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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: bpf@vger.kernel.org, linux-rt-users@vger.kernel.org,
	ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org
Subject: Re: bpf_ringbuf_reserve deadlock on rt kernels
Date: Wed, 12 Jun 2024 16:32:23 +0200	[thread overview]
Message-ID: <20240612143223.BO0LMFEZ@linutronix.de> (raw)
In-Reply-To: <jxkyec5jd54r3cmel4e3pep4ebo3pd4xgedwtb7gj65fntf4s7@om5r3mowjknb>

On 2024-06-10 17:17:35 [+0200], Dmitry Dolgov wrote:
> Hi,
Hi,

…
> The BPF program in question is attached to sched_switch. The issue seems
> to be similar to a couple of syzkaller reports [1], [2], although the
> latter one is about nested progs, which seems to be not the case here.
> Talking about nested progs, applying a similar approach as in [3]
> reworked for bpf_ringbuf, elliminates the issue.
> 
> Do I miss anything, is it a known issue? Any ideas how to address that?

I haven't attached bpf program to trace-events so this new to me. But if
you BPF attach programs to trace-events then there might be more things
that can go wrong…
Let me add this to the bpf-list-to-look-at.
Do you get more splats with CONFIG_DEBUG_ATOMIC_SLEEP=y?

Sebastian

  reply	other threads:[~2024-06-12 14:32 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-10 15:17 bpf_ringbuf_reserve deadlock on rt kernels Dmitry Dolgov
2024-06-12 14:32 ` Sebastian Andrzej Siewior [this message]
2024-06-13 10:23   ` Dmitry Dolgov
2024-06-13 10:40     ` Sebastian Andrzej Siewior

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