Re: [PATCH v17 11/12] selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc

[Roberto Sassu]

On Thu, 2022-09-15 at 17:11 +0100, KP Singh wrote:
> On Fri, Sep 9, 2022 at 1:10 PM Roberto Sassu
> <roberto.sassu@xxxxxxxxxxxxxxx> wrote:
> > From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> > 
> 
> [...]
> 
> > +}
> > diff --git
> > a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
> > b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
> > new file mode 100644
> > index 000000000000..4ceab545d99a
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
> > @@ -0,0 +1,100 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/*
> > + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> > + *
> > + * Author: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> > + */
> > +
> > +#include "vmlinux.h"
> > +#include <errno.h>
> > +#include <bpf/bpf_helpers.h>
> > +#include <bpf/bpf_tracing.h>
> > +
> > +#define MAX_DATA_SIZE (1024 * 1024)
> > +#define MAX_SIG_SIZE 1024
> > +
> > +typedef __u8 u8;
> > +typedef __u16 u16;
> > +typedef __u32 u32;
> > +typedef __u64 u64;
> 
> I think you can avoid this and just use u32 and u64 directly.

Thanks, yes.

> +
> > +struct bpf_dynptr {
> > +       __u64 :64;
> > +       __u64 :64;
> > +} __attribute__((aligned(8)));
> > +
> 
> I think you are doing this because including the uapi headers causes
> type conflicts.
> This does happen quite often. What do other folks think about doing
> something like
> 
> #define DYNPTR(x) ((void *)x)
> 
> It seems like this will be an issue anytime we use the helpers with
> vmlinux.h and users
> will always have to define this type in their tests.

It seems it is sufficient to use struct bpf_dynptr somehow in the
kernel code. That causes the definition to be exported with BTF. Not
sure what would be the proper place to do that. When I tried, I
declared a unused variable.

Roberto