From a0ac8e4df3ee2e683e6e6665a1887ae14755c3e3 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben@decadent.org.uk>
Date: Sat, 19 Oct 2013 19:43:35 +0100
Subject: [PATCH] kbuild: Use -nostdinc in compile tests

gcc 4.8 and later include <stdc-predef.h> by default.  In some
versions of eglibc that includes <bits/predefs.h>, but that may be
missing when building with a biarch compiler.  Also <stdc-predef.h>
itself could be missing as we are only trying to build a kernel, not
userland.

The -nostdinc option disables this, though it isn't explicitly
documented.  This option is already used when actually building
the kernel, but not by cc-option and other tests.  This can result
in silently miscompiling the kernel.

References: https://bugs.debian.org/717557
References: https://bugs.debian.org/726861
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name kbuild-use-nostdinc-in-compile-tests.patch
---
 Makefile               |  4 +++-
 scripts/Kbuild.include | 13 +++++++------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index aa1391d645d..f9ac9e4877a 100644
--- a/Makefile
+++ b/Makefile
@@ -665,6 +665,8 @@ endif
 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
 			$(call cc-disable-warning,maybe-uninitialized,))
 
+NOSTDINC_FLAGS += -nostdinc
+
 # Tell gcc to never replace conditional load with a non-conditional one
 KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
 
@@ -772,7 +774,7 @@ KBUILD_CFLAGS_KERNEL	+= $(call cc-option,-fdata-sections,)
 endif
 
 # arch Makefile may override CC so keep this after arch Makefile is included
-NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
+NOSTDINC_FLAGS += -isystem $(shell $(CC) -print-file-name=include)
 
 # warn about C99 declaration after statement
 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index ed303f552f9..81559c90121 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -121,7 +121,7 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call __cc-option, $(CC),\
-	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
+	$(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
 
 # hostcc-option
 # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
@@ -131,23 +131,24 @@ hostcc-option = $(call __cc-option, $(HOSTCC),\
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+	$(CC) -Werror $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+	$(CC) -Werror $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 
 # cc-name
 # Expands to either gcc or clang
 cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
 
 # cc-version
-cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
+cc-version = $(shell $(CONFIG_SHELL) \
+	$(srctree)/scripts/gcc-version.sh $(CC) $(NOSTDINC_FLAGS))
 
 # cc-fullversion
 cc-fullversion = $(shell $(CONFIG_SHELL) \
-	$(srctree)/scripts/gcc-version.sh -p $(CC))
+	$(srctree)/scripts/gcc-version.sh -p $(CC) $(NOSTDINC_FLAGS))
 
 # cc-ifversion
 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
@@ -160,7 +161,7 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo
 # cc-ldoption
 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
 cc-ldoption = $(call try-run,\
-	$(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(1) $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # ld-option
 # Usage: LDFLAGS += $(call ld-option, -X)
-- 
2.30.2