[PATCH RFC v2 09/21] kasan: inline kasan_reset_tag for tag-based modes

[Andrey Konovalov]

Using kasan_reset_tag() currently results in a function call. As it's
called quite often from the allocator code this leads to a noticeable
slowdown. Move it to include/linux/kasan.h and turn it into a static
inline function.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Link: https://linux-review.googlesource.com/id/I4d2061acfe91d480a75df00b07c22d8494ef14b5
---
 include/linux/kasan.h | 5 ++++-
 mm/kasan/hw_tags.c    | 5 -----
 mm/kasan/kasan.h      | 6 ++----
 mm/kasan/sw_tags.c    | 5 -----
 4 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 93d9834b7122..6377d7d3a951 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -187,7 +187,10 @@ static inline void kasan_record_aux_stack(void *ptr) {}
 
 void __init kasan_init_tags(void);
 
-void *kasan_reset_tag(const void *addr);
+static inline void *kasan_reset_tag(const void *addr)
+{
+	return (void *)arch_kasan_reset_tag(addr);
+}
 
 bool kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip);
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index b372421258c8..c3a0e83b5e7a 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -24,11 +24,6 @@ void __init kasan_init_tags(void)
 	pr_info("KernelAddressSanitizer initialized\n");
 }
 
-void *kasan_reset_tag(const void *addr)
-{
-	return reset_tag(addr);
-}
-
 void kasan_poison_memory(const void *address, size_t size, u8 value)
 {
 	set_mem_tag_range(reset_tag(address),
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 456b264e5124..0ccbb3c4c519 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -246,15 +246,13 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 	return addr;
 }
 #endif
-#ifndef arch_kasan_reset_tag
-#define arch_kasan_reset_tag(addr)	((void *)(addr))
-#endif
 #ifndef arch_kasan_get_tag
 #define arch_kasan_get_tag(addr)	0
 #endif
 
+/* kasan_reset_tag() defined in include/linux/kasan.h. */
+#define reset_tag(addr)		((void *)kasan_reset_tag(addr))
 #define set_tag(addr, tag)	((void *)arch_kasan_set_tag((addr), (tag)))
-#define reset_tag(addr)		((void *)arch_kasan_reset_tag(addr))
 #define get_tag(addr)		arch_kasan_get_tag(addr)
 
 #ifndef arch_init_tags
diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index 099af6dc8f7e..4db41f274702 100644
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -67,11 +67,6 @@ u8 random_tag(void)
 	return (u8)(state % (KASAN_TAG_MAX + 1));
 }
 
-void *kasan_reset_tag(const void *addr)
-{
-	return reset_tag(addr);
-}
-
 bool check_memory_region(unsigned long addr, size_t size, bool write,
 				unsigned long ret_ip)
 {
-- 
2.29.0.rc1.297.gfa9743e501-goog