powerpc/xmon: Relax frame size for clang

[ Upstream commit 9c87156 ] 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: ClangBuiltLinux#252 Signed-off-by: Joel Stanley <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
mrchapp · Nov 28, 2019 · 85bfc59 · 85bfc59
1 parent d88cc0f
commit 85bfc59
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
@@ -13,6 +13,12 @@ UBSAN_SANITIZE := n
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -mno-sched-epilog,,$(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