Commit 1146edcb authored Jun 09, 2014 by Paul E. McKenney

rcu: Loosen __call_rcu()'s rcu_head alignment constraint



The m68k architecture aligns only to 16-bit boundaries, which can cause
the align-to-32-bits check in __call_rcu() to trigger.  Because there is
currently no known potential need for more than one low-order bit, this
commit loosens the check to 16-bit boundaries.

Reported-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

parent a792563b

kernel/rcu/tree.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2662,7 +2662,7 @@ __call_rcu(struct rcu_head head, void (func)(struct rcu_head *rcu),
		unsigned long flags;
		struct rcu_data *rdp;

		WARN_ON_ONCE((unsigned long)head & 0x3); /* Misaligned rcu_head! */
		WARN_ON_ONCE((unsigned long)head & 0x1); /* Misaligned rcu_head! */
		if (debug_rcu_head_queue(head)) {
		/* Probable double call_rcu(), so leak the callback. */
		ACCESS_ONCE(head->func) = rcu_leak_callback;