1. 22 Oct, 2015 40 commits
    • Rusty Russell's avatar
      tools/lguest: Fix redefinition of struct virtio_pci_cfg_cap · 141b2ad2
      Rusty Russell authored
      commit e523caa6 upstream.
      
      Ours uses a u32 for the data, since we ensure it's always
      aligned and it's x86 so it doesn't matter anyway.
      
        lguest.c:128:8: error: redefinition of ‘struct virtio_pci_cfg_cap’
      Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Fixes: 3121bb02 ("virtio: define virtio_pci_cfg_cap in header.")
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      141b2ad2
    • Filipe Manana's avatar
      Btrfs: update fix for read corruption of compressed and shared extents · e83e472a
      Filipe Manana authored
      commit 808f80b4 upstream.
      
      My previous fix in commit 005efedf ("Btrfs: fix read corruption of
      compressed and shared extents") was effective only if the compressed
      extents cover a file range with a length that is not a multiple of 16
      pages. That's because the detection of when we reached a different range
      of the file that shares the same compressed extent as the previously
      processed range was done at extent_io.c:__do_contiguous_readpages(),
      which covers subranges with a length up to 16 pages, because
      extent_readpages() groups the pages in clusters no larger than 16 pages.
      So fix this by tracking the start of the previously processed file
      range's extent map at extent_readpages().
      
      The following test case for fstests reproduces the issue:
      
        seq=`basename $0`
        seqres=$RESULT_DIR/$seq
        echo "QA output created by $seq"
        tmp=/tmp/$$
        status=1	# failure is the default!
        trap "_cleanup; exit \$status" 0 1 2 3 15
      
        _cleanup()
        {
            rm -f $tmp.*
        }
      
        # get standard environment, filters and checks
        . ./common/rc
        . ./common/filter
      
        # real QA test starts here
        _need_to_be_root
        _supported_fs btrfs
        _supported_os Linux
        _require_scratch
        _require_cloner
      
        rm -f $seqres.full
      
        test_clone_and_read_compressed_extent()
        {
            local mount_opts=$1
      
            _scratch_mkfs >>$seqres.full 2>&1
            _scratch_mount $mount_opts
      
            # Create our test file with a single extent of 64Kb that is going to
            # be compressed no matter which compression algo is used (zlib/lzo).
            $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 64K" \
                $SCRATCH_MNT/foo | _filter_xfs_io
      
            # Now clone the compressed extent into an adjacent file offset.
            $CLONER_PROG -s 0 -d $((64 * 1024)) -l $((64 * 1024)) \
                $SCRATCH_MNT/foo $SCRATCH_MNT/foo
      
            echo "File digest before unmount:"
            md5sum $SCRATCH_MNT/foo | _filter_scratch
      
            # Remount the fs or clear the page cache to trigger the bug in
            # btrfs. Because the extent has an uncompressed length that is a
            # multiple of 16 pages, all the pages belonging to the second range
            # of the file (64K to 128K), which points to the same extent as the
            # first range (0K to 64K), had their contents full of zeroes instead
            # of the byte 0xaa. This was a bug exclusively in the read path of
            # compressed extents, the correct data was stored on disk, btrfs
            # just failed to fill in the pages correctly.
            _scratch_remount
      
            echo "File digest after remount:"
            # Must match the digest we got before.
            md5sum $SCRATCH_MNT/foo | _filter_scratch
        }
      
        echo -e "\nTesting with zlib compression..."
        test_clone_and_read_compressed_extent "-o compress=zlib"
      
        _scratch_unmount
      
        echo -e "\nTesting with lzo compression..."
        test_clone_and_read_compressed_extent "-o compress=lzo"
      
        status=0
        exit
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Tested-by: default avatarTimofey Titovets <nefelim4ag@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e83e472a
    • Filipe Manana's avatar
      Btrfs: fix read corruption of compressed and shared extents · ee81cb3d
      Filipe Manana authored
      commit 005efedf upstream.
      
      If a file has a range pointing to a compressed extent, followed by
      another range that points to the same compressed extent and a read
      operation attempts to read both ranges (either completely or part of
      them), the pages that correspond to the second range are incorrectly
      filled with zeroes.
      
      Consider the following example:
      
        File layout
        [0 - 8K]                      [8K - 24K]
            |                             |
            |                             |
         points to extent X,         points to extent X,
         offset 4K, length of 8K     offset 0, length 16K
      
        [extent X, compressed length = 4K uncompressed length = 16K]
      
      If a readpages() call spans the 2 ranges, a single bio to read the extent
      is submitted - extent_io.c:submit_extent_page() would only create a new
      bio to cover the second range pointing to the extent if the extent it
      points to had a different logical address than the extent associated with
      the first range. This has a consequence of the compressed read end io
      handler (compression.c:end_compressed_bio_read()) finish once the extent
      is decompressed into the pages covering the first range, leaving the
      remaining pages (belonging to the second range) filled with zeroes (done
      by compression.c:btrfs_clear_biovec_end()).
      
      So fix this by submitting the current bio whenever we find a range
      pointing to a compressed extent that was preceded by a range with a
      different extent map. This is the simplest solution for this corner
      case. Making the end io callback populate both ranges (or more, if we
      have multiple pointing to the same extent) is a much more complex
      solution since each bio is tightly coupled with a single extent map and
      the extent maps associated to the ranges pointing to the shared extent
      can have different offsets and lengths.
      
      The following test case for fstests triggers the issue:
      
        seq=`basename $0`
        seqres=$RESULT_DIR/$seq
        echo "QA output created by $seq"
        tmp=/tmp/$$
        status=1	# failure is the default!
        trap "_cleanup; exit \$status" 0 1 2 3 15
      
        _cleanup()
        {
            rm -f $tmp.*
        }
      
        # get standard environment, filters and checks
        . ./common/rc
        . ./common/filter
      
        # real QA test starts here
        _need_to_be_root
        _supported_fs btrfs
        _supported_os Linux
        _require_scratch
        _require_cloner
      
        rm -f $seqres.full
      
        test_clone_and_read_compressed_extent()
        {
            local mount_opts=$1
      
            _scratch_mkfs >>$seqres.full 2>&1
            _scratch_mount $mount_opts
      
            # Create a test file with a single extent that is compressed (the
            # data we write into it is highly compressible no matter which
            # compression algorithm is used, zlib or lzo).
            $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 4K"        \
                            -c "pwrite -S 0xbb 4K 8K"        \
                            -c "pwrite -S 0xcc 12K 4K"       \
                            $SCRATCH_MNT/foo | _filter_xfs_io
      
            # Now clone our extent into an adjacent offset.
            $CLONER_PROG -s $((4 * 1024)) -d $((16 * 1024)) -l $((8 * 1024)) \
                $SCRATCH_MNT/foo $SCRATCH_MNT/foo
      
            # Same as before but for this file we clone the extent into a lower
            # file offset.
            $XFS_IO_PROG -f -c "pwrite -S 0xaa 8K 4K"         \
                            -c "pwrite -S 0xbb 12K 8K"        \
                            -c "pwrite -S 0xcc 20K 4K"        \
                            $SCRATCH_MNT/bar | _filter_xfs_io
      
            $CLONER_PROG -s $((12 * 1024)) -d 0 -l $((8 * 1024)) \
                $SCRATCH_MNT/bar $SCRATCH_MNT/bar
      
            echo "File digests before unmounting filesystem:"
            md5sum $SCRATCH_MNT/foo | _filter_scratch
            md5sum $SCRATCH_MNT/bar | _filter_scratch
      
            # Evicting the inode or clearing the page cache before reading
            # again the file would also trigger the bug - reads were returning
            # all bytes in the range corresponding to the second reference to
            # the extent with a value of 0, but the correct data was persisted
            # (it was a bug exclusively in the read path). The issue happened
            # only if the same readpages() call targeted pages belonging to the
            # first and second ranges that point to the same compressed extent.
            _scratch_remount
      
            echo "File digests after mounting filesystem again:"
            # Must match the same digests we got before.
            md5sum $SCRATCH_MNT/foo | _filter_scratch
            md5sum $SCRATCH_MNT/bar | _filter_scratch
        }
      
        echo -e "\nTesting with zlib compression..."
        test_clone_and_read_compressed_extent "-o compress=zlib"
      
        _scratch_unmount
      
        echo -e "\nTesting with lzo compression..."
        test_clone_and_read_compressed_extent "-o compress=lzo"
      
        status=0
        exit
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Reviewed-by: Qu Wenruo<quwenruo@cn.fujitsu.com>
      Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ee81cb3d
    • Jeff Mahoney's avatar
      btrfs: skip waiting on ordered range for special files · 6117f993
      Jeff Mahoney authored
      commit a30e577c upstream.
      
      In btrfs_evict_inode, we properly truncate the page cache for evicted
      inodes but then we call btrfs_wait_ordered_range for every inode as well.
      It's the right thing to do for regular files but results in incorrect
      behavior for device inodes for block devices.
      
      filemap_fdatawrite_range gets called with inode->i_mapping which gets
      resolved to the block device inode before getting passed to
      wbc_attach_fdatawrite_inode and ultimately to inode_to_bdi.  What happens
      next depends on whether there's an open file handle associated with the
      inode.  If there is, we write to the block device, which is unexpected
      behavior.  If there isn't, we through normally and inode->i_data is used.
      We can also end up racing against open/close which can result in crashes
      when i_mapping points to a block device inode that has been closed.
      
      Since there can't be any page cache associated with special file inodes,
      it's safe to skip the btrfs_wait_ordered_range call entirely and avoid
      the problem.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=100911Tested-by: default avatarChristoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
      Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
      Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6117f993
    • Andreas Dannenberg's avatar
      ASoC: tas2552: fix dBscale-min declaration · 0bfc2f5b
      Andreas Dannenberg authored
      commit e2600460 upstream.
      
      The minimum volume level for the TAS2552 (control register value 0x00)
      is -7dB however the driver declares it as -0.07dB.
      
      Running amixer before the patch reports:
      dBscale-min=-0.07dB,step=1.00dB,mute=0
      
      Running amixer with the patch applied reports:
      dBscale-min=-7.00dB,step=1.00dB,mute=0
      Signed-off-by: default avatarAndreas Dannenberg <dannenberg@ti.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0bfc2f5b
    • Gianluca Renzi's avatar
    • Lars-Peter Clausen's avatar
      ASoC: db1200: Fix DAI link format for db1300 and db1550 · 795d7120
      Lars-Peter Clausen authored
      commit e74679b3 upstream.
      
      Commit b4508d0f ("ASoC: db1200: Use static DAI format setup") switched
      the db1200 driver over to using static DAI format setup instead of a
      callback function. But the commit only added the dai_fmt field to one of
      the three DAI links in the driver. This breaks audio on db1300 and db1550.
      
      Add the two missing dai_fmt settings to fix the issue.
      
      Fixes: b4508d0f ("ASoC: db1200: Use static DAI format setup")
      Reported-by: default avatarManuel Lauss <manuel.lauss@gmail.com>
      Tested-by: default avatarManuel Lauss <manuel.lauss@gmail.com>
      Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      795d7120
    • Yitian Bu's avatar
      ASoC: dwc: correct irq clear method · 0633d0e6
      Yitian Bu authored
      commit 4873867e upstream.
      
      from Designware I2S datasheet, tx/rx XRUN irq is cleared by
      reading register TOR/ROR, rather than by writing into them.
      Signed-off-by: default avatarYitian Bu <yitian.bu@tangramtek.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0633d0e6
    • Robert Jarzmik's avatar
      ASoC: fix broken pxa SoC support · a0e9b9f1
      Robert Jarzmik authored
      commit 3c8f7710 upstream.
      
      The previous fix of pxa library support, which was introduced to fix the
      library dependency, broke the previous SoC behavior, where a machine
      code binding pxa2xx-ac97 with a coded relied on :
       - sound/soc/pxa/pxa2xx-ac97.c
       - sound/soc/codecs/XXX.c
      
      For example, the mioa701_wm9713.c machine code is currently broken. The
      "select ARM" statement wrongly selects the soc/arm/pxa2xx-ac97 for
      compilation, as per an unfortunate fate SND_PXA2XX_AC97 is both declared
      in sound/arm/Kconfig and sound/soc/pxa/Kconfig.
      
      Fix this by ensuring that SND_PXA2XX_SOC correctly triggers the correct
      pxa2xx-ac97 compilation.
      
      Fixes: 846172df ("ASoC: fix SND_PXA2XX_LIB Kconfig warning")
      Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a0e9b9f1
    • Robert Jarzmik's avatar
      ASoC: pxa: pxa2xx-ac97: fix dma requestor lines · e23564c6
      Robert Jarzmik authored
      commit 8811191f upstream.
      
      PCM receive and transmit DMA requestor lines were reverted, breaking the
      PCM playback interface for PXA platforms using the sound/soc/ variant
      instead of the sound/arm variant.
      
      The commit below shows the inversion in the requestor lines.
      
      Fixes: d65a1458 ("ASoC: pxa: use snd_dmaengine_dai_dma_data")
      Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e23564c6
    • Takashi Iwai's avatar
      ALSA: hda - Disable power_save_node for IDT 92HD73xx chips · 403fd405
      Takashi Iwai authored
      commit c7e10080 upstream.
      
      The recent widget power saving introduced some unavoidable click
      noises on old IDT 92HD73xx chips while it still seems working on the
      compatible new chips.  In the bugzilla, we tried lots of tests and
      workarounds, but they didn't help much.  So, let's disable the feature
      for these specific chips as the least (but safest) fix.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=104981Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      403fd405
    • John Flatness's avatar
      ALSA: hda - Apply SPDIF pin ctl to MacBookPro 12,1 · 99b50c24
      John Flatness authored
      commit e8ff581f upstream.
      
      The MacBookPro 12,1 has the same setup as the 11 for controlling the
      status of the optical audio light. Simply apply the existing workaround
      to the subsystem ID for the 12,1.
      
      [sorted the fixup entry by tiwai]
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=105401Signed-off-by: default avatarJohn Flatness <john@zerocrates.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      99b50c24
    • Laura Abbott's avatar
      ALSA: hda: Add dock support for ThinkPad T550 · 22b502d4
      Laura Abbott authored
      commit d05ea7da upstream.
      
      Much like all the other Lenovo laptops, add a quirk to make
      sound work with docking.
      
      Reported-and-tested-by: lacknerflo@gmail.com
      Signed-off-by: default avatarLaura Abbott <labbott@fedoraproject.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      22b502d4
    • Takashi Iwai's avatar
      ALSA: synth: Fix conflicting OSS device registration on AWE32 · 4154d4e8
      Takashi Iwai authored
      commit 225db576 upstream.
      
      When OSS emulation is loaded on ISA SB AWE32 chip, we get now kernel
      warnings like:
        WARNING: CPU: 0 PID: 2791 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x51/0x80()
        sysfs: cannot create duplicate filename '/devices/isa/sbawe.0/sound/card0/seq-oss-0-0'
      
      It's because both emux synth and opl3 drivers try to register their
      OSS device object with the same static index number 0.  This hasn't
      been a big problem until the recent rewrite of device management code
      (that exposes sysfs at the same time), but it's been an obvious bug.
      
      This patch works around it just by using a different index number of
      emux synth object.  There can be a more elegant way to fix, but it's
      enough for now, as this code won't be touched so often, in anyway.
      Reported-and-tested-by: default avatarMichael Shell <list1@michaelshell.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4154d4e8
    • Takashi Iwai's avatar
      ALSA: hda - Disable power_save_node for Thinkpads · d061d1d5
      Takashi Iwai authored
      commit 7f57d803 upstream.
      
      Lenovo Thinkpads with recent Realtek codecs seem suffering from click
      noises at power transition since the introduction of widget power
      saving in 4.1 kernel.  Although this might be solved by some delays in
      appropriate points, as a quick workaround, just disable the
      power_save_node feature for now.  The gain it gives is relatively
      small, and this makes the situation back to pre 4.1 time.
      
      This patch ended up with a bit more code changes than usual because
      the existing fixup for Thinkpads is highly chained.  Instead of adding
      yet another chain, combine a few of them into a single fixup entry, as
      a gratis cleanup.
      
      Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=943982Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d061d1d5
    • Takashi Iwai's avatar
      ALSA: hda/tegra - async probe for avoiding module loading deadlock · 839fe740
      Takashi Iwai authored
      commit 83510441 upstream.
      
      The Tegra HD-audio controller driver causes deadlocks when loaded as a
      module since the driver invokes request_module() at binding with the
      codec driver.  This patch works around it by deferring the probe in a
      work like Intel HD-audio controller driver does.  Although hovering
      the codec probe stuff into udev would be a better solution, it may
      cause other regressions, so let's try this band-aid fix until the more
      proper solution gets landed.
      Reported-by: default avatarThierry Reding <treding@nvidia.com>
      Tested-by: default avatarThierry Reding <treding@nvidia.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      839fe740
    • Greg Thelen's avatar
      memcg: fix dirty page migration · aba3953d
      Greg Thelen authored
      commit 0610c25d upstream.
      
      The problem starts with a file backed dirty page which is charged to a
      memcg.  Then page migration is used to move oldpage to newpage.
      
      Migration:
       - copies the oldpage's data to newpage
       - clears oldpage.PG_dirty
       - sets newpage.PG_dirty
       - uncharges oldpage from memcg
       - charges newpage to memcg
      
      Clearing oldpage.PG_dirty decrements the charged memcg's dirty page
      count.
      
      However, because newpage is not yet charged, setting newpage.PG_dirty
      does not increment the memcg's dirty page count.  After migration
      completes newpage.PG_dirty is eventually cleared, often in
      account_page_cleaned().  At this time newpage is charged to a memcg so
      the memcg's dirty page count is decremented which causes underflow
      because the count was not previously incremented by migration.  This
      underflow causes balance_dirty_pages() to see a very large unsigned
      number of dirty memcg pages which leads to aggressive throttling of
      buffered writes by processes in non root memcg.
      
      This issue:
       - can harm performance of non root memcg buffered writes.
       - can report too small (even negative) values in
         memory.stat[(total_)dirty] counters of all memcg, including the root.
      
      To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce
      page_memcg() and set_page_memcg() helpers.
      
      Test:
          0) setup and enter limited memcg
          mkdir /sys/fs/cgroup/test
          echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes
          echo $$ > /sys/fs/cgroup/test/cgroup.procs
      
          1) buffered writes baseline
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
          2) buffered writes with compaction antagonist to induce migration
          yes 1 > /proc/sys/vm/compact_memory &
          rm -rf /data/tmp/foo
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          kill %
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
          3) buffered writes without antagonist, should match baseline
          rm -rf /data/tmp/foo
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
                             (speed, dirty residue)
                   unpatched                       patched
          1) 841 MB/s 0 dirty pages          886 MB/s 0 dirty pages
          2) 611 MB/s -33427456 dirty pages  793 MB/s 0 dirty pages
          3) 114 MB/s -33427456 dirty pages  891 MB/s 0 dirty pages
      
          Notice that unpatched baseline performance (1) fell after
          migration (3): 841 -> 114 MB/s.  In the patched kernel, post
          migration performance matches baseline.
      
      Fixes: c4843a75 ("memcg: add per cgroup dirty page accounting")
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Reported-by: default avatarDave Hansen <dave.hansen@intel.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      aba3953d
    • Mel Gorman's avatar
      mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault · 5c760d8e
      Mel Gorman authored
      commit 2f84a899 upstream.
      
      SunDong reported the following on
      
        https://bugzilla.kernel.org/show_bug.cgi?id=103841
      
      	I think I find a linux bug, I have the test cases is constructed. I
      	can stable recurring problems in fedora22(4.0.4) kernel version,
      	arch for x86_64.  I construct transparent huge page, when the parent
      	and child process with MAP_SHARE, MAP_PRIVATE way to access the same
      	huge page area, it has the opportunity to lead to huge page copy on
      	write failure, and then it will munmap the child corresponding mmap
      	area, but then the child mmap area with VM_MAYSHARE attributes, child
      	process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags
      	functions (vma - > vm_flags & VM_MAYSHARE).
      
      There were a number of problems with the report (e.g.  it's hugetlbfs that
      triggers this, not transparent huge pages) but it was fundamentally
      correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that
      looks like this
      
      	 vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000
      	 next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800
      	 prot 8000000000000027 anon_vma           (null) vm_ops ffffffff8182a7a0
      	 pgoff 0 file ffff88106bdb9800 private_data           (null)
      	 flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb)
      	 ------------
      	 kernel BUG at mm/hugetlb.c:462!
      	 SMP
      	 Modules linked in: xt_pkttype xt_LOG xt_limit [..]
      	 CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1
      	 Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012
      	 set_vma_resv_flags+0x2d/0x30
      
      The VM_BUG_ON is correct because private and shared mappings have
      different reservation accounting but the warning clearly shows that the
      VMA is shared.
      
      When a private COW fails to allocate a new page then only the process
      that created the VMA gets the page -- all the children unmap the page.
      If the children access that data in the future then they get killed.
      
      The problem is that the same file is mapped shared and private.  During
      the COW, the allocation fails, the VMAs are traversed to unmap the other
      private pages but a shared VMA is found and the bug is triggered.  This
      patch identifies such VMAs and skips them.
      Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
      Reported-by: default avatarSunDong <sund_sky@126.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: David Rientjes <rientjes@google.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5c760d8e
    • Joseph Qi's avatar
      ocfs2/dlm: fix deadlock when dispatch assert master · 6d48b1e9
      Joseph Qi authored
      commit 012572d4 upstream.
      
      The order of the following three spinlocks should be:
      dlm_domain_lock < dlm_ctxt->spinlock < dlm_lock_resource->spinlock
      
      But dlm_dispatch_assert_master() is called while holding
      dlm_ctxt->spinlock and dlm_lock_resource->spinlock, and then it calls
      dlm_grab() which will take dlm_domain_lock.
      
      Once another thread (for example, dlm_query_join_handler) has already
      taken dlm_domain_lock, and tries to take dlm_ctxt->spinlock deadlock
      happens.
      Signed-off-by: default avatarJoseph Qi <joseph.qi@huawei.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: "Junxiao Bi" <junxiao.bi@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6d48b1e9
    • Sowmini Varadhan's avatar
      lib/iommu-common.c: do not try to deref a null iommu->lazy_flush() pointer when n < pool->hint · 27a6aafa
      Sowmini Varadhan authored
      commit d046b770 upstream.
      
      The check for invoking iommu->lazy_flush() from iommu_tbl_range_alloc()
      has to be refactored so that we only call ->lazy_flush() if it is
      non-null.
      
      I had a sparc kernel that was crashing when I was trying to process some
      very large perf.data files- the crash happens when the scsi driver calls
      into dma_4v_map_sg and thus the iommu_tbl_range_alloc().
      Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Cc: David S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      27a6aafa
    • Naoya Horiguchi's avatar
      mm: migrate: hugetlb: putback destination hugepage to active list · 9a8d4105
      Naoya Horiguchi authored
      commit 3aaa76e1 upstream.
      
      Since commit bcc54222 ("mm: hugetlb: introduce page_huge_active")
      each hugetlb page maintains its active flag to avoid a race condition
      betwe= en multiple calls of isolate_huge_page(), but current kernel
      doesn't set the f= lag on a hugepage allocated by migration because the
      proper putback routine isn= 't called.  This means that users could
      still encounter the race referred to by bcc54222 in this special
      case, so this patch fixes it.
      
      Fixes: bcc54222 ("mm: hugetlb: introduce page_huge_active")
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Hugh Dickins <hughd@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9a8d4105
    • Sudip Mukherjee's avatar
      spi: spidev: fix possible NULL dereference · 1bda8dbe
      Sudip Mukherjee authored
      commit dd85ebf6 upstream.
      
      During the last close we are freeing spidev if spidev->spi is NULL, but
      just before checking if spidev->spi is NULL we are dereferencing it.
      Lets add a check there to avoid the NULL dereference.
      
      Fixes: 91690516 ("spi: spidev: Don't mangle max_speed_hz in underlying spi device")
      Signed-off-by: default avatarSudip Mukherjee <sudip@vectorindia.org>
      Reviewed-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Tested-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1bda8dbe
    • Tan, Jui Nee's avatar
      spi: spi-pxa2xx: Check status register to determine if SSSR_TINT is disabled · 9280d7dc
      Tan, Jui Nee authored
      commit 02bc933e upstream.
      
      On Intel Baytrail, there is case when interrupt handler get called, no SPI
      message is captured. The RX FIFO is indeed empty when RX timeout pending
      interrupt (SSSR_TINT) happens.
      
      Use the BIOS version where both HSUART and SPI are on the same IRQ. Both
      drivers are using IRQF_SHARED when calling the request_irq function. When
      running two separate and independent SPI and HSUART application that
      generate data traffic on both components, user will see messages like
      below on the console:
      
        pxa2xx-spi pxa2xx-spi.0: bad message state in interrupt handler
      
      This commit will fix this by first checking Receiver Time-out Interrupt,
      if it is disabled, ignore the request and return without servicing.
      Signed-off-by: default avatarTan, Jui Nee <jui.nee.tan@intel.com>
      Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9280d7dc
    • Martin Sperl's avatar
      spi: bcm2835: BUG: fix wrong use of PAGE_MASK · 3a06f82c
      Martin Sperl authored
      commit 2a3fffd4 upstream.
      
      There is a bug in the alignment checking of transfers,
      that results in DMA not being used for un-aligned
      transfers that do not cross page-boundries, which is valid.
      
      This is due to a missconception of the meaning PAGE_MASK
      when implementing that check originally - (PAGE_SIZE - 1)
      should have been used instead.
      
      Also fixes a copy/paste error.
      
      Reported-by: <robert@axium.co.nz>
      Signed-off-by: default avatarMartin Sperl <kernel@martin.sperl.org>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3a06f82c
    • Max Filippov's avatar
      spi: xtensa-xtfpga: fix register endianness · 980f841e
      Max Filippov authored
      commit b0b48550 upstream.
      
      XTFPGA SPI controller has native endian registers.
      Fix register acessors so that they work in big-endian configurations.
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      980f841e
    • Guenter Roeck's avatar
      spi: Fix documentation of spi_alloc_master() · 5bc7b6b3
      Guenter Roeck authored
      commit a394d635 upstream.
      
      Actually, spi_master_put() after spi_alloc_master() must _not_ be followed
      by kfree(). The memory is already freed with the call to spi_master_put()
      through spi_master_class, which registers a release function. Calling both
      spi_master_put() and kfree() results in often nasty (and delayed) crashes
      elsewhere in the kernel, often in the networking stack.
      
      This reverts commit eb4af0f5.
      
      Link to patch and concerns: https://lkml.org/lkml/2012/9/3/269
      or
      http://lkml.iu.edu/hypermail/linux/kernel/1209.0/00790.html
      
      Alexey Klimov: This revert becomes valid after
      94c69f76 when spi-imx.c
      has been fixed and there is no need to call kfree() so comment
      for spi_alloc_master() should be fixed.
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5bc7b6b3
    • Greg Thelen's avatar
      memcg: make mem_cgroup_read_stat() unsigned · 08a1208a
      Greg Thelen authored
      commit 484ebb3b upstream.
      
      mem_cgroup_read_stat() returns a page count by summing per cpu page
      counters.  The summing is racy wrt.  updates, so a transient negative
      sum is possible.  Callers don't want negative values:
      
       - mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback.
         This could confuse dirty throttling.
      
       - oom reports and memory.stat shouldn't show confusing negative usage.
      
       - tree_usage() already avoids negatives.
      
      Avoid returning negative page counts from mem_cgroup_read_stat() and
      convert it to unsigned.
      
      [akpm@linux-foundation.org: fix old typo while we're in there]
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      08a1208a
    • Tejun Heo's avatar
      Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem" · 205f6761
      Tejun Heo authored
      commit 0c986253 upstream.
      
      This reverts commit d59cfc09.
      
      d59cfc09 ("sched, cgroup: replace signal_struct->group_rwsem with
      a global percpu_rwsem") and b5ba75b5 ("cgroup: simplify
      threadgroup locking") changed how cgroup synchronizes against task
      fork and exits so that it uses global percpu_rwsem instead of
      per-process rwsem; unfortunately, the write [un]lock paths of
      percpu_rwsem always involve synchronize_rcu_expedited() which turned
      out to be too expensive.
      
      Improvements for percpu_rwsem are scheduled to be merged in the coming
      v4.4-rc1 merge window which alleviates this issue.  For now, revert
      the two commits to restore per-process rwsem.  They will be re-applied
      for the v4.4-rc1 merge window.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.comReported-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      205f6761
    • Tejun Heo's avatar
      Revert "cgroup: simplify threadgroup locking" · 38b329c2
      Tejun Heo authored
      commit f9f9e7b7 upstream.
      
      This reverts commit b5ba75b5.
      
      d59cfc09 ("sched, cgroup: replace signal_struct->group_rwsem with
      a global percpu_rwsem") and b5ba75b5 ("cgroup: simplify
      threadgroup locking") changed how cgroup synchronizes against task
      fork and exits so that it uses global percpu_rwsem instead of
      per-process rwsem; unfortunately, the write [un]lock paths of
      percpu_rwsem always involve synchronize_rcu_expedited() which turned
      out to be too expensive.
      
      Improvements for percpu_rwsem are scheduled to be merged in the coming
      v4.4-rc1 merge window which alleviates this issue.  For now, revert
      the two commits to restore per-process rwsem.  They will be re-applied
      for the v4.4-rc1 merge window.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.comReported-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      38b329c2
    • Christian Borntraeger's avatar
      s390/boot/decompression: disable floating point in decompressor · 048d7e86
      Christian Borntraeger authored
      commit adc0b7fb upstream.
      
      my gcc 5.1 used an ldgr instruction with a register != 0,2,4,6 for
      spilling/filling into a floating point register in our decompressor.
      
      This will cause an AFP-register data exception as the decompressor
      did not setup the additional floating point registers via cr0.
      That causes a program check loop that looked like a hang with
      one "Uncompressing Linux... " message (directly booted via kvm)
      or a loop of "Uncompressing Linux... " messages (when booted via
      zipl boot loader).
      
      The offending code in my build was
      
         48e400:       e3 c0 af ff ff 71       lay     %r12,-1(%r10)
      -->48e406:       b3 c1 00 1c             ldgr    %f1,%r12
         48e40a:       ec 6c 01 22 02 7f       clij    %r6,2,12,0x48e64e
      
      but gcc could do spilling into an fpr at any function. We can
      simply disable floating point support at that early stage.
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Acked-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      048d7e86
    • Martin Schwidefsky's avatar
      s390/compat: correct uc_sigmask of the compat signal frame · 2ef005e0
      Martin Schwidefsky authored
      commit 8d4bd0ed upstream.
      
      The uc_sigmask in the ucontext structure is an array of words to keep
      the 64 signal bits (or 1024 if you ask glibc but the kernel sigset_t
      only has 64 bits).
      
      For 64 bit the sigset_t contains a single 8 byte word, but for 31 bit
      there are two 4 byte words. The compat signal handler code uses a
      simple copy of the 64 bit sigset_t to the 31 bit compat_sigset_t.
      As s390 is a big-endian architecture this is incorrect, the two words
      in the 31 bit sigset_t array need to be swapped.
      Reported-by: default avatarStefan Liebler <stli@linux.vnet.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2ef005e0
    • Peter Zijlstra's avatar
      sched/core: Fix TASK_DEAD race in finish_task_switch() · 0738f699
      Peter Zijlstra authored
      commit 95913d97 upstream.
      
      So the problem this patch is trying to address is as follows:
      
              CPU0                            CPU1
      
              context_switch(A, B)
                                              ttwu(A)
                                                LOCK A->pi_lock
                                                A->on_cpu == 0
              finish_task_switch(A)
                prev_state = A->state  <-.
                WMB                      |
                A->on_cpu = 0;           |
                UNLOCK rq0->lock         |
                                         |    context_switch(C, A)
                                         `--  A->state = TASK_DEAD
                prev_state == TASK_DEAD
                  put_task_struct(A)
                                              context_switch(A, C)
                                              finish_task_switch(A)
                                                A->state == TASK_DEAD
                                                  put_task_struct(A)
      
      The argument being that the WMB will allow the load of A->state on CPU0
      to cross over and observe CPU1's store of A->state, which will then
      result in a double-drop and use-after-free.
      
      Now the comment states (and this was true once upon a long time ago)
      that we need to observe A->state while holding rq->lock because that
      will order us against the wakeup; however the wakeup will not in fact
      acquire (that) rq->lock; it takes A->pi_lock these days.
      
      We can obviously fix this by upgrading the WMB to an MB, but that is
      expensive, so we'd rather avoid that.
      
      The alternative this patch takes is: smp_store_release(&A->on_cpu, 0),
      which avoids the MB on some archs, but not important ones like ARM.
      Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Cc: manfred@colorfullife.com
      Cc: will.deacon@arm.com
      Fixes: e4a52bcb ("sched: Remove rq->lock from the first half of ttwu()")
      Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0738f699
    • Ricardo Ribalda Delgado's avatar
      leds/led-class: Add missing put_device() · 88d508eb
      Ricardo Ribalda Delgado authored
      commit e5b5a61f upstream.
      
      Devices found by class_find_device must be freed with put_device().
      Otherwise the reference count will not work properly.
      
      Fixes: a96aa64c ("leds/led-class: Handle LEDs with the same name")
      Reported-by: default avatarAlan Tull <delicious.quinoa@gmail.com>
      Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
      Signed-off-by: default avatarJacek Anaszewski <j.anaszewski@samsung.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      88d508eb
    • Takashi Iwai's avatar
      leds:lp55xx: Correct Kconfig dependency for f/w user helper · 24f0c28d
      Takashi Iwai authored
      commit 2338f73d upstream.
      
      The commit [b6789320: leds:lp55xx: fix firmware loading error]
      tries to address the firmware file handling with user helper, but it
      sets a wrong Kconfig CONFIG_FW_LOADER_USER_HELPER_FALLBACK.  Since the
      wrong option was enabled, the system got a regression -- it suffers
      from the unexpected long delays for non-present firmware files.
      
      This patch corrects the Kconfig dependency to the right one,
      CONFIG_FW_LOADER_USER_HELPER.  This doesn't change the fallback
      behavior but only enables UMH when needed.
      
      Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=944661
      Fixes: b6789320 ('leds:lp55xx: fix firmware loading error')
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarJacek Anaszewski <j.anaszewski@samsung.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      24f0c28d
    • Vitaly Kuznetsov's avatar
      x86/xen: Support kexec/kdump in HVM guests by doing a soft reset · a13999ec
      Vitaly Kuznetsov authored
      commit 0b34a166 upstream.
      
      Currently there is a number of issues preventing PVHVM Xen guests from
      doing successful kexec/kdump:
      
        - Bound event channels.
        - Registered vcpu_info.
        - PIRQ/emuirq mappings.
        - shared_info frame after XENMAPSPACE_shared_info operation.
        - Active grant mappings.
      
      Basically, newly booted kernel stumbles upon already set up Xen
      interfaces and there is no way to reestablish them. In Xen-4.7 a new
      feature called 'soft reset' is coming. A guest performing kexec/kdump
      operation is supposed to call SCHEDOP_shutdown hypercall with
      SHUTDOWN_soft_reset reason before jumping to new kernel. Hypervisor
      (with some help from toolstack) will do full domain cleanup (but
      keeping its memory and vCPU contexts intact) returning the guest to
      the state it had when it was first booted and thus allowing it to
      start over.
      
      Doing SHUTDOWN_soft_reset on Xen hypervisors which don't support it is
      probably OK as by default all unknown shutdown reasons cause domain
      destroy with a message in toolstack log: 'Unknown shutdown reason code
      5. Destroying domain.'  which gives a clue to what the problem is and
      eliminates false expectations.
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a13999ec
    • Stephen Smalley's avatar
      x86/mm: Set NX on gap between __ex_table and rodata · 3861de20
      Stephen Smalley authored
      commit ab76f7b4 upstream.
      
      Unused space between the end of __ex_table and the start of
      rodata can be left W+x in the kernel page tables.  Extend the
      setting of the NX bit to cover this gap by starting from
      text_end rather than rodata_start.
      
        Before:
        ---[ High Kernel Mapping ]---
        0xffffffff80000000-0xffffffff81000000          16M                               pmd
        0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
        0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
        0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB x  pte
        0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
        0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
        0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
        0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
        0xffffffff82200000-0xffffffffa0000000         478M                               pmd
      
        After:
        ---[ High Kernel Mapping ]---
        0xffffffff80000000-0xffffffff81000000          16M                               pmd
        0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
        0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
        0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB NX pte
        0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
        0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
        0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
        0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
        0xffffffff82200000-0xffffffffa0000000         478M                               pmd
      Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.govSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3861de20
    • Thomas Gleixner's avatar
      x86/process: Add proper bound checks in 64bit get_wchan() · 7450c228
      Thomas Gleixner authored
      commit eddd3826 upstream.
      
      Dmitry Vyukov reported the following using trinity and the memory
      error detector AddressSanitizer
      (https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).
      
      [ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
      address ffff88002e280000
      [ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
      the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
      [ 124.578633] Accessed by thread T10915:
      [ 124.579295] inlined in describe_heap_address
      ./arch/x86/mm/asan/report.c:164
      [ 124.579295] #0 ffffffff810dd277 in asan_report_error
      ./arch/x86/mm/asan/report.c:278
      [ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
      ./arch/x86/mm/asan/asan.c:37
      [ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
      [ 124.581893] #3 ffffffff8107c093 in get_wchan
      ./arch/x86/kernel/process_64.c:444
      
      The address checks in the 64bit implementation of get_wchan() are
      wrong in several ways:
      
       - The lower bound of the stack is not the start of the stack
         page. It's the start of the stack page plus sizeof (struct
         thread_info)
      
       - The upper bound must be:
      
             top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long).
      
         The 2 * sizeof(unsigned long) is required because the stack pointer
         points at the frame pointer. The layout on the stack is: ... IP FP
         ... IP FP. So we need to make sure that both IP and FP are in the
         bounds.
      
      Fix the bound checks and get rid of the mix of numeric constants, u64
      and unsigned long. Making all unsigned long allows us to use the same
      function for 32bit as well.
      
      Use READ_ONCE() when accessing the stack. This does not prevent a
      concurrent wakeup of the task and the stack changing, but at least it
      avoids TOCTOU.
      
      Also check task state at the end of the loop. Again that does not
      prevent concurrent changes, but it avoids walking for nothing.
      
      Add proper comments while at it.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: default avatarBorislav Petkov <bp@alien8.de>
      Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andrey Konovalov <andreyknvl@google.com>
      Cc: Kostya Serebryany <kcc@google.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: kasan-dev <kasan-dev@googlegroups.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
      Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7450c228
    • Lee, Chun-Yi's avatar
      x86/kexec: Fix kexec crash in syscall kexec_file_load() · 1e0b5616
      Lee, Chun-Yi authored
      commit e3c41e37 upstream.
      
      The original bug is a page fault crash that sometimes happens
      on big machines when preparing ELF headers:
      
          BUG: unable to handle kernel paging request at ffffc90613fc9000
          IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260
      
      The bug is caused by us under-counting the number of memory ranges
      and subsequently not allocating enough ELF header space for them.
      The bug is typically masked on smaller systems, because the ELF header
      allocation is rounded up to the next page.
      
      This patch modifies the code in fill_up_crash_elf_data() by using
      walk_system_ram_res() instead of walk_system_ram_range() to correctly
      count the max number of crash memory ranges. That's because the
      walk_system_ram_range() filters out small memory regions that
      reside in the same page, but walk_system_ram_res() does not.
      
      Here's how I found the bug:
      
      After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
      the code uses walk_system_ram_res() to fill-in crash memory regions information
      to the program header, so it counts those small memory regions that
      reside in a page area.
      
      But, when the kernel was using walk_system_ram_range() in
      fill_up_crash_elf_data() to count the number of crash memory regions,
      it filters out small regions.
      
      I printed those small memory regions, for example:
      
        kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0
      
      Based on the code in walk_system_ram_range(), this memory region
      will be filtered out:
      
        pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593
        end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593
        end_pfn - pfn = 0x77593 - 0x77593 = 0  <=== if (end_pfn > pfn) is FALSE
      
      So, the max_nr_ranges that's counted by the kernel doesn't include
      small memory regions - causing us to under-allocate the required space.
      That causes the page fault crash that happens in a later code path
      when preparing ELF headers.
      
      This bug is not easy to reproduce on small machines that have few
      CPUs, because the allocated page aligned ELF buffer has more free
      space to cover those small memory regions' PT_LOAD headers.
      Signed-off-by: default avatarLee, Chun-Yi <jlee@suse.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Jiang Liu <jiang.liu@linux.intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Viresh Kumar <viresh.kumar@linaro.org>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: kexec@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1e0b5616
    • Matt Fleming's avatar
      x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down · 496c2053
      Matt Fleming authored
      commit a5caa209 upstream.
      
      Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced
      that signals that the firmware PE/COFF loader supports splitting
      code and data sections of PE/COFF images into separate EFI
      memory map entries. This allows the kernel to map those regions
      with strict memory protections, e.g. EFI_MEMORY_RO for code,
      EFI_MEMORY_XP for data, etc.
      
      Unfortunately, an unwritten requirement of this new feature is
      that the regions need to be mapped with the same offsets
      relative to each other as observed in the EFI memory map. If
      this is not done crashes like this may occur,
      
        BUG: unable to handle kernel paging request at fffffffefe6086dd
        IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd
        Call Trace:
         [<ffffffff8104c90e>] efi_call+0x7e/0x100
         [<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90
         [<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70
         [<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392
         [<ffffffff81f37e1b>] start_kernel+0x38a/0x417
         [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c
         [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef
      
      Here 0xfffffffefe6086dd refers to an address the firmware
      expects to be mapped but which the OS never claimed was mapped.
      The issue is that included in these regions are relative
      addresses to other regions which were emitted by the firmware
      toolchain before the "splitting" of sections occurred at
      runtime.
      
      Needless to say, we don't satisfy this unwritten requirement on
      x86_64 and instead map the EFI memory map entries in reverse
      order. The above crash is almost certainly triggerable with any
      kernel newer than v3.13 because that's when we rewrote the EFI
      runtime region mapping code, in commit d2f7cbe7 ("x86/efi:
      Runtime services virtual mapping"). For kernel versions before
      v3.13 things may work by pure luck depending on the
      fragmentation of the kernel virtual address space at the time we
      map the EFI regions.
      
      Instead of mapping the EFI memory map entries in reverse order,
      where entry N has a higher virtual address than entry N+1, map
      them in the same order as they appear in the EFI memory map to
      preserve this relative offset between regions.
      
      This patch has been kept as small as possible with the intention
      that it should be applied aggressively to stable and
      distribution kernels. It is very much a bugfix rather than
      support for a new feature, since when EFI_PROPERTIES_TABLE is
      enabled we must map things as outlined above to even boot - we
      have no way of asking the firmware not to split the code/data
      regions.
      
      In fact, this patch doesn't even make use of the more strict
      memory protections available in UEFI v2.5. That will come later.
      Suggested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Reported-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Chun-Yi <jlee@suse.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: James Bottomley <JBottomley@Odin.com>
      Cc: Lee, Chun-Yi <jlee@suse.com>
      Cc: Leif Lindholm <leif.lindholm@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Jones <pjones@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.ukSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      496c2053
    • Dirk Müller's avatar
      Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS · bc533fbc
      Dirk Müller authored
      commit d2922422 upstream.
      
      The cpu feature flags are not ever going to change, so warning
      everytime can cause a lot of kernel log spam
      (in our case more than 10GB/hour).
      
      The warning seems to only occur when nested virtualization is
      enabled, so it's probably triggered by a KVM bug.  This is a
      sensible and safe change anyway, and the KVM bug fix might not
      be suitable for stable releases anyway.
      Signed-off-by: default avatarDirk Mueller <dmueller@suse.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bc533fbc