summaryrefslogtreecommitdiffstats
path: root/arch/s390/mm/fault.c
diff options
context:
space:
mode:
authorAnton Arapov <anton@redhat.com>2012-06-08 12:58:00 +0200
committerAnton Arapov <anton@redhat.com>2012-06-08 12:58:00 +0200
commit6792a3f47a2e42d7164292bf7f1a55cfc4c91652 (patch)
treeb90c002bfbbeaec92f5d8a2383dcabf6524016f7 /arch/s390/mm/fault.c
parentfe2895d3d55146cac65b273c0f83e2c7e543cd0e (diff)
downloadkernel-uprobes-6792a3f47a2e42d7164292bf7f1a55cfc4c91652.tar.gz
kernel-uprobes-6792a3f47a2e42d7164292bf7f1a55cfc4c91652.tar.xz
kernel-uprobes-6792a3f47a2e42d7164292bf7f1a55cfc4c91652.zip
fedora kernel: b920e9b748c595f970bf80ede7832d39f8d567dav3.4.1-2
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r--arch/s390/mm/fault.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index e8fcd928dc7..4e66860029f 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -32,10 +32,10 @@
#include <linux/uaccess.h>
#include <linux/hugetlb.h>
#include <asm/asm-offsets.h>
-#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
+#include <asm/facility.h>
#include "../kernel/entry.h"
#ifndef CONFIG_64BIT
@@ -532,7 +532,7 @@ void pfault_fini(void)
static DEFINE_SPINLOCK(pfault_lock);
static LIST_HEAD(pfault_list);
-static void pfault_interrupt(unsigned int ext_int_code,
+static void pfault_interrupt(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct task_struct *tsk;
@@ -545,7 +545,7 @@ static void pfault_interrupt(unsigned int ext_int_code,
* in the 'cpu address' field associated with the
* external interrupt.
*/
- subcode = ext_int_code >> 16;
+ subcode = ext_code.subcode;
if ((subcode & 0xff00) != __SUBCODE_MASK)
return;
kstat_cpu(smp_processor_id()).irqs[EXTINT_PFL]++;
@@ -574,6 +574,7 @@ static void pfault_interrupt(unsigned int ext_int_code,
tsk->thread.pfault_wait = 0;
list_del(&tsk->thread.list);
wake_up_process(tsk);
+ put_task_struct(tsk);
} else {
/* Completion interrupt was faster than initial
* interrupt. Set pfault_wait to -1 so the initial
@@ -588,14 +589,22 @@ static void pfault_interrupt(unsigned int ext_int_code,
put_task_struct(tsk);
} else {
/* signal bit not set -> a real page is missing. */
- if (tsk->thread.pfault_wait == -1) {
+ if (tsk->thread.pfault_wait == 1) {
+ /* Already on the list with a reference: put to sleep */
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ set_tsk_need_resched(tsk);
+ } else if (tsk->thread.pfault_wait == -1) {
/* Completion interrupt was faster than the initial
* interrupt (pfault_wait == -1). Set pfault_wait
* back to zero and exit. */
tsk->thread.pfault_wait = 0;
} else {
/* Initial interrupt arrived before completion
- * interrupt. Let the task sleep. */
+ * interrupt. Let the task sleep.
+ * An extra task reference is needed since a different
+ * cpu may set the task state to TASK_RUNNING again
+ * before the scheduler is reached. */
+ get_task_struct(tsk);
tsk->thread.pfault_wait = 1;
list_add(&tsk->thread.list, &pfault_list);
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
@@ -620,6 +629,7 @@ static int __cpuinit pfault_cpu_notify(struct notifier_block *self,
list_del(&thread->list);
tsk = container_of(thread, struct task_struct, thread);
wake_up_process(tsk);
+ put_task_struct(tsk);
}
spin_unlock_irq(&pfault_lock);
break;