From: Tao Chen <chen.dylane@gmail.com>
To: Qing Wang <wangqing7171@gmail.com>, andrii.nakryiko@gmail.com
Cc: acme@kernel.org, adrian.hunter@intel.com,
alexander.shishkin@linux.intel.com, bpf@vger.kernel.org,
irogers@google.com, jolsa@kernel.org,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
mark.rutland@arm.com, mingo@redhat.com, namhyung@kernel.org,
peterz@infradead.org, radoslaw.zielonek@gmail.com,
syzbot+72a43cdb78469f7fbad1@syzkaller.appspotmail.com
Subject: Re: [PATCH] perf callchain: Fix suspicious RCU usage in get_callchain_entry()
Date: Wed, 28 Jan 2026 16:19:14 +0800 [thread overview]
Message-ID: <874829ba-00b9-49cd-8f67-a4c33a8f409f@gmail.com> (raw)
In-Reply-To: <20260128062656.1860201-1-wangqing7171@gmail.com>
在 2026/1/28 14:26, Qing Wang 写道:
> On Fri, 19 Jul 2024 at 01:41, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
>> Which is what I'm doing in [0]. Radoslaw, can you please help
>> validating if those changes are enough to fix this issue or we need to
>> do some more?
>>
>> [0] https://patchwork.kernel.org/project/netdevbpf/patch/20240709204245.3=
>> 847811-10-andrii@kernel.org/
>>
>>>
>>>> ---
>>>> kernel/events/callchain.c | 11 +++++++++--
>>>> 1 file changed, 9 insertions(+), 2 deletions(-)
>>>>
>
> Hi,
>
> I found this issue still exists after your patch in upstream and I have a
> patch to fix it.
>
> Patch here: https://lore.kernel.org/all/20260128061753.1857803-1-wangqing7171@gmail.com/T/
>
> Looking forward to your review.
>
> --
> Best regards,
> Qing
>
Hi Qing,
I have a change that will remove RCU. As Andrii pointed out, using
get_callchain_entry without RCU lock in BPF appears to be safe for now.
Please point out if I've missed anything.
https://lore.kernel.org/bpf/fb745675-e25c-4dcc-be4b-4a4411056755@linux.dev/T/#mc0fc5e0fec2e6456f72f402308fd4e397ba19d09
--
Best Regards
Tao Chen
next prev parent reply other threads:[~2026-01-28 8:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-15 10:23 [PATCH] perf callchain: Fix suspicious RCU usage in get_callchain_entry() Radoslaw Zielonek
2024-07-15 10:47 ` Peter Zijlstra
2024-07-18 17:41 ` Andrii Nakryiko
2026-01-28 6:26 ` Qing Wang
2026-01-28 8:19 ` Tao Chen [this message]
2026-01-28 8:45 ` Qing Wang
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