powerpc/trace: Add a dummy stack frame for trace_hardirqs_off
[linux-3.10.git] / arch / powerpc / kernel / entry_32.S
index 56212bc..4f80cf1 100644 (file)
@@ -215,7 +215,22 @@ reenable_mmu:                              /* re-enable mmu so we can */
        stw     r9,8(r1)
        stw     r11,12(r1)
        stw     r3,ORIG_GPR3(r1)
+       /*
+        * The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1.
+        * If from user mode there is only one stack frame on the stack, and
+        * accessing CALLER_ADDR1 will cause oops. So we need create a dummy
+        * stack frame to make trace_hardirqs_off happy.
+        */
+       andi.   r12,r12,MSR_PR
+       beq     11f
+       stwu    r1,-16(r1)
+       bl      trace_hardirqs_off
+       addi    r1,r1,16
+       b       12f
+
+11:
        bl      trace_hardirqs_off
+12:
        lwz     r0,GPR0(r1)
        lwz     r3,ORIG_GPR3(r1)
        lwz     r4,GPR4(r1)