From: Ingo Molnar <mingo@kernel.org>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andi Kleen <ak@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Jessica Yu <jeyu@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH v5 1/6] kprobes: Remove dependency to the module_mutex
Date: Fri, 24 Jul 2020 11:17:11 +0200 [thread overview]
Message-ID: <20200724091711.GB517988@gmail.com> (raw)
In-Reply-To: <20200724050553.1724168-2-jarkko.sakkinen@linux.intel.com>
* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -564,7 +564,7 @@ static void kprobe_optimizer(struct work_struct *work)
> cpus_read_lock();
> mutex_lock(&text_mutex);
> /* Lock modules while optimizing kprobes */
> - mutex_lock(&module_mutex);
> + lock_modules();
>
> /*
> * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed)
> @@ -589,7 +589,7 @@ static void kprobe_optimizer(struct work_struct *work)
> /* Step 4: Free cleaned kprobes after quiesence period */
> do_free_cleaned_kprobes();
>
> - mutex_unlock(&module_mutex);
> + unlock_modules();
> mutex_unlock(&text_mutex);
> cpus_read_unlock();
BTW., it would be nice to expand on the comments above - exactly which
parts of the modules code is being serialized against and why?
We already hold the text_mutex here, which should protect against most
kprobes related activities interfering - and it's unclear (to me)
which part of the modules code is being serialized with here, and the
'lock modules while optimizing kprobes' comments is unhelpful. :-)
Thanks,
Ingo
next prev parent reply other threads:[~2020-07-24 9:17 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-24 5:05 [PATCH v5 0/6] arch/x86: kprobes: Remove MODULES dependency Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 1/6] kprobes: Remove dependency to the module_mutex Jarkko Sakkinen
2020-07-24 9:13 ` Ingo Molnar
2020-07-25 2:36 ` Jarkko Sakkinen
2020-07-24 9:17 ` Ingo Molnar [this message]
2020-07-25 3:01 ` Jarkko Sakkinen
2020-07-25 10:21 ` Ingo Molnar
2020-07-28 7:34 ` Masami Hiramatsu
2020-07-28 12:29 ` [tip: perf/core] kprobes: Remove unnecessary module_mutex locking from kprobe_optimizer() tip-bot2 for Masami Hiramatsu
2020-08-17 21:22 ` [PATCH v5 1/6] kprobes: Remove dependency to the module_mutex Jarkko Sakkinen
2020-07-24 10:22 ` Mike Rapoport
2020-07-25 2:42 ` Jarkko Sakkinen
2020-07-24 14:46 ` Masami Hiramatsu
2020-07-25 2:48 ` Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 2/6] vmalloc: Add text_alloc() and text_free() Jarkko Sakkinen
2020-07-24 10:22 ` Mike Rapoport
2020-07-25 2:20 ` Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 3/6] arch/x86: Implement " Jarkko Sakkinen
2020-07-24 9:22 ` Ingo Molnar
2020-07-25 2:03 ` Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 4/6] arch/x86: kprobes: Use " Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 5/6] " Jarkko Sakkinen
2020-07-24 9:27 ` Ingo Molnar
2020-07-24 12:16 ` Ard Biesheuvel
2020-07-24 12:16 ` Ard Biesheuvel
2020-07-25 3:19 ` [PATCH v5 5/6] kprobes: Use text_alloc() and text_free()] Jarkko Sakkinen
2020-07-25 3:16 ` [PATCH v5 5/6] kprobes: Use text_alloc() and text_free() Jarkko Sakkinen
2020-07-26 8:14 ` Mike Rapoport
2020-07-26 16:06 ` Ard Biesheuvel
2020-07-26 16:06 ` Ard Biesheuvel
2020-07-28 8:17 ` Masami Hiramatsu
2020-07-28 10:56 ` Ard Biesheuvel
2020-07-28 10:56 ` Ard Biesheuvel
2020-07-28 13:35 ` Masami Hiramatsu
2020-07-28 17:51 ` Ard Biesheuvel
2020-07-28 17:51 ` Ard Biesheuvel
2020-07-29 1:50 ` Masami Hiramatsu
2020-07-29 6:13 ` Ard Biesheuvel
2020-07-29 6:13 ` Ard Biesheuvel
2020-07-30 1:09 ` Masami Hiramatsu
2020-08-18 5:30 ` Jarkko Sakkinen
2020-08-18 11:51 ` Mike Rapoport
2020-08-18 16:30 ` Jarkko Sakkinen
2020-08-19 6:47 ` Mike Rapoport
2020-08-19 21:07 ` Jarkko Sakkinen
2020-07-24 10:27 ` Mike Rapoport
2020-07-24 14:57 ` Masami Hiramatsu
2020-07-24 23:38 ` Jarkko Sakkinen
2020-07-24 5:05 ` [PATCH v5 6/6] kprobes: Remove CONFIG_MODULES dependency Jarkko Sakkinen
2020-07-24 7:01 ` [PATCH v5 0/6] arch/x86: kprobes: Remove MODULES dependency Jarkko Sakkinen
2020-07-24 10:26 ` Mike Rapoport
-- strict thread matches above, loose matches on Subject: below --
2020-07-24 5:04 Jarkko Sakkinen
2020-07-24 5:04 ` [PATCH v5 1/6] kprobes: Remove dependency to the module_mutex Jarkko Sakkinen
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