kernel: canaries: Allow using TLS to store it
Add new option to use thread local storage for stack
canaries. This makes harder to find the canaries location
and value. This is made optional because there is
a performance and size penalty when using it.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
diff --git a/kernel/compiler_stack_protect.c b/kernel/compiler_stack_protect.c
index 790840c..2ee2d81 100644
--- a/kernel/compiler_stack_protect.c
+++ b/kernel/compiler_stack_protect.c
@@ -46,7 +46,9 @@
* Symbol referenced by GCC compiler generated code for canary value.
* The canary value gets initialized in z_cstart().
*/
-#ifdef CONFIG_USERSPACE
+#ifdef CONFIG_STACK_CANARIES_TLS
+__thread uintptr_t __stack_chk_guard;
+#elif CONFIG_USERSPACE
K_APP_DMEM(z_libc_partition) uintptr_t __stack_chk_guard;
#else
__noinit uintptr_t __stack_chk_guard;
