Two makefiles of ours pass `-D_FORTIFY_SOURCE` directly to the
preprocessor. While this does not pose any problems when the value has
not been previously set, it can break the build if it is part of the
standard build flags.
Fix the issue by undefining the flag with `-Wp,-U_FORTIFY_SOURCE` right
before redefining the value. This fixes builds with some hardened
compiler chains.
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
libselinux/src/Makefile | 3 ++-
libselinux/utils/Makefile | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/libselinux/src/Makefile b/libselinux/src/Makefile
index 4306dd0e..010b7ffe 100644
--- a/libselinux/src/Makefile
+++ b/libselinux/src/Makefile
@@ -59,7 +59,8 @@ ifeq ($(COMPILER), gcc)
EXTRA_CFLAGS = -fipa-pure-const -Wlogical-op -Wpacked-bitfield-compat -Wsync-nand \
-Wcoverage-mismatch -Wcpp -Wformat-contains-nul -Wnormalized=nfc -Wsuggest-attribute=const \
-Wsuggest-attribute=noreturn -Wsuggest-attribute=pure -Wtrampolines -Wjump-misses-init \
- -Wno-suggest-attribute=pure -Wno-suggest-attribute=const -Wp,-D_FORTIFY_SOURCE=2
+ -Wno-suggest-attribute=pure -Wno-suggest-attribute=const \
+ -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=2
else
EXTRA_CFLAGS = -Wunused-command-line-argument
endif
diff --git a/libselinux/utils/Makefile b/libselinux/utils/Makefile
index 474ee95b..c94d7cf2 100644
--- a/libselinux/utils/Makefile
+++ b/libselinux/utils/Makefile
@@ -32,7 +32,8 @@ CFLAGS ?= -O -Wall -W -Wundef -Wformat-y2k -Wformat-security -Winit-self -Wmissi
-Wformat-extra-args -Wformat-zero-length -Wformat=2 -Wmultichar \
-Woverflow -Wpointer-to-int-cast -Wpragmas \
-Wno-missing-field-initializers -Wno-sign-compare \
- -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) -Wp,-D_FORTIFY_SOURCE=2 \
+ -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) \
+ -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=2 \
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions \
-fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time \
-Werror -Wno-aggregate-return -Wno-redundant-decls \
--
2.13.1
