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-rw-r--r--arch/x86/kernel/process_64.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index bb1dc51bab0..45ab4d6fc8a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -363,6 +363,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
this_cpu_write(old_rsp, next->usersp);
this_cpu_write(current_task, next_p);
+ /*
+ * If it were not for PREEMPT_ACTIVE we could guarantee that the
+ * preempt_count of all tasks was equal here and this would not be
+ * needed.
+ */
+ task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count);
+ this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count);
+
this_cpu_write(kernel_stack,
(unsigned long)task_stack_page(next_p) +
THREAD_SIZE - KERNEL_STACK_OFFSET);