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| author | Catalin Marinas <catalin.marinas@arm.com> | 2017-07-06 15:40:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-06 16:24:34 -0700 |
| commit | 94f4a1618b4c2b268f9e70bd1516932927782293 (patch) | |
| tree | c8f76fa18273c8038f951dca271fd7871952a2c2 /mm/vmalloc.c | |
| parent | 04f70d13ca274d62a347815ca01fea871f9b9a40 (diff) | |
| download | linux-0-day-94f4a1618b4c2b268f9e70bd1516932927782293.tar.gz linux-0-day-94f4a1618b4c2b268f9e70bd1516932927782293.tar.xz | |
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.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ecc97f74ab182..6211a807cb31e 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; |