From: Leon Hwang <leon.hwang@linux.dev>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Quentin Monnet <qmo@kernel.org>, Shuah Khan <shuah@kernel.org>,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
kernel-patches-bot@fb.com
Subject: Re: [PATCH bpf-next v7 09/11] selftests/bpf: Add test to verify accessing rdonly percpu_array
Date: Thu, 25 Jun 2026 10:47:57 +0800 [thread overview]
Message-ID: <f3a0d1cc-9846-4ed4-a8ff-6bf697f28856@linux.dev> (raw)
In-Reply-To: <CAEf4BzZHC3_oyWyA8zC-ogNFktsGFd35Stst5bswO05O=dL+Sg@mail.gmail.com>
On 25/6/26 00:48, Andrii Nakryiko wrote:
> On Tue, Jun 23, 2026 at 9:16 PM Leon Hwang <leon.hwang@linux.dev> wrote:
[...]
>>
>> Makes sense.
>>
>> I think it is worth testing both positive and negative cases:
>>
>> 1. (read-only) direct access the data of read-only percpu data's
>> percpu_array map to test the above change.
>> 2. direct writing the data of read-only percpu data's percpu_array map
>> is disallowed.
>>
>
> both is even better, but negative test is testing a condition that is
> hard to miss because you won't try to do that in practice )
>
Got it.
Will implement both of them.
Thanks,
Leon
next prev parent reply other threads:[~2026-06-25 2:48 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-22 14:35 [PATCH bpf-next v7 00/11] bpf: Introduce global percpu data Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 01/11] bpf: Drop duplicate blank lines in verifier Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 02/11] bpf: Disallow interpreter fallback for user BPF_ADDR_SPACE_CAST insn Leon Hwang
2026-06-23 22:45 ` Andrii Nakryiko
2026-06-24 4:10 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 03/11] bpf: Disallow interpreter fallback for BPF_ADDR_PERCPU insn Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 04/11] bpf: Introduce global percpu data Leon Hwang
2026-06-23 22:45 ` Andrii Nakryiko
2026-06-24 4:11 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 05/11] libbpf: Probe percpu data feature Leon Hwang
2026-06-23 22:45 ` Andrii Nakryiko
2026-06-24 4:11 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 06/11] libbpf: Add support for global percpu data Leon Hwang
2026-06-23 22:45 ` Andrii Nakryiko
2026-06-24 4:13 ` Leon Hwang
2026-06-24 16:45 ` Andrii Nakryiko
2026-06-25 2:45 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 07/11] bpftool: Generate skeleton " Leon Hwang
2026-06-23 22:46 ` Andrii Nakryiko
2026-06-24 4:15 ` Leon Hwang
2026-06-24 16:47 ` Andrii Nakryiko
2026-06-25 2:47 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 08/11] selftests/bpf: Add tests to verify " Leon Hwang
2026-06-22 15:24 ` bot+bpf-ci
2026-06-23 4:02 ` Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 09/11] selftests/bpf: Add test to verify accessing rdonly percpu_array Leon Hwang
2026-06-23 22:46 ` Andrii Nakryiko
2026-06-24 4:16 ` Leon Hwang
2026-06-24 16:48 ` Andrii Nakryiko
2026-06-25 2:47 ` Leon Hwang [this message]
2026-06-22 14:35 ` [PATCH bpf-next v7 10/11] selftests/bpf: Add tests to verify verifier log for global percpu data Leon Hwang
2026-06-22 14:35 ` [PATCH bpf-next v7 11/11] selftests/bpf: Add test to verify bpf_iter " Leon Hwang
2026-06-22 15:24 ` bot+bpf-ci
2026-06-23 4:04 ` Leon Hwang
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