From: Kees Cook keescook@chromium.org
stable inclusion from stable-v5.10.150 commit ba52e685d29b942f436ce6d51e787510ed93ef5a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 607e57c6c62c00965ae276902c166834ce73014a upstream.
Now that Clang's -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang option is no longer required, remove it from the command line. Clang 16 and later will warn when it is used, which will cause Kconfig to think it can't use -ftrivial-auto-var-init=zero at all. Check for whether it is required and only use it when so.
Cc: Nathan Chancellor nathan@kernel.org Cc: Masahiro Yamada masahiroy@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: linux-kbuild@vger.kernel.org Cc: llvm@lists.linux.dev Cc: stable@vger.kernel.org Fixes: f02003c860d9 ("hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO") Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- Makefile | 4 ++-- security/Kconfig.hardening | 14 ++++++++++---- 2 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/Makefile b/Makefile index fc940b5a5daa..18c3521b7a92 100644 --- a/Makefile +++ b/Makefile @@ -819,8 +819,8 @@ endif # Initialize all stack variables with a zero value. ifdef CONFIG_INIT_STACK_ALL_ZERO KBUILD_CFLAGS += -ftrivial-auto-var-init=zero -ifdef CONFIG_CC_IS_CLANG -# https://bugs.llvm.org/show_bug.cgi?id=45497 +ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER +# https://github.com/llvm/llvm-project/issues/44842 KBUILD_CFLAGS += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang endif endif diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index 81368ce57d67..b54eb7177a31 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -22,11 +22,17 @@ menu "Memory initialization" config CC_HAS_AUTO_VAR_INIT_PATTERN def_bool $(cc-option,-ftrivial-auto-var-init=pattern)
-config CC_HAS_AUTO_VAR_INIT_ZERO - # GCC ignores the -enable flag, so we can test for the feature with - # a single invocation using the flag, but drop it as appropriate in - # the Makefile, depending on the presence of Clang. +config CC_HAS_AUTO_VAR_INIT_ZERO_BARE + def_bool $(cc-option,-ftrivial-auto-var-init=zero) + +config CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER + # Clang 16 and later warn about using the -enable flag, but it + # is required before then. def_bool $(cc-option,-ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang) + depends on !CC_HAS_AUTO_VAR_INIT_ZERO_BARE + +config CC_HAS_AUTO_VAR_INIT_ZERO + def_bool CC_HAS_AUTO_VAR_INIT_ZERO_BARE || CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
choice prompt "Initialize kernel stack variables at function entry"