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Diffstat (limited to 'mm')
-rw-r--r--mm/slab_common.c3
-rw-r--r--mm/slub.c154
2 files changed, 119 insertions, 38 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 46b2df8a7532..82c10b4d1203 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -661,7 +661,8 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
if (!s)
panic("Out of memory when creating slab %s\n", name);
- create_boot_cache(s, name, size, flags, useroffset, usersize);
+ create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,
+ usersize);
kasan_cache_create_kmalloc(s);
list_add(&s->list, &slab_caches);
s->refcount = 1;
diff --git a/mm/slub.c b/mm/slub.c
index 4aa18dd9c4e2..f5ebd177293a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -194,11 +194,24 @@ DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
#endif
#endif /* CONFIG_SLUB_DEBUG */
+/* Structure holding parameters for get_partial() call chain */
+struct partial_context {
+ struct slab **slab;
+ gfp_t flags;
+ unsigned int orig_size;
+};
+
static inline bool kmem_cache_debug(struct kmem_cache *s)
{
return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
}
+static inline bool slub_debug_orig_size(struct kmem_cache *s)
+{
+ return (kmem_cache_debug_flags(s, SLAB_STORE_USER) &&
+ (s->flags & SLAB_KMALLOC));
+}
+
void *fixup_red_left(struct kmem_cache *s, void *p)
{
if (kmem_cache_debug_flags(s, SLAB_RED_ZONE))
@@ -790,6 +803,39 @@ static void print_slab_info(const struct slab *slab)
folio_flags(folio, 0));
}
+/*
+ * kmalloc caches has fixed sizes (mostly power of 2), and kmalloc() API
+ * family will round up the real request size to these fixed ones, so
+ * there could be an extra area than what is requested. Save the original
+ * request size in the meta data area, for better debug and sanity check.
+ */
+static inline void set_orig_size(struct kmem_cache *s,
+ void *object, unsigned int orig_size)
+{
+ void *p = kasan_reset_tag(object);
+
+ if (!slub_debug_orig_size(s))
+ return;
+
+ p += get_info_end(s);
+ p += sizeof(struct track) * 2;
+
+ *(unsigned int *)p = orig_size;
+}
+
+static inline unsigned int get_orig_size(struct kmem_cache *s, void *object)
+{
+ void *p = kasan_reset_tag(object);
+
+ if (!slub_debug_orig_size(s))
+ return s->object_size;
+
+ p += get_info_end(s);
+ p += sizeof(struct track) * 2;
+
+ return *(unsigned int *)p;
+}
+
static void slab_bug(struct kmem_cache *s, char *fmt, ...)
{
struct va_format vaf;
@@ -849,6 +895,9 @@ static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p)
if (s->flags & SLAB_STORE_USER)
off += 2 * sizeof(struct track);
+ if (slub_debug_orig_size(s))
+ off += sizeof(unsigned int);
+
off += kasan_metadata_size(s);
if (off != size_from_object(s))
@@ -982,7 +1031,8 @@ skip_bug_print:
*
* A. Free pointer (if we cannot overwrite object on free)
* B. Tracking data for SLAB_STORE_USER
- * C. Padding to reach required alignment boundary or at minimum
+ * C. Original request size for kmalloc object (SLAB_STORE_USER enabled)
+ * D. Padding to reach required alignment boundary or at minimum
* one word if debugging is on to be able to detect writes
* before the word boundary.
*
@@ -1000,10 +1050,14 @@ static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p)
{
unsigned long off = get_info_end(s); /* The end of info */
- if (s->flags & SLAB_STORE_USER)
+ if (s->flags & SLAB_STORE_USER) {
/* We also have user information there */
off += 2 * sizeof(struct track);
+ if (s->flags & SLAB_KMALLOC)
+ off += sizeof(unsigned int);
+ }
+
off += kasan_metadata_size(s);
if (size_from_object(s) == off)
@@ -1298,7 +1352,7 @@ static inline int alloc_consistency_checks(struct kmem_cache *s,
}
static noinline int alloc_debug_processing(struct kmem_cache *s,
- struct slab *slab, void *object)
+ struct slab *slab, void *object, int orig_size)
{
if (s->flags & SLAB_CONSISTENCY_CHECKS) {
if (!alloc_consistency_checks(s, slab, object))
@@ -1307,6 +1361,7 @@ static noinline int alloc_debug_processing(struct kmem_cache *s,
/* Success. Perform special debug activities for allocs */
trace(s, slab, object, 1);
+ set_orig_size(s, object, orig_size);
init_object(s, object, SLUB_RED_ACTIVE);
return 1;
@@ -1575,7 +1630,7 @@ static inline
void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr) {}
static inline int alloc_debug_processing(struct kmem_cache *s,
- struct slab *slab, void *object) { return 0; }
+ struct slab *slab, void *object, int orig_size) { return 0; }
static inline void free_debug_processing(
struct kmem_cache *s, struct slab *slab,
@@ -2004,7 +2059,7 @@ static inline void remove_partial(struct kmem_cache_node *n,
* it to full list if it was the last free object.
*/
static void *alloc_single_from_partial(struct kmem_cache *s,
- struct kmem_cache_node *n, struct slab *slab)
+ struct kmem_cache_node *n, struct slab *slab, int orig_size)
{
void *object;
@@ -2014,7 +2069,7 @@ static void *alloc_single_from_partial(struct kmem_cache *s,
slab->freelist = get_freepointer(s, object);
slab->inuse++;
- if (!alloc_debug_processing(s, slab, object)) {
+ if (!alloc_debug_processing(s, slab, object, orig_size)) {
remove_partial(n, slab);
return NULL;
}
@@ -2033,7 +2088,7 @@ static void *alloc_single_from_partial(struct kmem_cache *s,
* and put the slab to the partial (or full) list.
*/
static void *alloc_single_from_new_slab(struct kmem_cache *s,
- struct slab *slab)
+ struct slab *slab, int orig_size)
{
int nid = slab_nid(slab);
struct kmem_cache_node *n = get_node(s, nid);
@@ -2045,7 +2100,7 @@ static void *alloc_single_from_new_slab(struct kmem_cache *s,
slab->freelist = get_freepointer(s, object);
slab->inuse = 1;
- if (!alloc_debug_processing(s, slab, object))
+ if (!alloc_debug_processing(s, slab, object, orig_size))
/*
* It's not really expected that this would fail on a
* freshly allocated slab, but a concurrent memory
@@ -2123,7 +2178,7 @@ static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags);
* Try to allocate a partial slab from a specific node.
*/
static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
- struct slab **ret_slab, gfp_t gfpflags)
+ struct partial_context *pc)
{
struct slab *slab, *slab2;
void *object = NULL;
@@ -2143,11 +2198,12 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
list_for_each_entry_safe(slab, slab2, &n->partial, slab_list) {
void *t;
- if (!pfmemalloc_match(slab, gfpflags))
+ if (!pfmemalloc_match(slab, pc->flags))
continue;
if (kmem_cache_debug(s)) {
- object = alloc_single_from_partial(s, n, slab);
+ object = alloc_single_from_partial(s, n, slab,
+ pc->orig_size);
if (object)
break;
continue;
@@ -2158,7 +2214,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
break;
if (!object) {
- *ret_slab = slab;
+ *pc->slab = slab;
stat(s, ALLOC_FROM_PARTIAL);
object = t;
} else {
@@ -2182,14 +2238,13 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
/*
* Get a slab from somewhere. Search in increasing NUMA distances.
*/
-static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
- struct slab **ret_slab)
+static void *get_any_partial(struct kmem_cache *s, struct partial_context *pc)
{
#ifdef CONFIG_NUMA
struct zonelist *zonelist;
struct zoneref *z;
struct zone *zone;
- enum zone_type highest_zoneidx = gfp_zone(flags);
+ enum zone_type highest_zoneidx = gfp_zone(pc->flags);
void *object;
unsigned int cpuset_mems_cookie;
@@ -2217,15 +2272,15 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
do {
cpuset_mems_cookie = read_mems_allowed_begin();
- zonelist = node_zonelist(mempolicy_slab_node(), flags);
+ zonelist = node_zonelist(mempolicy_slab_node(), pc->flags);
for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
struct kmem_cache_node *n;
n = get_node(s, zone_to_nid(zone));
- if (n && cpuset_zone_allowed(zone, flags) &&
+ if (n && cpuset_zone_allowed(zone, pc->flags) &&
n->nr_partial > s->min_partial) {
- object = get_partial_node(s, n, ret_slab, flags);
+ object = get_partial_node(s, n, pc);
if (object) {
/*
* Don't check read_mems_allowed_retry()
@@ -2246,8 +2301,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
/*
* Get a partial slab, lock it and return it.
*/
-static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
- struct slab **ret_slab)
+static void *get_partial(struct kmem_cache *s, int node, struct partial_context *pc)
{
void *object;
int searchnode = node;
@@ -2255,11 +2309,11 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
if (node == NUMA_NO_NODE)
searchnode = numa_mem_id();
- object = get_partial_node(s, get_node(s, searchnode), ret_slab, flags);
+ object = get_partial_node(s, get_node(s, searchnode), pc);
if (object || node != NUMA_NO_NODE)
return object;
- return get_any_partial(s, flags, ret_slab);
+ return get_any_partial(s, pc);
}
#ifdef CONFIG_PREEMPTION
@@ -2980,11 +3034,12 @@ static inline void *get_freelist(struct kmem_cache *s, struct slab *slab)
* already disabled (which is the case for bulk allocation).
*/
static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
- unsigned long addr, struct kmem_cache_cpu *c)
+ unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
{
void *freelist;
struct slab *slab;
unsigned long flags;
+ struct partial_context pc;
stat(s, ALLOC_SLOWPATH);
@@ -3098,7 +3153,10 @@ new_slab:
new_objects:
- freelist = get_partial(s, gfpflags, node, &slab);
+ pc.flags = gfpflags;
+ pc.slab = &slab;
+ pc.orig_size = orig_size;
+ freelist = get_partial(s, node, &pc);
if (freelist)
goto check_new_slab;
@@ -3114,7 +3172,7 @@ new_objects:
stat(s, ALLOC_SLAB);
if (kmem_cache_debug(s)) {
- freelist = alloc_single_from_new_slab(s, slab);
+ freelist = alloc_single_from_new_slab(s, slab, orig_size);
if (unlikely(!freelist))
goto new_objects;
@@ -3146,6 +3204,7 @@ check_new_slab:
*/
if (s->flags & SLAB_STORE_USER)
set_track(s, freelist, TRACK_ALLOC, addr);
+
return freelist;
}
@@ -3188,7 +3247,7 @@ retry_load_slab:
* pointer.
*/
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
- unsigned long addr, struct kmem_cache_cpu *c)
+ unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
{
void *p;
@@ -3201,7 +3260,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
c = slub_get_cpu_ptr(s->cpu_slab);
#endif
- p = ___slab_alloc(s, gfpflags, node, addr, c);
+ p = ___slab_alloc(s, gfpflags, node, addr, c, orig_size);
#ifdef CONFIG_PREEMPT_COUNT
slub_put_cpu_ptr(s->cpu_slab);
#endif
@@ -3286,7 +3345,7 @@ redo:
if (!USE_LOCKLESS_FAST_PATH() ||
unlikely(!object || !slab || !node_match(slab, node))) {
- object = __slab_alloc(s, gfpflags, node, addr, c);
+ object = __slab_alloc(s, gfpflags, node, addr, c, orig_size);
} else {
void *next_object = get_freepointer_safe(s, object);
@@ -3753,7 +3812,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
* of re-populating per CPU c->freelist
*/
p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
- _RET_IP_, c);
+ _RET_IP_, c, s->object_size);
if (unlikely(!p[i]))
goto error;
@@ -4156,12 +4215,17 @@ static int calculate_sizes(struct kmem_cache *s)
}
#ifdef CONFIG_SLUB_DEBUG
- if (flags & SLAB_STORE_USER)
+ if (flags & SLAB_STORE_USER) {
/*
* Need to store information about allocs and frees after
* the object.
*/
size += 2 * sizeof(struct track);
+
+ /* Save the original kmalloc request size */
+ if (flags & SLAB_KMALLOC)
+ size += sizeof(unsigned int);
+ }
#endif
kasan_cache_create(s, &size, &s->flags);
@@ -4945,6 +5009,7 @@ struct location {
depot_stack_handle_t handle;
unsigned long count;
unsigned long addr;
+ unsigned long waste;
long long sum_time;
long min_time;
long max_time;
@@ -4991,13 +5056,15 @@ static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
}
static int add_location(struct loc_track *t, struct kmem_cache *s,
- const struct track *track)
+ const struct track *track,
+ unsigned int orig_size)
{
long start, end, pos;
struct location *l;
- unsigned long caddr, chandle;
+ unsigned long caddr, chandle, cwaste;
unsigned long age = jiffies - track->when;
depot_stack_handle_t handle = 0;
+ unsigned int waste = s->object_size - orig_size;
#ifdef CONFIG_STACKDEPOT
handle = READ_ONCE(track->handle);
@@ -5015,11 +5082,13 @@ static int add_location(struct loc_track *t, struct kmem_cache *s,
if (pos == end)
break;
- caddr = t->loc[pos].addr;
- chandle = t->loc[pos].handle;
- if ((track->addr == caddr) && (handle == chandle)) {
+ l = &t->loc[pos];
+ caddr = l->addr;
+ chandle = l->handle;
+ cwaste = l->waste;
+ if ((track->addr == caddr) && (handle == chandle) &&
+ (waste == cwaste)) {
- l = &t->loc[pos];
l->count++;
if (track->when) {
l->sum_time += age;
@@ -5044,6 +5113,9 @@ static int add_location(struct loc_track *t, struct kmem_cache *s,
end = pos;
else if (track->addr == caddr && handle < chandle)
end = pos;
+ else if (track->addr == caddr && handle == chandle &&
+ waste < cwaste)
+ end = pos;
else
start = pos;
}
@@ -5067,6 +5139,7 @@ static int add_location(struct loc_track *t, struct kmem_cache *s,
l->min_pid = track->pid;
l->max_pid = track->pid;
l->handle = handle;
+ l->waste = waste;
cpumask_clear(to_cpumask(l->cpus));
cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
nodes_clear(l->nodes);
@@ -5079,13 +5152,16 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
unsigned long *obj_map)
{
void *addr = slab_address(slab);
+ bool is_alloc = (alloc == TRACK_ALLOC);
void *p;
__fill_map(obj_map, s, slab);
for_each_object(p, s, addr, slab->objects)
if (!test_bit(__obj_to_index(s, addr, p), obj_map))
- add_location(t, s, get_track(s, p, alloc));
+ add_location(t, s, get_track(s, p, alloc),
+ is_alloc ? get_orig_size(s, p) :
+ s->object_size);
}
#endif /* CONFIG_DEBUG_FS */
#endif /* CONFIG_SLUB_DEBUG */
@@ -5956,6 +6032,10 @@ static int slab_debugfs_show(struct seq_file *seq, void *v)
else
seq_puts(seq, "<not-available>");
+ if (l->waste)
+ seq_printf(seq, " waste=%lu/%lu",
+ l->count * l->waste, l->waste);
+
if (l->sum_time != l->min_time) {
seq_printf(seq, " age=%ld/%llu/%ld",
l->min_time, div_u64(l->sum_time, l->count),
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 16:46:15 +0000