mm: kmemleak: split __create_object into two functions

__create_object() consists of two part, the first part allocate a kmemleak
object and initialize it, the second part insert it into object tree.
This function need kmemleak_lock but actually only the second part need
lock.

Split it into two functions, the first function __alloc_object only
allocate a kmemleak object, and the second function __link_object() will
initialize the object and insert it into object tree, use the
kmemleak_lock to protect __link_object() only.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20231018102952.3339837-5-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Patrick Wang <patrick.wang.shcn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 289b3be..39732dc 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -623,25 +623,15 @@ static noinline depot_stack_handle_t set_track_prepare(void)
        return trace_handle;
 }
 
-/*
- * Create the metadata (struct kmemleak_object) corresponding to an allocated
- * memory block and add it to the object_list and object_tree_root (or
- * object_phys_tree_root).
- */
-static void __create_object(unsigned long ptr, size_t size,
-                           int min_count, gfp_t gfp, bool is_phys)
+static struct kmemleak_object *__alloc_object(gfp_t gfp)
 {
-       unsigned long flags;
-       struct kmemleak_object *object, *parent;
-       struct rb_node **link, *rb_parent;
-       unsigned long untagged_ptr;
-       unsigned long untagged_objp;
+       struct kmemleak_object *object;
 
        object = mem_pool_alloc(gfp);
        if (!object) {
                pr_warn("Cannot allocate a kmemleak_object structure\n");
                kmemleak_disable();
-               return;
+               return NULL;
        }
 
        INIT_LIST_HEAD(&object->object_list);
@@ -649,13 +639,8 @@ static void __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 | (is_phys ? OBJECT_PHYS : 0);
-       object->pointer = ptr;
-       object->size = kfence_ksize((void *)ptr) ?: size;
        object->excess_ref = 0;
-       object->min_count = min_count;
        object->count = 0;                      /* white color initially */
-       object->jiffies = jiffies;
        object->checksum = 0;
        object->del_state = 0;
 
@@ -680,7 +665,23 @@ static void __create_object(unsigned long ptr, size_t size,
        /* kernel backtrace */
        object->trace_handle = set_track_prepare();
 
-       raw_spin_lock_irqsave(&kmemleak_lock, flags);
+       return object;
+}
+
+static void __link_object(struct kmemleak_object *object, unsigned long ptr,
+                         size_t size, int min_count, bool is_phys)
+{
+
+       struct kmemleak_object *parent;
+       struct rb_node **link, *rb_parent;
+       unsigned long untagged_ptr;
+       unsigned long untagged_objp;
+
+       object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0);
+       object->pointer = ptr;
+       object->size = kfence_ksize((void *)ptr) ?: size;
+       object->min_count = min_count;
+       object->jiffies = jiffies;
 
        untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr);
        /*
@@ -711,14 +712,32 @@ static void __create_object(unsigned long ptr, size_t size,
                         */
                        dump_object_info(parent);
                        kmem_cache_free(object_cache, object);
-                       goto out;
+                       return;
                }
        }
        rb_link_node(&object->rb_node, rb_parent, link);
        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:
+}
+
+/*
+ * Create the metadata (struct kmemleak_object) corresponding to an allocated
+ * memory block and add it to the object_list and object_tree_root (or
+ * object_phys_tree_root).
+ */
+static void __create_object(unsigned long ptr, size_t size,
+                               int min_count, gfp_t gfp, bool is_phys)
+{
+       struct kmemleak_object *object;
+       unsigned long flags;
+
+       object = __alloc_object(gfp);
+       if (!object)
+               return;
+
+       raw_spin_lock_irqsave(&kmemleak_lock, flags);
+       __link_object(object, ptr, size, min_count, is_phys);
        raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
 }