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  1. 28 3月, 2018 1 次提交
    • G
      m68k: set dma and coherent masks for platform FEC ethernets · f61e6431
      由 Greg Ungerer 提交于 
      As of commit 205e1b7f ("dma-mapping: warn when there is no
coherent_dma_mask") the Freescale FEC driver is issuing the following
warning on driver initialization on ColdFire systems:

WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 0x40159e20
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc7-dirty #4
Stack from 41833dd8:
        41833dd8 40259c53 40025534 40279e26 00000003 00000000 4004e514 41827000
        400255de 40244e42 00000204 40159e20 00000009 00000000 00000000 4024531d
        40159e20 40244e42 00000204 00000000 00000000 00000000 00000007 00000000
        00000000 40279e26 4028d040 40226576 4003ae88 40279e26 418273f6 41833ef8
        7fffffff 418273f2 41867028 4003c9a2 4180ac6c 00000004 41833f8c 4013e71c
        40279e1c 40279e26 40226c16 4013ced2 40279e26 40279e58 4028d040 00000000
Call Trace:
        [<40025534>] 0x40025534
 [<4004e514>] 0x4004e514
 [<400255de>] 0x400255de
 [<40159e20>] 0x40159e20
 [<40159e20>] 0x40159e20

It is not fatal, the driver and the system continue to function normally.

As per the warning the coherent_dma_mask is not set on this device.
There is nothing special about the DMA memory coherency on this hardware
so we can just set the mask to 32bits in the platform data for the FEC
ethernet devices.
Signed-off-by: NGreg Ungerer <gerg@linux-m68k.org>
      f61e6431
  3. 26 3月, 2018 8 次提交
  5. 25 3月, 2018 3 次提交
    • L
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace · e43d40b3
      由 Linus Torvalds 提交于 
      Pull mqueuefs revert from Eric Biederman:
 "This fixes a regression that came in the merge window for v4.16.

  The problem is that the permissions for mounting and using the
  mqueuefs filesystem are broken. The necessary permission check is
  missing letting people who should not be able to mount mqueuefs mount
  mqueuefs. The field sb->s_user_ns is set incorrectly not allowing the
  mounter of mqueuefs to remount and otherwise have proper control over
  the filesystem.

  Al Viro and I see the path to the necessary fixes differently and I am
  not even certain at this point he actually sees all of the necessary
  fixes. Given a couple weeks we can probably work something out but I
  don't see the review being resolved in time for the final v4.16. I
  don't want v4.16 shipping with a nasty regression. So unfortunately I
  am sending a revert"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Revert "mqueue: switch to on-demand creation of internal mount"
      e43d40b3
    • E
      Revert "mqueue: switch to on-demand creation of internal mount" · cfb2f6f6
      由 Eric W. Biederman 提交于 
      This reverts commit 36735a6a.

Aleksa Sarai <asarai@suse.de> writes:
> [REGRESSION v4.16-rc6] [PATCH] mqueue: forbid unprivileged user access to internal mount
>
> Felix reported weird behaviour on 4.16.0-rc6 with regards to mqueue[1],
> which was introduced by 36735a6a ("mqueue: switch to on-demand
> creation of internal mount").
>
> Basically, the reproducer boils down to being able to mount mqueue if
> you create a new user namespace, even if you don't unshare the IPC
> namespace.
>
> Previously this was not possible, and you would get an -EPERM. The mount
> is the *host* mqueue mount, which is being cached and just returned from
> mqueue_mount(). To be honest, I'm not sure if this is safe or not (or if
> it was intentional -- since I'm not familiar with mqueue).
>
> To me it looks like there is a missing permission check. I've included a
> patch below that I've compile-tested, and should block the above case.
> Can someone please tell me if I'm missing something? Is this actually
> safe?
>
> [1]: https://github.com/docker/docker/issues/36674

The issue is a lot deeper than a missing permission check.  sb->s_user_ns
was is improperly set as well.  So in addition to the filesystem being
mounted when it should not be mounted, so things are not allow that should
be.

We are practically to the release of 4.16 and there is no agreement between
Al Viro and myself on what the code should looks like to fix things properly.
So revert the code to what it was before so that we can take our time
and discuss this properly.

Fixes: 36735a6a ("mqueue: switch to on-demand creation of internal mount")
Reported-by: NFelix Abecassis <fabecassis@nvidia.com>
Reported-by: NAleksa Sarai <asarai@suse.de>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      cfb2f6f6
    • L
      Merge tag 'pinctrl-v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl · bcfc1f45
      由 Linus Torvalds 提交于 
      Pull pin control fixes from Linus Walleij:
 "Two fixes for pin control for v4.16:

   - Renesas SH-PFC: remove a duplicate clkout pin which was causing
     crashes

   - fix Samsung out of bounds exceptions"

* tag 'pinctrl-v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: samsung: Validate alias coming from DT
  pinctrl: sh-pfc: r8a7795: remove duplicate of CLKOUT pin in pinmux_pins[]
      bcfc1f45
  7. 24 3月, 2018 14 次提交
  9. 23 3月, 2018 14 次提交
    • L
      Merge branch 'akpm' (patches from Andrew) · f36b7534
      由 Linus Torvalds 提交于 
      Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, thp: do not cause memcg oom for thp
  mm/vmscan: wake up flushers for legacy cgroups too
  Revert "mm: page_alloc: skip over regions of invalid pfns where possible"
  mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink()
  mm/thp: do not wait for lock_page() in deferred_split_scan()
  mm/khugepaged.c: convert VM_BUG_ON() to collapse fail
  x86/mm: implement free pmd/pte page interfaces
  mm/vmalloc: add interfaces to free unmapped page table
  h8300: remove extraneous __BIG_ENDIAN definition
  hugetlbfs: check for pgoff value overflow
  lockdep: fix fs_reclaim warning
  MAINTAINERS: update Mark Fasheh's e-mail
  mm/mempolicy.c: avoid use uninitialized preferred_node
      f36b7534
    • L
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 8401c72c
      由 Linus Torvalds 提交于 
      Pull libnvdimm fixes from Dan Williams:
 "Two regression fixes, two bug fixes for older issues, two fixes for
  new functionality added this cycle that have userspace ABI concerns,
  and a small cleanup. These have appeared in a linux-next release and
  have a build success report from the 0day robot.

   * The 4.16 rework of altmap handling led to some configurations
     leaking page table allocations due to freeing from the altmap
     reservation rather than the page allocator.

     The impact without the fix is leaked memory and a WARN() message
     when tearing down libnvdimm namespaces. The rework also missed a
     place where error handling code needed to be removed that can lead
     to a crash if devm_memremap_pages() fails.

   * acpi_map_pxm_to_node() had a latent bug whereby it could
     misidentify the closest online node to a given proximity domain.

   * Block integrity handling was reworked several kernels back to allow
     calling add_disk() after setting up the integrity profile.

     The nd_btt and nd_blk drivers are just now catching up to fix
     automatic partition detection at driver load time.

   * The new peristence_domain attribute, a platform indicator of
     whether cpu caches are powerfail protected for example, is meant to
     be a single value enum and not a set of flags.

     This oversight was caught while reviewing new userspace code in
     libndctl to communicate the attribute.

     Fix this new enabling up so that we are not stuck with an unwanted
     userspace ABI"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, nfit: fix persistence domain reporting
  libnvdimm, region: hide persistence_domain when unknown
  acpi, numa: fix pxm to online numa node associations
  x86, memremap: fix altmap accounting at free
  libnvdimm: remove redundant assignment to pointer 'dev'
  libnvdimm, {btt, blk}: do integrity setup before add_disk()
  kernel/memremap: Remove stale devres_free() call
      8401c72c
    • L
      Merge tag 'drm-fixes-for-v4.16-rc7' of git://people.freedesktop.org/~airlied/linux · 9ec7ccc8
      由 Linus Torvalds 提交于 
      Pull drm fixes from Dave Airlie:
 "A bunch of fixes all over the place (core, i915, amdgpu, imx, sun4i,
  ast, tegra, vmwgfx), nothing too serious or worrying at this stage.

   - one uapi fix to stop multi-planar images with getfb

   - Sun4i error path and clock fixes

   - udl driver mmap offset fix

   - i915 DP MST and GPU reset fixes

   - vmwgfx mutex and black screen fixes

   - imx array underflow fix and vblank fix

   - amdgpu: display fixes

   - exynos devicetree fix

   - ast mode fix"

* tag 'drm-fixes-for-v4.16-rc7' of git://people.freedesktop.org/~airlied/linux: (29 commits)
  drm/ast: Fixed 1280x800 Display Issue
  drm: udl: Properly check framebuffer mmap offsets
  drm/i915: Specify which engines to reset following semaphore/event lockups
  drm/vmwgfx: Fix a destoy-while-held mutex problem.
  drm/vmwgfx: Fix black screen and device errors when running without fbdev
  drm: Reject getfb for multi-plane framebuffers
  drm/amd/display: Add one to EDID's audio channel count when passing to DC
  drm/amd/display: We shouldn't set format_default on plane as atomic driver
  drm/amd/display: Fix FMT truncation programming
  drm/amd/display: Allow truncation to 10 bits
  drm/sun4i: hdmi: Fix another error handling path in 'sun4i_hdmi_bind()'
  drm/sun4i: hdmi: Fix an error handling path in 'sun4i_hdmi_bind()'
  drm/i915/dp: Write to SET_POWER dpcd to enable MST hub.
  drm/amd/display: fix dereferencing possible ERR_PTR()
  drm/amd/display: Refine disable VGA
  drm/tegra: Shutdown on driver unbind
  drm/tegra: dsi: Don't disable regulator on ->exit()
  drm/tegra: dc: Detach IOMMU group from domain only once
  dt-bindings: exynos: Document #sound-dai-cells property of the HDMI node
  drm/imx: move arming of the vblank event to atomic_flush
  ...
      9ec7ccc8
    • D
      mm, thp: do not cause memcg oom for thp · 9d3c3354
      由 David Rientjes 提交于 
      Commit 25160354 ("mm, thp: remove __GFP_NORETRY from khugepaged and
madvised allocations") changed the page allocator to no longer detect
thp allocations based on __GFP_NORETRY.

It did not, however, modify the mem cgroup try_charge() path to avoid
oom kill for either khugepaged collapsing or thp faulting.  It is never
expected to oom kill a process to allocate a hugepage for thp; reclaim
is governed by the thp defrag mode and MADV_HUGEPAGE, but allocations
(and charging) should fallback instead of oom killing processes.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803191409420.124411@chino.kir.corp.google.com
Fixes: 25160354 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations")
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9d3c3354
    • A
      mm/vmscan: wake up flushers for legacy cgroups too · 1c610d5f
      由 Andrey Ryabinin 提交于 
      Commit 726d061f ("mm: vmscan: kick flushers when we encounter dirty
pages on the LRU") added flusher invocation to shrink_inactive_list()
when many dirty pages on the LRU are encountered.

However, shrink_inactive_list() doesn't wake up flushers for legacy
cgroup reclaim, so the next commit bbef9384 ("mm: vmscan: remove old
flusher wakeup from direct reclaim path") removed the only source of
flusher's wake up in legacy mem cgroup reclaim path.

This leads to premature OOM if there is too many dirty pages in cgroup:
    # mkdir /sys/fs/cgroup/memory/test
    # echo $$ > /sys/fs/cgroup/memory/test/tasks
    # echo 50M > /sys/fs/cgroup/memory/test/memory.limit_in_bytes
    # dd if=/dev/zero of=tmp_file bs=1M count=100
    Killed

    dd invoked oom-killer: gfp_mask=0x14000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=0

    Call Trace:
     dump_stack+0x46/0x65
     dump_header+0x6b/0x2ac
     oom_kill_process+0x21c/0x4a0
     out_of_memory+0x2a5/0x4b0
     mem_cgroup_out_of_memory+0x3b/0x60
     mem_cgroup_oom_synchronize+0x2ed/0x330
     pagefault_out_of_memory+0x24/0x54
     __do_page_fault+0x521/0x540
     page_fault+0x45/0x50

    Task in /test killed as a result of limit of /test
    memory: usage 51200kB, limit 51200kB, failcnt 73
    memory+swap: usage 51200kB, limit 9007199254740988kB, failcnt 0
    kmem: usage 296kB, limit 9007199254740988kB, failcnt 0
    Memory cgroup stats for /test: cache:49632KB rss:1056KB rss_huge:0KB shmem:0KB
            mapped_file:0KB dirty:49500KB writeback:0KB swap:0KB inactive_anon:0KB
	    active_anon:1168KB inactive_file:24760KB active_file:24960KB unevictable:0KB
    Memory cgroup out of memory: Kill process 3861 (bash) score 88 or sacrifice child
    Killed process 3876 (dd) total-vm:8484kB, anon-rss:1052kB, file-rss:1720kB, shmem-rss:0kB
    oom_reaper: reaped process 3876 (dd), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

Wake up flushers in legacy cgroup reclaim too.

Link: http://lkml.kernel.org/r/20180315164553.17856-1-aryabinin@virtuozzo.com
Fixes: bbef9384 ("mm: vmscan: remove old flusher wakeup from direct reclaim path")
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by: NShakeel Butt <shakeelb@google.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1c610d5f
    • D
      Revert "mm: page_alloc: skip over regions of invalid pfns where possible" · f59f1caf
      由 Daniel Vacek 提交于 
      This reverts commit b92df1de ("mm: page_alloc: skip over regions of
invalid pfns where possible").  The commit is meant to be a boot init
speed up skipping the loop in memmap_init_zone() for invalid pfns.

But given some specific memory mapping on x86_64 (or more generally
theoretically anywhere but on arm with CONFIG_HAVE_ARCH_PFN_VALID) the
implementation also skips valid pfns which is plain wrong and causes
'kernel BUG at mm/page_alloc.c:1389!'

  crash> log | grep -e BUG -e RIP -e Call.Trace -e move_freepages_block -e rmqueue -e freelist -A1
  kernel BUG at mm/page_alloc.c:1389!
  invalid opcode: 0000 [#1] SMP
  --
  RIP: 0010: move_freepages+0x15e/0x160
  --
  Call Trace:
    move_freepages_block+0x73/0x80
    __rmqueue+0x263/0x460
    get_page_from_freelist+0x7e1/0x9e0
    __alloc_pages_nodemask+0x176/0x420
  --

  crash> page_init_bug -v | grep RAM
  <struct resource 0xffff88067fffd2f8>          1000 -        9bfff       System RAM (620.00 KiB)
  <struct resource 0xffff88067fffd3a0>        100000 -     430bffff       System RAM (  1.05 GiB = 1071.75 MiB = 1097472.00 KiB)
  <struct resource 0xffff88067fffd410>      4b0c8000 -     4bf9cfff       System RAM ( 14.83 MiB = 15188.00 KiB)
  <struct resource 0xffff88067fffd480>      4bfac000 -     646b1fff       System RAM (391.02 MiB = 400408.00 KiB)
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff       System RAM (480.00 KiB)
  <struct resource 0xffff88067fffd640>     100000000 -    67fffffff       System RAM ( 22.00 GiB)

  crash> page_init_bug | head -6
  <struct resource 0xffff88067fffd560>      7b788000 -     7b7fffff       System RAM (480.00 KiB)
  <struct page 0xffffea0001ede200>   1fffff00000000  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  <struct page 0xffffea0001ede200>       505736 505344 <struct page 0xffffea0001ed8000> 505855 <struct page 0xffffea0001edffc0>
  <struct page 0xffffea0001ed8000>                0  0 <struct pglist_data 0xffff88047ffd9000> 0 <struct zone 0xffff88047ffd9000> DMA               1       4095
  <struct page 0xffffea0001edffc0>   1fffff00000400  0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32          4096    1048575
  BUG, zones differ!

  crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b787000 7b788000
        PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
  ffffea0001e00000  78000000                0        0  0 0
  ffffea0001ed7fc0  7b5ff000                0        0  0 0
  ffffea0001ed8000  7b600000                0        0  0 0       <<<<
  ffffea0001ede1c0  7b787000                0        0  0 0
  ffffea0001ede200  7b788000                0        0  1 1fffff00000000

Link: http://lkml.kernel.org/r/20180316143855.29838-1-neelx@redhat.com
Fixes: b92df1de ("mm: page_alloc: skip over regions of invalid pfns where possible")
Signed-off-by: NDaniel Vacek <neelx@redhat.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f59f1caf
    • K
      mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink() · b3cd54b2
      由 Kirill A. Shutemov 提交于 
      shmem_unused_huge_shrink() gets called from reclaim path.  Waiting for
page lock may lead to deadlock there.

There was a bug report that may be attributed to this:

  http://lkml.kernel.org/r/alpine.LRH.2.11.1801242349220.30642@mail.ewheeler.net

Replace lock_page() with trylock_page() and skip the page if we failed
to lock it.  We will get to the page on the next scan.

We can test for the PageTransHuge() outside the page lock as we only
need protection against splitting the page under us.  Holding pin oni
the page is enough for this.

Link: http://lkml.kernel.org/r/20180316210830.43738-1-kirill.shutemov@linux.intel.com
Fixes: 779750d2 ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: NEric Wheeler <linux-mm@lists.ewheeler.net>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b3cd54b2
    • K
      mm/thp: do not wait for lock_page() in deferred_split_scan() · fa41b900
      由 Kirill A. Shutemov 提交于 
      deferred_split_scan() gets called from reclaim path.  Waiting for page
lock may lead to deadlock there.

Replace lock_page() with trylock_page() and skip the page if we failed
to lock it.  We will get to the page on the next scan.

Link: http://lkml.kernel.org/r/20180315150747.31945-1-kirill.shutemov@linux.intel.com
Fixes: 9a982250 ("thp: introduce deferred_split_huge_page()")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fa41b900
    • K
      mm/khugepaged.c: convert VM_BUG_ON() to collapse fail · fece2029
      由 Kirill A. Shutemov 提交于 
      khugepaged is not yet able to convert PTE-mapped huge pages back to PMD
mapped.  We do not collapse such pages.  See check
khugepaged_scan_pmd().

But if between khugepaged_scan_pmd() and __collapse_huge_page_isolate()
somebody managed to instantiate THP in the range and then split the PMD
back to PTEs we would have a problem --
VM_BUG_ON_PAGE(PageCompound(page)) will get triggered.

It's possible since we drop mmap_sem during collapse to re-take for
write.

Replace the VM_BUG_ON() with graceful collapse fail.

Link: http://lkml.kernel.org/r/20180315152353.27989-1-kirill.shutemov@linux.intel.com
Fixes: b1caa957 ("khugepaged: ignore pmd tables with THP mapped with ptes")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fece2029
    • T
      x86/mm: implement free pmd/pte page interfaces · 28ee90fe
      由 Toshi Kani 提交于 
      Implement pud_free_pmd_page() and pmd_free_pte_page() on x86, which
clear a given pud/pmd entry and free up lower level page table(s).

The address range associated with the pud/pmd entry must have been
purged by INVLPG.

Link: http://lkml.kernel.org/r/20180314180155.19492-3-toshi.kani@hpe.com
Fixes: e61ce6ad ("mm: change ioremap to set up huge I/O mappings")
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Reported-by: NLei Li <lious.lilei@hisilicon.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      28ee90fe
    • T
      mm/vmalloc: add interfaces to free unmapped page table · b6bdb751
      由 Toshi Kani 提交于 
      On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may
create pud/pmd mappings.  A kernel panic was observed on arm64 systems
with Cortex-A75 in the following steps as described by Hanjun Guo.

 1. ioremap a 4K size, valid page table will build,
 2. iounmap it, pte0 will set to 0;
 3. ioremap the same address with 2M size, pgd/pmd is unchanged,
    then set the a new value for pmd;
 4. pte0 is leaked;
 5. CPU may meet exception because the old pmd is still in TLB,
    which will lead to kernel panic.

This panic is not reproducible on x86.  INVLPG, called from iounmap,
purges all levels of entries associated with purged address on x86.  x86
still has memory leak.

The patch changes the ioremap path to free unmapped page table(s) since
doing so in the unmap path has the following issues:

 - The iounmap() path is shared with vunmap(). Since vmap() only
   supports pte mappings, making vunmap() to free a pte page is an
   overhead for regular vmap users as they do not need a pte page freed
   up.

 - Checking if all entries in a pte page are cleared in the unmap path
   is racy, and serializing this check is expensive.

 - The unmap path calls free_vmap_area_noflush() to do lazy TLB purges.
   Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB
   purge.

Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which
clear a given pud/pmd entry and free up a page for the lower level
entries.

This patch implements their stub functions on x86 and arm64, which work
as workaround.

[akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub]
Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com
Fixes: e61ce6ad ("mm: change ioremap to set up huge I/O mappings")
Reported-by: NLei Li <lious.lilei@hisilicon.com>
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Wang Xuefeng <wxf.wang@hisilicon.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b6bdb751
    • A
      h8300: remove extraneous __BIG_ENDIAN definition · 1705f7c5
      由 Arnd Bergmann 提交于 
      A bugfix I did earlier caused a build regression on h8300, which defines
the __BIG_ENDIAN macro in a slightly different way than the generic
code:

  arch/h8300/include/asm/byteorder.h:5:0: warning: "__BIG_ENDIAN" redefined

We don't need to define it here, as the same macro is already provided
by the linux/byteorder/big_endian.h, and that version does not conflict.

While this is a v4.16 regression, my earlier patch also got backported
to the 4.14 and 4.15 stable kernels, so we need the fixup there as well.

Link: http://lkml.kernel.org/r/20180313120752.2645129-1-arnd@arndb.de
Fixes: 101110f6 ("Kbuild: always define endianess in kconfig.h")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1705f7c5
    • M
      hugetlbfs: check for pgoff value overflow · 63489f8e
      由 Mike Kravetz 提交于 
      A vma with vm_pgoff large enough to overflow a loff_t type when
converted to a byte offset can be passed via the remap_file_pages system
call.  The hugetlbfs mmap routine uses the byte offset to calculate
reservations and file size.

A sequence such as:

  mmap(0x20a00000, 0x600000, 0, 0x66033, -1, 0);
  remap_file_pages(0x20a00000, 0x600000, 0, 0x20000000000000, 0);

will result in the following when task exits/file closed,

  kernel BUG at mm/hugetlb.c:749!
  Call Trace:
    hugetlbfs_evict_inode+0x2f/0x40
    evict+0xcb/0x190
    __dentry_kill+0xcb/0x150
    __fput+0x164/0x1e0
    task_work_run+0x84/0xa0
    exit_to_usermode_loop+0x7d/0x80
    do_syscall_64+0x18b/0x190
    entry_SYSCALL_64_after_hwframe+0x3d/0xa2

The overflowed pgoff value causes hugetlbfs to try to set up a mapping
with a negative range (end < start) that leaves invalid state which
causes the BUG.

The previous overflow fix to this code was incomplete and did not take
the remap_file_pages system call into account.

[mike.kravetz@oracle.com: v3]
  Link: http://lkml.kernel.org/r/20180309002726.7248-1-mike.kravetz@oracle.com
[akpm@linux-foundation.org: include mmdebug.h]
[akpm@linux-foundation.org: fix -ve left shift count on sh]
Link: http://lkml.kernel.org/r/20180308210502.15952-1-mike.kravetz@oracle.com
Fixes: 045c7a3f ("hugetlbfs: fix offset overflow in hugetlbfs mmap")
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reported-by: NNic Losby <blurbdust@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      63489f8e
    • T
      lockdep: fix fs_reclaim warning · 2e517d68
      由 Tetsuo Handa 提交于 
      Dave Jones reported fs_reclaim lockdep warnings.

  ============================================
  WARNING: possible recursive locking detected
  4.15.0-rc9-backup-debug+ #1 Not tainted
  --------------------------------------------
  sshd/24800 is trying to acquire lock:
   (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  but task is already holding lock:
   (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(fs_reclaim);
    lock(fs_reclaim);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  2 locks held by sshd/24800:
   #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000001a069652>] tcp_sendmsg+0x19/0x40
   #1:  (fs_reclaim){+.+.}, at: [<0000000084f438c2>] fs_reclaim_acquire.part.102+0x5/0x30

  stack backtrace:
  CPU: 3 PID: 24800 Comm: sshd Not tainted 4.15.0-rc9-backup-debug+ #1
  Call Trace:
   dump_stack+0xbc/0x13f
   __lock_acquire+0xa09/0x2040
   lock_acquire+0x12e/0x350
   fs_reclaim_acquire.part.102+0x29/0x30
   kmem_cache_alloc+0x3d/0x2c0
   alloc_extent_state+0xa7/0x410
   __clear_extent_bit+0x3ea/0x570
   try_release_extent_mapping+0x21a/0x260
   __btrfs_releasepage+0xb0/0x1c0
   btrfs_releasepage+0x161/0x170
   try_to_release_page+0x162/0x1c0
   shrink_page_list+0x1d5a/0x2fb0
   shrink_inactive_list+0x451/0x940
   shrink_node_memcg.constprop.88+0x4c9/0x5e0
   shrink_node+0x12d/0x260
   try_to_free_pages+0x418/0xaf0
   __alloc_pages_slowpath+0x976/0x1790
   __alloc_pages_nodemask+0x52c/0x5c0
   new_slab+0x374/0x3f0
   ___slab_alloc.constprop.81+0x47e/0x5a0
   __slab_alloc.constprop.80+0x32/0x60
   __kmalloc_track_caller+0x267/0x310
   __kmalloc_reserve.isra.40+0x29/0x80
   __alloc_skb+0xee/0x390
   sk_stream_alloc_skb+0xb8/0x340
   tcp_sendmsg_locked+0x8e6/0x1d30
   tcp_sendmsg+0x27/0x40
   inet_sendmsg+0xd0/0x310
   sock_write_iter+0x17a/0x240
   __vfs_write+0x2ab/0x380
   vfs_write+0xfb/0x260
   SyS_write+0xb6/0x140
   do_syscall_64+0x1e5/0xc05
   entry_SYSCALL64_slow_path+0x25/0x25

This warning is caused by commit d92a8cfc ("locking/lockdep:
Rework FS_RECLAIM annotation") which replaced the use of
lockdep_{set,clear}_current_reclaim_state() in __perform_reclaim()
and lockdep_trace_alloc() in slab_pre_alloc_hook() with
fs_reclaim_acquire()/ fs_reclaim_release().

Since __kmalloc_reserve() from __alloc_skb() adds __GFP_NOMEMALLOC |
__GFP_NOWARN to gfp_mask, and all reclaim path simply propagates
__GFP_NOMEMALLOC, fs_reclaim_acquire() in slab_pre_alloc_hook() is
trying to grab the 'fake' lock again when __perform_reclaim() already
grabbed the 'fake' lock.

The

  /* this guy won't enter reclaim */
  if ((current->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
          return false;

test which causes slab_pre_alloc_hook() to try to grab the 'fake' lock
was added by commit cf40bd16 ("lockdep: annotate reclaim context
(__GFP_NOFS)").  But that test is outdated because PF_MEMALLOC thread
won't enter reclaim regardless of __GFP_NOMEMALLOC after commit
341ce06f ("page allocator: calculate the alloc_flags for allocation
only once") added the PF_MEMALLOC safeguard (

  /* Avoid recursion of direct reclaim */
  if (p->flags & PF_MEMALLOC)
          goto nopage;

in __alloc_pages_slowpath()).

Thus, let's fix outdated test by removing __GFP_NOMEMALLOC test and
allow __need_fs_reclaim() to return false.

Link: http://lkml.kernel.org/r/201802280650.FJC73911.FOSOMLJVFFQtHO@I-love.SAKURA.ne.jp
Fixes: d92a8cfc ("locking/lockdep: Rework FS_RECLAIM annotation")
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: NDave Jones <davej@codemonkey.org.uk>
Tested-by: NDave Jones <davej@codemonkey.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2e517d68