[PATCH] hardening: Default to INIT_STACK_ALL_ZERO if CC_HAS_AUTO_VAR_INIT_ZERO

From: Will Deacon
Date: Tue Sep 14 2021 - 06:28:54 EST


CC_HAS_AUTO_VAR_INIT_ZERO requires a supported set of compiler options
distinct from those needed by CC_HAS_AUTO_VAR_INIT_PATTERN, Fix up
the Kconfig dependency for INIT_STACK_ALL_ZERO to test for the former
instead of the latter, as these are the options passed by the top-level
Makefile.

Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Fixes: dcb7c0b9461c ("hardening: Clarify Kconfig text for auto-var-init")
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---

I just noticed this while reading the code and I suspect it doesn't really
matter in practice.

security/Kconfig.hardening | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 90cbaff86e13..341e2fdcba94 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -29,7 +29,7 @@ choice
prompt "Initialize kernel stack variables at function entry"
default GCC_PLUGIN_STRUCTLEAK_BYREF_ALL if COMPILE_TEST && GCC_PLUGINS
default INIT_STACK_ALL_PATTERN if COMPILE_TEST && CC_HAS_AUTO_VAR_INIT_PATTERN
- default INIT_STACK_ALL_ZERO if CC_HAS_AUTO_VAR_INIT_PATTERN
+ default INIT_STACK_ALL_ZERO if CC_HAS_AUTO_VAR_INIT_ZERO
default INIT_STACK_NONE
help
This option enables initialization of stack variables at
--
2.33.0.309.g3052b89438-goog