From: Eduard Zingerman <eddyz87@gmail.com>
To: bot+bpf-ci@kernel.org, bpf@vger.kernel.org, ast@kernel.org,
andrii@kernel.org
Cc: daniel@iogearbox.net, martin.lau@linux.dev, kernel-team@fb.com,
yonghong.song@linux.dev, martin.lau@kernel.org, clm@meta.com,
ihor.solodrai@linux.dev
Subject: Re: [PATCH bpf-next v3 09/13] bpf: change logging scheme for live stack analysis
Date: Fri, 10 Apr 2026 10:12:07 -0700 [thread overview]
Message-ID: <1d7dff25bec3966fe74b56d47ea4a5ac694a805b.camel@gmail.com> (raw)
In-Reply-To: <14bdd17ba48246c7ed1add4332eb7df21ca1ba844b12d5f69317c9d1273d18fd@mail.kernel.org>
On Fri, 2026-04-10 at 09:57 +0000, bot+bpf-ci@kernel.org wrote:
> > diff --git a/kernel/bpf/liveness.c b/kernel/bpf/liveness.c
> > index 1d9c89a269e3..3c421ad8684c 100644
> > --- a/kernel/bpf/liveness.c
> > +++ b/kernel/bpf/liveness.c
>
> [ ... ]
>
> > +static char *fmt_subprog(struct bpf_verifier_env *env, int subprog)
> > +{
> > + const char *name = env->subprog_info[subprog].name;
> > +
> > + snprintf(env->tmp_str_buf, sizeof(env->tmp_str_buf),
> > + "subprog#%d%s%s", subprog, name ? " " : "", name ?: NULL);
> > + return env->tmp_str_buf;
> > +}
>
> Should `name ?: NULL` be `name ?: ""`? When subprog_info[].name is
> NULL (programs loaded without BTF func info), this passes NULL to the
> third %s. The kernel's vsnprintf prints "(null)", so the output
> becomes "subprog#0(null)" instead of "subprog#0".
>
> The conditional `name ? " " : ""` on the second %s shows the intent
> to suppress the name entirely when absent, but the NULL on the third
> %s defeats that.
Uh-oh.
Silly meatbag is going to be obsolete soon.
>
> ---
> 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/24236538770
next prev parent reply other threads:[~2026-04-10 17:12 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-10 9:29 [PATCH bpf-next v3 00/13] bpf: static stack liveness data flow analysis Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 01/13] bpf: share several utility functions as internal API Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 02/13] bpf: save subprogram name in bpf_subprog_info Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 03/13] bpf: Add spis_*() helpers for 4-byte stack slot bitmasks Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 04/13] bpf: make liveness.c track stack with 4-byte granularity Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 05/13] bpf: 4-byte precise clean_verifier_state Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 06/13] bpf: prepare bpf_liveness api for use by static analysis pass Eduard Zingerman
2026-04-10 9:57 ` bot+bpf-ci
2026-04-10 9:29 ` [PATCH bpf-next v3 07/13] bpf: introduce forward arg-tracking dataflow analysis Eduard Zingerman
2026-04-10 10:10 ` bot+bpf-ci
2026-04-10 9:29 ` [PATCH bpf-next v3 08/13] bpf: simplify liveness to use (callsite, depth) keyed func_instances Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 09/13] bpf: change logging scheme for live stack analysis Eduard Zingerman
2026-04-10 9:57 ` bot+bpf-ci
2026-04-10 17:12 ` Eduard Zingerman [this message]
2026-04-10 9:29 ` [PATCH bpf-next v3 10/13] selftests/bpf: update existing tests due to liveness changes Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 11/13] selftests/bpf: adjust verifier_log buffers Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 12/13] selftests/bpf: add new tests for static stack liveness analysis Eduard Zingerman
2026-04-10 9:29 ` [PATCH bpf-next v3 13/13] bpf: poison dead stack slots Eduard Zingerman
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