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-rw-r--r--mm/kmemleak.c260
1 files changed, 183 insertions, 77 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index a182f5ddaf68..1eddc0132f7f 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -14,14 +14,16 @@
* The following locks and mutexes are used by kmemleak:
*
* - kmemleak_lock (raw_spinlock_t): protects the object_list modifications and
- * accesses to the object_tree_root. The object_list is the main list
- * holding the metadata (struct kmemleak_object) for the allocated memory
- * blocks. The object_tree_root is a red black tree used to look-up
- * metadata based on a pointer to the corresponding memory block. The
- * kmemleak_object structures are added to the object_list and
- * object_tree_root in the create_object() function called from the
- * kmemleak_alloc() callback and removed in delete_object() called from the
- * kmemleak_free() callback
+ * accesses to the object_tree_root (or object_phys_tree_root). The
+ * object_list is the main list holding the metadata (struct kmemleak_object)
+ * for the allocated memory blocks. The object_tree_root and object_phys_tree_root
+ * are red black trees used to look-up metadata based on a pointer to the
+ * corresponding memory block. The object_phys_tree_root is for objects
+ * allocated with physical address. The kmemleak_object structures are
+ * added to the object_list and object_tree_root (or object_phys_tree_root)
+ * in the create_object() function called from the kmemleak_alloc() (or
+ * kmemleak_alloc_phys()) callback and removed in delete_object() called from
+ * the kmemleak_free() callback
* - kmemleak_object.lock (raw_spinlock_t): protects a kmemleak_object.
* Accesses to the metadata (e.g. count) are protected by this lock. Note
* that some members of this structure may be protected by other means
@@ -172,6 +174,8 @@ struct kmemleak_object {
#define OBJECT_NO_SCAN (1 << 2)
/* flag set to fully scan the object when scan_area allocation failed */
#define OBJECT_FULL_SCAN (1 << 3)
+/* flag set for object allocated with physical address */
+#define OBJECT_PHYS (1 << 4)
#define HEX_PREFIX " "
/* number of bytes to print per line; must be 16 or 32 */
@@ -193,7 +197,9 @@ static int mem_pool_free_count = ARRAY_SIZE(mem_pool);
static LIST_HEAD(mem_pool_free_list);
/* search tree for object boundaries */
static struct rb_root object_tree_root = RB_ROOT;
-/* protecting the access to object_list and object_tree_root */
+/* search tree for object (with OBJECT_PHYS flag) boundaries */
+static struct rb_root object_phys_tree_root = RB_ROOT;
+/* protecting the access to object_list, object_tree_root (or object_phys_tree_root) */
static DEFINE_RAW_SPINLOCK(kmemleak_lock);
/* allocation caches for kmemleak internal data */
@@ -285,6 +291,9 @@ static void hex_dump_object(struct seq_file *seq,
const u8 *ptr = (const u8 *)object->pointer;
size_t len;
+ if (WARN_ON_ONCE(object->flags & OBJECT_PHYS))
+ return;
+
/* limit the number of lines to HEX_MAX_LINES */
len = min_t(size_t, object->size, HEX_MAX_LINES * HEX_ROW_SIZE);
@@ -378,9 +387,11 @@ static void dump_object_info(struct kmemleak_object *object)
* beginning of the memory block are allowed. The kmemleak_lock must be held
* when calling this function.
*/
-static struct kmemleak_object *lookup_object(unsigned long ptr, int alias)
+static struct kmemleak_object *__lookup_object(unsigned long ptr, int alias,
+ bool is_phys)
{
- struct rb_node *rb = object_tree_root.rb_node;
+ struct rb_node *rb = is_phys ? object_phys_tree_root.rb_node :
+ object_tree_root.rb_node;
unsigned long untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr);
while (rb) {
@@ -406,6 +417,12 @@ static struct kmemleak_object *lookup_object(unsigned long ptr, int alias)
return NULL;
}
+/* Look-up a kmemleak object which allocated with virtual address. */
+static struct kmemleak_object *lookup_object(unsigned long ptr, int alias)
+{
+ return __lookup_object(ptr, alias, false);
+}
+
/*
* Increment the object use_count. Return 1 if successful or 0 otherwise. Note
* that once an object's use_count reached 0, the RCU freeing was already
@@ -515,14 +532,15 @@ static void put_object(struct kmemleak_object *object)
/*
* Look up an object in the object search tree and increase its use_count.
*/
-static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
+static struct kmemleak_object *__find_and_get_object(unsigned long ptr, int alias,
+ bool is_phys)
{
unsigned long flags;
struct kmemleak_object *object;
rcu_read_lock();
raw_spin_lock_irqsave(&kmemleak_lock, flags);
- object = lookup_object(ptr, alias);
+ object = __lookup_object(ptr, alias, is_phys);
raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
/* check whether the object is still available */
@@ -533,28 +551,39 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
return object;
}
+/* Look up and get an object which allocated with virtual address. */
+static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
+{
+ return __find_and_get_object(ptr, alias, false);
+}
+
/*
- * Remove an object from the object_tree_root and object_list. Must be called
- * with the kmemleak_lock held _if_ kmemleak is still enabled.
+ * Remove an object from the object_tree_root (or object_phys_tree_root)
+ * and object_list. Must be called with the kmemleak_lock held _if_ kmemleak
+ * is still enabled.
*/
static void __remove_object(struct kmemleak_object *object)
{
- rb_erase(&object->rb_node, &object_tree_root);
+ rb_erase(&object->rb_node, object->flags & OBJECT_PHYS ?
+ &object_phys_tree_root :
+ &object_tree_root);
list_del_rcu(&object->object_list);
}
/*
* Look up an object in the object search tree and remove it from both
- * object_tree_root and object_list. The returned object's use_count should be
- * at least 1, as initially set by create_object().
+ * object_tree_root (or object_phys_tree_root) and object_list. The
+ * returned object's use_count should be at least 1, as initially set
+ * by create_object().
*/
-static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int alias)
+static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int alias,
+ bool is_phys)
{
unsigned long flags;
struct kmemleak_object *object;
raw_spin_lock_irqsave(&kmemleak_lock, flags);
- object = lookup_object(ptr, alias);
+ object = __lookup_object(ptr, alias, is_phys);
if (object)
__remove_object(object);
raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
@@ -572,10 +601,12 @@ static int __save_stack_trace(unsigned long *trace)
/*
* Create the metadata (struct kmemleak_object) corresponding to an allocated
- * memory block and add it to the object_list and object_tree_root.
+ * memory block and add it to the object_list and object_tree_root (or
+ * object_phys_tree_root).
*/
-static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
- int min_count, gfp_t gfp)
+static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp,
+ bool is_phys)
{
unsigned long flags;
struct kmemleak_object *object, *parent;
@@ -595,7 +626,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
INIT_HLIST_HEAD(&object->area_list);
raw_spin_lock_init(&object->lock);
atomic_set(&object->use_count, 1);
- object->flags = OBJECT_ALLOCATED;
+ object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0);
object->pointer = ptr;
object->size = kfence_ksize((void *)ptr) ?: size;
object->excess_ref = 0;
@@ -628,9 +659,16 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
raw_spin_lock_irqsave(&kmemleak_lock, flags);
untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr);
- min_addr = min(min_addr, untagged_ptr);
- max_addr = max(max_addr, untagged_ptr + size);
- link = &object_tree_root.rb_node;
+ /*
+ * Only update min_addr and max_addr with object
+ * storing virtual address.
+ */
+ if (!is_phys) {
+ min_addr = min(min_addr, untagged_ptr);
+ max_addr = max(max_addr, untagged_ptr + size);
+ }
+ link = is_phys ? &object_phys_tree_root.rb_node :
+ &object_tree_root.rb_node;
rb_parent = NULL;
while (*link) {
rb_parent = *link;
@@ -654,7 +692,8 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
}
}
rb_link_node(&object->rb_node, rb_parent, link);
- rb_insert_color(&object->rb_node, &object_tree_root);
+ rb_insert_color(&object->rb_node, is_phys ? &object_phys_tree_root :
+ &object_tree_root);
list_add_tail_rcu(&object->object_list, &object_list);
out:
@@ -662,6 +701,20 @@ out:
return object;
}
+/* Create kmemleak object which allocated with virtual address. */
+static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp)
+{
+ return __create_object(ptr, size, min_count, gfp, false);
+}
+
+/* Create kmemleak object which allocated with physical address. */
+static struct kmemleak_object *create_object_phys(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp)
+{
+ return __create_object(ptr, size, min_count, gfp, true);
+}
+
/*
* Mark the object as not allocated and schedule RCU freeing via put_object().
*/
@@ -690,7 +743,7 @@ static void delete_object_full(unsigned long ptr)
{
struct kmemleak_object *object;
- object = find_and_remove_object(ptr, 0);
+ object = find_and_remove_object(ptr, 0, false);
if (!object) {
#ifdef DEBUG
kmemleak_warn("Freeing unknown object at 0x%08lx\n",
@@ -706,12 +759,12 @@ static void delete_object_full(unsigned long ptr)
* delete it. If the memory block is partially freed, the function may create
* additional metadata for the remaining parts of the block.
*/
-static void delete_object_part(unsigned long ptr, size_t size)
+static void delete_object_part(unsigned long ptr, size_t size, bool is_phys)
{
struct kmemleak_object *object;
unsigned long start, end;
- object = find_and_remove_object(ptr, 1);
+ object = find_and_remove_object(ptr, 1, is_phys);
if (!object) {
#ifdef DEBUG
kmemleak_warn("Partially freeing unknown object at 0x%08lx (size %zu)\n",
@@ -728,11 +781,11 @@ static void delete_object_part(unsigned long ptr, size_t size)
start = object->pointer;
end = object->pointer + object->size;
if (ptr > start)
- create_object(start, ptr - start, object->min_count,
- GFP_KERNEL);
+ __create_object(start, ptr - start, object->min_count,
+ GFP_KERNEL, is_phys);
if (ptr + size < end)
- create_object(ptr + size, end - ptr - size, object->min_count,
- GFP_KERNEL);
+ __create_object(ptr + size, end - ptr - size, object->min_count,
+ GFP_KERNEL, is_phys);
__delete_object(object);
}
@@ -753,11 +806,11 @@ static void paint_it(struct kmemleak_object *object, int color)
raw_spin_unlock_irqrestore(&object->lock, flags);
}
-static void paint_ptr(unsigned long ptr, int color)
+static void paint_ptr(unsigned long ptr, int color, bool is_phys)
{
struct kmemleak_object *object;
- object = find_and_get_object(ptr, 0);
+ object = __find_and_get_object(ptr, 0, is_phys);
if (!object) {
kmemleak_warn("Trying to color unknown object at 0x%08lx as %s\n",
ptr,
@@ -775,16 +828,16 @@ static void paint_ptr(unsigned long ptr, int color)
*/
static void make_gray_object(unsigned long ptr)
{
- paint_ptr(ptr, KMEMLEAK_GREY);
+ paint_ptr(ptr, KMEMLEAK_GREY, false);
}
/*
* Mark the object as black-colored so that it is ignored from scans and
* reporting.
*/
-static void make_black_object(unsigned long ptr)
+static void make_black_object(unsigned long ptr, bool is_phys)
{
- paint_ptr(ptr, KMEMLEAK_BLACK);
+ paint_ptr(ptr, KMEMLEAK_BLACK, is_phys);
}
/*
@@ -990,7 +1043,7 @@ void __ref kmemleak_free_part(const void *ptr, size_t size)
pr_debug("%s(0x%p)\n", __func__, ptr);
if (kmemleak_enabled && ptr && !IS_ERR(ptr))
- delete_object_part((unsigned long)ptr, size);
+ delete_object_part((unsigned long)ptr, size, false);
}
EXPORT_SYMBOL_GPL(kmemleak_free_part);
@@ -1078,7 +1131,7 @@ void __ref kmemleak_ignore(const void *ptr)
pr_debug("%s(0x%p)\n", __func__, ptr);
if (kmemleak_enabled && ptr && !IS_ERR(ptr))
- make_black_object((unsigned long)ptr);
+ make_black_object((unsigned long)ptr, false);
}
EXPORT_SYMBOL(kmemleak_ignore);
@@ -1125,15 +1178,18 @@ EXPORT_SYMBOL(kmemleak_no_scan);
* address argument
* @phys: physical address of the object
* @size: size of the object
- * @min_count: minimum number of references to this object.
- * See kmemleak_alloc()
* @gfp: kmalloc() flags used for kmemleak internal memory allocations
*/
-void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
- gfp_t gfp)
+void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_alloc(__va(phys), size, min_count, gfp);
+ pr_debug("%s(0x%pa, %zu)\n", __func__, &phys, size);
+
+ if (kmemleak_enabled)
+ /*
+ * Create object with OBJECT_PHYS flag and
+ * assume min_count 0.
+ */
+ create_object_phys((unsigned long)phys, size, 0, gfp);
}
EXPORT_SYMBOL(kmemleak_alloc_phys);
@@ -1146,22 +1202,12 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
*/
void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_free_part(__va(phys), size);
-}
-EXPORT_SYMBOL(kmemleak_free_part_phys);
+ pr_debug("%s(0x%pa)\n", __func__, &phys);
-/**
- * kmemleak_not_leak_phys - similar to kmemleak_not_leak but taking a physical
- * address argument
- * @phys: physical address of the object
- */
-void __ref kmemleak_not_leak_phys(phys_addr_t phys)
-{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_not_leak(__va(phys));
+ if (kmemleak_enabled)
+ delete_object_part((unsigned long)phys, size, true);
}
-EXPORT_SYMBOL(kmemleak_not_leak_phys);
+EXPORT_SYMBOL(kmemleak_free_part_phys);
/**
* kmemleak_ignore_phys - similar to kmemleak_ignore but taking a physical
@@ -1170,8 +1216,10 @@ EXPORT_SYMBOL(kmemleak_not_leak_phys);
*/
void __ref kmemleak_ignore_phys(phys_addr_t phys)
{
- if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
- kmemleak_ignore(__va(phys));
+ pr_debug("%s(0x%pa)\n", __func__, &phys);
+
+ if (kmemleak_enabled)
+ make_black_object((unsigned long)phys, true);
}
EXPORT_SYMBOL(kmemleak_ignore_phys);
@@ -1182,6 +1230,9 @@ static bool update_checksum(struct kmemleak_object *object)
{
u32 old_csum = object->checksum;
+ if (WARN_ON_ONCE(object->flags & OBJECT_PHYS))
+ return false;
+
kasan_disable_current();
kcsan_disable_current();
object->checksum = crc32(0, kasan_reset_tag((void *)object->pointer), object->size);
@@ -1335,6 +1386,7 @@ static void scan_object(struct kmemleak_object *object)
{
struct kmemleak_scan_area *area;
unsigned long flags;
+ void *obj_ptr;
/*
* Once the object->lock is acquired, the corresponding memory block
@@ -1346,10 +1398,15 @@ static void scan_object(struct kmemleak_object *object)
if (!(object->flags & OBJECT_ALLOCATED))
/* already freed object */
goto out;
+
+ obj_ptr = object->flags & OBJECT_PHYS ?
+ __va((phys_addr_t)object->pointer) :
+ (void *)object->pointer;
+
if (hlist_empty(&object->area_list) ||
object->flags & OBJECT_FULL_SCAN) {
- void *start = (void *)object->pointer;
- void *end = (void *)(object->pointer + object->size);
+ void *start = obj_ptr;
+ void *end = obj_ptr + object->size;
void *next;
do {
@@ -1413,18 +1470,21 @@ static void scan_gray_list(void)
*/
static void kmemleak_scan(void)
{
- unsigned long flags;
struct kmemleak_object *object;
struct zone *zone;
int __maybe_unused i;
int new_leaks = 0;
+ int loop1_cnt = 0;
jiffies_last_scan = jiffies;
/* prepare the kmemleak_object's */
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- raw_spin_lock_irqsave(&object->lock, flags);
+ bool obj_pinned = false;
+
+ loop1_cnt++;
+ raw_spin_lock_irq(&object->lock);
#ifdef DEBUG
/*
* With a few exceptions there should be a maximum of
@@ -1436,12 +1496,45 @@ static void kmemleak_scan(void)
dump_object_info(object);
}
#endif
+
+ /* ignore objects outside lowmem (paint them black) */
+ if ((object->flags & OBJECT_PHYS) &&
+ !(object->flags & OBJECT_NO_SCAN)) {
+ unsigned long phys = object->pointer;
+
+ if (PHYS_PFN(phys) < min_low_pfn ||
+ PHYS_PFN(phys + object->size) >= max_low_pfn)
+ __paint_it(object, KMEMLEAK_BLACK);
+ }
+
/* reset the reference count (whiten the object) */
object->count = 0;
- if (color_gray(object) && get_object(object))
+ if (color_gray(object) && get_object(object)) {
list_add_tail(&object->gray_list, &gray_list);
+ obj_pinned = true;
+ }
- raw_spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irq(&object->lock);
+
+ /*
+ * Do a cond_resched() to avoid soft lockup every 64k objects.
+ * Make sure a reference has been taken so that the object
+ * won't go away without RCU read lock.
+ */
+ if (!(loop1_cnt & 0xffff)) {
+ if (!obj_pinned && !get_object(object)) {
+ /* Try the next object instead */
+ loop1_cnt--;
+ continue;
+ }
+
+ rcu_read_unlock();
+ cond_resched();
+ rcu_read_lock();
+
+ if (!obj_pinned)
+ put_object(object);
+ }
}
rcu_read_unlock();
@@ -1509,14 +1602,21 @@ static void kmemleak_scan(void)
*/
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- raw_spin_lock_irqsave(&object->lock, flags);
+ /*
+ * This is racy but we can save the overhead of lock/unlock
+ * calls. The missed objects, if any, should be caught in
+ * the next scan.
+ */
+ if (!color_white(object))
+ continue;
+ raw_spin_lock_irq(&object->lock);
if (color_white(object) && (object->flags & OBJECT_ALLOCATED)
&& update_checksum(object) && get_object(object)) {
/* color it gray temporarily */
object->count = object->min_count;
list_add_tail(&object->gray_list, &gray_list);
}
- raw_spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irq(&object->lock);
}
rcu_read_unlock();
@@ -1536,7 +1636,14 @@ static void kmemleak_scan(void)
*/
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- raw_spin_lock_irqsave(&object->lock, flags);
+ /*
+ * This is racy but we can save the overhead of lock/unlock
+ * calls. The missed objects, if any, should be caught in
+ * the next scan.
+ */
+ if (!color_white(object))
+ continue;
+ raw_spin_lock_irq(&object->lock);
if (unreferenced_object(object) &&
!(object->flags & OBJECT_REPORTED)) {
object->flags |= OBJECT_REPORTED;
@@ -1546,7 +1653,7 @@ static void kmemleak_scan(void)
new_leaks++;
}
- raw_spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irq(&object->lock);
}
rcu_read_unlock();
@@ -1748,15 +1855,14 @@ static int dump_str_object_info(const char *str)
static void kmemleak_clear(void)
{
struct kmemleak_object *object;
- unsigned long flags;
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- raw_spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irq(&object->lock);
if ((object->flags & OBJECT_REPORTED) &&
unreferenced_object(object))
__paint_it(object, KMEMLEAK_GREY);
- raw_spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irq(&object->lock);
}
rcu_read_unlock();