From: Steven Rostedt <rostedt@goodmis.org>
To: Douglas RAILLARD <douglas.raillard@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org (open list:TRACING),
linux-trace-kernel@vger.kernel.org (open list:TRACING),
"Paul E. McKenney" <paulmck@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
rcu@vger.kernel.org
Subject: Re: [PATCH] rcu: Fix rcu_torture_read ftrace event
Date: Mon, 20 Mar 2023 11:20:15 -0400 [thread overview]
Message-ID: <20230320112015.2271da9c@gandalf.local.home> (raw)
In-Reply-To: <20230306122744.236790-1-douglas.raillard@arm.com>
[ Wondering why this didn't get picked up in v6.3-rc3, I see that the
maintainers of RCU were not Cc'd :-( ]
This is a bug that will cause unwanted results. I have a patch that will not
let the kernel build when code like this is added.
https://patchwork.kernel.org/project/linux-trace-kernel/patch/20230309221302.642e82d9@gandalf.local.home/
( The kernel robot even failed when applying the above patch, because it
caught the code that this patch fixes )
On Mon, 6 Mar 2023 12:27:43 +0000
Douglas RAILLARD <douglas.raillard@arm.com> wrote:
> From: Douglas Raillard <douglas.raillard@arm.com>
>
> Fix the rcutorturename field so that its size is correctly reported in
> the text format embedded in trace.dat files. As it stands, it is
> reported as being of size 1:
And that the offsets of the following fields will be incorrect as well.
>
> field:char rcutorturename[8]; offset:8; size:1; signed:0;
>
Please add:
Cc: stable@vger.kernel.org
Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Thanks,
-- Steve
> Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
> ---
> include/trace/events/rcu.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
> index 90b2fb0292cb..012fa0d171b2 100644
> --- a/include/trace/events/rcu.h
> +++ b/include/trace/events/rcu.h
> @@ -768,7 +768,7 @@ TRACE_EVENT_RCU(rcu_torture_read,
> TP_ARGS(rcutorturename, rhp, secs, c_old, c),
>
> TP_STRUCT__entry(
> - __field(char, rcutorturename[RCUTORTURENAME_LEN])
> + __array(char, rcutorturename, RCUTORTURENAME_LEN)
> __field(struct rcu_head *, rhp)
> __field(unsigned long, secs)
> __field(unsigned long, c_old)
next prev parent reply other threads:[~2023-03-20 15:27 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-06 12:27 [PATCH] rcu: Fix rcu_torture_read ftrace event Douglas RAILLARD
2023-03-06 12:54 ` Mukesh Ojha
2023-03-20 15:20 ` Steven Rostedt [this message]
2023-03-20 16:58 ` Paul E. McKenney
2023-03-20 17:36 ` Steven Rostedt
2023-03-20 18:49 ` Paul E. McKenney
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