From: Andrey Konovalov <andreyknvl@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Marco Elver <elver@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH mm] kasan: untag addresses for KFENCE
Date: Fri, 29 Jan 2021 19:50:22 +0100 [thread overview]
Message-ID: <9dc196006921b191d25d10f6e611316db7da2efc.1611946152.git.andreyknvl@google.com> (raw)
KFENCE annotations operate on untagged addresses.
Untag addresses in KASAN runtime where they might be tagged.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
This can be squashed into:
revert kasan-remove-kfence-leftovers
kfence, kasan: make KFENCE compatible with KASA
---
mm/kasan/common.c | 2 +-
mm/kasan/kasan.h | 12 +++++++++---
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index a390fae9d64b..fe852f3cfa42 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -416,7 +416,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
if (unlikely(object == NULL))
return NULL;
- if (is_kfence_address(object))
+ if (is_kfence_address(kasan_reset_tag(object)))
return (void *)object;
redzone_start = round_up((unsigned long)(object + size),
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 11c6e3650468..4fb8106f8e31 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -320,22 +320,28 @@ static inline u8 kasan_random_tag(void) { return 0; }
static inline void kasan_poison(const void *address, size_t size, u8 value)
{
+ address = kasan_reset_tag(address);
+
/* 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),
+ hw_set_mem_tag_range((void *)address,
round_up(size, KASAN_GRANULE_SIZE), value);
}
static inline void kasan_unpoison(const void *address, size_t size)
{
+ u8 tag = get_tag(address);
+
+ address = kasan_reset_tag(address);
+
/* 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));
+ hw_set_mem_tag_range((void *)address,
+ round_up(size, KASAN_GRANULE_SIZE), tag);
}
static inline bool kasan_byte_accessible(const void *addr)
--
2.30.0.365.g02bc693789-goog
next reply other threads:[~2021-01-29 18:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-29 18:50 Andrey Konovalov [this message]
2021-02-01 10:40 ` [PATCH mm] kasan: untag addresses for KFENCE Marco Elver
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