From: Masami Hiramatsu <mhiramat@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 23:46:31 +0900 [thread overview]
Message-ID: <20200724234631.40f4ffec6adae57ac3df8ea3@kernel.org> (raw)
In-Reply-To: <20200724050553.1724168-2-jarkko.sakkinen@linux.intel.com>
On Fri, 24 Jul 2020 08:05:48 +0300
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
> Add lock_modules() and unlock_modules() wrappers for acquiring module_mutex
> in order to remove the compile time dependency to it.
This subject is a bit confusing. This is just wrapping modules_mutex in
kpprobes. We still have compile time dependency, e.g. module_state, right?
Thank you,
>
> Cc: linux-mm@kvack.org
> Cc: Andi Kleen <ak@linux.intel.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> include/linux/module.h | 18 ++++++++++++++++++
> kernel/kprobes.c | 4 ++--
> kernel/trace/trace_kprobe.c | 4 ++--
> 3 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 2e6670860d27..8850b9692b8f 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -705,6 +705,16 @@ static inline bool is_livepatch_module(struct module *mod)
> bool is_module_sig_enforced(void);
> void set_module_sig_enforced(void);
>
> +static inline void lock_modules(void)
> +{
> + mutex_lock(&module_mutex);
> +}
> +
> +static inline void unlock_modules(void)
> +{
> + mutex_unlock(&module_mutex);
> +}
> +
> #else /* !CONFIG_MODULES... */
>
> static inline struct module *__module_address(unsigned long addr)
> @@ -852,6 +862,14 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
> return ptr;
> }
>
> +static inline void lock_modules(void)
> +{
> +}
> +
> +static inline void unlock_modules(void)
> +{
> +}
> +
> #endif /* CONFIG_MODULES */
>
> #ifdef CONFIG_SYSFS
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 2e97febeef77..4e46d96d4e16 100644
> --- 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();
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index aefb6065b508..710ec6a6aa8f 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -122,9 +122,9 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
> if (!p)
> return true;
> *p = '\0';
> - mutex_lock(&module_mutex);
> + lock_modules();
> ret = !!find_module(tk->symbol);
> - mutex_unlock(&module_mutex);
> + unlock_modules();
> *p = ':';
>
> return ret;
> --
> 2.25.1
>
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2020-07-24 14:46 UTC|newest]
Thread overview: 46+ 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
2020-07-25 3:01 ` Jarkko Sakkinen
2020-07-25 10:21 ` Ingo Molnar
2020-07-28 7:34 ` Masami Hiramatsu
2020-08-17 21:22 ` Jarkko Sakkinen
2020-07-24 10:22 ` Mike Rapoport
2020-07-25 2:42 ` Jarkko Sakkinen
2020-07-24 14:46 ` Masami Hiramatsu [this message]
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
2020-07-25 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
2020-07-28 8:17 ` Masami Hiramatsu
2020-07-28 10:56 ` Ard Biesheuvel
2020-07-28 13:35 ` Masami Hiramatsu
2020-07-28 17:51 ` Ard Biesheuvel
2020-07-29 1:50 ` Masami Hiramatsu
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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