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Message-ID: <20200518062730.4665-1-walter-zh.wu@mediatek.com>
Date: Mon, 18 May 2020 14:27:30 +0800
From: Walter Wu <walter-zh.wu@...iatek.com>
To: Andrey Ryabinin <aryabinin@...tuozzo.com>,
Alexander Potapenko <glider@...gle.com>,
Dmitry Vyukov <dvyukov@...gle.com>,
Matthias Brugger <matthias.bgg@...il.com>
CC: <kasan-dev@...glegroups.com>, <linux-mm@...ck.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
wsd_upstream <wsd_upstream@...iatek.com>,
<linux-mediatek@...ts.infradead.org>,
Walter Wu <walter-zh.wu@...iatek.com>
Subject: [PATCH v3 2/4] kasan: record and print the free track
Move free track from slub alloc meta-data to slub free meta-data in
order to make struct kasan_free_meta size is 16 bytes. It is a good
size because it is the minimal redzone size and a good number of
alignment.
For free track in generic KASAN, we do the modification in struct
kasan_alloc_meta and kasan_free_meta:
- remove free track from kasan_alloc_meta.
- add free track into kasan_free_meta.
[1]https://bugzilla.kernel.org/show_bug.cgi?id=198437
Signed-off-by: Walter Wu <walter-zh.wu@...iatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@...gle.com>
Cc: Andrey Ryabinin <aryabinin@...tuozzo.com>
Cc: Dmitry Vyukov <dvyukov@...gle.com>
Cc: Alexander Potapenko <glider@...gle.com>
---
mm/kasan/common.c | 33 ++++++++++-----------------------
mm/kasan/generic.c | 18 ++++++++++++++++++
mm/kasan/kasan.h | 7 +++++++
mm/kasan/report.c | 20 --------------------
mm/kasan/tags.c | 37 +++++++++++++++++++++++++++++++++++++
5 files changed, 72 insertions(+), 43 deletions(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 8bc618289bb1..6500bc2bb70c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -51,7 +51,7 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags)
return stack_depot_save(entries, nr_entries, flags);
}
-static inline void set_track(struct kasan_track *track, gfp_t flags)
+void kasan_set_track(struct kasan_track *track, gfp_t flags)
{
track->pid = current->pid;
track->stack = kasan_save_stack(flags);
@@ -249,9 +249,7 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
*size += sizeof(struct kasan_alloc_meta);
/* Add free meta. */
- if (IS_ENABLED(CONFIG_KASAN_GENERIC) &&
- (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor ||
- cache->object_size < sizeof(struct kasan_free_meta))) {
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) {
cache->kasan_info.free_meta_offset = *size;
*size += sizeof(struct kasan_free_meta);
}
@@ -299,24 +297,6 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
return (void *)object + cache->kasan_info.free_meta_offset;
}
-
-static void kasan_set_free_info(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
- u8 idx = 0;
-
- alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
- idx = alloc_meta->free_track_idx;
- alloc_meta->free_pointer_tag[idx] = tag;
- alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
-#endif
-
- set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
-}
-
void kasan_poison_slab(struct page *page)
{
unsigned long i;
@@ -396,6 +376,13 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
alloc_info = get_alloc_info(cache, object);
__memset(alloc_info, 0, sizeof(*alloc_info));
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) {
+ struct kasan_free_meta *free_info;
+
+ free_info = get_free_info(cache, object);
+ __memset(free_info, 0, sizeof(*free_info));
+ }
+
if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
object = set_tag(object,
assign_tag(cache, object, true, false));
@@ -492,7 +479,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
KASAN_KMALLOC_REDZONE);
if (cache->flags & SLAB_KASAN)
- set_track(&get_alloc_info(cache, object)->alloc_track, flags);
+ kasan_set_track(&get_alloc_info(cache, object)->alloc_track, flags);
return set_tag(object, tag);
}
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 78d8e0a75a8a..988bc095b738 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -345,3 +345,21 @@ void kasan_record_aux_stack(void *addr)
alloc_info->rcu_stack[1] = alloc_info->rcu_stack[0];
alloc_info->rcu_stack[0] = kasan_save_stack(GFP_NOWAIT);
}
+
+void kasan_set_free_info(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_free_meta *free_meta;
+
+ free_meta = get_free_info(cache, object);
+ kasan_set_track(&free_meta->free_track, GFP_NOWAIT);
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_free_meta *free_meta;
+
+ free_meta = get_free_info(cache, object);
+ return &free_meta->free_track;
+}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 870c5dd07756..87ee3626b8b0 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -127,6 +127,9 @@ struct kasan_free_meta {
* Otherwise it might be used for the allocator freelist.
*/
struct qlist_node quarantine_link;
+#ifdef CONFIG_KASAN_GENERIC
+ struct kasan_track free_track;
+#endif
};
struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
@@ -168,6 +171,10 @@ void kasan_report_invalid_free(void *object, unsigned long ip);
struct page *kasan_addr_to_page(const void *addr);
depot_stack_handle_t kasan_save_stack(gfp_t flags);
+void kasan_set_track(struct kasan_track *track, gfp_t flags);
+void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag);
#if defined(CONFIG_KASAN_GENERIC) && \
(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 5ee66cf7e27c..7e9f9f6d5e85 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -159,26 +159,6 @@ static void describe_object_addr(struct kmem_cache *cache, void *object,
(void *)(object_addr + cache->object_size));
}
-static struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
- int i = 0;
-
- alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
- for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
- if (alloc_meta->free_pointer_tag[i] == tag)
- break;
- }
- if (i == KASAN_NR_FREE_STACKS)
- i = alloc_meta->free_track_idx;
-#endif
-
- return &alloc_meta->free_track[i];
-}
-
#ifdef CONFIG_KASAN_GENERIC
static void print_stack(depot_stack_handle_t stack)
{
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index 25b7734e7013..201dee5d6ae0 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -162,3 +162,40 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
kasan_poison_shadow((void *)addr, size, tag);
}
EXPORT_SYMBOL(__hwasan_tag_memory);
+
+void kasan_set_free_info(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ u8 idx = 0;
+
+ alloc_meta = get_alloc_info(cache, object);
+
+#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
+ idx = alloc_meta->free_track_idx;
+ alloc_meta->free_pointer_tag[idx] = tag;
+ alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
+#endif
+
+ kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ int i = 0;
+
+ alloc_meta = get_alloc_info(cache, object);
+
+#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
+ for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
+ if (alloc_meta->free_pointer_tag[i] == tag)
+ break;
+ }
+ if (i == KASAN_NR_FREE_STACKS)
+ i = alloc_meta->free_track_idx;
+#endif
+
+ return &alloc_meta->free_track[i];
+}
--
2.18.0
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