kernel-fxtec-pro1x/kernel/user-return-notifier.c
Stephen Rothwell 3c912b6eda x86: Fix user return notifier put_cpu_var() invocation
Today's linux-next build (x86_64 allmodconfig) failed like this:

  kernel/user-return-notifier.c: In function
  'fire_user_return_notifiers': kernel/user-return-notifier.c:45:
  error: expected expression before ')' token

Introduced by commit 7c68af6e32
("core, x86: Add user return notifiers") from the tip and kvm trees
but revealed by commit e0fdb0e050
("percpu: add __percpu for sparse") from the percpu tree.

Before that percpu tree commit, "put_cpu_var()" would compile
without error (even though it really needs a parameter).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
LKML-Reference: <20091102161722.eea4358d.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 07:58:59 +01:00

46 lines
1.4 KiB
C

#include <linux/user-return-notifier.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/module.h>
static DEFINE_PER_CPU(struct hlist_head, return_notifier_list);
#define URN_LIST_HEAD per_cpu(return_notifier_list, raw_smp_processor_id())
/*
* Request a notification when the current cpu returns to userspace. Must be
* called in atomic context. The notifier will also be called in atomic
* context.
*/
void user_return_notifier_register(struct user_return_notifier *urn)
{
set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
hlist_add_head(&urn->link, &URN_LIST_HEAD);
}
EXPORT_SYMBOL_GPL(user_return_notifier_register);
/*
* Removes a registered user return notifier. Must be called from atomic
* context, and from the same cpu registration occured in.
*/
void user_return_notifier_unregister(struct user_return_notifier *urn)
{
hlist_del(&urn->link);
if (hlist_empty(&URN_LIST_HEAD))
clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
}
EXPORT_SYMBOL_GPL(user_return_notifier_unregister);
/* Calls registered user return notifiers */
void fire_user_return_notifiers(void)
{
struct user_return_notifier *urn;
struct hlist_node *tmp1, *tmp2;
struct hlist_head *head;
head = &get_cpu_var(return_notifier_list);
hlist_for_each_entry_safe(urn, tmp1, tmp2, head, link)
urn->on_user_return(urn);
put_cpu_var(return_notifier_list);
}