)
+{
+	const struct bpf_struct_ops *st_ops;
+
+	st_ops = bpf_struct_ops_find(prog->aux->attach_btf_id);
Checking bpf_bpf_dummy_ops.type_id == prog->aux->attach_btf_id is as good?
then the bpf_struct_ops_find() should not be needed.
+	if (st_ops != &bpf_bpf_dummy_ops)
+		return -EOPNOTSUPP;
+
+	return bpf_dummy_struct_ops_test_run(prog, kattr, uattr);
The function bpf_dummy_struct_ops_test_run() is available under
CONFIG_NET.

How about checking the attach_btf_id in bpf_dummy_struct_ops_test_run().
and then rename s/bpf_dummy_struct_ops_test_run/bpf_struct_ops_test_run/.

and do this in bpf_struct_ops_prog_ops:

const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
#ifdef CONFIG_NET
	.test_run = bpf_struct_ops_test_run,
#endif
};

Take a look at some test_run in bpf_trace.c as examples.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help