linux-imx

#include <linux/kdebug.h>

#include <linux/kprobes.h>

#include <linux/export.h>

#include <linux/notifier.h>

#include <linux/rcupdate.h>

#include <linux/vmalloc.h>

#include <linux/reboot.h>

​

/*

 *  Notifier list for kernel code which wants to be called

 *  at shutdown. This is used to stop any idling DMA operations

 *  and the like.

 */

BLOCKING_NOTIFIER_HEAD(reboot_notifier_list);

​

/*

 *  Notifier chain core routines.  The exported routines below

 *  are layered on top of these, with appropriate locking added.

 */

​

static int notifier_chain_register(struct notifier_block **nl,

        struct notifier_block *n)

{

    while ((*nl) != NULL) {

        if (n->priority > (*nl)->priority)

            break;

        nl = &((*nl)->next);

    }

    n->next = *nl;

    rcu_assign_pointer(*nl, n);

    return 0;

}

​

static int notifier_chain_cond_register(struct notifier_block **nl,

        struct notifier_block *n)

{

    while ((*nl) != NULL) {

        if ((*nl) == n)

            return 0;

        if (n->priority > (*nl)->priority)

            break;

        nl = &((*nl)->next);

    }

    n->next = *nl;

    rcu_assign_pointer(*nl, n);

    return 0;

}

​

static int notifier_chain_unregister(struct notifier_block **nl,

        struct notifier_block *n)

{

    while ((*nl) != NULL) {

        if ((*nl) == n) {

            rcu_assign_pointer(*nl, n->next);

            return 0;

        }

        nl = &((*nl)->next);

    }

    return -ENOENT;

}

​

/**

 * notifier_call_chain - Informs the registered notifiers about an event.

 *  @nl:        Pointer to head of the blocking notifier chain

 *  @val:       Value passed unmodified to notifier function

 *  @v:     Pointer passed unmodified to notifier function

 *  @nr_to_call:    Number of notifier functions to be called. Don't care

 *          value of this parameter is -1.

 *  @nr_calls:  Records the number of notifications sent. Don't care

 *          value of this field is NULL.

 *  @returns:   notifier_call_chain returns the value returned by the

 *          last notifier function called.

 */

static int notifier_call_chain(struct notifier_block **nl,

                   unsigned long val, void *v,

                   int nr_to_call, int *nr_calls)

{

    int ret = NOTIFY_DONE;

    struct notifier_block *nb, *next_nb;

​

    nb = rcu_dereference_raw(*nl);

​

    while (nb && nr_to_call) {

        next_nb = rcu_dereference_raw(nb->next);

​

#ifdef CONFIG_DEBUG_NOTIFIERS

        if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {

            WARN(1, "Invalid notifier called!");

            nb = next_nb;

            continue;

        }

#endif