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.