kasan: init memory in kasan_(un)poison for HW_TAGS

This change adds an argument to kasan_poison() and kasan_unpoison() that
allows initializing memory along with setting the tags for HW_TAGS.

Combining setting allocation tags with memory initialization will improve
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

This change doesn't integrate memory initialization with KASAN, this is
done is subsequent patches in this series.

Link: https://lkml.kernel.org/r/3054314039fa64510947e674180d675cab1b4c41.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 0583033a7df6..071c456a3579 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -359,7 +359,7 @@ static inline u8 kasan_random_tag(void) { return 0; }
 
 #ifdef CONFIG_KASAN_HW_TAGS
 
-static inline void kasan_poison(const void *addr, size_t size, u8 value)
+static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
 {
 	addr = kasan_reset_tag(addr);
 
@@ -372,10 +372,10 @@ static inline void kasan_poison(const void *addr, size_t size, u8 value)
 	if (WARN_ON(size & KASAN_GRANULE_MASK))
 		return;
 
-	hw_set_mem_tag_range((void *)addr, size, value, false);
+	hw_set_mem_tag_range((void *)addr, size, value, init);
 }
 
-static inline void kasan_unpoison(const void *addr, size_t size)
+static inline void kasan_unpoison(const void *addr, size_t size, bool init)
 {
 	u8 tag = get_tag(addr);
 
@@ -389,7 +389,7 @@ static inline void kasan_unpoison(const void *addr, size_t size)
 		return;
 	size = round_up(size, KASAN_GRANULE_SIZE);
 
-	hw_set_mem_tag_range((void *)addr, size, tag, false);
+	hw_set_mem_tag_range((void *)addr, size, tag, init);
 }
 
 static inline bool kasan_byte_accessible(const void *addr)
@@ -407,22 +407,24 @@ static inline bool kasan_byte_accessible(const void *addr)
  * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
  * @size - range size, must be aligned to KASAN_GRANULE_SIZE
  * @value - value that's written to metadata for the range
+ * @init - whether to initialize the memory range (only for hardware tag-based)
  *
  * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
  */
-void kasan_poison(const void *addr, size_t size, u8 value);
+void kasan_poison(const void *addr, size_t size, u8 value, bool init);
 
 /**
  * kasan_unpoison - mark the memory range as accessible
  * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
  * @size - range size, can be unaligned
+ * @init - whether to initialize the memory range (only for hardware tag-based)
  *
  * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
  * marking the range.
  * For the generic mode, the last granule of the memory range gets partially
  * unpoisoned based on the @size.
  */
-void kasan_unpoison(const void *addr, size_t size);
+void kasan_unpoison(const void *addr, size_t size, bool init);
 
 bool kasan_byte_accessible(const void *addr);