From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan, arm64: only use kasan_depth for software modes 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. Link: https://lkml.kernel.org/r/e16f15aeda90bc7fb4dfc2e243a14b74cc5c8219.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/arch/arm64/mm/kasan_init.c~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/arch/arm64/mm/kasan_init.c @@ -273,17 +273,22 @@ static void __init kasan_init_shadow(voi 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"); } --- a/include/linux/kasan.h~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/include/linux/kasan.h @@ -52,6 +52,12 @@ static inline void *kasan_mem_to_shadow( 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) @@ -62,16 +68,13 @@ static inline void kasan_remove_zero_sha 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_range(const void *address, size_t size); void kasan_unpoison_task_stack(struct task_struct *task); @@ -122,9 +125,6 @@ static inline void kasan_unpoison_range( 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) {} --- a/include/linux/sched.h~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/include/linux/sched.h @@ -1234,7 +1234,7 @@ 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 --- a/init/init_task.c~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/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 --- a/mm/kasan/common.c~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/mm/kasan/common.c @@ -46,6 +46,7 @@ void kasan_set_track(struct kasan_track 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 */ void kasan_unpoison_range(const void *address, size_t size) { --- a/mm/kasan/report.c~kasan-arm64-only-use-kasan_depth-for-software-modes +++ a/mm/kasan/report.c @@ -292,8 +292,10 @@ static void print_shadow_for_address(con 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); _
