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Date:   Sat, 25 Jul 2020 05:42:27 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Mike Rapoport <rppt@kernel.org>
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
Message-ID: <20200725024227.GD17052@linux.intel.com>
References: <20200724050553.1724168-1-jarkko.sakkinen@linux.intel.com>
 <20200724050553.1724168-2-jarkko.sakkinen@linux.intel.com>
 <20200724102258.GB2831654@kernel.org>
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On Fri, Jul 24, 2020 at 01:22:58PM +0300, Mike Rapoport wrote:
> On Fri, Jul 24, 2020 at 08:05:48AM +0300, Jarkko Sakkinen wrote:
> > Add lock_modules() and unlock_modules() wrappers for acquiring module_mutex
> > in order to remove the compile time dependency to it.
> > 
> > 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(-)
> 
> Any reason to convert only kprobes to the new API and leave others with
> opencoded implementation?

Not anything particular.

Lets see:

$ git --no-pager grep "mutex_lock(&module_mutex)"
arch/powerpc/platforms/powernv/pci-cxl.c:       mutex_lock(&module_mutex);
drivers/gpu/drm/drm_fb_helper.c:        mutex_lock(&module_mutex);
include/linux/module.h: mutex_lock(&module_mutex);
kernel/livepatch/core.c:        mutex_lock(&module_mutex);
kernel/livepatch/core.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);
kernel/module.c:        mutex_lock(&module_mutex);

I could refine this commit to patch these sites. Or should I split it
into multiple?

/Jarkko