From 02c587733c8161355a43e6e110c2e29bd0acff72 Mon Sep 17 00:00:00 2001
From: Walter Wu <walter-zh.wu@mediatek.com>
Date: Fri, 16 Apr 2021 15:46:00 -0700
Subject: [PATCH] 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]
[akpm@linux-foundation.org: fix merge snafu]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=210221 [1]
Link: https://lkml.kernel.org/r/20210226012531.29231-1-walter-zh.wu@mediatek.com
Fixes: d9b571c885a8 ("kasan: fix KASAN_STACK dependency for HW_TAGS")
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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(-)
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 5bfd9b87f85df..4ea9392f86e01 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 56b6865afb2ac..d5d8a352eafaa 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 b91732bd05d78..14f72ec964922 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 fba9909e31b71..cffc2ebbf185d 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
@@ -154,12 +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
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index b5e08d4cefecc..7b53291dafa17 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 8c55634d6edd9..3436c6bf7c0c7 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 41f3745851444..de732bc341c5c 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 127012f45166e..3d791908ed364 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -4,6 +4,12 @@ KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
+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)
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 269967c4fc1b6..a56c36470cb19 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
--
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