[PATCH] powerpc64[le]: Allocate extra stack frame on syscall.S

[Matheus Castanho <msc@linux.ibm.com>]

The syscall function does not allocate the extra stack frame for scv like other
assembly syscalls using DO_CALL_SCV. So after commit d120fb9941 changed the
offset that is used to save LR, syscall ended up using an invalid offset,
causing regressions on powerpc64. So make sure the extra stack frame is
allocated in syscall.S as well to make it consistent with other uses of
DO_CALL_SCV and avoid similar issues in the future.

Tested on powerpc, powerpc64, and powerpc64le
---
 sysdeps/unix/sysv/linux/powerpc/syscall.S | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/powerpc/syscall.S b/sysdeps/unix/sysv/linux/powerpc/syscall.S
index a29652feaf..037dd3c4c6 100644
--- a/sysdeps/unix/sysv/linux/powerpc/syscall.S
+++ b/sysdeps/unix/sysv/linux/powerpc/syscall.S
@@ -26,8 +26,12 @@ ENTRY (syscall)
 	mr   r7,r8
 	mr   r8,r9
 #if defined(USE_PPC_SCV) && !IS_IN(rtld) && (defined(__PPC64__) || defined(__powerpc64__))
+	stdu r1,-SCV_FRAME_SIZE(r1)
+	cfi_adjust_cfa_offset(SCV_FRAME_SIZE)
 	CHECK_SCV_SUPPORT r9 0f
 	DO_CALL_SCV
+	addi r1,r1,SCV_FRAME_SIZE
+	cfi_adjust_cfa_offset(-SCV_FRAME_SIZE)
 	RET_SCV
 	b 1f
 #endif
-- 
2.31.1