On Fri, Nov 13, 2020 at 11:16 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > > 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. > > 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> > --- > Change-Id: I0b627b24187d06c8b9bb2f1d04d94b3d06945e73 > --- > mm/kasan/init.c | 10 ++++------ > mm/kasan/kasan.h | 2 ++ > mm/kasan/shadow.c | 16 +++++++--------- > 3 files changed, 13 insertions(+), 15 deletions(-) > > diff --git a/mm/kasan/init.c b/mm/kasan/init.c > index 1a71eaa8c5f9..bc0ad208b3a7 100644 > --- a/mm/kasan/init.c > +++ b/mm/kasan/init.c > @@ -441,9 +441,8 @@ void kasan_remove_zero_shadow(void *start, unsigned long size) > 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, unsigned long size) > 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); > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index 53b095f56f28..eec88bf28c64 100644 > --- a/mm/kasan/kasan.h > +++ b/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 */ > diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c > index 4264bfbdca1a..80522d2c447b 100644 > --- a/mm/kasan/shadow.c > +++ b/mm/kasan/shadow.c > @@ -174,7 +174,7 @@ static int __meminit kasan_mem_notifier(struct notifier_block *nb, > 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 start, unsigned long end, > 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); > -- > 2.29.2.299.gdc1121823c-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