Commit cb0b50b8 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Luis Chamberlain
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module: Remove preempt_disable() from module reference counting. 



The preempt_disable() section in module_put() was added in commit
   e1783a24 ("module: Use this_cpu_xx to dynamically allocate counters")

while the per-CPU counter were switched to another API. The API requires
that during the RMW operation the CPU remained the same.

This counting API was later replaced with atomic_t in commit
   2f35c41f ("module: Replace module_ref with atomic_t refcnt")

Since this atomic_t replacement there is no need to keep preemption
disabled while the reference counter is modified.

Remove preempt_disable() from module_put(), __module_get() and
try_module_get().

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent d36f6efb

kernel/module/main.c

+0 −7
Original line number Diff line number Diff line
@@ -820,10 +820,8 @@ static struct module_attribute modinfo_refcnt = 
void __module_get(struct module *module)

{

	if (module) {

		preempt_disable();

		atomic_inc(&module->refcnt);

		trace_module_get(module, _RET_IP_);

		preempt_enable();

	}

}

EXPORT_SYMBOL(__module_get);
@@ -833,15 +831,12 @@ bool try_module_get(struct module *module) 
	bool ret = true;



	if (module) {

		preempt_disable();

		/* Note: here, we can fail to get a reference */

		if (likely(module_is_live(module) &&

			   atomic_inc_not_zero(&module->refcnt) != 0))

			trace_module_get(module, _RET_IP_);

		else

			ret = false;



		preempt_enable();

	}

	return ret;

}
@@ -852,11 +847,9 @@ void module_put(struct module *module) 
	int ret;



	if (module) {

		preempt_disable();

		ret = atomic_dec_if_positive(&module->refcnt);

		WARN_ON(ret < 0);	/* Failed to put refcount */

		trace_module_put(module, _RET_IP_);

		preempt_enable();

	}

}

EXPORT_SYMBOL(module_put);