From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: define KASAN_MEMORY_PER_SHADOW_PAGE Define KASAN_MEMORY_PER_SHADOW_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT), which is the same as (KASAN_GRANULE_SIZE * PAGE_SIZE) for software modes that use shadow memory, and use it across KASAN code to simplify it. Link: https://lkml.kernel.org/r/8329391cfe14b5cffd3decf3b5c535b6ce21eef6.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> 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> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/init.c | 10 ++++------ mm/kasan/kasan.h | 2 ++ mm/kasan/shadow.c | 16 +++++++--------- 3 files changed, 13 insertions(+), 15 deletions(-) --- a/mm/kasan/init.c~kasan-define-kasan_memory_per_shadow_page +++ a/mm/kasan/init.c @@ -441,9 +441,8 @@ void kasan_remove_zero_shadow(void *star addr = (unsigned long)kasan_mem_to_shadow(start); end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); - if (WARN_ON((unsigned long)start % - (KASAN_GRANULE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_GRANULE_SIZE * PAGE_SIZE))) + if (WARN_ON((unsigned long)start % KASAN_MEMORY_PER_SHADOW_PAGE) || + WARN_ON(size % KASAN_MEMORY_PER_SHADOW_PAGE)) return; for (; addr < end; addr = next) { @@ -476,9 +475,8 @@ int kasan_add_zero_shadow(void *start, u shadow_start = kasan_mem_to_shadow(start); shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); - if (WARN_ON((unsigned long)start % - (KASAN_GRANULE_SIZE * PAGE_SIZE)) || - WARN_ON(size % (KASAN_GRANULE_SIZE * PAGE_SIZE))) + if (WARN_ON((unsigned long)start % KASAN_MEMORY_PER_SHADOW_PAGE) || + WARN_ON(size % KASAN_MEMORY_PER_SHADOW_PAGE)) return -EINVAL; ret = kasan_populate_early_shadow(shadow_start, shadow_end); --- a/mm/kasan/kasan.h~kasan-define-kasan_memory_per_shadow_page +++ a/mm/kasan/kasan.h @@ -8,6 +8,8 @@ #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1) +#define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) + #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ #define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ #define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ --- a/mm/kasan/shadow.c~kasan-define-kasan_memory_per_shadow_page +++ a/mm/kasan/shadow.c @@ -174,7 +174,7 @@ static int __meminit kasan_mem_notifier( shadow_end = shadow_start + shadow_size; if (WARN_ON(mem_data->nr_pages % KASAN_GRANULE_SIZE) || - WARN_ON(start_kaddr % (KASAN_GRANULE_SIZE << PAGE_SHIFT))) + WARN_ON(start_kaddr % KASAN_MEMORY_PER_SHADOW_PAGE)) return NOTIFY_BAD; switch (action) { @@ -445,22 +445,20 @@ void kasan_release_vmalloc(unsigned long unsigned long region_start, region_end; unsigned long size; - region_start = ALIGN(start, PAGE_SIZE * KASAN_GRANULE_SIZE); - region_end = ALIGN_DOWN(end, PAGE_SIZE * KASAN_GRANULE_SIZE); + region_start = ALIGN(start, KASAN_MEMORY_PER_SHADOW_PAGE); + region_end = ALIGN_DOWN(end, KASAN_MEMORY_PER_SHADOW_PAGE); - free_region_start = ALIGN(free_region_start, - PAGE_SIZE * KASAN_GRANULE_SIZE); + free_region_start = ALIGN(free_region_start, KASAN_MEMORY_PER_SHADOW_PAGE); if (start != region_start && free_region_start < region_start) - region_start -= PAGE_SIZE * KASAN_GRANULE_SIZE; + region_start -= KASAN_MEMORY_PER_SHADOW_PAGE; - free_region_end = ALIGN_DOWN(free_region_end, - PAGE_SIZE * KASAN_GRANULE_SIZE); + free_region_end = ALIGN_DOWN(free_region_end, KASAN_MEMORY_PER_SHADOW_PAGE); if (end != region_end && free_region_end > region_end) - region_end += PAGE_SIZE * KASAN_GRANULE_SIZE; + region_end += KASAN_MEMORY_PER_SHADOW_PAGE; shadow_start = kasan_mem_to_shadow((void *)region_start); shadow_end = kasan_mem_to_shadow((void *)region_end); _
