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mm: kmemleak: add rbtree and store physical address for objects allocated with PA

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Add object_phys_tree_root to store the objects allocated with physical
address.  Distinguish it from object_tree_root by OBJECT_PHYS flag or
function argument.  The physical address is stored directly in those
objects.

Link: https://lkml.kernel.org/r/20220611035551.1823303-4-patrick.wang.shcn@gmail.com
Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Patrick Wang 2022-06-11 11:55:50 +08:00 committed by akpm
parent 8e0c4ab36c
commit 0c24e06119
1 changed files with 91 additions and 42 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

129
mm/kmemleak.c
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@ -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
@ -195,7 +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 */
@ -287,6 +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);
@ -380,9 +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) {
@ -408,6 +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
@ -517,14 +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 */
@ -535,28 +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);
@ -574,7 +601,8 @@ 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,
@ -631,9 +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);
/*
* 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 = &object_tree_root.rb_node;
}
link = is_phys ? &object_phys_tree_root.rb_node :
&object_tree_root.rb_node;
rb_parent = NULL;
while (*link) {
rb_parent = *link;
@ -657,7 +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:
@ -707,7 +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",
@ -723,12 +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",
@ -746,10 +782,10 @@ static void delete_object_part(unsigned long ptr, size_t size)
end = object->pointer + object->size;
if (ptr > start)
__create_object(start, ptr - start, object->min_count,
GFP_KERNEL, object->flags & OBJECT_PHYS);
GFP_KERNEL, is_phys);
if (ptr + size < end)
__create_object(ptr + size, end - ptr - size, object->min_count,
GFP_KERNEL, object->flags & OBJECT_PHYS);
GFP_KERNEL, is_phys);
__delete_object(object);
}
@ -770,11 +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,
@ -792,16 +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);
}
/*
@ -1007,7 +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);
@ -1095,7 +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);
@ -1153,7 +1189,7 @@ void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp)
* Create object with OBJECT_PHYS flag and
* assume min_count 0.
*/
create_object_phys((unsigned long)__va(phys), size, 0, gfp);
create_object_phys((unsigned long)phys, size, 0, gfp);
}
EXPORT_SYMBOL(kmemleak_alloc_phys);
@ -1166,8 +1202,10 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
*/
void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
{
pr_debug("%s(0x%pa)\n", __func__, &phys);
if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
kmemleak_free_part(__va(phys), size);
delete_object_part((unsigned long)phys, size, true);
}
EXPORT_SYMBOL(kmemleak_free_part_phys);
@ -1178,8 +1216,10 @@ EXPORT_SYMBOL(kmemleak_free_part_phys);
*/
void __ref kmemleak_ignore_phys(phys_addr_t phys)
{
pr_debug("%s(0x%pa)\n", __func__, &phys);
if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
kmemleak_ignore(__va(phys));
make_black_object((unsigned long)phys, true);
}
EXPORT_SYMBOL(kmemleak_ignore_phys);
@ -1190,6 +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);
@ -1343,6 +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
@ -1354,10 +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 {