Merge branch 'linux-2.6'

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 7c8e3da23810..8d506d86e2df 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -353,6 +353,12 @@ struct task_struct *__switch_to(struct task_struct *prev,
         account_process_vtime(current);
         calculate_steal_time();
 
+        /*
+         * We can't take a PMU exception inside _switch() since there is a
+         * window where the kernel stack SLB and the kernel stack are out
+         * of sync. Hard disable here.
+         */
+        hard_irq_disable();
         last = _switch(old_thread, new_thread);
 
         local_irq_restore(flags);