1. 21 Apr, 2018 8 commits
    • Uwe Kleine-König's avatar
      MAINTAINERS: add personal addresses for Sascha and Uwe · 1551cf74
      Uwe Kleine-König authored
      The idea behind using kernel@pengutronix.de (i.e. the mail alias for the
      kernel people at Pengutronix) as email address was to have a backup when
      a given developer is on vacation or run over by a bus. Make this more
      explicit by adding the alias as reviewer and use the personal address
      for Sascha and me.
      
      Link: http://lkml.kernel.org/r/20180413083312.11213-1-u.kleine-koenig@pengutronix.deSigned-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
      Acked-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1551cf74
    • Andrey Konovalov's avatar
      kasan: add no_sanitize attribute for clang builds · 12c8f25a
      Andrey Konovalov authored
      KASAN uses the __no_sanitize_address macro to disable instrumentation of
      particular functions.  Right now it's defined only for GCC build, which
      causes false positives when clang is used.
      
      This patch adds a definition for clang.
      
      Note, that clang's revision 329612 or higher is required.
      
      [andreyknvl@google.com: remove redundant #ifdef CONFIG_KASAN check]
        Link: http://lkml.kernel.org/r/c79aa31a2a2790f6131ed607c58b0dd45dd62a6c.1523967959.git.andreyknvl@google.com
      Link: http://lkml.kernel.org/r/4ad725cc903f8534f8c8a60f0daade5e3d674f8d.1523554166.git.andreyknvl@google.comSigned-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Acked-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: David Woodhouse <dwmw@amazon.co.uk>
      Cc: Andrey Konovalov <andreyknvl@google.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Paul Lawrence <paullawrence@google.com>
      Cc: Sandipan Das <sandipan@linux.vnet.ibm.com>
      Cc: Kees Cook <keescook@chromium.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      12c8f25a
    • Ioan Nicu's avatar
      rapidio: fix rio_dma_transfer error handling · c5157b76
      Ioan Nicu authored
      Some of the mport_dma_req structure members were initialized late
      inside the do_dma_request() function, just before submitting the
      request to the dma engine. But we have some error branches before
      that. In case of such an error, the code would return on the error
      path and trigger the calling of dma_req_free() with a req structure
      which is not completely initialized. This causes a NULL pointer
      dereference in dma_req_free().
      
      This patch fixes these error branches by making sure that all
      necessary mport_dma_req structure members are initialized in
      rio_dma_transfer() immediately after the request structure gets
      allocated.
      
      Link: http://lkml.kernel.org/r/20180412150605.GA31409@nokia.com
      Fixes: bbd876ad ("rapidio: use a reference count for struct mport_dma_req")
      Signed-off-by: default avatarIoan Nicu <ioan.nicu.ext@nokia.com>
      Tested-by: default avatarAlexander Sverdlin <alexander.sverdlin@nokia.com>
      Acked-by: default avatarAlexandre Bounine <alex.bou9@gmail.com>
      Cc: Barry Wood <barry.wood@idt.com>
      Cc: Matt Porter <mporter@kernel.crashing.org>
      Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Frank Kunz <frank.kunz@nokia.com>
      Cc: <stable@vger.kernel.org>	[4.6+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c5157b76
    • Naoya Horiguchi's avatar
      mm: enable thp migration for shmem thp · e71769ae
      Naoya Horiguchi authored
      My testing for the latest kernel supporting thp migration showed an
      infinite loop in offlining the memory block that is filled with shmem
      thps.  We can get out of the loop with a signal, but kernel should return
      with failure in this case.
      
      What happens in the loop is that scan_movable_pages() repeats returning
      the same pfn without any progress.  That's because page migration always
      fails for shmem thps.
      
      In memory offline code, memory blocks containing unmovable pages should be
      prevented from being offline targets by has_unmovable_pages() inside
      start_isolate_page_range().  So it's possible to change migratability for
      non-anonymous thps to avoid the issue, but it introduces more complex and
      thp-specific handling in migration code, so it might not good.
      
      So this patch is suggesting to fix the issue by enabling thp migration for
      shmem thp.  Both of anon/shmem thp are migratable so we don't need
      precheck about the type of thps.
      
      Link: http://lkml.kernel.org/r/20180406030706.GA2434@hori1.linux.bs1.fc.nec.co.jp
      Fixes: commit 72b39cfc ("mm, memory_hotplug: do not fail offlining too early")
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Zi Yan <zi.yan@sent.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Michal Hocko <mhocko@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e71769ae
    • Greg Thelen's avatar
      writeback: safer lock nesting · 2e898e4c
      Greg Thelen authored
      lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if
      the page's memcg is undergoing move accounting, which occurs when a
      process leaves its memcg for a new one that has
      memory.move_charge_at_immigrate set.
      
      unlocked_inode_to_wb_begin,end() use spin_lock_irq/spin_unlock_irq() if
      the given inode is switching writeback domains.  Switches occur when
      enough writes are issued from a new domain.
      
      This existing pattern is thus suspicious:
          lock_page_memcg(page);
          unlocked_inode_to_wb_begin(inode, &locked);
          ...
          unlocked_inode_to_wb_end(inode, locked);
          unlock_page_memcg(page);
      
      If both inode switch and process memcg migration are both in-flight then
      unlocked_inode_to_wb_end() will unconditionally enable interrupts while
      still holding the lock_page_memcg() irq spinlock.  This suggests the
      possibility of deadlock if an interrupt occurs before unlock_page_memcg().
      
          truncate
          __cancel_dirty_page
          lock_page_memcg
          unlocked_inode_to_wb_begin
          unlocked_inode_to_wb_end
          <interrupts mistakenly enabled>
                                          <interrupt>
                                          end_page_writeback
                                          test_clear_page_writeback
                                          lock_page_memcg
                                          <deadlock>
          unlock_page_memcg
      
      Due to configuration limitations this deadlock is not currently possible
      because we don't mix cgroup writeback (a cgroupv2 feature) and
      memory.move_charge_at_immigrate (a cgroupv1 feature).
      
      If the kernel is hacked to always claim inode switching and memcg
      moving_account, then this script triggers lockup in less than a minute:
      
        cd /mnt/cgroup/memory
        mkdir a b
        echo 1 > a/memory.move_charge_at_immigrate
        echo 1 > b/memory.move_charge_at_immigrate
        (
          echo $BASHPID > a/cgroup.procs
          while true; do
            dd if=/dev/zero of=/mnt/big bs=1M count=256
          done
        ) &
        while true; do
          sync
        done &
        sleep 1h &
        SLEEP=$!
        while true; do
          echo $SLEEP > a/cgroup.procs
          echo $SLEEP > b/cgroup.procs
        done
      
      The deadlock does not seem possible, so it's debatable if there's any
      reason to modify the kernel.  I suggest we should to prevent future
      surprises.  And Wang Long said "this deadlock occurs three times in our
      environment", so there's more reason to apply this, even to stable.
      Stable 4.4 has minor conflicts applying this patch.  For a clean 4.4 patch
      see "[PATCH for-4.4] writeback: safer lock nesting"
      https://lkml.org/lkml/2018/4/11/146
      
      Wang Long said "this deadlock occurs three times in our environment"
      
      [gthelen@google.com: v4]
        Link: http://lkml.kernel.org/r/20180411084653.254724-1-gthelen@google.com
      [akpm@linux-foundation.org: comment tweaks, struct initialization simplification]
      Change-Id: Ibb773e8045852978f6207074491d262f1b3fb613
      Link: http://lkml.kernel.org/r/20180410005908.167976-1-gthelen@google.com
      Fixes: 682aa8e1 ("writeback: implement unlocked_inode_to_wb transaction and use it for stat updates")
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Reported-by: default avatarWang Long <wanglong19@meituan.com>
      Acked-by: default avatarWang Long <wanglong19@meituan.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: <stable@vger.kernel.org>	[v4.2+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2e898e4c
    • Huang Ying's avatar
      mm, pagemap: fix swap offset value for PMD migration entry · 88c28f24
      Huang Ying authored
      The swap offset reported by /proc/<pid>/pagemap may be not correct for
      PMD migration entries.  If addr passed into pagemap_pmd_range() isn't
      aligned with PMD start address, the swap offset reported doesn't
      reflect this.  And in the loop to report information of each sub-page,
      the swap offset isn't increased accordingly as that for PFN.
      
      This may happen after opening /proc/<pid>/pagemap and seeking to a page
      whose address doesn't align with a PMD start address.  I have verified
      this with a simple test program.
      
      BTW: migration swap entries have PFN information, do we need to restrict
      whether to show them?
      
      [akpm@linux-foundation.org: fix typo, per Huang, Ying]
      Link: http://lkml.kernel.org/r/20180408033737.10897-1-ying.huang@intel.comSigned-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Andrei Vagin <avagin@openvz.org>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: "Jerome Glisse" <jglisse@redhat.com>
      Cc: Daniel Colascione <dancol@google.com>
      Cc: Zi Yan <zi.yan@cs.rutgers.edu>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      88c28f24
    • Michal Hocko's avatar
      mm: fix do_pages_move status handling · 8f175cf5
      Michal Hocko authored
      Li Wang has reported that LTP move_pages04 test fails with the current
      tree:
      
      LTP move_pages04:
         TFAIL  :  move_pages04.c:143: status[1] is EPERM, expected EFAULT
      
      The test allocates an array of two pages, one is present while the other
      is not (resp.  backed by zero page) and it expects EFAULT for the second
      page as the man page suggests.  We are reporting EPERM which doesn't make
      any sense and this is a result of a bug from cf5f16b23ec9 ("mm: unclutter
      THP migration").
      
      do_pages_move tries to handle as many pages in one batch as possible so we
      queue all pages with the same node target together and that corresponds to
      [start, i] range which is then used to update status array.
      add_page_for_migration will correctly notice the zero (resp.  !present)
      page and returns with EFAULT which gets written to the status.  But if
      this is the last page in the array we do not update start and so the last
      store_status after the loop will overwrite the range of the last batch
      with NUMA_NO_NODE (which corresponds to EPERM).
      
      Fix this by simply bailing out from the last flush if the pagelist is
      empty as there is clearly nothing more to do.
      
      Link: http://lkml.kernel.org/r/20180418121255.334-1-mhocko@kernel.org
      Fixes: cf5f16b23ec9 ("mm: unclutter THP migration")
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Reported-by: default avatarLi Wang <liwang@redhat.com>
      Tested-by: default avatarLi Wang <liwang@redhat.com>
      Cc: Zi Yan <zi.yan@cs.rutgers.edu>
      Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8f175cf5
    • Kees Cook's avatar
      fork: unconditionally clear stack on fork · e01e8063
      Kees Cook authored
      One of the classes of kernel stack content leaks[1] is exposing the
      contents of prior heap or stack contents when a new process stack is
      allocated.  Normally, those stacks are not zeroed, and the old contents
      remain in place.  In the face of stack content exposure flaws, those
      contents can leak to userspace.
      
      Fixing this will make the kernel no longer vulnerable to these flaws, as
      the stack will be wiped each time a stack is assigned to a new process.
      There's not a meaningful change in runtime performance; it almost looks
      like it provides a benefit.
      
      Performing back-to-back kernel builds before:
      	Run times: 157.86 157.09 158.90 160.94 160.80
      	Mean: 159.12
      	Std Dev: 1.54
      
      and after:
      	Run times: 159.31 157.34 156.71 158.15 160.81
      	Mean: 158.46
      	Std Dev: 1.46
      
      Instead of making this a build or runtime config, Andy Lutomirski
      recommended this just be enabled by default.
      
      [1] A noisy search for many kinds of stack content leaks can be seen here:
      https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=linux+kernel+stack+leak
      
      I did some more with perf and cycle counts on running 100,000 execs of
      /bin/true.
      
      before:
      Cycles: 218858861551 218853036130 214727610969 227656844122 224980542841
      Mean:  221015379122.60
      Std Dev: 4662486552.47
      
      after:
      Cycles: 213868945060 213119275204 211820169456 224426673259 225489986348
      Mean:  217745009865.40
      Std Dev: 5935559279.99
      
      It continues to look like it's faster, though the deviation is rather
      wide, but I'm not sure what I could do that would be less noisy.  I'm
      open to ideas!
      
      Link: http://lkml.kernel.org/r/20180221021659.GA37073@beastSigned-off-by: default avatarKees Cook <keescook@chromium.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Laura Abbott <labbott@redhat.com>
      Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e01e8063
  2. 20 Apr, 2018 13 commits
    • David Howells's avatar
      vfs: Undo an overly zealous MS_RDONLY -> SB_RDONLY conversion · a9e5b732
      David Howells authored
      In do_mount() when the MS_* flags are being converted to MNT_* flags,
      MS_RDONLY got accidentally convered to SB_RDONLY.
      
      Undo this change.
      
      Fixes: e462ec50 ("VFS: Differentiate mount flags (MS_*) from internal superblock flags")
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a9e5b732
    • David Howells's avatar
      afs: Fix server record deletion · 66062592
      David Howells authored
      AFS server records get removed from the net->fs_servers tree when
      they're deleted, but not from the net->fs_addresses{4,6} lists, which
      can lead to an oops in afs_find_server() when a server record has been
      removed, for instance during rmmod.
      
      Fix this by deleting the record from the by-address lists before posting
      it for RCU destruction.
      
      The reason this hasn't been noticed before is that the fileserver keeps
      probing the local cache manager, thereby keeping the service record
      alive, so the oops would only happen when a fileserver eventually gets
      bored and stops pinging or if the module gets rmmod'd and a call comes
      in from the fileserver during the window between the server records
      being destroyed and the socket being closed.
      
      The oops looks something like:
      
        BUG: unable to handle kernel NULL pointer dereference at 000000000000001c
        ...
        Workqueue: kafsd afs_process_async_call [kafs]
        RIP: 0010:afs_find_server+0x271/0x36f [kafs]
        ...
        Call Trace:
         afs_deliver_cb_init_call_back_state3+0x1f2/0x21f [kafs]
         afs_deliver_to_call+0x1ee/0x5e8 [kafs]
         afs_process_async_call+0x5b/0xd0 [kafs]
         process_one_work+0x2c2/0x504
         worker_thread+0x1d4/0x2ac
         kthread+0x11f/0x127
         ret_from_fork+0x24/0x30
      
      Fixes: d2ddc776 ("afs: Overhaul volume and server record caching and fileserver rotation")
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      66062592
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · a72db42c
      Linus Torvalds authored
      Pull networking fixes from David Miller:
      
       1) Unbalanced refcounting in TIPC, from Jon Maloy.
      
       2) Only allow TCP_MD5SIG to be set on sockets in close or listen state.
          Once the connection is established it makes no sense to change this.
          From Eric Dumazet.
      
       3) Missing attribute validation in neigh_dump_table(), also from Eric
          Dumazet.
      
       4) Fix address comparisons in SCTP, from Xin Long.
      
       5) Neigh proxy table clearing can deadlock, from Wolfgang Bumiller.
      
       6) Fix tunnel refcounting in l2tp, from Guillaume Nault.
      
       7) Fix double list insert in team driver, from Paolo Abeni.
      
       8) af_vsock.ko module was accidently made unremovable, from Stefan
          Hajnoczi.
      
       9) Fix reference to freed llc_sap object in llc stack, from Cong Wang.
      
      10) Don't assume netdevice struct is DMA'able memory in virtio_net
          driver, from Michael S. Tsirkin.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (62 commits)
        net/smc: fix shutdown in state SMC_LISTEN
        bnxt_en: Fix memory fault in bnxt_ethtool_init()
        virtio_net: sparse annotation fix
        virtio_net: fix adding vids on big-endian
        virtio_net: split out ctrl buffer
        net: hns: Avoid action name truncation
        docs: ip-sysctl.txt: fix name of some ipv6 variables
        vmxnet3: fix incorrect dereference when rxvlan is disabled
        llc: hold llc_sap before release_sock()
        MAINTAINERS: Direct networking documentation changes to netdev
        atm: iphase: fix spelling mistake: "Tansmit" -> "Transmit"
        net: qmi_wwan: add Wistron Neweb D19Q1
        net: caif: fix spelling mistake "UKNOWN" -> "UNKNOWN"
        net: stmmac: Disable ACS Feature for GMAC >= 4
        net: mvpp2: Fix DMA address mask size
        net: change the comment of dev_mc_init
        net: qualcomm: rmnet: Fix warning seen with fill_info
        tun: fix vlan packet truncation
        tipc: fix infinite loop when dumping link monitor summary
        tipc: fix use-after-free in tipc_nametbl_stop
        ...
      a72db42c
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · b9abdcfd
      Linus Torvalds authored
      Pull vfs fixes from Al Viro:
       "Assorted fixes.
      
        Some of that is only a matter with fault injection (broken handling of
        small allocation failure in various mount-related places), but the
        last one is a root-triggerable stack overflow, and combined with
        userns it gets really nasty ;-/"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        Don't leak MNT_INTERNAL away from internal mounts
        mm,vmscan: Allow preallocating memory for register_shrinker().
        rpc_pipefs: fix double-dput()
        orangefs_kill_sb(): deal with allocation failures
        jffs2_kill_sb(): deal with failed allocations
        hypfs_kill_super(): deal with failed allocations
      b9abdcfd
    • Linus Torvalds's avatar
      Merge tag 'ecryptfs-4.17-rc2-fixes' of... · 43f70c96
      Linus Torvalds authored
      Merge tag 'ecryptfs-4.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
      
      Pull eCryptfs fixes from Tyler Hicks:
       "Minor cleanups and a bug fix to completely ignore unencrypted
        filenames in the lower filesystem when filename encryption is enabled
        at the eCryptfs layer"
      
      * tag 'ecryptfs-4.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
        eCryptfs: don't pass up plaintext names when using filename encryption
        ecryptfs: fix spelling mistake: "cadidate" -> "candidate"
        ecryptfs: lookup: Don't check if mount_crypt_stat is NULL
      43f70c96
    • Linus Torvalds's avatar
      Merge tag 'for_v4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs · 0d9cf33b
      Linus Torvalds authored
       - isofs memory leak fix
      
       - two fsnotify fixes of event mask handling
      
       - udf fix of UTF-16 handling
      
       - couple other smaller cleanups
      
      * tag 'for_v4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
        udf: Fix leak of UTF-16 surrogates into encoded strings
        fs: ext2: Adding new return type vm_fault_t
        isofs: fix potential memory leak in mount option parsing
        MAINTAINERS: add an entry for FSNOTIFY infrastructure
        fsnotify: fix typo in a comment about mark->g_list
        fsnotify: fix ignore mask logic in send_to_group()
        isofs compress: Remove VLA usage
        fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_init
        fanotify: fix logic of events on child
      0d9cf33b
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid · 4d189053
      Linus Torvalds authored
      Pull HID updates from Jiri Kosina:
      
       - suspend/resume handling fix for Raydium I2C-connected touchscreen
         from Aaron Ma
      
       - protocol fixup for certain BT-connected Wacoms from Aaron Armstrong
         Skomra
      
       - battery level reporting fix on BT-connected mice from Dmitry Torokhov
      
       - hidraw race condition fix from Rodrigo Rivas Costa
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
        HID: i2c-hid: fix inverted return value from i2c_hid_command()
        HID: i2c-hid: Fix resume issue on Raydium touchscreen device
        HID: wacom: bluetooth: send exit report for recent Bluetooth devices
        HID: hidraw: Fix crash on HIDIOCGFEATURE with a destroyed device
        HID: input: fix battery level reporting on BT mice
      4d189053
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching · 41e3bef5
      Linus Torvalds authored
      Pull livepatching fix from Jiri Kosina:
       "Shadow variable API list_head initialization fix from Petr Mladek"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
        livepatch: Allow to call a custom callback when freeing shadow variables
        livepatch: Initialize shadow variables safely by a custom callback
      41e3bef5
    • Linus Torvalds's avatar
      Merge tag 'for-linus-4.17-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip · 36e584de
      Linus Torvalds authored
      Pull xen fixes from Juergen Gross:
      
       - some fixes of kmalloc() flags
      
       - one fix of the xenbus driver
      
       - an update of the pv sound driver interface needed for a driver which
         will go through the sound tree
      
      * tag 'for-linus-4.17-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
        xen: xenbus_dev_frontend: Really return response string
        xen/sndif: Sync up with the canonical definition in Xen
        xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_reg_add
        xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in xen_pcibk_config_quirks_init
        xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_device_alloc
        xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_init_device
        xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_probe
      36e584de
    • Linus Torvalds's avatar
      Merge tag 'mips_fixes_4.17_1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips · 854da238
      Linus Torvalds authored
      Pull MIPS fixes from James Hogan:
      
       - io: Add barriers to read*() & write*()
      
       - dts: Fix boston PCI bus DTC warnings (4.17)
      
       - memset: Several corner case fixes (one 3.10, others longer)
      
      * tag 'mips_fixes_4.17_1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
        MIPS: uaccess: Add micromips clobbers to bzero invocation
        MIPS: memset.S: Fix clobber of v1 in last_fixup
        MIPS: memset.S: Fix return of __clear_user from Lpartial_fixup
        MIPS: memset.S: EVA & fault support for small_memset
        MIPS: dts: Boston: Fix PCI bus dtc warnings:
        MIPS: io: Add barrier after register read in readX()
        MIPS: io: Prevent compiler reordering writeX()
      854da238
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · d08de37b
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
      
       - Fix an off-by-one bug in our alternative asm patching which leads to
         incorrectly patched code. This bug lay dormant for nearly 10 years
         but we finally hit it due to a recent change.
      
       - Fix lockups when running KVM guests on Power8 due to a missing check
         when a thread that's running KVM comes out of idle.
      
       - Fix an out-of-spec behaviour in the XIVE code (P9 interrupt
         controller).
      
       - Fix EEH handling of bridge MMIO windows.
      
       - Prevent crashes in our RFI fallback flush handler if firmware didn't
         tell us the size of the L1 cache (only seen on simulators).
      
      Thanks to: Benjamin Herrenschmidt, Madhavan Srinivasan, Michael Neuling.
      
      * tag 'powerpc-4.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/kvm: Fix lockups when running KVM guests on Power8
        powerpc/eeh: Fix enabling bridge MMIO windows
        powerpc/xive: Fix trying to "push" an already active pool VP
        powerpc/64s: Default l1d_size to 64K in RFI fallback flush
        powerpc/lib: Fix off-by-one in alternate feature patching
      d08de37b
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · c2d94c52
      Linus Torvalds authored
      Pull s390 fixes and kexec-file-load from Martin Schwidefsky:
       "After the common code kexec patches went in via Andrew we can now push
        the architecture parts to implement the kexec-file-load system call.
      
        Plus a few more bug fixes and cleanups, this includes an update to the
        default configurations"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
        s390/signal: cleanup uapi struct sigaction
        s390: rename default_defconfig to debug_defconfig
        s390: remove gcov defconfig
        s390: update defconfig
        s390: add support for IBM z14 Model ZR1
        s390: remove couple of duplicate includes
        s390/boot: remove unused COMPILE_VERSION and ccflags-y
        s390/nospec: include cpu.h
        s390/decompressor: Ignore file vmlinux.bin.full
        s390/kexec_file: add generated files to .gitignore
        s390/Kconfig: Move kexec config options to "Processor type and features"
        s390/kexec_file: Add ELF loader
        s390/kexec_file: Add crash support to image loader
        s390/kexec_file: Add image loader
        s390/kexec_file: Add kexec_file_load system call
        s390/kexec_file: Add purgatory
        s390/kexec_file: Prepare setup.h for kexec_file_load
        s390/smsgiucv: disable SMSG on module unload
        s390/sclp: avoid potential usage of uninitialized value
      c2d94c52
    • Al Viro's avatar
      Don't leak MNT_INTERNAL away from internal mounts · 16a34adb
      Al Viro authored
      We want it only for the stuff created by SB_KERNMOUNT mounts, *not* for
      their copies.  As it is, creating a deep stack of bindings of /proc/*/ns/*
      somewhere in a new namespace and exiting yields a stack overflow.
      
      Cc: stable@kernel.org
      Reported-by: default avatarAlexander Aring <aring@mojatatu.com>
      Bisected-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
      Tested-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
      Tested-by: default avatarAlexander Aring <aring@mojatatu.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      16a34adb
  3. 19 Apr, 2018 19 commits
    • Ursula Braun's avatar
      net/smc: fix shutdown in state SMC_LISTEN · 1255fcb2
      Ursula Braun authored
      Calling shutdown with SHUT_RD and SHUT_RDWR for a listening SMC socket
      crashes, because
         commit 127f4970 ("net/smc: release clcsock from tcp_listen_worker")
      releases the internal clcsock in smc_close_active() and sets smc->clcsock
      to NULL.
      For SHUT_RD the smc_close_active() call is removed.
      For SHUT_RDWR the kernel_sock_shutdown() call is omitted, since the
      clcsock is already released.
      
      Fixes: 127f4970 ("net/smc: release clcsock from tcp_listen_worker")
      Signed-off-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
      Reported-by: default avatarStephen Hemminger <stephen@networkplumber.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1255fcb2
    • Vasundhara Volam's avatar
      bnxt_en: Fix memory fault in bnxt_ethtool_init() · a60faa60
      Vasundhara Volam authored
      In some firmware images, the length of BNX_DIR_TYPE_PKG_LOG nvram type
      could be greater than the fixed buffer length of 4096 bytes allocated by
      the driver.  This was causing HWRM_NVM_READ to copy more data to the buffer
      than the allocated size, causing general protection fault.
      
      Fix the issue by allocating the exact buffer length returned by
      HWRM_NVM_FIND_DIR_ENTRY, instead of 4096.  Move the kzalloc() call
      into the bnxt_get_pkgver() function.
      
      Fixes: 3ebf6f0a ("bnxt_en: Add installed-package firmware version reporting via Ethtool GDRVINFO")
      Signed-off-by: default avatarVasundhara Volam <vasundhara-v.volam@broadcom.com>
      Signed-off-by: default avatarMichael Chan <michael.chan@broadcom.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a60faa60
    • David S. Miller's avatar
      Merge branch 'virtio-ctrl-buffer-fixes' · 0df8bb01
      David S. Miller authored
      Michael S. Tsirkin says:
      
      ====================
      virtio: ctrl buffer fixes
      
      Here are a couple of fixes related to the virtio control buffer.
      Lightly tested on x86 only.
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0df8bb01
    • Michael S. Tsirkin's avatar
      virtio_net: sparse annotation fix · f4ee703a
      Michael S. Tsirkin authored
      offloads is a buffer in virtio format, should use
      the __virtio64 tag.
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Acked-by: default avatarJason Wang <jasowang@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f4ee703a
    • Michael S. Tsirkin's avatar
      virtio_net: fix adding vids on big-endian · d7fad4c8
      Michael S. Tsirkin authored
      Programming vids (adding or removing them) still passes
      guest-endian values in the DMA buffer. That's wrong
      if guest is big-endian and when virtio 1 is enabled.
      
      Note: this is on top of a previous patch:
      	virtio_net: split out ctrl buffer
      
      Fixes: 9465a7a6 ("virtio_net: enable v1.0 support")
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Acked-by: default avatarJason Wang <jasowang@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d7fad4c8
    • Michael S. Tsirkin's avatar
      virtio_net: split out ctrl buffer · 12e57169
      Michael S. Tsirkin authored
      When sending control commands, virtio net sets up several buffers for
      DMA. The buffers are all part of the net device which means it's
      actually allocated by kvmalloc so it's in theory (on extreme memory
      pressure) possible to get a vmalloc'ed buffer which on some platforms
      means we can't DMA there.
      
      Fix up by moving the DMA buffers into a separate structure.
      Reported-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Suggested-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Acked-by: default avatarJason Wang <jasowang@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      12e57169
    • dann frazier's avatar
      net: hns: Avoid action name truncation · f4ea8911
      dann frazier authored
      When longer interface names are used, the action names exposed in
      /proc/interrupts and /proc/irq/* maybe truncated. For example, when
      using the predictable name algorithm in systemd on a HiSilicon D05,
      I see:
      
        ubuntu@d05-3:~$  grep enahisic2i0-tx /proc/interrupts | sed 's/.* //'
        enahisic2i0-tx0
        enahisic2i0-tx1
        [...]
        enahisic2i0-tx8
        enahisic2i0-tx9
        enahisic2i0-tx1
        enahisic2i0-tx1
        enahisic2i0-tx1
        enahisic2i0-tx1
        enahisic2i0-tx1
        enahisic2i0-tx1
      
      Increase the max ring name length to allow for an interface name
      of IFNAMSIZE. After this change, I now see:
      
        $ grep enahisic2i0-tx /proc/interrupts | sed 's/.* //'
        enahisic2i0-tx0
        enahisic2i0-tx1
        enahisic2i0-tx2
        [...]
        enahisic2i0-tx8
        enahisic2i0-tx9
        enahisic2i0-tx10
        enahisic2i0-tx11
        enahisic2i0-tx12
        enahisic2i0-tx13
        enahisic2i0-tx14
        enahisic2i0-tx15
      Signed-off-by: default avatardann frazier <dann.frazier@canonical.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f4ea8911
    • Olivier Gayot's avatar
      docs: ip-sysctl.txt: fix name of some ipv6 variables · ab913455
      Olivier Gayot authored
      The name of the following proc/sysctl entries were incorrectly
      documented:
      
          /proc/sys/net/ipv6/conf/<interface>/max_dst_opts_number
          /proc/sys/net/ipv6/conf/<interface>/max_hbt_opts_number
          /proc/sys/net/ipv6/conf/<interface>/max_dst_opts_length
          /proc/sys/net/ipv6/conf/<interface>/max_hbt_length
      
      Their name was set to the name of the symbol in the .data field of the
      control table instead of their .proc name.
      Signed-off-by: default avatarOlivier Gayot <olivier.gayot@sigexec.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ab913455
    • Ronak Doshi's avatar
      vmxnet3: fix incorrect dereference when rxvlan is disabled · 65ec0bd1
      Ronak Doshi authored
      vmxnet3_get_hdr_len() is used to calculate the header length which in
      turn is used to calculate the gso_size for skb. When rxvlan offload is
      disabled, vlan tag is present in the header and the function references
      ip header from sizeof(ethhdr) and leads to incorrect pointer reference.
      
      This patch fixes this issue by taking sizeof(vlan_ethhdr) into account
      if vlan tag is present and correctly references the ip hdr.
      Signed-off-by: default avatarRonak Doshi <doshir@vmware.com>
      Acked-by: default avatarGuolin Yang <gyang@vmware.com>
      Acked-by: default avatarLouis Luo <llouis@vmware.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      65ec0bd1
    • Cong Wang's avatar
      llc: hold llc_sap before release_sock() · f7e43672
      Cong Wang authored
      syzbot reported we still access llc->sap in llc_backlog_rcv()
      after it is freed in llc_sap_remove_socket():
      
      Call Trace:
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x1b9/0x294 lib/dump_stack.c:113
       print_address_description+0x6c/0x20b mm/kasan/report.c:256
       kasan_report_error mm/kasan/report.c:354 [inline]
       kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
       __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
       llc_conn_ac_send_sabme_cmd_p_set_x+0x3a8/0x460 net/llc/llc_c_ac.c:785
       llc_exec_conn_trans_actions net/llc/llc_conn.c:475 [inline]
       llc_conn_service net/llc/llc_conn.c:400 [inline]
       llc_conn_state_process+0x4e1/0x13a0 net/llc/llc_conn.c:75
       llc_backlog_rcv+0x195/0x1e0 net/llc/llc_conn.c:891
       sk_backlog_rcv include/net/sock.h:909 [inline]
       __release_sock+0x12f/0x3a0 net/core/sock.c:2335
       release_sock+0xa4/0x2b0 net/core/sock.c:2850
       llc_ui_release+0xc8/0x220 net/llc/af_llc.c:204
      
      llc->sap is refcount'ed and llc_sap_remove_socket() is paired
      with llc_sap_add_socket(). This can be amended by holding its refcount
      before llc_sap_remove_socket() and releasing it after release_sock().
      
      Reported-by: <syzbot+6e181fc95081c2cf9051@syzkaller.appspotmail.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f7e43672
    • Jonathan Corbet's avatar
      MAINTAINERS: Direct networking documentation changes to netdev · 02b94fc7
      Jonathan Corbet authored
      Networking docs changes go through the networking tree, so patch the
      MAINTAINERS file to direct authors to the right place.
      Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      02b94fc7
    • Colin Ian King's avatar
      atm: iphase: fix spelling mistake: "Tansmit" -> "Transmit" · f3335545
      Colin Ian King authored
      Trivial fix to spelling mistake in message text.
      Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f3335545
    • Pawel Dembicki's avatar
      net: qmi_wwan: add Wistron Neweb D19Q1 · 4ec7eb3f
      Pawel Dembicki authored
      This modem is embedded on dlink dwr-960 router.
      The oem configuration states:
      
      T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=480 MxCh= 0
      D: Ver= 2.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
      P: Vendor=1435 ProdID=d191 Rev=ff.ff
      S: Manufacturer=Android
      S: Product=Android
      S: SerialNumber=0123456789ABCDEF
      C:* #Ifs= 6 Cfg#= 1 Atr=80 MxPwr=500mA
      I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
      E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none)
      E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
      E: Ad=84(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
      E: Ad=83(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
      E: Ad=86(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
      E: Ad=85(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=04(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
      E: Ad=88(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
      E: Ad=87(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 5 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=(none)
      E: Ad=89(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E: Ad=06(O) Atr=02(Bulk) MxPS= 512 Ivl=125us
      
      Tested on openwrt distribution
      Signed-off-by: default avatarPawel Dembicki <paweldembicki@gmail.com>
      Acked-by: default avatarBjørn Mork <bjorn@mork.no>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4ec7eb3f
    • Colin Ian King's avatar
      net: caif: fix spelling mistake "UKNOWN" -> "UNKNOWN" · 5e84b38b
      Colin Ian King authored
      Trivial fix to spelling mistake
      Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5e84b38b
    • Jose Abreu's avatar
      net: stmmac: Disable ACS Feature for GMAC >= 4 · 565020aa
      Jose Abreu authored
      ACS Feature is currently enabled for GMAC >= 4 but the llc_snap status
      is never checked in descriptor rx_status callback. This will cause
      stmmac to always strip packets even that ACS feature is already
      stripping them.
      
      Lets be safe and disable the ACS feature for GMAC >= 4 and always strip
      the packets for this GMAC version.
      
      Fixes: 477286b5 ("stmmac: add GMAC4 core support")
      Signed-off-by: default avatarJose Abreu <joabreu@synopsys.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Joao Pinto <jpinto@synopsys.com>
      Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
      Cc: Alexandre Torgue <alexandre.torgue@st.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      565020aa
    • Maxime Chevallier's avatar
      net: mvpp2: Fix DMA address mask size · da42bb27
      Maxime Chevallier authored
      PPv2 TX/RX descriptors uses 40bits DMA addresses, but 41 bits masks were
      used (GENMASK_ULL(40, 0)).
      
      This commit fixes that by using the correct mask.
      
      Fixes: e7c5359f ("net: mvpp2: introduce PPv2.2 HW descriptors and adapt accessors")
      Signed-off-by: default avatarMaxime Chevallier <maxime.chevallier@bootlin.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      da42bb27
    • sunlianwen's avatar
      net: change the comment of dev_mc_init · bb9aaaa1
      sunlianwen authored
      The comment of dev_mc_init() is wrong. which use dev_mc_flush
      instead of dev_mc_init.
      
      Signed-off-by: Lianwen Sun <sunlw.fnst@cn.fujitsu.com
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bb9aaaa1
    • Jiri Kosina's avatar
      HID: i2c-hid: fix inverted return value from i2c_hid_command() · b658912c
      Jiri Kosina authored
      i2c_hid_command() returns non-zero in error cases (the actual
      errno). Error handling in for I2C_HID_QUIRK_RESEND_REPORT_DESCR
      case in i2c_hid_resume() had the check inverted; fix that.
      
      Fixes: 3e83eda4 ("HID: i2c-hid: Fix resume issue on Raydium touchscreen device")
      Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      b658912c
    • Michael Ellerman's avatar
      powerpc/kvm: Fix lockups when running KVM guests on Power8 · 56376c58
      Michael Ellerman authored
      When running KVM guests on Power8 we can see a lockup where one CPU
      stops responding. This often leads to a message such as:
      
        watchdog: CPU 136 detected hard LOCKUP on other CPUs 72
        Task dump for CPU 72:
        qemu-system-ppc R  running task    10560 20917  20908 0x00040004
      
      And then backtraces on other CPUs, such as:
      
        Task dump for CPU 48:
        ksmd            R  running task    10032  1519      2 0x00000804
        Call Trace:
          ...
          --- interrupt: 901 at smp_call_function_many+0x3c8/0x460
              LR = smp_call_function_many+0x37c/0x460
          pmdp_invalidate+0x100/0x1b0
          __split_huge_pmd+0x52c/0xdb0
          try_to_unmap_one+0x764/0x8b0
          rmap_walk_anon+0x15c/0x370
          try_to_unmap+0xb4/0x170
          split_huge_page_to_list+0x148/0xa30
          try_to_merge_one_page+0xc8/0x990
          try_to_merge_with_ksm_page+0x74/0xf0
          ksm_scan_thread+0x10ec/0x1ac0
          kthread+0x160/0x1a0
          ret_from_kernel_thread+0x5c/0x78
      
      This is caused by commit 8c1c7fb0 ("powerpc/64s/idle: avoid sync
      for KVM state when waking from idle"), which added a check in
      pnv_powersave_wakeup() to see if the kvm_hstate.hwthread_state is
      already set to KVM_HWTHREAD_IN_KERNEL, and if so to skip the store and
      test of kvm_hstate.hwthread_req.
      
      The problem is that the primary does not set KVM_HWTHREAD_IN_KVM when
      entering the guest, so it can then come out to cede with
      KVM_HWTHREAD_IN_KERNEL set. It can then go idle in kvm_do_nap after
      setting hwthread_req to 1, but because hwthread_state is still
      KVM_HWTHREAD_IN_KERNEL we will skip the test of hwthread_req when we
      wake up from idle and won't go to kvm_start_guest. From there the
      thread will return somewhere garbage and crash.
      
      Fix it by skipping the store of hwthread_state, but not the test of
      hwthread_req, when coming out of idle. It's OK to skip the sync in
      that case because hwthread_req will have been set on the same thread,
      so there is no synchronisation required.
      
      Fixes: 8c1c7fb0 ("powerpc/64s/idle: avoid sync for KVM state when waking from idle")
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      56376c58