ftrace: Replace read_barrier_depends() with rcu_dereference_raw()

#include <linux/ctype.h>

#include <linux/list.h>

#include <linux/hash.h>

#include <linux/rcupdate.h>

#include <trace/events/sched.h>

static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);

#endif

/*

 * Traverse the ftrace_list, invoking all entries.  The reason that we

 * can use rcu_dereference_raw() is that elements removed from this list

 * are simply leaked, so there is no need to interact with a grace-period

 * mechanism.  The rcu_dereference_raw() calls are needed to handle

 * concurrent insertions into the ftrace_list.

 *

 * Silly Alpha and silly pointer-speculation compiler optimizations!

 */

static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)

{

	struct ftrace_ops *op = ftrace_list;

	/* in case someone actually ports this to alpha! */

	read_barrier_depends();

	struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/

	while (op != &ftrace_list_end) {

		/* silly alpha */

		read_barrier_depends();

		op->func(ip, parent_ip);

		op = op->next;

		op = rcu_dereference_raw(op->next); /*see above*/

	};

}

	 * the ops->next pointer is valid before another CPU sees

	 * the ops pointer included into the ftrace_list.

	 */

	smp_wmb();

	ftrace_list = ops;

	rcu_assign_pointer(ftrace_list, ops);

	if (ftrace_enabled) {

		ftrace_func_t func;