[PATCH v3 09/39] kasan: define KASAN_GRANULE_PAGE

Andrey Konovalov
2020-09-24T22:51:26Z

Define KASAN_GRANULE_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT), which is
the same as (KASAN_GRANULE_SIZE * PAGE_SIZE), and use it across KASAN code
to simplify it.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
Change-Id: I0b627b24187d06c8b9bb2f1d04d94b3d06945e73
---
mm/kasan/init.c | 10 ++++------
mm/kasan/kasan.h | 1 +
mm/kasan/shadow.c | 16 +++++++---------
3 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index 1a71eaa8c5f9..26b2663b3a42 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_GRANULE_PAGE) ||
+ WARN_ON(size % KASAN_GRANULE_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_GRANULE_PAGE) ||
+ WARN_ON(size % KASAN_GRANULE_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 c31e2c739301..1865bb92d47a 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -7,6 +7,7 @@

#define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
#define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
+#define KASAN_GRANULE_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT)

#define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */
#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index ca0cc4c31454..1fadd4930d54 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -161,7 +161,7 @@ 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_GRANULE_PAGE))
return NOTIFY_BAD;

switch (action) {
@@ -432,22 +432,20 @@ 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_GRANULE_PAGE);
+ region_end = ALIGN_DOWN(end, KASAN_GRANULE_PAGE);

- free_region_start = ALIGN(free_region_start,
- PAGE_SIZE * KASAN_GRANULE_SIZE);
+ free_region_start = ALIGN(free_region_start, KASAN_GRANULE_PAGE);

if (start != region_start &&
free_region_start < region_start)
- region_start -= PAGE_SIZE * KASAN_GRANULE_SIZE;
+ region_start -= KASAN_GRANULE_PAGE;

- free_region_end = ALIGN_DOWN(free_region_end,
- PAGE_SIZE * KASAN_GRANULE_SIZE);
+ free_region_end = ALIGN_DOWN(free_region_end, KASAN_GRANULE_PAGE);

if (end != region_end &&
free_region_end > region_end)
- region_end += PAGE_SIZE * KASAN_GRANULE_SIZE;
+ region_end += KASAN_GRANULE_PAGE;

shadow_start = kasan_mem_to_shadow((void *)region_start);
shadow_end = kasan_mem_to_shadow((void *)region_end);
--
2.28.0.681.g6f77f65b4e-goog