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.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=210221

Signed-off-by: Walter Wu <redacted>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Nathan Chancellor <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <redacted>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---

v4: After this patch sent, someone had modification about KASAN_STACK,
    so I need to rebase codebase. Thank Andrey for your pointing.

---
 arch/arm64/kernel/sleep.S        |  2 +-
 arch/x86/kernel/acpi/wakeup_64.S |  2 +-
 include/linux/kasan.h            |  2 +-
 lib/Kconfig.kasan                |  8 ++------
 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(+), 16 deletions(-)

diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 5bfd9b87f85d..4ea9392f86e0 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/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

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index 56b6865afb2a..d5d8a352eafa 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/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.

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index b91732bd05d7..14f72ec96492 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h

@@ -330,7 +330,7 @@ static inline bool kasan_check_byte(const void *address)

 #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) {}

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 624ae1df7984..cffc2ebbf185 100644
--- a/lib/Kconfig.kasan
+++ b/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

@@ -154,11 +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
-       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

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index b5e08d4cefec..7b53291dafa1 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c

@@ -63,7 +63,7 @@ void __kasan_unpoison_range(const void *address, size_t size)
        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)
 {

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 8c55634d6edd..3436c6bf7c0c 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h

@@ -231,7 +231,7 @@ void *kasan_find_first_bad_addr(void *addr, size_t size);
 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) { }

diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
index 41f374585144..de732bc341c5 100644
--- a/mm/kasan/report_generic.c
+++ b/mm/kasan/report_generic.c

@@ -128,7 +128,7 @@ void kasan_metadata_fetch_row(char *buffer, void *row)
        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)

diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1e000cc2e7b4..abf231d209b1 100644
--- a/scripts/Makefile.kasan
+++ b/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 \
-               -mllvm -hwasan-instrument-stack=$(CONFIG_KASAN_STACK) \
+               -mllvm -hwasan-instrument-stack=$(stack_enable) \
                -mllvm -hwasan-use-short-granules=0 \
                $(instrumentation_flags)

diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 269967c4fc1b..a56c36470cb1 100644
--- a/security/Kconfig.hardening
+++ b/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
--

2.18.0

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