Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

[pandora-kernel.git] / arch / powerpc / kernel / entry_32.S

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index c22dc1e..4f80cf1 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -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)
@@ -880,7 +895,18 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
         */
        andi.   r10,r9,MSR_EE
        beq     1f
+       /*
+        * Since the ftrace irqsoff latency trace checks CALLER_ADDR1,
+        * which is the stack frame here, we need to force a stack frame
+        * in case we came from user space.
+        */
+       stwu    r1,-32(r1)
+       mflr    r0
+       stw     r0,4(r1)
+       stwu    r1,-32(r1)
        bl      trace_hardirqs_on
+       lwz     r1,0(r1)
+       lwz     r1,0(r1)
        lwz     r9,_MSR(r1)
 1:
 #endif /* CONFIG_TRACE_IRQFLAGS */