[PATCH] ARM: atags_to_fdt: don't warn about stack size

[David Heidelberg]

The merge_fdt_bootargs() function by definition consumes more than 1024
bytes of stack because it has a 1024 byte command line on the stack,
meaning that we always get a warning when building this file:

arch/arm/boot/compressed/atags_to_fdt.c: In function 'merge_fdt_bootargs':
arch/arm/boot/compressed/atags_to_fdt.c:98:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

However, as this is the decompressor and we know that it has a very shallow
call chain, and we do not actually risk overflowing the kernel stack
at runtime here.

This just shuts up the warning by disabling the warning flag for this
file.

Tested on Nexus 7 2012 builds.

Original Author: Arnd Bergmann <arnd at arndb.de>
Reference: https://lore.kernel.org/lkml/8232115.18ykgQ6J5T@wuerfel/

Cc: Arnd Bergmann <arnd at arndb.de>
Cc: Nicolas Pitre <nico at linaro.org>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Cc: Marc Zyngier <marc.zyngier at arm.com>
Cc: linux-kernel at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org

Signed-off-by: David Heidelberg <david at ixit.cz>
---
 arch/arm/boot/compressed/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 9d91ae1091b0..91265e7ff672 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -85,6 +85,8 @@ compress-$(CONFIG_KERNEL_LZ4)  = lz4
 libfdt_objs := fdt_rw.o fdt_ro.o fdt_wip.o fdt.o
 
 ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
+CFLAGS_REMOVE_atags_to_fdt.o += -Wframe-larger-than=${CONFIG_FRAME_WARN}
+CFLAGS_atags_to_fdt.o += -Wframe-larger-than=1280
 OBJS	+= $(libfdt_objs) atags_to_fdt.o
 endif
 ifeq ($(CONFIG_USE_OF),y)
-- 
2.30.2