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authorCatalin Marinas <catalin.marinas@arm.com>2017-07-06 15:40:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-06 16:24:34 -0700
commit94f4a1618b4c2b268f9e70bd1516932927782293 (patch)
treec8f76fa18273c8038f951dca271fd7871952a2c2 /mm/vmalloc.c
parent04f70d13ca274d62a347815ca01fea871f9b9a40 (diff)
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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 <catalin.marinas@arm.com> Reported-by: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c7
1 files changed, 1 insertions, 6 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ecc97f74ab18..6211a807cb31 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1770,12 +1770,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
*/
clear_vm_uninitialized_flag(area);
- /*
- * A ref_count = 2 is needed because vm_struct allocated in
- * __get_vm_area_node() contains a reference to the virtual address of
- * the vmalloc'ed block.
- */
- kmemleak_alloc(addr, real_size, 2, gfp_mask);
+ kmemleak_vmalloc(area, size, gfp_mask);
return addr;