powerpc: Add TIF_NOTIFY_RESUME support for tracehook

This adds TIF_NOTIFY_RESUME support for powerpc.  When set,
we call tracehook_notify_resume() on the way to user mode.
This overloads do_signal() to do the work, but changes its
arguments to it has the TIF_* bits handy in a register and
drops the useless first argument that was always zero.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e6fca6a9014d..1cbbf7033641 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1060,8 +1060,8 @@ do_user_signal:			/* r10 contains MSR_KERNEL here */
         SAVE_NVGPRS(r1)
         rlwinm  r3,r3,0,0,30
         stw     r3,_TRAP(r1)
-2:      li      r3,0
-        addi    r4,r1,STACK_FRAME_OVERHEAD
+2:      addi    r3,r1,STACK_FRAME_OVERHEAD
+        mr      r4,r9
         bl      do_signal
         REST_NVGPRS(r1)
         b       recheck