Re: [PATCH v4 6/6] selftests/io_uring: add a bpf io_uring selftest

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Tue, Jan 27, 2026 at 10:42 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
>
> On 1/27/26 17:32, Alexei Starovoitov wrote:
> > On Tue, Jan 27, 2026 at 2:15 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
> >>
> >> index 000000000000..7a170cb2f388
> >> --- /dev/null
> >> +++ b/tools/testing/selftests/io_uring/types.bpf.h
> >> @@ -0,0 +1,131 @@
> >> +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> >> +#include <linux/types.h>
> >> +#include <bpf/bpf_helpers.h>
> >> +
> >> +struct io_ring_ctx {
> >> +};
> >> +
> >> +struct io_uring_sqe {
> >> +       __u8    opcode;         /* type of operation for this sqe */
> >> +       __u8    flags;          /* IOSQE_ flags */
> >> +       __u16   ioprio;         /* ioprio for the request */
> >> +       __s32   fd;             /* file descriptor to do IO on */
> >
> > 1.
> > No need to copy paste. Just include vmlinux.h. It's there.
> >
> > 2.
> > drop KF_TRUSTED_ARGS from kfunc. It's a default now and this flag
> > was removed.
>
> Got it, will change both, thanks
>
> > 3.
> > add a runtime logic to check that the return value is either IOU_LOOP_CONTINUE
> > or IOU_LOOP_STOP or instruct the verifier do it statically.
> > Otherwise it will be less convenient to extend to other commands,
> > since the way I read it IOU_LOOP_CONTINUE == 0 aliases to any value > 1.
>
> Is there a struct_ops hook that can help with that? check_return_code()
> has some hard-coded checks, but I can't find anything customizable for
> struct_ops.

yep. check_return_code() is the one and you're correct. It's not
customizable atm. Much simpler to do a runtime check for now and
improve through the verifier support later.