From: Masami Hiramatsu <mhiramat@kernel.org>
To: fche@redhat.com (Frank Ch. Eigler)
Cc: peterz@infradead.org, Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org, Eddy_Wu@trendmicro.com,
x86@kernel.org, davem@davemloft.net, rostedt@goodmis.org,
naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com,
linux-arch@vger.kernel.org, cameron@moodycamel.com,
oleg@redhat.com, will@kernel.org, paulmck@kernel.org,
systemtap@sourceware.org
Subject: Re: [PATCH v5 00/21] kprobes: Unify kretprobe trampoline handlers and make kretprobe lockless
Date: Tue, 8 Sep 2020 11:55:27 +0900 [thread overview]
Message-ID: <20200908115527.cf8d2b106bf1a9c4416bbc89@kernel.org> (raw)
In-Reply-To: <87eendo51o.fsf@redhat.com>
On Mon, 07 Sep 2020 13:44:19 -0400
fche@redhat.com (Frank Ch. Eigler) wrote:
> Masami Hiramatsu <mhiramat@kernel.org> writes:
>
> > Sorry, for noticing this point, I Cc'd to systemtap. Is systemtap taking
> > care of spinlock too?
>
> On PRREMPT_RT configurations, systemtap uses the raw_spinlock_t
> types/functions, to keep its probe handlers as atomic as we can make them.
OK, if the lock is only used in the probe handlers, there should be
no problem. Even if a probe hits in the NMI which happens in another
kprobe handler, the probe does not call its handler (because we don't
support nested kprobes* yet).
But maybe you'll get warnings if you enable the lockdep.
* https://lkml.kernel.org/r/158894789510.14896.13461271606820304664.stgit@devnote2
It seems that we need more work for the nested kprobes.
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2020-09-08 2:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <159870598914.1229682.15230803449082078353.stgit@devnote2>
[not found] ` <20200901190808.GK29142@worktop.programming.kicks-ass.net>
[not found] ` <20200902093739.8bd13603380951eaddbcd8a5@kernel.org>
[not found] ` <20200902070226.GG2674@hirez.programming.kicks-ass.net>
[not found] ` <20200902171755.b126672093a3c5d1b3a62a4f@kernel.org>
[not found] ` <20200902093613.GY1362448@hirez.programming.kicks-ass.net>
[not found] ` <20200902221926.f5cae5b4ad00b8d8f9ad99c7@kernel.org>
[not found] ` <20200902134252.GH1362448@hirez.programming.kicks-ass.net>
2020-09-03 1:39 ` Masami Hiramatsu
2020-09-03 2:02 ` Masami Hiramatsu
2020-09-07 17:44 ` Frank Ch. Eigler
2020-09-08 2:55 ` Masami Hiramatsu [this message]
2020-09-08 10:37 ` peterz
2020-09-08 11:15 ` Eddy_Wu
2020-09-08 11:33 ` peterz
2020-09-08 15:09 ` Masami Hiramatsu
2020-09-09 5:28 ` Masami Hiramatsu
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