Add a build knob for _FORTIFY_SOURCE

In the future, we will Default to _FORTIFY_SOURCE=2 if SSP is enabled,
otherwise default to _FORTIFY_SOURCE=0.  For now we default it to 0
unconditionally to ease bisect across older versions without the new
symbols, and we'll put out a call for testing.

include/*.h include their ssp/*.h equivalents as needed based on the
knob. Programs and users are allowed to override FORTIFY_SOURCE in their
Makefiles or src.conf/make.conf to force it off.

Reviewed by:	des, markj
Relnotes:	yes
Sponsored by:	Stormshield
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D32308

This commit is contained in:

Kyle Evans

2024-05-13 00:23:50 -05:00

parent e55512504d

commit 9bfd3b4076

10 changed files with 108 additions and 0 deletions

									
										share/mk/bsd.sys.mk
									
		+7
		
												View File
												
				@@ -294,11 +294,18 @@ CFLAGS.clang+=	 -Qunused-arguments

				# but not yet.

				CXXFLAGS.clang+=	 -Wno-c++11-extensions

				# XXX This should be defaulted to 2 when WITH_SSP is in use after further

				# testing and soak time.

				FORTIFY_SOURCE?=	0

				.if ${MK_SSP} != "no"

				# Don't use -Wstack-protector as it breaks world with -Werror.

				SSP_CFLAGS?=	-fstack-protector-strong

				CFLAGS+=	${SSP_CFLAGS}

				.endif # SSP

				.if ${FORTIFY_SOURCE} > 0

				CFLAGS+=	-D_FORTIFY_SOURCE=${FORTIFY_SOURCE}

				CXXFLAGS+=	-D_FORTIFY_SOURCE=${FORTIFY_SOURCE}

				.endif

				# Additional flags passed in CFLAGS and CXXFLAGS when MK_DEBUG_FILES is

				# enabled.