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>

diff --git a/Documentation/dev-tools/kmemleak.rst b/Documentation/dev-tools/kmemleak.rst
index 1788722..b2391b8 100644 (file)
--- a/Documentation/dev-tools/kmemleak.rst
+++ b/Documentation/dev-tools/kmemleak.rst
@@ -162,6 +162,15 @@ See the include/linux/kmemleak.h header for the functions prototype.
 - ``kmemleak_alloc_recursive`` - as kmemleak_alloc but checks the recursiveness
 - ``kmemleak_free_recursive``   - as kmemleak_free but checks the recursiveness
 
+The following functions take a physical address as the object pointer
+and 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``
+
 Dealing with false positives/negatives
 --------------------------------------
 

diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h
index 4894c68..1c2a328 100644 (file)
--- a/include/linux/kmemleak.h
+++ b/include/linux/kmemleak.h
@@ -38,6 +38,11 @@ extern void kmemleak_not_leak(const void *ptr) __ref;
 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,
+                               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;
+extern void kmemleak_ignore_phys(phys_addr_t phys) __ref;
 
 static inline void kmemleak_alloc_recursive(const void *ptr, size_t size,
                                            int min_count, unsigned long flags,
@@ -106,6 +111,19 @@ static inline void kmemleak_erase(void **ptr)
 static inline void kmemleak_no_scan(const void *ptr)
 {
 }
+static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
+                                      int min_count, gfp_t gfp)
+{
+}
+static inline void kmemleak_free_part_phys(phys_addr_t phys, size_t size)
+{
+}
+static inline void kmemleak_not_leak_phys(phys_addr_t phys)
+{
+}
+static inline void kmemleak_ignore_phys(phys_addr_t phys)
+{
+}
 
 #endif /* CONFIG_DEBUG_KMEMLEAK */
 

diff --git a/mm/bootmem.c b/mm/bootmem.c
index a869f84..e8a55a3 100644 (file)
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -155,7 +155,7 @@ void __init free_bootmem_late(unsigned long physaddr, unsigned long size)
 {
        unsigned long cursor, end;
 
-       kmemleak_free_part(__va(physaddr), size);
+       kmemleak_free_part_phys(physaddr, size);
 
        cursor = PFN_UP(physaddr);
        end = PFN_DOWN(physaddr + size);
@@ -399,7 +399,7 @@ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 {
        unsigned long start, end;
 
-       kmemleak_free_part(__va(physaddr), size);
+       kmemleak_free_part_phys(physaddr, size);
 
        start = PFN_UP(physaddr);
        end = PFN_DOWN(physaddr + size);
@@ -420,7 +420,7 @@ void __init free_bootmem(unsigned long physaddr, unsigned long size)
 {
        unsigned long start, end;
 
-       kmemleak_free_part(__va(physaddr), size);
+       kmemleak_free_part_phys(physaddr, size);
 
        start = PFN_UP(physaddr);
        end = PFN_DOWN(physaddr + size);

diff --git a/mm/cma.c b/mm/cma.c
index bd0e141..384c2cb 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -336,7 +336,7 @@ int __init cma_declare_contiguous(phys_addr_t base,
                 * kmemleak scans/reads tracked objects for pointers to other
                 * objects but this address isn't mapped and accessible
                 */
-               kmemleak_ignore(phys_to_virt(addr));
+               kmemleak_ignore_phys(addr);
                base = addr;
        }
 

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 086292f..a5e453c 100644 (file)
--- 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.
  */

diff --git a/mm/memblock.c b/mm/memblock.c
index c8dfa43..7608bc3 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -723,7 +723,7 @@ int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
                     (unsigned long long)base + size - 1,
                     (void *)_RET_IP_);
 
-       kmemleak_free_part(__va(base), size);
+       kmemleak_free_part_phys(base, size);
        return memblock_remove_range(&memblock.reserved, base, size);
 }
 
@@ -1152,7 +1152,7 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
                 * The min_count is set to 0 so that memblock allocations are
                 * never reported as leaks.
                 */
-               kmemleak_alloc(__va(found), size, 0, 0);
+               kmemleak_alloc_phys(found, size, 0, 0);
                return found;
        }
        return 0;
@@ -1399,7 +1399,7 @@ void __init __memblock_free_early(phys_addr_t base, phys_addr_t size)
        memblock_dbg("%s: [%#016llx-%#016llx] %pF\n",
                     __func__, (u64)base, (u64)base + size - 1,
                     (void *)_RET_IP_);
-       kmemleak_free_part(__va(base), size);
+       kmemleak_free_part_phys(base, size);
        memblock_remove_range(&memblock.reserved, base, size);
 }
 
@@ -1419,7 +1419,7 @@ void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
        memblock_dbg("%s: [%#016llx-%#016llx] %pF\n",
                     __func__, (u64)base, (u64)base + size - 1,
                     (void *)_RET_IP_);
-       kmemleak_free_part(__va(base), size);
+       kmemleak_free_part_phys(base, size);
        cursor = PFN_UP(base);
        end = PFN_DOWN(base + size);
 

diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index ba609b6..487dad6 100644 (file)
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -84,7 +84,7 @@ void __init free_bootmem_late(unsigned long addr, unsigned long size)
 {
        unsigned long cursor, end;
 
-       kmemleak_free_part(__va(addr), size);
+       kmemleak_free_part_phys(addr, size);
 
        cursor = PFN_UP(addr);
        end = PFN_DOWN(addr + size);