summaryrefslogtreecommitdiffstats
path: root/kernel/sys.c
diff options
context:
space:
mode:
authorAlexey Dobriyan <adobriyan@sw.ru>2007-10-18 23:39:16 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:34 -0700
commitfe9d4f576324999ac521c931f3b3eee0c8e45544 (patch)
tree8ff6ad770e15e81d00c87b945cb60326f28aee6b /kernel/sys.c
parent3ed75eb8f1cd89565966599c4f77d2edb086d5b0 (diff)
downloadlinux-fe9d4f576324999ac521c931f3b3eee0c8e45544.tar.gz
linux-fe9d4f576324999ac521c931f3b3eee0c8e45544.tar.bz2
linux-fe9d4f576324999ac521c931f3b3eee0c8e45544.zip
Add kernel/notifier.c
There is separate notifier header, but no separate notifier .c file. Extract notifier code out of kernel/sys.c which will remain for misc syscalls I hope. Merge kernel/die_notifier.c into kernel/notifier.c. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sys.c')
-rw-r--r--kernel/sys.c531
1 files changed, 0 insertions, 531 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index bc8879c822a5..b8fcbc640193 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -106,537 +106,6 @@ EXPORT_SYMBOL(cad_pid);
void (*pm_power_off_prepare)(void);
-/*
- * Notifier list for kernel code which wants to be called
- * at shutdown. This is used to stop any idling DMA operations
- * and the like.
- */
-
-static 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_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 __kprobes 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(*nl);
-
- while (nb && nr_to_call) {
- next_nb = rcu_dereference(nb->next);
- ret = nb->notifier_call(nb, val, v);
-
- if (nr_calls)
- (*nr_calls)++;
-
- if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
- break;
- nb = next_nb;
- nr_to_call--;
- }
- return ret;
-}
-
-/*
- * Atomic notifier chain routines. Registration and unregistration
- * use a spinlock, and call_chain is synchronized by RCU (no locks).
- */
-
-/**
- * atomic_notifier_chain_register - Add notifier to an atomic notifier chain
- * @nh: Pointer to head of the atomic notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to an atomic notifier chain.
- *
- * Currently always returns zero.
- */
-
-int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
- struct notifier_block *n)
-{
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&nh->lock, flags);
- ret = notifier_chain_register(&nh->head, n);
- spin_unlock_irqrestore(&nh->lock, flags);
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(atomic_notifier_chain_register);
-
-/**
- * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain
- * @nh: Pointer to head of the atomic notifier chain
- * @n: Entry to remove from notifier chain
- *
- * Removes a notifier from an atomic notifier chain.
- *
- * Returns zero on success or %-ENOENT on failure.
- */
-int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
- struct notifier_block *n)
-{
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&nh->lock, flags);
- ret = notifier_chain_unregister(&nh->head, n);
- spin_unlock_irqrestore(&nh->lock, flags);
- synchronize_rcu();
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
-
-/**
- * __atomic_notifier_call_chain - Call functions in an atomic notifier chain
- * @nh: Pointer to head of the atomic notifier chain
- * @val: Value passed unmodified to notifier function
- * @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See the comment for notifier_call_chain.
- * @nr_calls: See the comment for notifier_call_chain.
- *
- * Calls each function in a notifier chain in turn. The functions
- * run in an atomic context, so they must not block.
- * This routine uses RCU to synchronize with changes to the chain.
- *
- * If the return value of the notifier can be and'ed
- * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain()
- * will return immediately, with the return value of
- * the notifier function which halted execution.
- * Otherwise the return value is the return value
- * of the last notifier function called.
- */
-
-int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
-{
- int ret;
-
- rcu_read_lock();
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
- rcu_read_unlock();
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
-
-int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
-}
-
-EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
-/*
- * Blocking notifier chain routines. All access to the chain is
- * synchronized by an rwsem.
- */
-
-/**
- * blocking_notifier_chain_register - Add notifier to a blocking notifier chain
- * @nh: Pointer to head of the blocking notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to a blocking notifier chain.
- * Must be called in process context.
- *
- * Currently always returns zero.
- */
-
-int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- /*
- * This code gets used during boot-up, when task switching is
- * not yet working and interrupts must remain disabled. At
- * such times we must not call down_write().
- */
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_register(&nh->head, n);
-
- down_write(&nh->rwsem);
- ret = notifier_chain_register(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
-
-/**
- * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
- * @nh: Pointer to head of the blocking notifier chain
- * @n: Entry to remove from notifier chain
- *
- * Removes a notifier from a blocking notifier chain.
- * Must be called from process context.
- *
- * Returns zero on success or %-ENOENT on failure.
- */
-int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- /*
- * This code gets used during boot-up, when task switching is
- * not yet working and interrupts must remain disabled. At
- * such times we must not call down_write().
- */
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_unregister(&nh->head, n);
-
- down_write(&nh->rwsem);
- ret = notifier_chain_unregister(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister);
-
-/**
- * __blocking_notifier_call_chain - Call functions in a blocking notifier chain
- * @nh: 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: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain.
- *
- * Calls each function in a notifier chain in turn. The functions
- * run in a process context, so they are allowed to block.
- *
- * If the return value of the notifier can be and'ed
- * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain()
- * will return immediately, with the return value of
- * the notifier function which halted execution.
- * Otherwise the return value is the return value
- * of the last notifier function called.
- */
-
-int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
-{
- int ret = NOTIFY_DONE;
-
- /*
- * We check the head outside the lock, but if this access is
- * racy then it does not matter what the result of the test
- * is, we re-check the list after having taken the lock anyway:
- */
- if (rcu_dereference(nh->head)) {
- down_read(&nh->rwsem);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
- nr_calls);
- up_read(&nh->rwsem);
- }
- return ret;
-}
-EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain);
-
-int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __blocking_notifier_call_chain(nh, val, v, -1, NULL);
-}
-EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
-
-/*
- * Raw notifier chain routines. There is no protection;
- * the caller must provide it. Use at your own risk!
- */
-
-/**
- * raw_notifier_chain_register - Add notifier to a raw notifier chain
- * @nh: Pointer to head of the raw notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to a raw notifier chain.
- * All locking must be provided by the caller.
- *
- * Currently always returns zero.
- */
-
-int raw_notifier_chain_register(struct raw_notifier_head *nh,
- struct notifier_block *n)
-{
- return notifier_chain_register(&nh->head, n);
-}
-
-EXPORT_SYMBOL_GPL(raw_notifier_chain_register);
-
-/**
- * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain
- * @nh: Pointer to head of the raw notifier chain
- * @n: Entry to remove from notifier chain
- *
- * Removes a notifier from a raw notifier chain.
- * All locking must be provided by the caller.
- *
- * Returns zero on success or %-ENOENT on failure.
- */
-int raw_notifier_chain_unregister(struct raw_notifier_head *nh,
- struct notifier_block *n)
-{
- return notifier_chain_unregister(&nh->head, n);
-}
-
-EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister);
-
-/**
- * __raw_notifier_call_chain - Call functions in a raw notifier chain
- * @nh: Pointer to head of the raw notifier chain
- * @val: Value passed unmodified to notifier function
- * @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain
- *
- * Calls each function in a notifier chain in turn. The functions
- * run in an undefined context.
- * All locking must be provided by the caller.
- *
- * If the return value of the notifier can be and'ed
- * with %NOTIFY_STOP_MASK then raw_notifier_call_chain()
- * will return immediately, with the return value of
- * the notifier function which halted execution.
- * Otherwise the return value is the return value
- * of the last notifier function called.
- */
-
-int __raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
-{
- return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
-}
-
-EXPORT_SYMBOL_GPL(__raw_notifier_call_chain);
-
-int raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __raw_notifier_call_chain(nh, val, v, -1, NULL);
-}
-
-EXPORT_SYMBOL_GPL(raw_notifier_call_chain);
-
-/*
- * SRCU notifier chain routines. Registration and unregistration
- * use a mutex, and call_chain is synchronized by SRCU (no locks).
- */
-
-/**
- * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain
- * @nh: Pointer to head of the SRCU notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to an SRCU notifier chain.
- * Must be called in process context.
- *
- * Currently always returns zero.
- */
-
-int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- /*
- * This code gets used during boot-up, when task switching is
- * not yet working and interrupts must remain disabled. At
- * such times we must not call mutex_lock().
- */
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_register(&nh->head, n);
-
- mutex_lock(&nh->mutex);
- ret = notifier_chain_register(&nh->head, n);
- mutex_unlock(&nh->mutex);
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(srcu_notifier_chain_register);
-
-/**
- * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain
- * @nh: Pointer to head of the SRCU notifier chain
- * @n: Entry to remove from notifier chain
- *
- * Removes a notifier from an SRCU notifier chain.
- * Must be called from process context.
- *
- * Returns zero on success or %-ENOENT on failure.
- */
-int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- /*
- * This code gets used during boot-up, when task switching is
- * not yet working and interrupts must remain disabled. At
- * such times we must not call mutex_lock().
- */
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_unregister(&nh->head, n);
-
- mutex_lock(&nh->mutex);
- ret = notifier_chain_unregister(&nh->head, n);
- mutex_unlock(&nh->mutex);
- synchronize_srcu(&nh->srcu);
- return ret;
-}
-
-EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister);
-
-/**
- * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain
- * @nh: Pointer to head of the SRCU notifier chain
- * @val: Value passed unmodified to notifier function
- * @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain
- *
- * Calls each function in a notifier chain in turn. The functions
- * run in a process context, so they are allowed to block.
- *
- * If the return value of the notifier can be and'ed
- * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain()
- * will return immediately, with the return value of
- * the notifier function which halted execution.
- * Otherwise the return value is the return value
- * of the last notifier function called.
- */
-
-int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
-{
- int ret;
- int idx;
-
- idx = srcu_read_lock(&nh->srcu);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
- srcu_read_unlock(&nh->srcu, idx);
- return ret;
-}
-EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain);
-
-int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __srcu_notifier_call_chain(nh, val, v, -1, NULL);
-}
-EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
-
-/**
- * srcu_init_notifier_head - Initialize an SRCU notifier head
- * @nh: Pointer to head of the srcu notifier chain
- *
- * Unlike other sorts of notifier heads, SRCU notifier heads require
- * dynamic initialization. Be sure to call this routine before
- * calling any of the other SRCU notifier routines for this head.
- *
- * If an SRCU notifier head is deallocated, it must first be cleaned
- * up by calling srcu_cleanup_notifier_head(). Otherwise the head's
- * per-cpu data (used by the SRCU mechanism) will leak.
- */
-
-void srcu_init_notifier_head(struct srcu_notifier_head *nh)
-{
- mutex_init(&nh->mutex);
- if (init_srcu_struct(&nh->srcu) < 0)
- BUG();
- nh->head = NULL;
-}
-
-EXPORT_SYMBOL_GPL(srcu_init_notifier_head);
-
-/**
- * register_reboot_notifier - Register function to be called at reboot time
- * @nb: Info about notifier function to be called
- *
- * Registers a function with the list of functions
- * to be called at reboot time.
- *
- * Currently always returns zero, as blocking_notifier_chain_register()
- * always returns zero.
- */
-
-int register_reboot_notifier(struct notifier_block * nb)
-{
- return blocking_notifier_chain_register(&reboot_notifier_list, nb);
-}
-
-EXPORT_SYMBOL(register_reboot_notifier);
-
-/**
- * unregister_reboot_notifier - Unregister previously registered reboot notifier
- * @nb: Hook to be unregistered
- *
- * Unregisters a previously registered reboot
- * notifier function.
- *
- * Returns zero on success, or %-ENOENT on failure.
- */
-
-int unregister_reboot_notifier(struct notifier_block * nb)
-{
- return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
-}
-
-EXPORT_SYMBOL(unregister_reboot_notifier);
-
static int set_one_prio(struct task_struct *p, int niceval, int error)
{
int no_nice;