[v4,0/4] mm: kmemleak: store objects allocated with physical address separately and check when scan

Message

patrick wang June 11, 2022, 3:55 a.m. UTC

The kmemleak_*_phys() interface uses "min_low_pfn" and
"max_low_pfn" to check address. But on some architectures,
kmemleak_*_phys() is called before those two variables
initialized. The following steps will be taken:

1) Add OBJECT_PHYS flag and rbtree for the objects allocated
   with physical address
2) Store physical address in objects if allocated with OBJECT_PHYS
3) Check the boundary when scan instead of in kmemleak_*_phys()

This patch set will solve:
https://lore.kernel.org/r/[e-mail]
https://lore.kernel.org/r/[e-mail]

v3: https://lore.kernel.org/r/[e-mail]
v2: https://lore.kernel.org/r/[e-mail]
v1: https://lore.kernel.org/r/[e-mail]

v3->v4:
 - fix a build warning
 - move the prototype change of kmemleak_alloc_phys() and the
   kmemleak_not_leak_phys() removal to a separate patch (patch 1)

v2->v3:
 - remove the min_count argument to kmemleak_alloc_phys() function and assume it's 0
 - remove unused kmemleak_not_leak_phys() function
 - add functions to reduce unnecessary changes
 - remove the check for kasan_reset_tag()
 - add Fixes tag in patch 3

v1->v2:
 - add rbtree for the objects allocated with physical address
 - store physical address in objects if allocated with OBJECT_PHYS
 - check the upper object boundary as well and avoid duplicate check

Patrick Wang (4):
  mm: kmemleak: remove kmemleak_not_leak_phys() and the min_count
    argument to kmemleak_alloc_phys()
  mm: kmemleak: add OBJECT_PHYS flag for objects allocated with physical
    address
  mm: kmemleak: add rbtree and store physical address for objects
    allocated with PA
  mm: kmemleak: check physical address when scan

 Documentation/dev-tools/kmemleak.rst    |   1 -
 drivers/of/fdt.c                        |   2 +-
 include/linux/kmemleak.h                |   8 +-
 mm/kmemleak.c                           | 200 ++++++++++++++++--------
 mm/memblock.c                           |  14 +-
 tools/testing/memblock/linux/kmemleak.h |   2 +-
 6 files changed, 145 insertions(+), 82 deletions(-)

Comments

Geert Uytterhoeven July 12, 2022, 1:43 p.m. UTC | #1

Hi Patrick,

On Sat, Jun 11, 2022 at 8:50 AM Patrick Wang
<[e-mail]> wrote:
> The kmemleak_*_phys() interface uses "min_low_pfn" and
> "max_low_pfn" to check address. But on some architectures,
> kmemleak_*_phys() is called before those two variables
> initialized. The following steps will be taken:
>
> 1) Add OBJECT_PHYS flag and rbtree for the objects allocated
>    with physical address
> 2) Store physical address in objects if allocated with OBJECT_PHYS
> 3) Check the boundary when scan instead of in kmemleak_*_phys()

Thanks for your series!

> This patch set will solve:
> https://lore.kernel.org/r/[e-mail]
> https://lore.kernel.org/r/[e-mail]

Thanks, this finally gets rid of the thousands of suspected memory
leaks reported since commit 23c2d497de21f258 ("mm: kmemleak: take
a full lowmem check in kmemleak_*_phys()") in v5.18-rc3 on my arm64
boards.

Tested-by: Geert Uytterhoeven <[e-mail]>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [e-mail]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds