Re: [PATCH bpf-next] selftests/bpf: fix attach point for non-x86 arches in test_progs/lsm

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 8/15/22 2:24 PM, Artem Savkov wrote:
> Use SYS_PREFIX macro from bpf_misc.h instead of hard-coded '__x64_'
> prefix for sys_setdomainname attach point in lsm test.
>
> Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
> ---
>   tools/testing/selftests/bpf/progs/lsm.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/lsm.c b/tools/testing/selftests/bpf/progs/lsm.c
> index 33694ef8acfa..d8d8af623bc2 100644
> --- a/tools/testing/selftests/bpf/progs/lsm.c
> +++ b/tools/testing/selftests/bpf/progs/lsm.c
> @@ -4,6 +4,7 @@
>    * Copyright 2020 Google LLC.
>    */
>   
> +#include "bpf_misc.h"
>   #include "vmlinux.h"
>   #include <bpf/bpf_helpers.h>
>   #include <bpf/bpf_tracing.h>
> @@ -160,7 +161,7 @@ int BPF_PROG(test_task_free, struct task_struct *task)
>   
>   int copy_test = 0;
>   
> -SEC("fentry.s/__x64_sys_setdomainname")
> +SEC("fentry.s/" SYS_PREFIX "sys_setdomainname")
>   int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
>   {
>   	void *ptr = (void *)PT_REGS_PARM1(regs);

Good catch! Could you also update the comment in tools/testing/selftests/bpf/DENYLIST.s390x +46 :

[...]
test_lsm                                 # failed to find kernel BTF type ID of '__x64_sys_setdomainname': -3          (?)
[...]

It should likely say sth like `attach fentry unexpected error: -524 (trampoline)`.

Thanks,
Daniel