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, 1 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 79c089e97ce4..2d802e97097c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -643,8 +643,7 @@ user_work:
         b       .ret_from_except_lite
 
 1:      bl      .save_nvgprs
-        li      r3,0
-        addi    r4,r1,STACK_FRAME_OVERHEAD
+        addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      .do_signal
         b       .ret_from_except