[RFC PATCH 1/3] powerpc/kernel: Get pt_regs from r9 before calling do_syscall_trace_enter()

[Michael Ellerman]

To call do_syscall_trace_enter() we need pt_regs in r3, but we don't need
to recalculate it based on r1, it's already in r9.

Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/kernel/entry_64.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index afbc20019c2e..b55c393310f3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -236,7 +236,9 @@ syscall_error:
 /* Traced system call support */
 syscall_dotrace:
 	bl	save_nvgprs
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+
+	/* Get pt_regs into r3 */
+	mr	r3, r9
 	bl	do_syscall_trace_enter
 	/*
 	 * Restore argument registers possibly just changed.
-- 
2.1.0