linux-kernel - Re: [PATCH bpf-next v9 9/9] selftests/bpf: Add tests to verify map create failure log

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAADnVQKYwi2bNc8Hsg-r9dF0ACYYEzRyZDc33G2Kr_o0bu3bow@mail.gmail.com>
Date: Thu, 5 Feb 2026 15:18:01 -0800
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Leon Hwang <leon.hwang@...ux.dev>
Cc: bpf <bpf@...r.kernel.org>, Alexei Starovoitov <ast@...nel.org>, 
	Daniel Borkmann <daniel@...earbox.net>, John Fastabend <john.fastabend@...il.com>, 
	Andrii Nakryiko <andrii@...nel.org>, Martin KaFai Lau <martin.lau@...ux.dev>, 
	Eduard Zingerman <eddyz87@...il.com>, Song Liu <song@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, KP Singh <kpsingh@...nel.org>, 
	Stanislav Fomichev <sdf@...ichev.me>, Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>, 
	Shuah Khan <shuah@...nel.org>, Christian Brauner <brauner@...nel.org>, 
	Seth Forshee <sforshee@...nel.org>, Yuichiro Tsuji <yuichtsu@...zon.com>, 
	Andrey Albershteyn <aalbersh@...hat.com>, Willem de Bruijn <willemb@...gle.com>, 
	Jason Xing <kerneljasonxing@...il.com>, Tao Chen <chen.dylane@...ux.dev>, 
	Mykyta Yatsenko <yatsenko@...a.com>, Kumar Kartikeya Dwivedi <memxor@...il.com>, 
	Anton Protopopov <a.s.protopopov@...il.com>, Amery Hung <ameryhung@...il.com>, 
	Rong Tao <rongtao@...tc.cn>, LKML <linux-kernel@...r.kernel.org>, 
	Linux API <linux-api@...r.kernel.org>, 
	"open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@...r.kernel.org>, kernel-patches-bot@...com
Subject: Re: [PATCH bpf-next v9 9/9] selftests/bpf: Add tests to verify map
 create failure log

On Wed, Feb 4, 2026 at 7:54 PM Leon Hwang <leon.hwang@...ux.dev> wrote:
>
>
>
> On 5/2/26 04:14, Alexei Starovoitov wrote:
> > On Mon, Feb 2, 2026 at 6:43 AM Leon Hwang <leon.hwang@...ux.dev> wrote:
> >>
> >> +
> >> +#define BPF_LOG_FIXED  8
> >> +
> >> +static void test_map_create(enum bpf_map_type map_type, const char *map_name,
> >> +                           struct bpf_map_create_opts *opts, const char *exp_msg)
> >> +{
> >> +       const int key_size = 4, value_size = 4, max_entries = 1;
> >> +       char log_buf[128];
> >> +       int fd;
> >> +       LIBBPF_OPTS(bpf_log_opts, log_opts);
> >> +
> >> +       log_buf[0] = '\0';
> >> +       log_opts.log_buf = log_buf;
> >> +       log_opts.log_size = sizeof(log_buf);
> >> +       log_opts.log_level = BPF_LOG_FIXED;
> >
> > Why? Which part of the test needs the log with this flag?
>
> BPF_LOG_FIXED looks odd here.
>
> This test sets 'log_level = BPF_LOG_FIXED' to match the behavior of
> bpf_vlog_init() as initialized by bpf_log_attr_create_vlog() in
> patch #7. BPF_LOG_FIXED is intended to be the default log_level
> there.

I don't think you answered my question.
bpf_vlog_init() is using whatever log_level user space provided.
Why do you pass BPF_LOG_FIXED ?