mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping

Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a
physical address to a virtual one using __va().  However, such physical
addresses may sometimes be located in highmem and using __va() is
incorrect, leading to inconsistent object tracking in kmemleak.

The following functions have been added to the kmemleak API and they take
a physical address as the object pointer.  They only perform the
corresponding action if the address has a lowmem mapping:

kmemleak_alloc_phys
kmemleak_free_part_phys
kmemleak_not_leak_phys
kmemleak_ignore_phys

The affected calling places have been updated to use the new kmemleak
API.

Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 086292f7c59d..a5e453cf05c4 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -90,6 +90,8 @@
 #include <linux/cache.h>
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/bootmem.h>
+#include <linux/pfn.h>
 #include <linux/mmzone.h>
 #include <linux/slab.h>
 #include <linux/thread_info.h>
@@ -1121,6 +1123,51 @@ void __ref kmemleak_no_scan(const void *ptr)
 }
 EXPORT_SYMBOL(kmemleak_no_scan);
 
+/**
+ * kmemleak_alloc_phys - similar to kmemleak_alloc but taking a physical
+ *			 address argument
+ */
+void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
+			       gfp_t gfp)
+{
+	if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn)
+		kmemleak_alloc(__va(phys), size, min_count, gfp);
+}
+EXPORT_SYMBOL(kmemleak_alloc_phys);
+
+/**
+ * kmemleak_free_part_phys - similar to kmemleak_free_part but taking a
+ *			     physical address argument
+ */
+void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
+{
+	if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn)
+		kmemleak_free_part(__va(phys), size);
+}
+EXPORT_SYMBOL(kmemleak_free_part_phys);
+
+/**
+ * kmemleak_not_leak_phys - similar to kmemleak_not_leak but taking a physical
+ *			    address argument
+ */
+void __ref kmemleak_not_leak_phys(phys_addr_t phys)
+{
+	if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn)
+		kmemleak_not_leak(__va(phys));
+}
+EXPORT_SYMBOL(kmemleak_not_leak_phys);
+
+/**
+ * kmemleak_ignore_phys - similar to kmemleak_ignore but taking a physical
+ *			  address argument
+ */
+void __ref kmemleak_ignore_phys(phys_addr_t phys)
+{
+	if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn)
+		kmemleak_ignore(__va(phys));
+}
+EXPORT_SYMBOL(kmemleak_ignore_phys);
+
 /*
  * Update an object's checksum and return true if it was modified.
  */