From: Steven Rostedt <rostedt@goodmis.org>
To: Luo Gengkun <luogengkun@huaweicloud.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>,
mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH] tracing: Fix tracing_marker may trigger page fault during preempt_disable
Date: Tue, 2 Sep 2025 10:14:54 -0400 [thread overview]
Message-ID: <20250902101454.08ac4b51@batman.local.home> (raw)
In-Reply-To: <cc6eb973-d82b-4afc-83fb-a2c28cc79d36@huaweicloud.com>
On Tue, 2 Sep 2025 11:47:32 +0800
Luo Gengkun <luogengkun@huaweicloud.com> wrote:
> > If this does not check the preempt flag, it is a problem.
> > Maybe arm64 needs to do fixup and abort instead of do_mem_abort()?
>
> My kernel was built without CONFIG_PREEMPT_COUNT, so the preempt_disable()
> does nothing more than act as a barrier. In this case, it can pass the
> check by schedule(). Perhaps this is another issue?
This is why I never triggered it. I always have PREEMPT_COUNT enabled.
I have tests that test without it, but I don't think those tests access
trace_marker, and if they do, they don't stress it.
-- Steve
prev parent reply other threads:[~2025-09-02 21:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20250819105152.2766363-1-luogengkun@huaweicloud.com>
[not found] ` <20250819135008.5f1ba00e@gandalf.local.home>
[not found] ` <436e4fa7-f8c7-4c23-a28a-4e5eebe2f854@huaweicloud.com>
2025-08-29 12:26 ` [PATCH] tracing: Fix tracing_marker may trigger page fault during preempt_disable Steven Rostedt
2025-08-29 12:36 ` Steven Rostedt
2025-08-29 19:53 ` Catalin Marinas
2025-08-29 22:13 ` Steven Rostedt
2025-08-30 10:22 ` Catalin Marinas
2025-09-01 9:56 ` Mark Rutland
2025-09-01 12:28 ` Catalin Marinas
2025-09-01 13:07 ` Mark Rutland
2025-09-01 9:43 ` Mark Rutland
2025-09-02 14:11 ` Steven Rostedt
2025-09-01 16:01 ` Masami Hiramatsu
2025-09-01 15:56 ` Masami Hiramatsu
2025-09-02 3:47 ` Luo Gengkun
2025-09-02 7:35 ` Masami Hiramatsu
2025-09-02 14:14 ` Steven Rostedt [this message]
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