Commit 9c87156c authored Oct 31, 2018 by Joel Stanley Committed by Michael Ellerman Oct 31, 2018

powerpc/xmon: Relax frame size for clang

When building with clang (8 trunk, 7.0 release) the frame size limit is
hit:

 arch/powerpc/xmon/xmon.c:452:12: warning: stack frame size of 2576
 bytes in function 'xmon_core' [-Wframe-larger-than=]

Some investigation by Naveen indicates this is due to clang saving the
addresses to printf format strings on the stack.

While this issue is investigated, bump up the frame size limit for xmon
when building with clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/252


Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent a0aebae0

arch/powerpc/xmon/Makefile

+6 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,12 @@ UBSAN_SANITIZE := n
		ORIG_CFLAGS := $(KBUILD_CFLAGS)
		KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))

		ifdef CONFIG_CC_IS_CLANG
		# clang stores addresses on the stack causing the frame size to blow
		# out. See https://github.com/ClangBuiltLinux/linux/issues/252
		KBUILD_CFLAGS += -Wframe-larger-than=4096
		endif

		ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)

		obj-y += xmon.o nonstdio.o spr_access.o

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