# Setup extra CFLAGS and LDFLAGS which have 'security' benefits. These
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# don't work universally, there are recipes which can't use one, the other
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# or both so a blacklist is maintained here. The idea would be over
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# time to reduce this list to nothing.
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# From a Yocto Project perspective, this file is included and tested
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# in the DISTRO="poky" configuration.
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GCCPIE ?= "--enable-default-pie"
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# If static PIE is known to work well, GLIBCPIE="--enable-static-pie" can be set
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# _FORTIFY_SOURCE requires -O1 or higher, so disable in debug builds as they use
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# -O0 which then results in a compiler warning.
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OPTLEVEL = "${@bb.utils.filter('SELECTED_OPTIMIZATION', '-O0 -O1 -O2 -O3 -Ofast -Og -Os -Oz -O', d)}"
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lcl_maybe_fortify ?= "${@oe.utils.conditional('OPTLEVEL','-O0','','${OPTLEVEL} -D_FORTIFY_SOURCE=2',d)}"
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# Error on use of format strings that represent possible security problems
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SECURITY_STRINGFORMAT ?= "-Wformat -Wformat-security -Werror=format-security"
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# Inject pie flags into compiler flags if not configured with gcc itself
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# especially useful with external toolchains
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SECURITY_PIE_CFLAGS ?= "${@'' if '${GCCPIE}' else '-pie -fPIE'}"
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SECURITY_NOPIE_CFLAGS ?= "-no-pie -fno-PIE"
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SECURITY_STACK_PROTECTOR ?= "-fstack-protector-strong"
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SECURITY_CFLAGS ?= "${SECURITY_STACK_PROTECTOR} ${SECURITY_PIE_CFLAGS} ${lcl_maybe_fortify} ${SECURITY_STRINGFORMAT}"
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SECURITY_NO_PIE_CFLAGS ?= "${SECURITY_STACK_PROTECTOR} ${lcl_maybe_fortify} ${SECURITY_STRINGFORMAT}"
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SECURITY_LDFLAGS ?= "-Wl,-z,relro,-z,now"
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SECURITY_X_LDFLAGS ?= "-Wl,-z,relro"
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# powerpc does not get on with pie for reasons not looked into as yet
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GCCPIE:powerpc = ""
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GLIBCPIE:powerpc = ""
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SECURITY_CFLAGS:remove:powerpc = "${SECURITY_PIE_CFLAGS}"
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SECURITY_CFLAGS:pn-libgcc:powerpc = ""
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SECURITY_CFLAGS:pn-glibc = ""
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SECURITY_CFLAGS:pn-glibc-testsuite = ""
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SECURITY_CFLAGS:pn-gcc-runtime = ""
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SECURITY_CFLAGS:pn-grub = ""
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SECURITY_CFLAGS:pn-grub-efi = ""
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SECURITY_CFLAGS:pn-mkelfimage:x86 = ""
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SECURITY_CFLAGS:pn-valgrind = "${SECURITY_NOPIE_CFLAGS}"
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SECURITY_LDFLAGS:pn-valgrind = ""
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SECURITY_CFLAGS:pn-sysklogd = "${SECURITY_NOPIE_CFLAGS}"
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SECURITY_LDFLAGS:pn-sysklogd = ""
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# Recipes which fail to compile when elevating -Wformat-security to an error
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SECURITY_STRINGFORMAT:pn-busybox = ""
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SECURITY_STRINGFORMAT:pn-gcc = ""
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TARGET_CC_ARCH:append:class-target = " ${SECURITY_CFLAGS}"
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TARGET_LDFLAGS:append:class-target = " ${SECURITY_LDFLAGS}"
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TARGET_CC_ARCH:append:class-cross-canadian = " ${SECURITY_CFLAGS}"
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TARGET_LDFLAGS:append:class-cross-canadian = " ${SECURITY_LDFLAGS}"
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SECURITY_STACK_PROTECTOR:pn-gcc-runtime = ""
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SECURITY_STACK_PROTECTOR:pn-glibc = ""
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SECURITY_STACK_PROTECTOR:pn-glibc-testsuite = ""
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# All xorg module drivers need to be linked this way as well and are
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# handled in recipes-graphics/xorg-driver/xorg-driver-common.inc
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SECURITY_LDFLAGS:pn-xserver-xorg = "${SECURITY_X_LDFLAGS}"
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TARGET_CC_ARCH:append:pn-binutils = " ${SELECTED_OPTIMIZATION}"
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TARGET_CC_ARCH:append:pn-gcc = " ${SELECTED_OPTIMIZATION}"
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TARGET_CC_ARCH:append:pn-gdb = " ${SELECTED_OPTIMIZATION}"
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TARGET_CC_ARCH:append:pn-perf = " ${SELECTED_OPTIMIZATION}"
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