1 files changed, 35 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index b40e0b4815b3..0e931aaffca2 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -593,6 +593,41 @@ _GLOBAL(ret_from_except_lite)
         b       .ret_from_except
 
 resume_kernel:
+        /* check current_thread_info, _TIF_EMULATE_STACK_STORE */
+        CURRENT_THREAD_INFO(r9, r1)
+        ld      r8,TI_FLAGS(r9)
+        andis.  r8,r8,_TIF_EMULATE_STACK_STORE@h
+        beq+    1f
+
+        addi    r8,r1,INT_FRAME_SIZE    /* Get the kprobed function entry */
+
+        lwz     r3,GPR1(r1)
+        subi    r3,r3,INT_FRAME_SIZE    /* dst: Allocate a trampoline exception frame */
+        mr      r4,r1                   /* src:  current exception frame */
+        mr      r1,r3                   /* Reroute the trampoline frame to r1 */
+
+        /* Copy from the original to the trampoline. */
+        li      r5,INT_FRAME_SIZE/8     /* size: INT_FRAME_SIZE */
+        li      r6,0                    /* start offset: 0 */
+        mtctr   r5
+2:      ldx     r0,r6,r4
+        stdx    r0,r6,r3
+        addi    r6,r6,8
+        bdnz    2b
+
+        /* Do real store operation to complete stwu */
+        lwz     r5,GPR1(r1)
+        std     r8,0(r5)
+
+        /* Clear _TIF_EMULATE_STACK_STORE flag */
+        lis     r11,_TIF_EMULATE_STACK_STORE@h
+        addi    r5,r9,TI_FLAGS
+        ldarx   r4,0,r5
+        andc    r4,r4,r11
+        stdcx.  r4,0,r5
+        bne-    0b
+1:
+
 #ifdef CONFIG_PREEMPT
         /* Check if we need to preempt */
         andi.   r0,r4,_TIF_NEED_RESCHED