mm: kmemleak: check physical address when scan

Check the physical address of objects for its boundary when scan instead
of in kmemleak_*_phys().

Link: https://lkml.kernel.org/r/20220611035551.1823303-5-patrick.wang.shcn@gmail.com
Fixes: 23c2d497de21 ("mm: kmemleak: take a full lowmem check in kmemleak_*_phys()")
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 ee94b02..4661266 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1184,7 +1184,7 @@ 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)
+       if (kmemleak_enabled)
                /*
                 * Create object with OBJECT_PHYS flag and
                 * assume min_count 0.
@@ -1204,7 +1204,7 @@ 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)
+       if (kmemleak_enabled)
                delete_object_part((unsigned long)phys, size, true);
 }
 EXPORT_SYMBOL(kmemleak_free_part_phys);
@@ -1218,7 +1218,7 @@ 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)
+       if (kmemleak_enabled)
                make_black_object((unsigned long)phys, true);
 }
 EXPORT_SYMBOL(kmemleak_ignore_phys);
@@ -1493,6 +1493,17 @@ 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))