Messages in this thread |  | | Date | Wed, 26 Nov 2025 23:24:09 +0800 | | Subject | Re: [PATCH bpf-next v12 2/7] bpf: Add BPF_F_CPU and BPF_F_ALL_CPUS flags support for percpu_array maps | | From | Leon Hwang <> |
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On 2025/11/26 23:11, bot+bpf-ci@kernel.org 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
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