Commit d593e0ca authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Petr Pavlu
Browse files

module: Use RCU in all users of __module_text_address(). 



__module_text_address() can be invoked within a RCU section, there is no
requirement to have preemption disabled.

Replace the preempt_disable() section around __module_text_address()
with RCU.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-16-bigeasy@linutronix.de


Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
parent 6593a2c9

kernel/module/main.c

+5 −11
Original line number Diff line number Diff line
@@ -823,13 +823,12 @@ void symbol_put_addr(void *addr) 


	/*

	 * Even though we hold a reference on the module; we still need to

	 * disable preemption in order to safely traverse the data structure.

	 * RCU read section in order to safely traverse the data structure.

	 */

	preempt_disable();

	guard(rcu)();

	modaddr = __module_text_address(a);

	BUG_ON(!modaddr);

	module_put(modaddr);

	preempt_enable();

}

EXPORT_SYMBOL_GPL(symbol_put_addr);
@@ -3776,20 +3775,15 @@ struct module *__module_address(unsigned long addr) 
 */

bool is_module_text_address(unsigned long addr)

{

	bool ret;



	preempt_disable();

	ret = __module_text_address(addr) != NULL;

	preempt_enable();



	return ret;

	guard(rcu)();

	return __module_text_address(addr) != NULL;

}



/**

 * __module_text_address() - get the module whose code contains an address.

 * @addr: the address.

 *

 * Must be called with preempt disabled or module mutex held so that

 * Must be called within RCU read section or module mutex held so that

 * module doesn't get freed during this.

 */

struct module *__module_text_address(unsigned long addr)