From 94f4a1618b4c2b268f9e70bd1516932927782293 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 6 Jul 2017 15:40:22 -0700 Subject: mm: kmemleak: treat vm_struct as alternative reference to vmalloc'ed objects Kmemleak requires that vmalloc'ed objects have a minimum reference count of 2: one in the corresponding vm_struct object and the other owned by the vmalloc() caller. There are cases, however, where the original vmalloc() returned pointer is lost and, instead, a pointer to vm_struct is stored (see free_thread_stack()). Kmemleak currently reports such objects as leaks. This patch adds support for treating any surplus references to an object as additional references to a specified object. It introduces the kmemleak_vmalloc() API function which takes a vm_struct pointer and sets its surplus reference passing to the actual vmalloc() returned pointer. The __vmalloc_node_range() calling site has been modified accordingly. Link: http://lkml.kernel.org/r/1495726937-23557-4-git-send-email-catalin.marinas@arm.com Signed-off-by: Catalin Marinas Reported-by: "Luis R. Rodriguez" Cc: Michal Hocko Cc: Andy Lutomirski Cc: "Luis R. Rodriguez" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/dev-tools/kmemleak.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/dev-tools') diff --git a/Documentation/dev-tools/kmemleak.rst b/Documentation/dev-tools/kmemleak.rst index b2391b829169..cb8862659178 100644 --- a/Documentation/dev-tools/kmemleak.rst +++ b/Documentation/dev-tools/kmemleak.rst @@ -150,6 +150,7 @@ See the include/linux/kmemleak.h header for the functions prototype. - ``kmemleak_init`` - initialize kmemleak - ``kmemleak_alloc`` - notify of a memory block allocation - ``kmemleak_alloc_percpu`` - notify of a percpu memory block allocation +- ``kmemleak_vmalloc`` - notify of a vmalloc() memory allocation - ``kmemleak_free`` - notify of a memory block freeing - ``kmemleak_free_part`` - notify of a partial memory block freeing - ``kmemleak_free_percpu`` - notify of a percpu memory block freeing -- cgit v1.2.3-59-g8ed1b