linux/include
Gerald Schaefer e513b90a9a numa: fix /proc/<pid>/numa_maps for THP
commit 28093f9f34 upstream.

In gather_pte_stats() a THP pmd is cast into a pte, which is wrong
because the layouts may differ depending on the architecture.  On s390
this will lead to inaccurate numa_maps accounting in /proc because of
misguided pte_present() and pte_dirty() checks on the fake pte.

On other architectures pte_present() and pte_dirty() may work by chance,
but there may be an issue with direct-access (dax) mappings w/o
underlying struct pages when HAVE_PTE_SPECIAL is set and THP is
available.  In vm_normal_page() the fake pte will be checked with
pte_special() and because there is no "special" bit in a pmd, this will
always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be
skipped.  On dax mappings w/o struct pages, an invalid struct page
pointer would then be returned that can crash the kernel.

This patch fixes the numa_maps THP handling by introducing new "_pmd"
variants of the can_gather_numa_stats() and vm_normal_page() functions.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04 14:48:49 -07:00
..
acpi Merge branch 'acpi-pci' 2015-11-07 01:30:10 +01:00
asm-generic asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic() 2016-05-04 14:48:43 -07:00
clocksource
crypto crypto: af_alg - Allow af_af_alg_release_parent to be called on nokey path 2016-02-17 12:31:03 -08:00
drm drm: Loongson-3 doesn't fully support wc memory 2016-05-04 14:48:46 -07:00
dt-bindings ARM: DT updates for v4.4 2015-11-10 15:06:26 -08:00
keys
kvm KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active 2015-11-24 18:07:40 +01:00
linux numa: fix /proc/<pid>/numa_maps for THP 2016-05-04 14:48:49 -07:00
math-emu
media
memory
misc
net bonding: fix bond_get_stats() 2016-04-20 15:42:04 +09:00
pcmcia
ras
rdma IB/security: Restrict use of the write() interface 2016-05-04 14:48:48 -07:00
rxrpc
scsi Merge branch 'mkp-fixes' into fixes 2015-12-03 09:32:33 -08:00
soc ARM: SoC driver updates for v4.4 2015-11-10 15:00:03 -08:00
sound ALSA: rawmidi: Make snd_rawmidi_transmit() race-free 2016-02-17 12:30:58 -08:00
target target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors 2016-03-09 15:34:51 -08:00
trace Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2015-11-11 09:03:01 -08:00
uapi v4l2-dv-timings.h: fix polarity for 4k formats 2016-05-04 14:48:48 -07:00
video gpu: ipu-v3: drop unused dmfc field from client platform data 2015-11-24 11:30:15 +01:00
xen xen: Add RING_COPY_REQUEST() 2015-12-18 10:00:17 -05:00
Kbuild