powerpc: Make syscall tracing use tracehook.h helpers

This changes powerpc syscall tracing to use the new tracehook.h entry
points.  There is no change, only cleanup.

In addition, the assembly changes allow do_syscall_trace_enter() to
abort the syscall without losing the information about the original
r0 value.

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

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index da52269aec1e..e6fca6a9014d 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -343,7 +343,12 @@ syscall_dotrace:
         stw     r0,_TRAP(r1)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      do_syscall_trace_enter
-        lwz     r0,GPR0(r1)     /* Restore original registers */
+        /*
+         * Restore argument registers possibly just changed.
+         * We use the return value of do_syscall_trace_enter
+         * for call number to look up in the table (r0).
+         */
+        mr      r0,r3
         lwz     r3,GPR3(r1)
         lwz     r4,GPR4(r1)
         lwz     r5,GPR5(r1)