This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't use kasan_depth. Only define and use it
when one of the software KASAN modes are enabled.
No functional changes for software modes.
Signed-off-by: Andrey Konovalov <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
---
Change-Id: I6109ea96c8df41ef6d75ad71bf22c1c8fa234a9a
---
arch/arm64/mm/kasan_init.c | 11 ++++++++---
include/linux/kasan.h | 18 +++++++++---------
include/linux/sched.h | 2 +-
init/init_task.c | 2 +-
mm/kasan/common.c | 2 ++
mm/kasan/report.c | 2 ++
6 files changed, 23 insertions(+), 14 deletions(-)
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index ffeb80d5aa8d..5172799f831f 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -273,17 +273,22 @@ static void __init kasan_init_shadow(void)
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
}
+static void __init kasan_init_depth(void)
+{
+ init_task.kasan_depth = 0;
+}
+
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
static inline void __init kasan_init_shadow(void) { }
+static inline void __init kasan_init_depth(void) { }
+
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
void __init kasan_init(void)
{
kasan_init_shadow();
-
- /* At this point kasan is fully initialized. Enable error messages */
- init_task.kasan_depth = 0;
+ kasan_init_depth();
pr_info("KernelAddressSanitizer initialized\n");
}
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index f6435b9f889c..979d598e1c30 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -51,6 +51,12 @@ static inline void *kasan_mem_to_shadow(const void *addr)
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);
+/* Enable reporting bugs after kasan_disable_current() */
+extern void kasan_enable_current(void);
+
+/* Disable reporting bugs for current task */
+extern void kasan_disable_current(void);
+
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
static inline int kasan_add_zero_shadow(void *start, unsigned long size)
@@ -61,16 +67,13 @@ static inline void kasan_remove_zero_shadow(void *start,
unsigned long size)
{}
+static inline void kasan_enable_current(void) {}
+static inline void kasan_disable_current(void) {}
+
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
#ifdef CONFIG_KASAN
-/* Enable reporting bugs after kasan_disable_current() */
-extern void kasan_enable_current(void);
-
-/* Disable reporting bugs for current task */
-extern void kasan_disable_current(void);
-
void kasan_unpoison_memory(const void *address, size_t size);
void kasan_unpoison_task_stack(struct task_struct *task);
@@ -121,9 +124,6 @@ static inline void kasan_unpoison_memory(const void *address, size_t size) {}
static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
-static inline void kasan_enable_current(void) {}
-static inline void kasan_disable_current(void) {}
-
static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
static inline void kasan_free_pages(struct page *page, unsigned int order) {}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 063cd120b459..81b09bd31186 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1197,7 +1197,7 @@ struct task_struct {
u64 timer_slack_ns;
u64 default_timer_slack_ns;
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
unsigned int kasan_depth;
#endif
diff --git a/init/init_task.c b/init/init_task.c
index a56f0abb63e9..39703b4ef1f1 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -176,7 +176,7 @@ struct task_struct init_task
.numa_group = NULL,
.numa_faults = NULL,
#endif
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
.kasan_depth = 1,
#endif
#ifdef CONFIG_KCSAN
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 543e6bf2168f..d0b3ff410b0c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -46,6 +46,7 @@ void kasan_set_track(struct kasan_track *track, gfp_t flags)
track->stack = kasan_save_stack(flags);
}
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
void kasan_enable_current(void)
{
current->kasan_depth++;
@@ -55,6 +56,7 @@ void kasan_disable_current(void)
{
current->kasan_depth--;
}
+#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
{
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index b18d193f7f58..af9138ea54ad 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -292,8 +292,10 @@ static void print_shadow_for_address(const void *addr)
static bool report_enabled(void)
{
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
if (current->kasan_depth)
return false;
+#endif
if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
return true;
return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
--
2.29.2.222.g5d2a92d10f8-goog
On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <[email protected]> wrote:
>
> This is a preparatory commit for the upcoming addition of a new hardware
> tag-based (MTE-based) KASAN mode.
>
> Hardware tag-based KASAN won't use kasan_depth. Only define and use it
> when one of the software KASAN modes are enabled.
>
> No functional changes for software modes.
>
> Signed-off-by: Andrey Konovalov <[email protected]>
> Signed-off-by: Vincenzo Frascino <[email protected]>
> Reviewed-by: Catalin Marinas <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
> ---
> Change-Id: I6109ea96c8df41ef6d75ad71bf22c1c8fa234a9a
> ---
> arch/arm64/mm/kasan_init.c | 11 ++++++++---
> include/linux/kasan.h | 18 +++++++++---------
> include/linux/sched.h | 2 +-
> init/init_task.c | 2 +-
> mm/kasan/common.c | 2 ++
> mm/kasan/report.c | 2 ++
> 6 files changed, 23 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> index ffeb80d5aa8d..5172799f831f 100644
> --- a/arch/arm64/mm/kasan_init.c
> +++ b/arch/arm64/mm/kasan_init.c
> @@ -273,17 +273,22 @@ static void __init kasan_init_shadow(void)
> cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
> }
>
> +static void __init kasan_init_depth(void)
> +{
> + init_task.kasan_depth = 0;
> +}
> +
> #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
>
> static inline void __init kasan_init_shadow(void) { }
>
> +static inline void __init kasan_init_depth(void) { }
> +
> #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
>
> void __init kasan_init(void)
> {
> kasan_init_shadow();
> -
> - /* At this point kasan is fully initialized. Enable error messages */
> - init_task.kasan_depth = 0;
> + kasan_init_depth();
> pr_info("KernelAddressSanitizer initialized\n");
> }
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index f6435b9f889c..979d598e1c30 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -51,6 +51,12 @@ static inline void *kasan_mem_to_shadow(const void *addr)
> int kasan_add_zero_shadow(void *start, unsigned long size);
> void kasan_remove_zero_shadow(void *start, unsigned long size);
>
> +/* Enable reporting bugs after kasan_disable_current() */
> +extern void kasan_enable_current(void);
> +
> +/* Disable reporting bugs for current task */
> +extern void kasan_disable_current(void);
> +
> #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
>
> static inline int kasan_add_zero_shadow(void *start, unsigned long size)
> @@ -61,16 +67,13 @@ static inline void kasan_remove_zero_shadow(void *start,
> unsigned long size)
> {}
>
> +static inline void kasan_enable_current(void) {}
> +static inline void kasan_disable_current(void) {}
> +
> #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
>
> #ifdef CONFIG_KASAN
>
> -/* Enable reporting bugs after kasan_disable_current() */
> -extern void kasan_enable_current(void);
> -
> -/* Disable reporting bugs for current task */
> -extern void kasan_disable_current(void);
> -
> void kasan_unpoison_memory(const void *address, size_t size);
>
> void kasan_unpoison_task_stack(struct task_struct *task);
> @@ -121,9 +124,6 @@ static inline void kasan_unpoison_memory(const void *address, size_t size) {}
>
> static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
>
> -static inline void kasan_enable_current(void) {}
> -static inline void kasan_disable_current(void) {}
> -
> static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
> static inline void kasan_free_pages(struct page *page, unsigned int order) {}
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 063cd120b459..81b09bd31186 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1197,7 +1197,7 @@ struct task_struct {
> u64 timer_slack_ns;
> u64 default_timer_slack_ns;
>
> -#ifdef CONFIG_KASAN
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> unsigned int kasan_depth;
> #endif
>
> diff --git a/init/init_task.c b/init/init_task.c
> index a56f0abb63e9..39703b4ef1f1 100644
> --- a/init/init_task.c
> +++ b/init/init_task.c
> @@ -176,7 +176,7 @@ struct task_struct init_task
> .numa_group = NULL,
> .numa_faults = NULL,
> #endif
> -#ifdef CONFIG_KASAN
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> .kasan_depth = 1,
> #endif
> #ifdef CONFIG_KCSAN
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 543e6bf2168f..d0b3ff410b0c 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -46,6 +46,7 @@ void kasan_set_track(struct kasan_track *track, gfp_t flags)
> track->stack = kasan_save_stack(flags);
> }
>
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> void kasan_enable_current(void)
> {
> current->kasan_depth++;
> @@ -55,6 +56,7 @@ void kasan_disable_current(void)
> {
> current->kasan_depth--;
> }
> +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
>
> static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
> {
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index b18d193f7f58..af9138ea54ad 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -292,8 +292,10 @@ static void print_shadow_for_address(const void *addr)
>
> static bool report_enabled(void)
> {
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> if (current->kasan_depth)
> return false;
> +#endif
> if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
> return true;
> return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
> --
> 2.29.2.222.g5d2a92d10f8-goog
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg