+ mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: kmemleak: add OBJECT_PHYS flag for objects allocated with physical address
has been added to the -mm mm-unstable branch.  Its filename is
     mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Patrick Wang <patrick.wang.shcn@gmail.com>
Subject: mm: kmemleak: add OBJECT_PHYS flag for objects allocated with physical address
Date: Thu, 9 Jun 2022 20:49:48 +0800

Patch series "mm: kmemleak: store objects allocated with physical address
separately and check when scan", v3.

The kmemleak_*_phys() interface uses "min_low_pfn" and "max_low_pfn" to
check address.  But on some architectures, kmemleak_*_phys() is called
before those two variables initialized.  The following steps will be
taken:

1) Add OBJECT_PHYS flag and rbtree for the objects allocated
   with physical address
2) Store physical address in objects if allocated with OBJECT_PHYS
3) Check the boundary when scan instead of in kmemleak_*_phys()

This patch set will solve:
https://lore.kernel.org/r/20220527032504.30341-1-yee.lee@mediatek.com
https://lore.kernel.org/r/9dd08bb5-f39e-53d8-f88d-bec598a08c93@gmail.com


This patch (of 3):

Add OBJECT_PHYS flag for object.  This flag is used to identify the
objects allocated with physical addresses.  create_object_phys() is added
as well to set that flag.  And remove the min_count argument to
kmemleak_alloc_phys() function, assume it's 0.

Link: https://lkml.kernel.org/r/20220609124950.1694394-1-patrick.wang.shcn@gmail.com
Link: https://lkml.kernel.org/r/20220609124950.1694394-2-patrick.wang.shcn@gmail.com
Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/of/fdt.c                        |    2 -
 include/linux/kmemleak.h                |    4 +-
 mm/kmemleak.c                           |   44 ++++++++++++++++------
 mm/memblock.c                           |   14 +++----
 tools/testing/memblock/linux/kmemleak.h |    2 -
 5 files changed, 43 insertions(+), 23 deletions(-)

--- a/drivers/of/fdt.c~mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address
+++ a/drivers/of/fdt.c
@@ -529,7 +529,7 @@ static int __init __reserved_mem_reserve
 			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
 				uname, &base, (unsigned long)(size / SZ_1M));
 			if (!nomap)
-				kmemleak_alloc_phys(base, size, 0, 0);
+				kmemleak_alloc_phys(base, size, 0);
 		}
 		else
 			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
--- a/include/linux/kmemleak.h~mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address
+++ a/include/linux/kmemleak.h
@@ -29,7 +29,7 @@ extern void kmemleak_not_leak(const void
 extern void kmemleak_ignore(const void *ptr) __ref;
 extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref;
 extern void kmemleak_no_scan(const void *ptr) __ref;
-extern void kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
+extern void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
 				gfp_t gfp) __ref;
 extern void kmemleak_free_part_phys(phys_addr_t phys, size_t size) __ref;
 extern void kmemleak_not_leak_phys(phys_addr_t phys) __ref;
@@ -107,7 +107,7 @@ static inline void kmemleak_no_scan(cons
 {
 }
 static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
-				       int min_count, gfp_t gfp)
+				       gfp_t gfp)
 {
 }
 static inline void kmemleak_free_part_phys(phys_addr_t phys, size_t size)
--- a/mm/kmemleak.c~mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address
+++ a/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 l
  * 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_ob
 	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
 	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);
 }
@@ -1125,15 +1142,18 @@ 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)
 {
+	pr_debug("%s(0x%pa, %zu)\n", __func__, &phys, size);
+
 	if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < max_low_pfn)
-		kmemleak_alloc(__va(phys), size, min_count, 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);
 
--- a/mm/memblock.c~mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address
+++ a/mm/memblock.c
@@ -1345,8 +1345,8 @@ __next_mem_pfn_range_in_zone(u64 *idx, s
  * from the regions with mirroring enabled and then retried from any
  * memory region.
  *
- * In addition, function sets the min_count to 0 using kmemleak_alloc_phys for
- * allocated boot memory block, so that it is never reported as leaks.
+ * In addition, function using kmemleak_alloc_phys for allocated boot
+ * memory block, it is never reported as leaks.
  *
  * Return:
  * Physical address of allocated memory block on success, %0 on failure.
@@ -1398,12 +1398,12 @@ done:
 	 */
 	if (end != MEMBLOCK_ALLOC_NOLEAKTRACE)
 		/*
-		 * The min_count is set to 0 so that memblock allocated
-		 * blocks are never reported as leaks. This is because many
-		 * of these blocks are only referred via the physical
-		 * address which is not looked up by kmemleak.
+		 * Memblock allocated blocks are never reported as
+		 * leaks. This is because many of these blocks are
+		 * only referred via the physical address which is
+		 * not looked up by kmemleak.
 		 */
-		kmemleak_alloc_phys(found, size, 0, 0);
+		kmemleak_alloc_phys(found, size, 0);
 
 	return found;
 }
--- a/tools/testing/memblock/linux/kmemleak.h~mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address
+++ a/tools/testing/memblock/linux/kmemleak.h
@@ -7,7 +7,7 @@ static inline void kmemleak_free_part_ph
 }
 
 static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
-				       int min_count, gfp_t gfp)
+				       gfp_t gfp)
 {
 }
 
_

Patches currently in -mm which might be from patrick.wang.shcn@gmail.com are

mm-kmemleak-add-object_phys-flag-for-objects-allocated-with-physical-address.patch
mm-kmemleak-add-rbtree-and-store-physical-address-for-objects-allocated-with-pa.patch
mm-kmemleak-check-physical-address-when-scan.patch