Re: [BPF selftests]:bpf_arena_common.h: error: conflicting types for 'bpf_arena_alloc_pages'

[Yonghong Song <yonghong.song@linux.dev>]

On 11/9/25 9:09 AM, Vincent Li wrote:
> Hi,
>
> Sorry if this is a known issue,  but I could not find it.  my build environment:
>
> [root@fedora linux-loongson]# pahole --version
> v1.30
> [root@fedora linux-loongson]# clang --version
> clang version 21.1.5
> Target: loongarch64-redhat-linux
> Thread model: posix
> InstalledDir: /usr/bin
>
> [root@fedora linux-loongson]# bpftool version
> bpftool v7.6.0
> using libbpf v1.6
> features: llvm, skeletons
>
> I got errors below while building bpf selftests with bpf-next branch,
> I had to comment out the bpf_arena_alloc_pages,
> bpf_arena_reserve_pages, bpf_arena_free_pages in
> tools/include/vmlinux.h, then progs/stream.c build succeeded. It looks
> like these functions in tools/include/vmlinux.h generated by bpftool
> are not the same as in bpf_arena_common.h. is there something wrong in
> my build environment?

Could you try pahole master branch? See the conversion in
   https://lore.kernel.org/bpf/8a94c764c5fa4ff04fa7dd69ed47fcdf782b814e@linux.dev/

>
>
> In file included from progs/stream.c:8:
> /usr/src/linux-loongson/tools/testing/selftests/bpf/bpf_arena_common.h:47:15:
> error:
>        conflicting types for 'bpf_arena_alloc_pages'
>     47 | void __arena* bpf_arena_alloc_pages(void *map, void __arena
> *addr, __u32 page_cnt,
>        |               ^
> /usr/src/linux-loongson/tools/testing/selftests/bpf/tools/include/vmlinux.h:180401:14:
> note:
>        previous declaration is here
>   180401 | extern void *bpf_arena_alloc_pages(void *p__map, void
> *addr__ign, u32 page_cnt, int node_i...
>          |              ^
> In file included from progs/stream.c:8:
> /usr/src/linux-loongson/tools/testing/selftests/bpf/bpf_arena_common.h:49:5:
> error:
>        conflicting types for 'bpf_arena_reserve_pages'
>     49 | int bpf_arena_reserve_pages(void *map, void __arena *addr,
> __u32 page_cnt) __ksym __weak;
>        |     ^
> /usr/src/linux-loongson/tools/testing/selftests/bpf/tools/include/vmlinux.h:180403:12:
> note:
>        previous declaration is here
>   180403 | extern int bpf_arena_reserve_pages(void *p__map, void
> *ptr__ign, u32 page_cnt) __weak __ksym;
>          |            ^
> In file included from progs/stream.c:8:
> /usr/src/linux-loongson/tools/testing/selftests/bpf/bpf_arena_common.h:50:6:
> error:
>        conflicting types for 'bpf_arena_free_pages'
>     50 | void bpf_arena_free_pages(void *map, void __arena *ptr, __u32
> page_cnt) __ksym __weak;
>        |      ^
> /usr/src/linux-loongson/tools/testing/selftests/bpf/tools/include/vmlinux.h:180402:13:
> note:
>        previous declaration is here
>   180402 | extern void bpf_arena_free_pages(void *p__map, void
> *ptr__ign, u32 page_cnt) __weak __ksym;
>          |             ^
> 3 errors generated.
>
> Vincent