Re: [PATCH bpf-next v2 2/3] selftests/bpf: Check __TARGET_ARCH_loongarch if target is bpf for LoongArch

[Andrii Nakryiko]

On Fri, Feb 24, 2023 at 2:37 AM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
>
> If target is bpf, there is no __loongarch__ definition, __BITS_PER_LONG
> defaults to 32, __NR_nanosleep is not defined:
>
>   #if defined(__ARCH_WANT_TIME32_SYSCALLS) || __BITS_PER_LONG != 32
>   #define __NR_nanosleep 101
>   __SC_3264(__NR_nanosleep, sys_nanosleep_time32, sys_nanosleep)
>   #endif
>
> Check __TARGET_ARCH_loongarch to include arch specified bitsperlong.h,
> then __BITS_PER_LONG is 64, __NR_nanosleep can also be defined to fix
> the following build errors:
>
>   clang  -g -Werror -D__TARGET_ARCH_loongarch ... -target bpf -c progs/test_vmlinux.c ...
>   progs/test_vmlinux.c:24:18: error: use of undeclared identifier '__NR_nanosleep'
>           if (args->id != __NR_nanosleep)
>                           ^
>   progs/test_vmlinux.c:42:12: error: use of undeclared identifier '__NR_nanosleep'
>           if (id != __NR_nanosleep)
>                     ^
>   progs/test_vmlinux.c:60:12: error: use of undeclared identifier '__NR_nanosleep'
>           if (id != __NR_nanosleep)
>                     ^
>   3 errors generated.
>   make: *** [Makefile:572: tools/testing/selftests/bpf/test_vmlinux.bpf.o] Error 1
>   make: Leaving directory 'tools/testing/selftests/bpf'
>
> Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> ---
>  tools/include/uapi/asm/bitsperlong.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/include/uapi/asm/bitsperlong.h b/tools/include/uapi/asm/bitsperlong.h
> index da52065..10b4023 100644
> --- a/tools/include/uapi/asm/bitsperlong.h
> +++ b/tools/include/uapi/asm/bitsperlong.h
> @@ -17,7 +17,7 @@
>  #include "../../../arch/riscv/include/uapi/asm/bitsperlong.h"
>  #elif defined(__alpha__)
>  #include "../../../arch/alpha/include/uapi/asm/bitsperlong.h"
> -#elif defined(__loongarch__)
> +#elif defined(__loongarch__) || defined(__TARGET_ARCH_loongarch)

__TARGET_ARCH_ is libbpf-specific convention, we can't add that to UAPI headers


let's think about some other solution


>  #include "../../../arch/loongarch/include/uapi/asm/bitsperlong.h"
>  #else
>  #include <asm-generic/bitsperlong.h>
> --
> 2.1.0
>