kasan: inline kasan_reset_tag for tag-based modes

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. Also remove the now unneeded reset_tag() internal KASAN
macro and use kasan_reset_tag() instead.

Link: https://lkml.kernel.org/r/6940383a3a9dfb416134d338d8fac97a9ebb8686.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I4d2061acfe91d480a75df00b07c22d8494ef14b5
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
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>

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index e638255..3bb72de 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -194,7 +194,10 @@ static inline void kasan_record_aux_stack(void *ptr) {}
 
 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 
-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/common.c b/mm/kasan/common.c
index b71dfe7..780ec27 100644 (file)
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -179,14 +179,14 @@ size_t kasan_metadata_size(struct kmem_cache *cache)
 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
                                              const void *object)
 {
-       return (void *)reset_tag(object) + cache->kasan_info.alloc_meta_offset;
+       return kasan_reset_tag(object) + cache->kasan_info.alloc_meta_offset;
 }
 
 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
                                            const void *object)
 {
        BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
-       return (void *)reset_tag(object) + cache->kasan_info.free_meta_offset;
+       return kasan_reset_tag(object) + cache->kasan_info.free_meta_offset;
 }
 
 void kasan_poison_slab(struct page *page)
@@ -283,7 +283,7 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
 
        tag = get_tag(object);
        tagged_object = object;
-       object = reset_tag(object);
+       object = kasan_reset_tag(object);
 
        if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
            object)) {

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index cb849c8..227599e 100644 (file)
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -30,20 +30,15 @@ void __init kasan_init_hw_tags(void)
        pr_info("KernelAddressSanitizer initialized\n");
 }
 
-void *kasan_reset_tag(const void *addr)
-{
-       return reset_tag(addr);
-}
-
 void poison_range(const void *address, size_t size, u8 value)
 {
-       hw_set_mem_tag_range(reset_tag(address),
+       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)
 {
-       hw_set_mem_tag_range(reset_tag(address),
+       hw_set_mem_tag_range(kasan_reset_tag(address),
                        round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
 }
 

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 0eab7e4..5e8cd20 100644 (file)
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -248,15 +248,11 @@ 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
 
 #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)
 
 #ifdef CONFIG_KASAN_HW_TAGS

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 85ce2cb..00c590e 100644 (file)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -328,7 +328,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
        unsigned long flags;
        u8 tag = get_tag(object);
 
-       object = reset_tag(object);
+       object = kasan_reset_tag(object);
 
 #if IS_ENABLED(CONFIG_KUNIT)
        if (current->kunit_test)
@@ -361,7 +361,7 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
        disable_trace_on_warning();
 
        tagged_addr = (void *)addr;
-       untagged_addr = reset_tag(tagged_addr);
+       untagged_addr = kasan_reset_tag(tagged_addr);
 
        info.access_addr = tagged_addr;
        if (addr_has_metadata(untagged_addr))

diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c
index da543eb..57114f0 100644 (file)
--- a/mm/kasan/report_hw_tags.c
+++ b/mm/kasan/report_hw_tags.c
@@ -22,7 +22,7 @@ const char *get_bug_type(struct kasan_access_info *info)
 
 void *find_first_bad_addr(void *addr, size_t size)
 {
-       return reset_tag(addr);
+       return kasan_reset_tag(addr);
 }
 
 void metadata_fetch_row(char *buffer, void *row)

diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c
index 317100f..7604b46 100644 (file)
--- a/mm/kasan/report_sw_tags.c
+++ b/mm/kasan/report_sw_tags.c
@@ -41,7 +41,7 @@ const char *get_bug_type(struct kasan_access_info *info)
        int i;
 
        tag = get_tag(info->access_addr);
-       addr = reset_tag(info->access_addr);
+       addr = kasan_reset_tag(info->access_addr);
        page = kasan_addr_to_page(addr);
        if (page && PageSlab(page)) {
                cache = page->slab_cache;
@@ -72,7 +72,7 @@ const char *get_bug_type(struct kasan_access_info *info)
 void *find_first_bad_addr(void *addr, size_t size)
 {
        u8 tag = get_tag(addr);
-       void *p = reset_tag(addr);
+       void *p = kasan_reset_tag(addr);
        void *end = p + size;
 
        while (p < end && tag == *(u8 *)kasan_mem_to_shadow(p))

diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index ac6a5f5..44a2b74 100644 (file)
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -81,7 +81,7 @@ void poison_range(const void *address, size_t size, u8 value)
         * some of the callers (e.g. kasan_poison_object_data) pass tagged
         * addresses to this function.
         */
-       address = reset_tag(address);
+       address = kasan_reset_tag(address);
 
        shadow_start = kasan_mem_to_shadow(address);
        shadow_end = kasan_mem_to_shadow(address + size);
@@ -98,7 +98,7 @@ void unpoison_range(const void *address, size_t size)
         * some of the callers (e.g. kasan_unpoison_object_data) pass tagged
         * addresses to this function.
         */
-       address = reset_tag(address);
+       address = kasan_reset_tag(address);
 
        poison_range(address, size, tag);
 

diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index 6d7648c..e17de26 100644 (file)
--- 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)
 {
@@ -107,7 +102,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
        if (tag == KASAN_TAG_KERNEL)
                return true;
 
-       untagged_addr = reset_tag((const void *)addr);
+       untagged_addr = kasan_reset_tag((const void *)addr);
        if (unlikely(untagged_addr <
                        kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
                return !kasan_report(addr, size, write, ret_ip);
@@ -126,7 +121,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
 bool check_invalid_free(void *addr)
 {
        u8 tag = get_tag(addr);
-       u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(reset_tag(addr)));
+       u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(kasan_reset_tag(addr)));
 
        return (shadow_byte == KASAN_TAG_INVALID) ||
                (tag != KASAN_TAG_KERNEL && tag != shadow_byte);