[PATCH mm v3 10/19] kasan: inline (un)poison_range and check_invalid_free

From: Andrey Konovalov
Date: Fri Nov 13 2020 - 17:21:05 EST


Using (un)poison_range() or check_invalid_free() currently results in
function calls. Move their definitions to mm/kasan/kasan.h and turn them
into static inline functions for hardware tag-based mode to avoid
unneeded function calls.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Link: https://linux-review.googlesource.com/id/Ia9d8191024a12d1374675b3d27197f10193f50bb
---
mm/kasan/hw_tags.c | 30 ------------------------------
mm/kasan/kasan.h | 45 ++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 3cdd87d189f6..863fed4edd3f 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -10,7 +10,6 @@

#include <linux/kasan.h>
#include <linux/kernel.h>
-#include <linux/kfence.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/string.h>
@@ -31,35 +30,6 @@ void __init kasan_init_hw_tags(void)
pr_info("KernelAddressSanitizer initialized\n");
}

-void poison_range(const void *address, size_t size, u8 value)
-{
- /* Skip KFENCE memory if called explicitly outside of sl*b. */
- if (is_kfence_address(address))
- return;
-
- hw_set_mem_tag_range(kasan_reset_tag(address),
- round_up(size, KASAN_GRANULE_SIZE), value);
-}
-
-void unpoison_range(const void *address, size_t size)
-{
- /* Skip KFENCE memory if called explicitly outside of sl*b. */
- if (is_kfence_address(address))
- return;
-
- hw_set_mem_tag_range(kasan_reset_tag(address),
- round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
-}
-
-bool check_invalid_free(void *addr)
-{
- u8 ptr_tag = get_tag(addr);
- u8 mem_tag = hw_get_mem_tag(addr);
-
- return (mem_tag == KASAN_TAG_INVALID) ||
- (ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag);
-}
-
void kasan_set_free_info(struct kmem_cache *cache,
void *object, u8 tag)
{
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 7876a2547b7d..8aa83b7ad79e 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -3,6 +3,7 @@
#define __MM_KASAN_KASAN_H

#include <linux/kasan.h>
+#include <linux/kfence.h>
#include <linux/stackdepot.h>

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
@@ -154,9 +155,6 @@ struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
const void *object);

-void poison_range(const void *address, size_t size, u8 value);
-void unpoison_range(const void *address, size_t size);
-
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
@@ -196,8 +194,6 @@ void print_tags(u8 addr_tag, const void *addr);
static inline void print_tags(u8 addr_tag, const void *addr) { }
#endif

-bool check_invalid_free(void *addr);
-
void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);
void metadata_fetch_row(char *buffer, void *row);
@@ -278,6 +274,45 @@ static inline u8 random_tag(void) { return hw_get_random_tag(); }
static inline u8 random_tag(void) { return 0; }
#endif

+#ifdef CONFIG_KASAN_HW_TAGS
+
+static inline void poison_range(const void *address, size_t size, u8 value)
+{
+ /* Skip KFENCE memory if called explicitly outside of sl*b. */
+ if (is_kfence_address(address))
+ return;
+
+ hw_set_mem_tag_range(kasan_reset_tag(address),
+ round_up(size, KASAN_GRANULE_SIZE), value);
+}
+
+static inline void unpoison_range(const void *address, size_t size)
+{
+ /* Skip KFENCE memory if called explicitly outside of sl*b. */
+ if (is_kfence_address(address))
+ return;
+
+ hw_set_mem_tag_range(kasan_reset_tag(address),
+ round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
+}
+
+static inline bool check_invalid_free(void *addr)
+{
+ u8 ptr_tag = get_tag(addr);
+ u8 mem_tag = hw_get_mem_tag(addr);
+
+ return (mem_tag == KASAN_TAG_INVALID) ||
+ (ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag);
+}
+
+#else /* CONFIG_KASAN_HW_TAGS */
+
+void poison_range(const void *address, size_t size, u8 value);
+void unpoison_range(const void *address, size_t size);
+bool check_invalid_free(void *addr);
+
+#endif /* CONFIG_KASAN_HW_TAGS */
+
/*
* Exported functions for interfaces called from assembly or from generated
* code. Declarations here to avoid warning about missing declarations.
--
2.29.2.299.gdc1121823c-goog