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Commit e679af62 authored by Petr Mladek's avatar Petr Mladek Committed by Jiri Kosina
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livepatch: Cancel transition a safe way for immediate patches 



klp_init_transition() does not set func->transition for immediate patches.
Then klp_ftrace_handler() could use the new code immediately. As a result,
it is not safe to put the livepatch module in klp_cancel_transition().

This patch reverts most of the last minute changes klp_cancel_transition().
It keeps the warning about a misuse because it still makes sense.

Fixes: 3ec24776 ("livepatch: allow removal of a disabled patch")
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Acked-by: default avatarMiroslav Benes <mbenes@suse.cz>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 10517429

kernel/livepatch/transition.c

+0 −20
Original line number Diff line number Diff line
@@ -120,31 +120,11 @@ static void klp_complete_transition(void) 
 */

void klp_cancel_transition(void)

{

	struct klp_patch *patch = klp_transition_patch;

	struct klp_object *obj;

	struct klp_func *func;

	bool immediate_func = false;



	if (WARN_ON_ONCE(klp_target_state != KLP_PATCHED))

		return;



	klp_target_state = KLP_UNPATCHED;

	klp_complete_transition();



	/*

	 * In the enable error path, even immediate patches can be safely

	 * removed because the transition hasn't been started yet.

	 *

	 * klp_complete_transition() doesn't have a module_put() for immediate

	 * patches, so do it here.

	 */

	klp_for_each_object(patch, obj)

		klp_for_each_func(obj, func)

			if (func->immediate)

				immediate_func = true;



	if (patch->immediate || immediate_func)

		module_put(patch->mod);

}



/*