From: Walter Wu <walter-zh.wu@xxxxxxxxxxxx> Subject: kasan: remove redundant config option CONFIG_KASAN_STACK and CONFIG_KASAN_STACK_ENABLE both enable KASAN stack instrumentation, but we should only need one config, so that we remove CONFIG_KASAN_STACK_ENABLE and make CONFIG_KASAN_STACK workable. see [1]. When enable KASAN stack instrumentation, then for gcc we could do no prompt and default value y, and for clang prompt and default value n. This patch fixes the following compilation warning: include/linux/kasan.h:333:30: warning: 'CONFIG_KASAN_STACK' is not defined, evaluates to 0 [-Wundef] [1]: https://bugzilla.kernel.org/show_bug.cgi?id=210221 [akpm@xxxxxxxxxxxxxxxxxxxx: fix merge snafu] Link: https://lkml.kernel.org/r/20210226012531.29231-1-walter-zh.wu@xxxxxxxxxxxx Fixes: d9b571c885a8 ("kasan: fix KASAN_STACK dependency for HW_TAGS") Signed-off-by: Walter Wu <walter-zh.wu@xxxxxxxxxxxx> Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Acked-by: Arnd Bergmann <arnd@xxxxxxxx> Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/kernel/sleep.S | 2 +- arch/x86/kernel/acpi/wakeup_64.S | 2 +- include/linux/kasan.h | 2 +- lib/Kconfig.kasan | 9 ++------- mm/kasan/common.c | 2 +- mm/kasan/kasan.h | 2 +- mm/kasan/report_generic.c | 2 +- scripts/Makefile.kasan | 10 ++++++++-- security/Kconfig.hardening | 4 ++-- 9 files changed, 18 insertions(+), 17 deletions(-) --- a/arch/arm64/kernel/sleep.S~kasan-remove-redundant-config-option +++ a/arch/arm64/kernel/sleep.S @@ -134,7 +134,7 @@ SYM_FUNC_START(_cpu_resume) */ bl cpu_do_resume -#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK +#if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK) mov x0, sp bl kasan_unpoison_task_stack_below #endif --- a/arch/x86/kernel/acpi/wakeup_64.S~kasan-remove-redundant-config-option +++ a/arch/x86/kernel/acpi/wakeup_64.S @@ -115,7 +115,7 @@ SYM_FUNC_START(do_suspend_lowlevel) movq pt_regs_r14(%rax), %r14 movq pt_regs_r15(%rax), %r15 -#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK +#if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK) /* * The suspend path may have poisoned some areas deeper in the stack, * which we now need to unpoison. --- a/include/linux/kasan.h~kasan-remove-redundant-config-option +++ a/include/linux/kasan.h @@ -330,7 +330,7 @@ static inline bool kasan_check_byte(cons #endif /* CONFIG_KASAN */ -#if defined(CONFIG_KASAN) && CONFIG_KASAN_STACK +#if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK) void kasan_unpoison_task_stack(struct task_struct *task); #else static inline void kasan_unpoison_task_stack(struct task_struct *task) {} --- a/lib/Kconfig.kasan~kasan-remove-redundant-config-option +++ a/lib/Kconfig.kasan @@ -138,9 +138,10 @@ config KASAN_INLINE endchoice -config KASAN_STACK_ENABLE +config KASAN_STACK bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST depends on KASAN_GENERIC || KASAN_SW_TAGS + default y if CC_IS_GCC help The LLVM stack address sanitizer has a know problem that causes excessive stack usage in a lot of functions, see @@ -154,12 +155,6 @@ config KASAN_STACK_ENABLE CONFIG_COMPILE_TEST. On gcc it is assumed to always be safe to use and enabled by default. -config KASAN_STACK - int - depends on KASAN_GENERIC || KASAN_SW_TAGS - default 1 if KASAN_STACK_ENABLE || CC_IS_GCC - default 0 - config KASAN_SW_TAGS_IDENTIFY bool "Enable memory corruption identification" depends on KASAN_SW_TAGS --- a/mm/kasan/common.c~kasan-remove-redundant-config-option +++ a/mm/kasan/common.c @@ -63,7 +63,7 @@ void __kasan_unpoison_range(const void * kasan_unpoison(address, size); } -#if CONFIG_KASAN_STACK +#ifdef CONFIG_KASAN_STACK /* Unpoison the entire stack for a task. */ void kasan_unpoison_task_stack(struct task_struct *task) { --- a/mm/kasan/kasan.h~kasan-remove-redundant-config-option +++ a/mm/kasan/kasan.h @@ -231,7 +231,7 @@ void *kasan_find_first_bad_addr(void *ad const char *kasan_get_bug_type(struct kasan_access_info *info); void kasan_metadata_fetch_row(char *buffer, void *row); -#if defined(CONFIG_KASAN_GENERIC) && CONFIG_KASAN_STACK +#if defined(CONFIG_KASAN_GENERIC) && defined(CONFIG_KASAN_STACK) void kasan_print_address_stack_frame(const void *addr); #else static inline void kasan_print_address_stack_frame(const void *addr) { } --- a/mm/kasan/report_generic.c~kasan-remove-redundant-config-option +++ a/mm/kasan/report_generic.c @@ -128,7 +128,7 @@ void kasan_metadata_fetch_row(char *buff memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW); } -#if CONFIG_KASAN_STACK +#ifdef CONFIG_KASAN_STACK static bool __must_check tokenize_frame_descr(const char **frame_descr, char *token, size_t max_tok_len, unsigned long *value) --- a/scripts/Makefile.kasan~kasan-remove-redundant-config-option +++ a/scripts/Makefile.kasan @@ -2,6 +2,12 @@ CFLAGS_KASAN_NOSANITIZE := -fno-builtin KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET) +ifdef CONFIG_KASAN_STACK + stack_enable := 1 +else + stack_enable := 0 +endif + ifdef CONFIG_KASAN_GENERIC ifdef CONFIG_KASAN_INLINE @@ -27,7 +33,7 @@ else CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \ $(call cc-param,asan-globals=1) \ $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \ - $(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \ + $(call cc-param,asan-stack=$(stack_enable)) \ $(call cc-param,asan-instrument-allocas=1) endif @@ -42,7 +48,7 @@ else endif CFLAGS_KASAN := -fsanitize=kernel-hwaddress \ - $(call cc-param,hwasan-instrument-stack=$(CONFIG_KASAN_STACK)) \ + $(call cc-param,hwasan-instrument-stack=$(stack_enable)) \ $(call cc-param,hwasan-use-short-granules=0) \ $(instrumentation_flags) --- a/security/Kconfig.hardening~kasan-remove-redundant-config-option +++ a/security/Kconfig.hardening @@ -64,7 +64,7 @@ choice config GCC_PLUGIN_STRUCTLEAK_BYREF bool "zero-init structs passed by reference (strong)" depends on GCC_PLUGINS - depends on !(KASAN && KASAN_STACK=1) + depends on !(KASAN && KASAN_STACK) select GCC_PLUGIN_STRUCTLEAK help Zero-initialize any structures on the stack that may @@ -82,7 +82,7 @@ choice config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL bool "zero-init anything passed by reference (very strong)" depends on GCC_PLUGINS - depends on !(KASAN && KASAN_STACK=1) + depends on !(KASAN && KASAN_STACK) select GCC_PLUGIN_STRUCTLEAK help Zero-initialize any stack variables that may be passed _
