[PATCH] Add the Kconfig option for the stackprotector feature
This patch adds the config options for -fstack-protector.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 927b392..0c61d00 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -533,6 +533,30 @@
If unsure, say Y. Only embedded should say N here.
+config CC_STACKPROTECTOR
+ bool "Enable -fstack-protector buffer overflow detection (EXPRIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ This option turns on the -fstack-protector GCC feature. This
+ feature puts, at the beginning of critical functions, a canary
+ value on the stack just before the return address, and validates
+ the value just before actually returning. Stack based buffer
+ overflows (that need to overwrite this return address) now also
+ overwrite the canary, which gets detected and the attack is then
+ neutralized via a kernel panic.
+
+ This feature requires gcc version 4.2 or above, or a distribution
+ gcc with the feature backported. Older versions are automatically
+ detected and for those versions, this configuration option is ignored.
+
+config CC_STACKPROTECTOR_ALL
+ bool "Use stack-protector for all functions"
+ depends on CC_STACKPROTECTOR
+ help
+ Normally, GCC only inserts the canary value protection for
+ functions that use large-ish on-stack buffers. By enabling
+ this option, GCC will be asked to do this for ALL functions.
+
source kernel/Kconfig.hz
config REORDER