On Tue, 23 Mar 2021 13:51:32 +0100 Marco Elver <elver@xxxxxxxxxx> wrote:
> On Tue, 23 Mar 2021 at 13:41, Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
> >
> > From: Arnd Bergmann <arnd@xxxxxxxx>
> >
> > gcc-11 adds support for -fsanitize=kernel-hwaddress, so it becomes
> > possible to enable CONFIG_KASAN_SW_TAGS.
> >
> > Unfortunately this fails to build at the moment, because the
> > corresponding command line arguments use llvm specific syntax.
> >
> > Change it to use the cc-param macro instead, which works on both
> > clang and gcc.
> >
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
>
> Although I think you need to rebase against either -mm or -next,
> because there have been changes to the CONFIG_KASAN_STACK variable.
This fix is applicable to 5.12, so it's better than the 5.13 patches in
-mm be changed to accomodate this patch.
afaict the only needed change was to update
kasan-remove-redundant-config-option.patch as below. The
scripts/Makefile.kasan part was changed:
@@ -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)
Whole patch:
--- 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
@@ -155,7 +156,7 @@ config KASAN_STACK_ENABLE
to use and enabled by default.
config KASAN_STACK
- int
+ bool
depends on KASAN_GENERIC || KASAN_SW_TAGS
default 1 if KASAN_STACK_ENABLE || CC_IS_GCC
default 0
--- 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
_
