mm: kmemleak: add OBJECT_PHYS flag for objects allocated with physical address

Add OBJECT_PHYS flag for object.  This flag is used to identify the
objects allocated with physical address.  The create_object_phys()
function is added as well to set that flag and is used by
kmemleak_alloc_phys().

Link: https://lkml.kernel.org/r/20220611035551.1823303-3-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>

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 156eafa..d82d8db 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -172,6 +172,8 @@ 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 */
@@ -574,8 +576,9 @@ 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.
  */
-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 +598,7 @@ 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;
@@ -662,6 +665,20 @@ 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().
  */
@@ -728,11 +745,11 @@ 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, object->flags & OBJECT_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, object->flags & OBJECT_PHYS);
 
        __delete_object(object);
 }
@@ -1129,9 +1146,14 @@ EXPORT_SYMBOL(kmemleak_no_scan);
  */
 void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp)
 {
+       pr_debug("%s(0x%pa, %zu)\n", __func__, &phys, size);
+
        if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
-               /* assume min_count 0 */
-               kmemleak_alloc(__va(phys), size, 0, gfp);
+               /*
+                * Create object with OBJECT_PHYS flag and
+                * assume min_count 0.
+                */
+               create_object_phys((unsigned long)__va(phys), size, 0, gfp);
 }
 EXPORT_SYMBOL(kmemleak_alloc_phys);