Makefile: Enable _FORTIFY_SOURCE iff needed

On some systems source fortification is enabled whenever code
optimization is enabled (e.g. with -O2). Since code fortification
is explicitly enabled too (with possibly different value than the
system wants, there are three levels [1]), distros are required
to patch our Makefile, e.g. [2].

Detect whether fortification is not already enabled and enable it
explicitly only if really needed.

1: https://www.gnu.org/software/libc/manual/html_node/Source-Fortification.html
2: edfeb8763a

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Michal Privoznik 2024-08-29 16:16:03 +02:00 committed by Stefano Brivio
parent eedc81b6ef
commit 38363964fc

View file

@ -33,9 +33,16 @@ AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/MIPS64EL/MIPSEL64/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/HPPA/PARISC/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/SH4/SH/')
# On some systems enabling optimization also enables source fortification,
# automagically. Do not override it.
FORTIFY_FLAG :=
ifeq ($(shell $(CC) -O2 -dM -E - < /dev/null 2>&1 | grep ' _FORTIFY_SOURCE ' > /dev/null; echo $$?),1)
FORTIFY_FLAG := -D_FORTIFY_SOURCE=2
endif
FLAGS := -Wall -Wextra -Wno-format-zero-length
FLAGS += -pedantic -std=c11 -D_XOPEN_SOURCE=700 -D_GNU_SOURCE
FLAGS += -D_FORTIFY_SOURCE=2 -O2 -pie -fPIE
FLAGS += $(FORTIFY_FLAG) -O2 -pie -fPIE
FLAGS += -DPAGE_SIZE=$(shell getconf PAGE_SIZE)
FLAGS += -DNETNS_RUN_DIR=\"/run/netns\"
FLAGS += -DPASST_AUDIT_ARCH=AUDIT_ARCH_$(AUDIT_ARCH)