On 2025/11/26 23:11, [email protected] wrote:
>> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
>> index d84af3719..01a99e3a3 100644
>> --- a/include/linux/bpf.h
>> +++ b/include/linux/bpf.h
>
> [ ... ]
>
>> diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
>> index 1eeb31c5b..67e9e811d 100644
>> --- a/kernel/bpf/arraymap.c
>> +++ b/kernel/bpf/arraymap.c
>
> [ ... ]
>
>> @@ -398,10 +405,11 @@ int bpf_percpu_array_update(struct bpf_map *map, void
>> *key, void *value,
>> struct bpf_array *array = container_of(map, struct bpf_array, map);
>> u32 index = *(u32 *)key;
>> void __percpu *pptr;
>> - int cpu, off = 0;
>> + void *ptr, *val;
>> u32 size;
>> + int cpu;
>>
>> - if (unlikely(map_flags > BPF_EXIST))
>> + if (unlikely((map_flags & BPF_F_LOCK) || (u32)map_flags >
>> BPF_F_ALL_CPUS))
>> /* unknown flags */
>> return -EINVAL;
>>
>> @@ -409,7 +417,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void
>> *key, void *value,
>> /* all elements were pre-allocated, cannot insert a new one */
>> return -E2BIG;
>>
>> - if (unlikely(map_flags & BPF_NOEXIST))
>> + if (unlikely(map_flags == BPF_NOEXIST))
> ^^
>
?
No such change in this version.
It seems that this change was inferred from v11 to v12 by AI itself.
Thanks,
Leon
> Does changing this from bitwise-AND to equality break flag combination
> handling? The old code checked (map_flags & BPF_NOEXIST), which would
> trigger for any flag combination including BPF_NOEXIST. The new code only
> checks (map_flags == BPF_NOEXIST), so if userspace passes
> (BPF_F_CPU | BPF_NOEXIST), the BPF_NOEXIST flag gets silently ignored
> instead of returning -EEXIST as before.
>
> While all elements in percpu_array maps are pre-allocated and BPF_NOEXIST
> should always fail anyway, silently ignoring a flag the user explicitly set
> seems inconsistent with the principle of rejecting invalid flag combinations
> at validation time.
>
>> /* all elements already exist */
>> return -EEXIST;
>>
>
> [ ... ]
>
>
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
>
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19708012130
