security: Add default stack protection level
STACK_CANARIES was enabling canaries in all functions using the compiler
flag -fstack-protector-all. This became confuse with the addition of the
options STRONG and EXPLICIT.
This commit adds the missing option (default level) and disambiguous the
options mapping them close to the compiler flags.
Now we have the following options:
STACK_CANARIES -> fstack-protector
STACK_CANARIES_STRONG -> fstack-protector-strong
STACK_CANARIES_ALL -> fstack-protector-all
STACK_CANARIES_EXPLICIT -> fstack-protector-explicit
Note that from now on STACK_CANARIES_ALL is the symbol that adds canaries
for all functions.
Signed-off-by: Flavio Ceolin <flavio.ceolin@gmail.com>
diff --git a/kernel/compiler_stack_protect.c b/kernel/compiler_stack_protect.c
index d48190c..30da82d 100644
--- a/kernel/compiler_stack_protect.c
+++ b/kernel/compiler_stack_protect.c
@@ -11,7 +11,7 @@
* This module provides functions to support compiler stack protection
* using canaries. This feature is enabled with configuration
* CONFIG_STACK_CANARIES=y or CONFIG_STACK_CANARIES_STRONG=y or
- * CONFIG_STACK_CANARIES_EXPLICIT=y.
+ * CONFIG_STACK_CANARIES_ALL=y or CONFIG_STACK_CANARIES_EXPLICIT=y.
*
* When this feature is enabled, the compiler generated code refers to
* function __stack_chk_fail and global variable __stack_chk_guard.
