Re: [PATCH bpf-next v4 04/10] bpf: Introduce load-acquire and store-release instructions

Alexei Starovoitov
2025-03-03T18:43:21Z

On Mon, Mar 3, 2025 at 12:55 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Peilin,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on bpf-next/master]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Peilin-Ye/bpf-verifier-Factor-out-atomic_ptr_type_ok/20250303-134110
> base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
> patch link: https://lore.kernel.org/r/2c82b29f3530b961b41f94a4942e490ab35a31c8.1740978603.git.yepeilin%40google.com
> patch subject: [PATCH bpf-next v4 04/10] bpf: Introduce load-acquire and store-release instructions
> config: arc-randconfig-002-20250303 (https://download.01.org/0day-ci/archive/20250303/202503031631.OeUhVRHz-lkp@intel.com/config)
> compiler: arc-elf-gcc (GCC) 13.2.0

...

> kernel/bpf/core.c:2228:25: note: in expansion of macro 'LOAD_ACQUIRE'
> 2228 | LOAD_ACQUIRE(DW, u64)
> | ^~~~~~~~~~~~

Peilin,

how do you plan on fixing this?
So far I could only think of making compilation conditional for CONFIG_64BIT
and let the verifier reject these insns on 32-bit arches.
Other ideas?