From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: shadow declarations only for software modes This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Group shadow-related KASAN function declarations and only define them for the two existing software modes. No functional changes for software modes. Link: https://lkml.kernel.org/r/e88d94eff94db883a65dca52e1736d80d28dd9bc.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@xxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> 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: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> [valdis.kletnieks@xxxxxx: fix build issue with asmlinkage] Link: https://lkml.kernel.org/r/35126.1606402815@turing-police Link: https://lore.kernel.org/linux-arm-kernel/24105.1606397102@turing-police/ Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/kasan.h | 48 ++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 16 deletions(-) --- a/include/linux/kasan.h~kasan-shadow-declarations-only-for-software-modes +++ a/include/linux/kasan.h @@ -11,7 +11,7 @@ struct task_struct; #ifdef CONFIG_KASAN -#include <linux/pgtable.h> +#include <linux/linkage.h> #include <asm/kasan.h> /* kasan_data struct is used in KUnit tests for KASAN expected failures */ @@ -20,6 +20,20 @@ struct kunit_kasan_expectation { bool report_found; }; +#endif + +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) + +#include <linux/pgtable.h> + +/* Software KASAN implementations use shadow memory. */ + +#ifdef CONFIG_KASAN_SW_TAGS +#define KASAN_SHADOW_INIT 0xFF +#else +#define KASAN_SHADOW_INIT 0 +#endif + extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE]; extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD]; @@ -35,6 +49,23 @@ static inline void *kasan_mem_to_shadow( + KASAN_SHADOW_OFFSET; } +int kasan_add_zero_shadow(void *start, unsigned long size); +void kasan_remove_zero_shadow(void *start, unsigned long size); + +#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ + +static inline int kasan_add_zero_shadow(void *start, unsigned long size) +{ + return 0; +} +static inline void kasan_remove_zero_shadow(void *start, + unsigned long size) +{} + +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ + +#ifdef CONFIG_KASAN + /* Enable reporting bugs after kasan_disable_current() */ extern void kasan_enable_current(void); @@ -75,9 +106,6 @@ struct kasan_cache { int free_meta_offset; }; -int kasan_add_zero_shadow(void *start, unsigned long size); -void kasan_remove_zero_shadow(void *start, unsigned long size); - size_t __ksize(const void *); static inline void kasan_unpoison_slab(const void *ptr) { @@ -143,14 +171,6 @@ static inline bool kasan_slab_free(struc return false; } -static inline int kasan_add_zero_shadow(void *start, unsigned long size) -{ - return 0; -} -static inline void kasan_remove_zero_shadow(void *start, - unsigned long size) -{} - static inline void kasan_unpoison_slab(const void *ptr) { } static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } @@ -158,8 +178,6 @@ static inline size_t kasan_metadata_size #ifdef CONFIG_KASAN_GENERIC -#define KASAN_SHADOW_INIT 0 - void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); void kasan_record_aux_stack(void *ptr); @@ -174,8 +192,6 @@ static inline void kasan_record_aux_stac #ifdef CONFIG_KASAN_SW_TAGS -#define KASAN_SHADOW_INIT 0xFF - void kasan_init_tags(void); void *kasan_reset_tag(const void *addr); _
