From d73b49365ee65ac48074bdb5aa717bb4644dbbb7 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 22 Dec 2020 12:00:56 -0800 Subject: [PATCH] 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@google.com Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Catalin Marinas Reviewed-by: Alexander Potapenko Tested-by: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Marco Elver Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 ffeb80d5aa8d4..5172799f831f9 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 9740c06a04a14..b272960e8396b 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -52,6 +52,12 @@ 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) @@ -62,16 +68,13 @@ 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_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(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 51d535b69bd6f..6e3a5eeec509a 100644 --- a/include/linux/sched.h +++ b/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 diff --git a/init/init_task.c b/init/init_task.c index 15f6eb93a04fa..8a992d73e6fb7 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 663ffa71cd20a..d5f23b2f170ab 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 */ void kasan_unpoison_range(const void *address, size_t size) { diff --git a/mm/kasan/report.c b/mm/kasan/report.c index d140d26cfb316..914ab5cfc3ea2 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); -- 2.39.5