On Mon, Apr 14, 2025 at 6:35 PM Jiri Olsa <olsaj...@gmail.com> wrote:
>
> On Sun, Apr 13, 2025 at 01:06:26AM +0800, KaFai Wan wrote:
> > Adding verifier test for accessing const void pointer argument in
> > tracing programs.
> >
> > The test program loads 2nd argument of kfree tp_btf which is
> > const void pointer and checks that verifier allows that.
> >
> > Signed-off-by: KaFai Wan <kafai....@hotmail.com>
> > ---
> > .../selftests/bpf/progs/verifier_btf_ctx_access.c | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c
> > b/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c
> > index 28b939572cda..a6cec7f73dcd 100644
> > --- a/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c
> > +++ b/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c
> > @@ -65,4 +65,13 @@ __naked void ctx_access_u32_pointer_reject_8(void)
> > " ::: __clobber_all);
> > }
> >
> > +SEC("tp_btf/kfree")
> > +__description("btf_ctx_access const void pointer accept")
> > +int ctx_access_const_void_pointer_accept(void)
> > +{
> > + /* load 2nd argument value (const void pointer) */
> > + asm volatile ("r2 = *(u64 *)(r1 + 8); ");
>
> I think we should follow formatting of other tests in the file,
> a do smth like:
>
> asm volatile (" \
> r2 = *(u64 *)(r1 + 8); "); /* load 2nd argument value (const void
> pointer) */\
> ...
I will fix it. and I find out the kernel does not support test_run of tp_btf, I
will change to fentry.
>
> thanks,
> jirka
>
>
> > + return 0;
> > +}
> > +
> > char _license[] SEC("license") = "GPL";
> > --
> > 2.43.0
> >
thanks,
kafai
