Various portions of the kernel, especially per-architecture pieces, need to know if the compiler is building it with the stack protector. This was done in the arch/Kconfig with 'select', but this doesn't allow a way to do auto-detected compiler support. In preparation for creating an on-if-available default, move the logic for the definition of CONFIG_CC_STACKPROTECTOR into the Makefile.
Cc: Masahiro Yamada <[email protected]> Cc: Michal Marek <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Al Viro <[email protected]> Cc: [email protected] Signed-off-by: Kees Cook <[email protected]> --- Makefile | 7 +++++-- arch/Kconfig | 8 -------- 2 files changed, 5 insertions(+), 10 deletions(-) diff --git a/Makefile b/Makefile index d1119941261c..e122a9cf0399 100644 --- a/Makefile +++ b/Makefile @@ -688,8 +688,11 @@ else stackp-flag := $(call cc-option, -fno-stack-protector) endif endif -# Find arch-specific stack protector compiler sanity-checking script. -ifdef CONFIG_CC_STACKPROTECTOR +ifdef stackp-name + # If the stack protector has been selected, inform the rest of the build. + KBUILD_CFLAGS += -DCONFIG_CC_STACKPROTECTOR + KBUILD_AFLAGS += -DCONFIG_CC_STACKPROTECTOR + # Find arch-specific stack protector compiler sanity-checking script. stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh stackp-check := $(wildcard $(stackp-path)) endif diff --git a/arch/Kconfig b/arch/Kconfig index 1aafb4efbb51..7007c1bfa79c 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -523,12 +523,6 @@ config HAVE_CC_STACKPROTECTOR - its compiler supports the -fstack-protector option - it has implemented a stack canary (e.g. __stack_chk_guard) -config CC_STACKPROTECTOR - def_bool n - help - Set when a stack-protector mode is enabled, so that the build - can enable kernel-side support for the GCC feature. - choice prompt "Stack Protector buffer overflow detection" depends on HAVE_CC_STACKPROTECTOR @@ -549,7 +543,6 @@ config CC_STACKPROTECTOR_NONE config CC_STACKPROTECTOR_REGULAR bool "Regular" - select CC_STACKPROTECTOR help Functions will have the stack-protector canary logic added if they have an 8-byte or larger character array on the stack. @@ -563,7 +556,6 @@ config CC_STACKPROTECTOR_REGULAR config CC_STACKPROTECTOR_STRONG bool "Strong" - select CC_STACKPROTECTOR help Functions will have the stack-protector canary logic added in any of the following conditions: -- 2.7.4
