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-rw-r--r--include/linux/slub_def.h1
-rw-r--r--mm/slub.c100
2 files changed, 72 insertions, 29 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index b7e57927f521..ac5143f95ee6 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -81,6 +81,7 @@ struct kmem_cache {
int reserved; /* Reserved bytes at the end of slabs */
const char *name; /* Name (only for display!) */
struct list_head list; /* List of slab caches */
+ int red_left_pad; /* Left redzone padding size */
#ifdef CONFIG_SYSFS
struct kobject kobj; /* For sysfs */
#endif
diff --git a/mm/slub.c b/mm/slub.c
index c2a227d8a4ee..2d4d817f3d7a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -124,6 +124,14 @@ static inline int kmem_cache_debug(struct kmem_cache *s)
#endif
}
+static inline void *fixup_red_left(struct kmem_cache *s, void *p)
+{
+ if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE)
+ p += s->red_left_pad;
+
+ return p;
+}
+
static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
{
#ifdef CONFIG_SLUB_CPU_PARTIAL
@@ -232,24 +240,6 @@ static inline void stat(const struct kmem_cache *s, enum stat_item si)
* Core slab cache functions
*******************************************************************/
-/* Verify that a pointer has an address that is valid within a slab page */
-static inline int check_valid_pointer(struct kmem_cache *s,
- struct page *page, const void *object)
-{
- void *base;
-
- if (!object)
- return 1;
-
- base = page_address(page);
- if (object < base || object >= base + page->objects * s->size ||
- (object - base) % s->size) {
- return 0;
- }
-
- return 1;
-}
-
static inline void *get_freepointer(struct kmem_cache *s, void *object)
{
return *(void **)(object + s->offset);
@@ -279,12 +269,14 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
/* Loop over all objects in a slab */
#define for_each_object(__p, __s, __addr, __objects) \
- for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
- __p += (__s)->size)
+ for (__p = fixup_red_left(__s, __addr); \
+ __p < (__addr) + (__objects) * (__s)->size; \
+ __p += (__s)->size)
#define for_each_object_idx(__p, __idx, __s, __addr, __objects) \
- for (__p = (__addr), __idx = 1; __idx <= __objects;\
- __p += (__s)->size, __idx++)
+ for (__p = fixup_red_left(__s, __addr), __idx = 1; \
+ __idx <= __objects; \
+ __p += (__s)->size, __idx++)
/* Determine object index from a given position */
static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
@@ -442,6 +434,22 @@ static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
set_bit(slab_index(p, s, addr), map);
}
+static inline int size_from_object(struct kmem_cache *s)
+{
+ if (s->flags & SLAB_RED_ZONE)
+ return s->size - s->red_left_pad;
+
+ return s->size;
+}
+
+static inline void *restore_red_left(struct kmem_cache *s, void *p)
+{
+ if (s->flags & SLAB_RED_ZONE)
+ p -= s->red_left_pad;
+
+ return p;
+}
+
/*
* Debug settings:
*/
@@ -475,6 +483,26 @@ static inline void metadata_access_disable(void)
/*
* Object debugging
*/
+
+/* Verify that a pointer has an address that is valid within a slab page */
+static inline int check_valid_pointer(struct kmem_cache *s,
+ struct page *page, void *object)
+{
+ void *base;
+
+ if (!object)
+ return 1;
+
+ base = page_address(page);
+ object = restore_red_left(s, object);
+ if (object < base || object >= base + page->objects * s->size ||
+ (object - base) % s->size) {
+ return 0;
+ }
+
+ return 1;
+}
+
static void print_section(char *text, u8 *addr, unsigned int length)
{
metadata_access_enable();
@@ -614,7 +642,9 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
pr_err("INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
p, p - addr, get_freepointer(s, p));
- if (p > addr + 16)
+ if (s->flags & SLAB_RED_ZONE)
+ print_section("Redzone ", p - s->red_left_pad, s->red_left_pad);
+ else if (p > addr + 16)
print_section("Bytes b4 ", p - 16, 16);
print_section("Object ", p, min_t(unsigned long, s->object_size,
@@ -631,9 +661,9 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
if (s->flags & SLAB_STORE_USER)
off += 2 * sizeof(struct track);
- if (off != s->size)
+ if (off != size_from_object(s))
/* Beginning of the filler is the free pointer */
- print_section("Padding ", p + off, s->size - off);
+ print_section("Padding ", p + off, size_from_object(s) - off);
dump_stack();
}
@@ -663,6 +693,9 @@ static void init_object(struct kmem_cache *s, void *object, u8 val)
{
u8 *p = object;
+ if (s->flags & SLAB_RED_ZONE)
+ memset(p - s->red_left_pad, val, s->red_left_pad);
+
if (s->flags & __OBJECT_POISON) {
memset(p, POISON_FREE, s->object_size - 1);
p[s->object_size - 1] = POISON_END;
@@ -755,11 +788,11 @@ static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
/* We also have user information there */
off += 2 * sizeof(struct track);
- if (s->size == off)
+ if (size_from_object(s) == off)
return 1;
return check_bytes_and_report(s, page, p, "Object padding",
- p + off, POISON_INUSE, s->size - off);
+ p + off, POISON_INUSE, size_from_object(s) - off);
}
/* Check the pad bytes at the end of a slab page */
@@ -804,6 +837,10 @@ static int check_object(struct kmem_cache *s, struct page *page,
if (s->flags & SLAB_RED_ZONE) {
if (!check_bytes_and_report(s, page, object, "Redzone",
+ object - s->red_left_pad, val, s->red_left_pad))
+ return 0;
+
+ if (!check_bytes_and_report(s, page, object, "Redzone",
endobject, val, s->inuse - s->object_size))
return 0;
} else {
@@ -1445,7 +1482,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
set_freepointer(s, p, NULL);
}
- page->freelist = start;
+ page->freelist = fixup_red_left(s, start);
page->inuse = page->objects;
page->frozen = 1;
@@ -3274,7 +3311,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
*/
size += 2 * sizeof(struct track);
- if (flags & SLAB_RED_ZONE)
+ if (flags & SLAB_RED_ZONE) {
/*
* Add some empty padding so that we can catch
* overwrites from earlier objects rather than let
@@ -3283,6 +3320,11 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
* of the object.
*/
size += sizeof(void *);
+
+ s->red_left_pad = sizeof(void *);
+ s->red_left_pad = ALIGN(s->red_left_pad, s->align);
+ size += s->red_left_pad;
+ }
#endif
/*
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-28 23:26:19 +0300