The patch titled
Subject: kasan: hide invalid free check implementation
has been removed from the -mm tree. Its filename was
kasan-hide-invalid-free-check-implementation.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: hide invalid free check implementation
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
For software KASAN modes the check is based on the value in the shadow
memory. Hardware tag-based KASAN won't be using shadow, so hide the
implementation of the check in check_invalid_free().
Also simplify the code for software tag-based mode.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/d01534a4b977f97d87515dc590e6348e1406de81.1606161801.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/common.c | 19 +------------------
mm/kasan/generic.c | 7 +++++++
mm/kasan/kasan.h | 2 ++
mm/kasan/sw_tags.c | 9 +++++++++
4 files changed, 19 insertions(+), 18 deletions(-)
--- a/mm/kasan/common.c~kasan-hide-invalid-free-check-implementation
+++ a/mm/kasan/common.c
@@ -277,25 +277,9 @@ void * __must_check kasan_init_slab_obj(
return (void *)object;
}
-static inline bool shadow_invalid(u8 tag, s8 shadow_byte)
-{
- if (IS_ENABLED(CONFIG_KASAN_GENERIC))
- return shadow_byte < 0 ||
- shadow_byte >= KASAN_GRANULE_SIZE;
-
- /* else CONFIG_KASAN_SW_TAGS: */
- if ((u8)shadow_byte == KASAN_TAG_INVALID)
- return true;
- if ((tag != KASAN_TAG_KERNEL) && (tag != (u8)shadow_byte))
- return true;
-
- return false;
-}
-
static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
unsigned long ip, bool quarantine)
{
- s8 shadow_byte;
u8 tag;
void *tagged_object;
unsigned long rounded_up_size;
@@ -314,8 +298,7 @@ static bool __kasan_slab_free(struct kme
if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return false;
- shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
- if (shadow_invalid(tag, shadow_byte)) {
+ if (check_invalid_free(tagged_object)) {
kasan_report_invalid_free(tagged_object, ip);
return true;
}
--- a/mm/kasan/generic.c~kasan-hide-invalid-free-check-implementation
+++ a/mm/kasan/generic.c
@@ -187,6 +187,13 @@ bool check_memory_region(unsigned long a
return check_memory_region_inline(addr, size, write, ret_ip);
}
+bool check_invalid_free(void *addr)
+{
+ s8 shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr));
+
+ return shadow_byte < 0 || shadow_byte >= KASAN_GRANULE_SIZE;
+}
+
void kasan_cache_shrink(struct kmem_cache *cache)
{
quarantine_remove_cache(cache);
--- a/mm/kasan/kasan.h~kasan-hide-invalid-free-check-implementation
+++ a/mm/kasan/kasan.h
@@ -166,6 +166,8 @@ void unpoison_range(const void *address,
bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip);
+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);
--- a/mm/kasan/sw_tags.c~kasan-hide-invalid-free-check-implementation
+++ a/mm/kasan/sw_tags.c
@@ -121,6 +121,15 @@ bool check_memory_region(unsigned long a
return true;
}
+bool check_invalid_free(void *addr)
+{
+ u8 tag = get_tag(addr);
+ u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(reset_tag(addr)));
+
+ return (shadow_byte == KASAN_TAG_INVALID) ||
+ (tag != KASAN_TAG_KERNEL && tag != shadow_byte);
+}
+
#define DEFINE_HWASAN_LOAD_STORE(size) \
void __hwasan_load##size##_noabort(unsigned long addr) \
{ \
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
