blob: 2a4e41821a5fea116ff1ebe38ea2ff375a858c7e [file] [log] [blame]
From 1c2f5ccb23610341215b3d38d246bbb6e3958d5a Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <>
Date: Wed, 8 Jan 2020 14:46:00 +0100
Subject: [PATCH] s390: adjust -mpacked-stack support check for clang 10
commit 253b3c4b2920e07ce9e2b18800b9b65245e2fafa upstream.
clang 10 introduces -mpacked-stack compiler option implementation. At the
same time currently it does not support a combination of -mpacked-stack
and -mbackchain. This leads to the following build error:
clang: error: unsupported option '-mpacked-stack with -mbackchain' for
target 's390x-ibm-linux'
If/when clang adds support for a combination of -mpacked-stack and
-mbackchain it would also require -msoft-float (like gcc does). According
to Ulrich Weigand "stack slot assigned to the kernel backchain overlaps
the stack slot assigned to the FPR varargs (both are required to be
placed immediately after the saved r15 slot if present)."
Extend -mpacked-stack compiler option support check to include all 3
options -mpacked-stack -mbackchain -msoft-float which must present to
support -mpacked-stack with -mbackchain.
Acked-by: Heiko Carstens <>
Signed-off-by: Vasily Gorbik <>
Signed-off-by: Paul Gortmaker <>
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index e48013cf50a2..b525c795587e 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -69,7 +69,7 @@ cflags-y += -Wa,-I$(srctree)/arch/$(ARCH)/include
cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
-ifeq ($(call cc-option-yn,-mpacked-stack),y)
+ifeq ($(call cc-option-yn,-mpacked-stack -mbackchain -msoft-float),y)
cflags-$(CONFIG_PACK_STACK) += -mpacked-stack -D__PACK_STACK