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| author | Tejun Heo <tj@kernel.org> | 2009-02-09 22:17:39 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-10 00:41:54 +0100 |
| commit | 5d707e9c8ef2a3596ed5c975c6ff05cec890c2b4 (patch) | |
| tree | d0088b317ee562f6655d58f5d561e2bb6aa5332c | |
| parent | 76397f72fb9f4c9a96dfe05462887811c81b0e17 (diff) | |
| download | lwn-5d707e9c8ef2a3596ed5c975c6ff05cec890c2b4.tar.gz lwn-5d707e9c8ef2a3596ed5c975c6ff05cec890c2b4.zip | |
stackprotector: update make rules
Impact: no default -fno-stack-protector if stackp is enabled, cleanup
Stackprotector make rules had the following problems.
* cc support test and warning are scattered across makefile and
kernel/panic.c.
* -fno-stack-protector was always added regardless of configuration.
Update such that cc support test and warning are contained in makefile
and -fno-stack-protector is added iff stackp is turned off. While at
it, prepare for 32bit support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | Makefile | 3 | ||||
| -rw-r--r-- | arch/x86/Makefile | 17 | ||||
| -rw-r--r-- | kernel/panic.c | 4 | ||||
| -rw-r--r-- | scripts/gcc-x86_64-has-stack-protector.sh | 4 |
4 files changed, 15 insertions, 13 deletions
@@ -532,8 +532,9 @@ KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN}) endif # Force gcc to behave correct even for buggy distributions -# Arch Makefiles may override this setting +ifndef CONFIG_CC_STACKPROTECTOR KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector) +endif ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls diff --git a/arch/x86/Makefile b/arch/x86/Makefile index cacee981d166..ab48ab497e5a 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -70,14 +70,17 @@ else # this works around some issues with generating unwind tables in older gccs # newer gccs do it by default KBUILD_CFLAGS += -maccumulate-outgoing-args +endif - stackp := $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh - stackp-$(CONFIG_CC_STACKPROTECTOR) := $(shell $(stackp) \ - "$(CC)" "-fstack-protector -DGCC_HAS_SP" ) - stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(stackp) \ - "$(CC)" -fstack-protector-all ) - - KBUILD_CFLAGS += $(stackp-y) +ifdef CONFIG_CC_STACKPROTECTOR + cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh + ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC)),y) + stackp-y := -fstack-protector + stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += -fstack-protector-all + KBUILD_CFLAGS += $(stackp-y) + else + $(warning stack protector enabled but no compiler support) + endif endif # Stackpointer is addressed different for 32 bit and 64 bit x86 diff --git a/kernel/panic.c b/kernel/panic.c index 33cab3de1763..32fe4eff1b89 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -359,10 +359,6 @@ EXPORT_SYMBOL(warn_slowpath); #ifdef CONFIG_CC_STACKPROTECTOR -#ifndef GCC_HAS_SP -#warning You have selected the CONFIG_CC_STACKPROTECTOR option, but the gcc used does not support this. -#endif - /* * Called when gcc's -fstack-protector feature is used, and * gcc detects corruption of the on-stack canary value diff --git a/scripts/gcc-x86_64-has-stack-protector.sh b/scripts/gcc-x86_64-has-stack-protector.sh index 325c0a1b03b6..2d69fcdc5609 100644 --- a/scripts/gcc-x86_64-has-stack-protector.sh +++ b/scripts/gcc-x86_64-has-stack-protector.sh @@ -2,5 +2,7 @@ echo "int foo(void) { char X[200]; return 3; }" | $1 -S -xc -c -O0 -mcmodel=kernel -fstack-protector - -o - 2> /dev/null | grep -q "%gs" if [ "$?" -eq "0" ] ; then - echo $2 + echo y +else + echo n fi |