From: Petr Mladek <pmladek@suse.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Artem Savkov <asavkov@redhat.com>,
bpf@vger.kernel.org, linux-modules@vger.kernel.org,
linux-kernel@vger.kernel.org, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
"Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>,
Viktor Malik <vmalik@redhat.com>
Subject: Re: [PATCH bpf-next] kallsyms: Disable preemption for find_kallsyms_symbol_value
Date: Thu, 6 Apr 2023 16:47:49 +0200 [thread overview]
Message-ID: <ZC7blVqUwiHWWJOg@alley> (raw)
In-Reply-To: <20230403220254.2191240-1-jolsa@kernel.org>
On Tue 2023-04-04 00:02:54, Jiri Olsa wrote:
> Artem reported suspicious RCU usage [1]. The reason is that verifier
> calls find_kallsyms_symbol_value with preemption enabled which will
> trigger suspicious RCU usage warning in rcu_dereference_sched call.
>
> Disabling preemption in find_kallsyms_symbol_value and adding
> __find_kallsyms_symbol_value function.
>
> Fixes: 31bf1dbccfb0 ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules")
> [1] https://lore.kernel.org/bpf/ZBrPMkv8YVRiWwCR@samus.usersys.redhat.com/
> Reported-by: Artem Savkov <asavkov@redhat.com>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Just for record:
Reviewed-by: Petr Mladek <pmladek@suse.com>
Best Regards,
Petr
next prev parent reply other threads:[~2023-04-06 14:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-03 22:02 [PATCH bpf-next] kallsyms: Disable preemption for find_kallsyms_symbol_value Jiri Olsa
2023-04-04 1:43 ` Leizhen (ThunderTown)
2023-04-04 6:56 ` Artem Savkov
2023-04-05 0:20 ` patchwork-bot+netdevbpf
2023-04-06 14:47 ` Petr Mladek [this message]
2023-04-06 14:56 ` Aaron Tomlin
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