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authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-05-10 10:47:21 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-05-16 14:42:43 +0200
commitd49f47f83d15f3142d482a29de76f45360e34082 (patch)
tree255724f1f3d0e6b395c14ca91829ed6141be7964 /arch
parents390/pfault: use __set_task_state (diff)
downloadlinux-d49f47f83d15f3142d482a29de76f45360e34082.tar.xz
linux-d49f47f83d15f3142d482a29de76f45360e34082.zip
s390/pfault: add sanity check
If the task that was found on an initial interrupt doesn't match the current task execute a WARN_ON_ONCE() and don't put the task to sleep. When this happened something went wrong between the interface of the hypervisor and the kernel. In such a case keep the tasks alive to avoid a hanging system. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/mm/fault.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index a9c11aa57450..72cec9ecd96c 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -584,6 +584,8 @@ static void pfault_interrupt(struct ext_code ext_code,
}
} else {
/* signal bit not set -> a real page is missing. */
+ if (WARN_ON_ONCE(tsk != current))
+ goto out;
if (tsk->thread.pfault_wait == 1) {
/* Already on the list with a reference: put to sleep */
__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
@@ -606,6 +608,7 @@ static void pfault_interrupt(struct ext_code ext_code,
set_tsk_need_resched(tsk);
}
}
+out:
spin_unlock(&pfault_lock);
put_task_struct(tsk);
}