1. 24 Jun, 2014 2 commits
  2. 23 Jun, 2014 34 commits
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew Morton) · 04b5da4a
      Linus Torvalds authored
      Merge fixes from Andrew Morton:
       "The nmi patch and watchdog patch aren't actually fixes - they're
        features which needed a few last-minutes touchups.
      
        Otherwise, a rather large batch of fixes - ocfs2 review takes a while
        and I got distracted and missed last week's batch"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits)
        ocfs2/dlm: do not purge lockres that is queued for assert master
        ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount
        ocfs2: manually do the iput once ocfs2_add_entry failed in ocfs2_symlink and ocfs2_mknod
        ocfs2: fix a tiny race when running dirop_fileop_racer
        ocfs2/dlm: fix misuse of list_move_tail() in dlm_run_purge_list()
        ocfs2: refcount: take rw_lock in ocfs2_reflink
        ocfs2: revert "ocfs2: fix NULL pointer dereference when dismount and ocfs2rec simultaneously"
        ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and idletimeout closes conn
        ocfs2: should add inode into orphan dir after updating entry in ocfs2_rename()
        mm: fix crashes from mbind() merging vmas
        checkpatch: reduce false positives when checking void function return statements
        ia64: arch/ia64/include/uapi/asm/fcntl.h needs personality.h
        DMA, CMA: fix possible memory leak
        slab: fix oops when reading /proc/slab_allocators
        shmem: fix faulting into a hole while it's punched
        mm: let mm_find_pmd fix buggy race with THP fault
        mm: thp: fix DEBUG_PAGEALLOC oops in copy_page_rep()
        kernel/watchdog.c: print traces for all cpus on lockup detection
        nmi: provide the option to issue an NMI back trace to every cpu but current
        Documentation/accounting/getdelays.c: add missing null-terminate after strncpy call
        ...
      04b5da4a
    • Xue jiufei's avatar
      ocfs2/dlm: do not purge lockres that is queued for assert master · ac4fef4d
      Xue jiufei authored
      
      
      When workqueue is delayed, it may occur that a lockres is purged while it
      is still queued for master assert.  it may trigger BUG() as follows.
      
      N1                                         N2
      dlm_get_lockres()
      ->dlm_do_master_requery
                                        is the master of lockres,
                                        so queue assert_master work
      
                                        dlm_thread() start running
                                        and purge the lockres
      
                                        dlm_assert_master_worker()
                                        send assert master message
                                        to other nodes
      receiving the assert_master
      message, set master to N2
      
      dlmlock_remote() send create_lock message to N2, but receive DLM_IVLOCKID,
      if it is RECOVERY lockres, it triggers the BUG().
      
      Another BUG() is triggered when N3 become the new master and send
      assert_master to N1, N1 will trigger the BUG() because owner doesn't
      match.  So we should not purge lockres when it is queued for assert
      master.
      Signed-off-by: default avatarjoyce.xue <xuejiufei@huawei.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ac4fef4d
    • jiangyiwen's avatar
      ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount · b9aaac5a
      jiangyiwen authored
      
      
      The following case may lead to endless loop during umount.
      
      node A         node B               node C       node D
      umount volume,
      migrate lockres1
      to B
                                                       want to lock lockres1,
                                                       send
                                                       MASTER_REQUEST_MSG
                                                       to C
                                          init block mle
                     send
                     MIGRATE_REQUEST_MSG
                     to C
                                          find a block
                                          mle, and then
                                          return
                                          DLM_MIGRATE_RESPONSE_MASTERY_REF
                                          to B
                     set C in refmap
                                          umount successfully
                     try to umount, endless
                     loop occurs when migrate
                     lockres1 since C is in
                     refmap
      
      So we can fix this endless loop case by only returning
      DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving
      MIGRATE_REQUEST_MSG.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarjiangyiwen <jiangyiwen@huawei.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Xue jiufei <xuejiufei@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b9aaac5a
    • jiangyiwen's avatar
      ocfs2: manually do the iput once ocfs2_add_entry failed in ocfs2_symlink and ocfs2_mknod · 595297a8
      jiangyiwen authored
      
      
      When the call to ocfs2_add_entry() failed in ocfs2_symlink() and
      ocfs2_mknod(), iput() will not be called during dput(dentry) because no
      d_instantiate(), and this will lead to umount hung.
      Signed-off-by: default avatarjiangyiwen <jiangyiwen@huawei.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      595297a8
    • Yiwen Jiang's avatar
      ocfs2: fix a tiny race when running dirop_fileop_racer · f7a14f32
      Yiwen Jiang authored
      
      
      When running dirop_fileop_racer we found a dead lock case.
      
      2 nodes, say Node A and Node B, mount the same ocfs2 volume.  Create
      /race/16/1 in the filesystem, and let the inode number of dir 16 is less
      than the inode number of dir race.
      
      Node A                            Node B
      mv /race/16/1 /race/
                                        right after Node A has got the
                                        EX mode of /race/16/, and tries to
                                        get EX mode of /race
                                        ls /race/16/
      
      In this case, Node A has got the EX mode of /race/16/, and wants to get EX
      mode of /race/.  Node B has got the PR mode of /race/, and wants to get
      the PR mode of /race/16/.  Since EX and PR are mutually exclusive, dead
      lock happens.
      
      This patch fixes this case by locking in ancestor order before trying
      inode number order.
      Signed-off-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
      Signed-off-by: default avatarJoseph Qi <joseph.qi@huawei.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f7a14f32
    • Xue jiufei's avatar
      ocfs2/dlm: fix misuse of list_move_tail() in dlm_run_purge_list() · a270c6d3
      Xue jiufei authored
      
      
      When a lockres in purge list but is still in use, it should be moved to
      the tail of purge list.  dlm_thread will continue to check next lockres in
      purge list.  However, code list_move_tail(&dlm->purge_list,
      &lockres->purge) will do *no* movements, so dlm_thread will purge the same
      lockres in this loop again and again.  If it is in use for a long time,
      other lockres will not be processed.
      Signed-off-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
      Signed-off-by: default avatarjoyce.xue <xuejiufei@huawei.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a270c6d3
    • Wengang Wang's avatar
      ocfs2: refcount: take rw_lock in ocfs2_reflink · 8a8ad1c2
      Wengang Wang authored
      
      
      This patch tries to fix this crash:
      
       #5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5
       #6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de
          [exception RIP: ocfs2_direct_IO_get_blocks+359]
          RIP: ffffffffa05dfa27  RSP: ffff88003c1cd7e8  RFLAGS: 00010202
          RAX: 0000000000000000  RBX: ffff88003c1cdaa8  RCX: 0000000000000000
          RDX: 000000000000000c  RSI: ffff880027a95000  RDI: ffff88003c79b540
          RBP: ffff88003c1cd858   R8: 0000000000000000   R9: ffffffff815f6ba0
          R10: 00000000000001c9  R11: 00000000000001c9  R12: ffff88002d271500
          R13: 0000000000000001  R14: 0000000000000000  R15: 0000000000001000
          ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
       #7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b
       #8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c
       #9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764
      #10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc
      #11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2]
      #12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935
      #13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2]
      #14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c
      #15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4
      #16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880
      #17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238
      #18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437
      #19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530
      #20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159
      
      It crashes at
              BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
      in ocfs2_direct_IO_get_blocks.
      
      ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in
      ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken
      during the time before (or inside) ocfs2_prepare_inode_for_write() and after
      ocfs2_direct_IO_get_blocks().
      
      It can happen in this case:
      
      Node A(which crashes)				Node B
      ------------------------                 ---------------------------
      ocfs2_file_aio_write
        ocfs2_prepare_inode_for_write
          ocfs2_inode_lock
          ...
          ocfs2_inode_unlock
        #no refcount found
      ....					ocfs2_reflink
                                                ocfs2_inode_lock
                                                ...
                                                ocfs2_inode_unlock
                                                #now, refcount flag set on extent
      
                                              ...
                                              flush change to disk
      
      ocfs2_direct_IO_get_blocks
        ocfs2_get_clusters
          #extent map miss
          #buffer_head miss
          read extents from disk
        found refcount flag on extent
        crash..
      
      Fix:
      Take rw_lock in ocfs2_reflink path
      Signed-off-by: default avatarWengang Wang <wen.gang.wang@oracle.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8a8ad1c2
    • Xue jiufei's avatar
      ocfs2: revert "ocfs2: fix NULL pointer dereference when dismount and ocfs2rec simultaneously" · b253bfd8
      Xue jiufei authored
      75f82eaa
      
       ("ocfs2: fix NULL pointer dereference when dismount and
      ocfs2rec simultaneously") may cause umount hang while shutting down
      truncate log.
      
      The situation is as followes:
      ocfs2_dismout_volume
      -> ocfs2_recovery_exit
        -> free osb->recovery_map
      -> ocfs2_truncate_shutdown
        -> lock global bitmap inode
          -> ocfs2_wait_for_recovery
                -> check whether osb->recovery_map->rm_used is zero
      
      Because osb->recovery_map is already freed, rm_used can be any other
      values, so it may yield umount hang.
      Signed-off-by: default avatarjoyce.xue <xuejiufei@huawei.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b253bfd8
    • Tariq Saeed's avatar
      ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and... · 27bf6305
      Tariq Saeed authored
      
      ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and idletimeout closes conn
      
      Orabug: 18639535
      
      Two node cluster and both nodes hold a lock at PR level and both want to
      convert to EX at the same time.  Master node 1 has sent BAST and then
      closes the connection due to idletime out.  Node 0 receives BAST, sends
      unlock req with cancel flag but gets error -ENOTCONN.  The problem is
      this error is ignored in dlm_send_remote_unlock_request() on the
      **incorrect** assumption that the master is dead.  See NOTE in comment
      why it returns DLM_NORMAL.  Upon getting DLM_NORMAL, node 0 proceeds to
      sends convert (without cancel flg) which fails with -ENOTCONN.  waits 5
      sec and resends.
      
      This time gets DLM_IVLOCKID from the master since lock not found in
      grant, it had been moved to converting queue in response to conv PR->EX
      req.  No way out.
      
      Node 1 (master)				Node 0
      ==============				======
      
        lock mode PR				PR
      
        convert PR -> EX
        mv grant -> convert and que BAST
        ...
                           <-------- convert PR -> EX
        convert que looks like this: ((node 1, PR -> EX) (node 0, PR -> EX))
        ...
                              BAST (want PR -> NL)
                           ------------------>
        ...
        idle timout, conn closed
                                      ...
                                      In response to BAST,
                                      sends unlock with cancel convert flag
                                      gets -ENOTCONN. Ignores and
                                      sends remote convert request
                                      gets -ENOTCONN, waits 5 Sec, retries
        ...
        reconnects
                         <----------------- convert req goes through on next try
        does not find lock on grant que
                         status DLM_IVLOCKID
                         ------------------>
        ...
      
      No way out.  Fix is to keep retrying unlock with cancel flag until it
      succeeds or the master dies.
      Signed-off-by: default avatarTariq Saeed <tariq.x.saeed@oracle.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      27bf6305
    • alex chen's avatar
      ocfs2: should add inode into orphan dir after updating entry in ocfs2_rename() · 5fb1beb0
      alex chen authored
      
      
      There are two files a and b in dir /mnt/ocfs2.
      
          node A                           node B
      
        mv a b
        In ocfs2_rename(), after calling
        ocfs2_orphan_add(), the inode of
        file b will be added into orphan
        dir.
      
        If ocfs2_update_entry() fails,
        ocfs2_rename return error and mv
        operation fails. But file b still
        exists in the parent dir.
      
        ocfs2_queue_orphan_scan
         -> ocfs2_queue_recovery_completion
         -> ocfs2_complete_recovery
         -> ocfs2_recover_orphans
        The inode of the file b will be
        put with iput().
      
        ocfs2_evict_inode
         -> ocfs2_delete_inode
         -> ocfs2_wipe_inode
         -> ocfs2_remove_inode
        OCFS2_VALID_FL in the inode
        i_flags will be cleared.
      
                                         The file b still can be accessed
                                         on node B.
                                         ls /mnt/ocfs2
                                         When first read the file b with
                                         ocfs2_read_inode_block(). It will
                                         validate the inode using
                                         ocfs2_validate_inode_block().
                                         Because OCFS2_VALID_FL not set in
                                         the inode i_flags, so the file
                                         system will be readonly.
      
      So we should add inode into orphan dir after updating entry in
      ocfs2_rename().
      Signed-off-by: default avataralex.chen <alex.chen@huawei.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5fb1beb0
    • Hugh Dickins's avatar
      mm: fix crashes from mbind() merging vmas · d05f0cdc
      Hugh Dickins authored
      In v2.6.34 commit 9d8cebd4 ("mm: fix mbind vma merge problem")
      introduced vma merging to mbind(), but it should have also changed the
      convention of passing start vma from queue_pages_range() (formerly
      check_range()) to new_vma_page(): vma merging may have already freed
      that structure, resulting in BUG at mm/mempolicy.c:1738 and probably
      worse crashes.
      
      Fixes: 9d8cebd4
      
       ("mm: fix mbind vma merge problem")
      Reported-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Tested-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Acked-by: default avatarChristoph Lameter <cl@linux.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Minchan Kim <minchan.kim@gmail.com>
      Cc: <stable@vger.kernel.org>	[2.6.34+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d05f0cdc
    • Joe Perches's avatar
      checkpatch: reduce false positives when checking void function return statements · b43ae21b
      Joe Perches authored
      
      
      The previous patch had a few too many false positives on styles that
      should be acceptable.
      Signed-off-by: default avatarJoe Perches <joe@perches.com>
      Tested-by: default avatarAnish Bhatt <anish@chelsio.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b43ae21b
    • Andrew Morton's avatar
      ia64: arch/ia64/include/uapi/asm/fcntl.h needs personality.h · f9af420f
      Andrew Morton authored
      
      
      fs/notify/fanotify/fanotify_user.c: In function 'SYSC_fanotify_init':
      fs/notify/fanotify/fanotify_user.c:726: error: implicit declaration of function 'personality'
      fs/notify/fanotify/fanotify_user.c:726: error: 'PER_LINUX32' undeclared (first use in this function)
      fs/notify/fanotify/fanotify_user.c:726: error: (Each undeclared identifier is reported only once
      fs/notify/fanotify/fanotify_user.c:726: error: for each function it appears in.)
      Reported-by: default avatarWu Fengguang <fengguang.wu@intel.com>
      Cc: Will Woods <wwoods@redhat.com>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: <stable@vger.kernel.org>	[3.15.x]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f9af420f
    • Joonsoo Kim's avatar
      DMA, CMA: fix possible memory leak · fe8eea4f
      Joonsoo Kim authored
      
      
      We should free memory for bitmap when we find zone mismatch, otherwise
      this memory will leak.
      
      Additionally, I copy code comment from PPC KVM's CMA code to inform why
      we need to check zone mis-match.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Reviewed-by: default avatarMichal Nazarewicz <mina86@mina86.com>
      Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Acked-by: default avatarMinchan Kim <minchan@kernel.org>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Alexander Graf <agraf@suse.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fe8eea4f
    • Joonsoo Kim's avatar
      slab: fix oops when reading /proc/slab_allocators · 03787301
      Joonsoo Kim authored
      Commit b1cb0982
      
       ("change the management method of free objects of
      the slab") introduced a bug on slab leak detector
      ('/proc/slab_allocators').  This detector works like as following
      decription.
      
       1. traverse all objects on all the slabs.
       2. determine whether it is active or not.
       3. if active, print who allocate this object.
      
      but that commit changed the way how to manage free objects, so the logic
      determining whether it is active or not is also changed.  In before, we
      regard object in cpu caches as inactive one, but, with this commit, we
      mistakenly regard object in cpu caches as active one.
      
      This intoduces kernel oops if DEBUG_PAGEALLOC is enabled.  If
      DEBUG_PAGEALLOC is enabled, kernel_map_pages() is used to detect who
      corrupt free memory in the slab.  It unmaps page table mapping if object
      is free and map it if object is active.  When slab leak detector check
      object in cpu caches, it mistakenly think this object active so try to
      access object memory to retrieve caller of allocation.  At this point,
      page table mapping to this object doesn't exist, so oops occurs.
      
      Following is oops message reported from Dave.
      
      It blew up when something tried to read /proc/slab_allocators
      (Just cat it, and you should see the oops below)
      
        Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
        Modules linked in:
        [snip...]
        CPU: 1 PID: 9386 Comm: trinity-c33 Not tainted 3.14.0-rc5+ #131
        task: ffff8801aa46e890 ti: ffff880076924000 task.ti: ffff880076924000
        RIP: 0010:[<ffffffffaa1a8f4a>]  [<ffffffffaa1a8f4a>] handle_slab+0x8a/0x180
        RSP: 0018:ffff880076925de0  EFLAGS: 00010002
        RAX: 0000000000001000 RBX: 0000000000000000 RCX: 000000005ce85ce7
        RDX: ffffea00079be100 RSI: 0000000000001000 RDI: ffff880107458000
        RBP: ffff880076925e18 R08: 0000000000000001 R09: 0000000000000000
        R10: 0000000000000000 R11: 000000000000000f R12: ffff8801e6f84000
        R13: ffffea00079be100 R14: ffff880107458000 R15: ffff88022bb8d2c0
        FS:  00007fb769e45740(0000) GS:ffff88024d040000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
        CR2: ffff8801e6f84ff8 CR3: 00000000a22db000 CR4: 00000000001407e0
        DR0: 0000000002695000 DR1: 0000000002695000 DR2: 0000000000000000
        DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000070602
        Call Trace:
          leaks_show+0xce/0x240
          seq_read+0x28e/0x490
          proc_reg_read+0x3d/0x80
          vfs_read+0x9b/0x160
          SyS_read+0x58/0xb0
          tracesys+0xd4/0xd9
        Code: f5 00 00 00 0f 1f 44 00 00 48 63 c8 44 3b 0c 8a 0f 84 e3 00 00 00 83 c0 01 44 39 c0 72 eb 41 f6 47 1a 01 0f 84 e9 00 00 00 89 f0 <4d> 8b 4c 04 f8 4d 85 c9 0f 84 88 00 00 00 49 8b 7e 08 4d 8d 46
        RIP   handle_slab+0x8a/0x180
      
      To fix the problem, I introduce an object status buffer on each slab.
      With this, we can track object status precisely, so slab leak detector
      would not access active object and no kernel oops would occur.  Memory
      overhead caused by this fix is only imposed to CONFIG_DEBUG_SLAB_LEAK
      which is mainly used for debugging, so memory overhead isn't big
      problem.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Reported-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Reviewed-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      03787301
    • Hugh Dickins's avatar
      shmem: fix faulting into a hole while it's punched · f00cdc6d
      Hugh Dickins authored
      
      
      Trinity finds that mmap access to a hole while it's punched from shmem
      can prevent the madvise(MADV_REMOVE) or fallocate(FALLOC_FL_PUNCH_HOLE)
      from completing, until the reader chooses to stop; with the puncher's
      hold on i_mutex locking out all other writers until it can complete.
      
      It appears that the tmpfs fault path is too light in comparison with its
      hole-punching path, lacking an i_data_sem to obstruct it; but we don't
      want to slow down the common case.
      
      Extend shmem_fallocate()'s existing range notification mechanism, so
      shmem_fault() can refrain from faulting pages into the hole while it's
      punched, waiting instead on i_mutex (when safe to sleep; or repeatedly
      faulting when not).
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Dave Jones <davej@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f00cdc6d
    • Hugh Dickins's avatar
      mm: let mm_find_pmd fix buggy race with THP fault · f72e7dcd
      Hugh Dickins authored
      
      
      Trinity has reported:
      
          BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
          IP: __lock_acquire (kernel/locking/lockdep.c:3070 (discriminator 1))
          CPU: 6 PID: 16173 Comm: trinity-c364 Tainted: G        W
                                  3.15.0-rc1-next-20140415-sasha-00020-gaa90d09 #398
          lock_acquire (arch/x86/include/asm/current.h:14
                        kernel/locking/lockdep.c:3602)
          _raw_spin_lock (include/linux/spinlock_api_smp.h:143
                          kernel/locking/spinlock.c:151)
          remove_migration_pte (mm/migrate.c:137)
          rmap_walk (mm/rmap.c:1628 mm/rmap.c:1699)
          remove_migration_ptes (mm/migrate.c:224)
          migrate_pages (mm/migrate.c:922 mm/migrate.c:960 mm/migrate.c:1126)
          migrate_misplaced_page (mm/migrate.c:1733)
          __handle_mm_fault (mm/memory.c:3762 mm/memory.c:3812 mm/memory.c:3925)
          handle_mm_fault (mm/memory.c:3948)
          __get_user_pages (mm/memory.c:1851)
          __mlock_vma_pages_range (mm/mlock.c:255)
          __mm_populate (mm/mlock.c:711)
          SyS_mlockall (include/linux/mm.h:1799 mm/mlock.c:817 mm/mlock.c:791)
      
      I believe this comes about because, whereas collapsing and splitting THP
      functions take anon_vma lock in write mode (which excludes concurrent
      rmap walks), faulting THP functions (write protection and misplaced
      NUMA) do not - and mostly they do not need to.
      
      But they do use a pmdp_clear_flush(), set_pmd_at() sequence which, for
      an instant (indeed, for a long instant, given the inter-CPU TLB flush in
      there), leaves *pmd neither present not trans_huge.
      
      Which can confuse a concurrent rmap walk, as when removing migration
      ptes, seen in the dumped trace.  Although that rmap walk has a 4k page
      to insert, anon_vmas containing THPs are in no way segregated from
      4k-page anon_vmas, so the 4k-intent mm_find_pmd() does need to cope with
      that instant when a trans_huge pmd is temporarily absent.
      
      I don't think we need strengthen the locking at the THP end: it's easily
      handled with an ACCESS_ONCE() before testing both conditions.
      
      And since mm_find_pmd() had only one caller who wanted a THP rather than
      a pmd, let's slightly repurpose it to fail when it hits a THP or
      non-present pmd, and open code split_huge_page_address() again.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Konstantin Khlebnikov <koct9i@gmail.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Bob Liu <bob.liu@oracle.com>
      Cc: Christoph Lameter <cl@gentwo.org>
      Cc: Dave Jones <davej@redhat.com>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f72e7dcd
    • Hugh Dickins's avatar
      mm: thp: fix DEBUG_PAGEALLOC oops in copy_page_rep() · 5338a937
      Hugh Dickins authored
      
      
      Trinity has for over a year been reporting a CONFIG_DEBUG_PAGEALLOC oops
      in copy_page_rep() called from copy_user_huge_page() called from
      do_huge_pmd_wp_page().
      
      I believe this is a DEBUG_PAGEALLOC false positive, due to the source
      page being split, and a tail page freed, while copy is in progress; and
      not a problem without DEBUG_PAGEALLOC, since the pmd_same() check will
      prevent a miscopy from being made visible.
      
      Fix by adding get_user_huge_page() and put_user_huge_page(): reducing to
      the usual get_page() and put_page() on head page in the usual config;
      but get and put references to all of the tail pages when
      DEBUG_PAGEALLOC.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5338a937
    • Aaron Tomlin's avatar
      kernel/watchdog.c: print traces for all cpus on lockup detection · ed235875
      Aaron Tomlin authored
      
      
      A 'softlockup' is defined as a bug that causes the kernel to loop in
      kernel mode for more than a predefined period to time, without giving
      other tasks a chance to run.
      
      Currently, upon detection of this condition by the per-cpu watchdog
      task, debug information (including a stack trace) is sent to the system
      log.
      
      On some occasions, we have observed that the "victim" rather than the
      actual "culprit" (i.e.  the owner/holder of the contended resource) is
      reported to the user.  Often this information has proven to be
      insufficient to assist debugging efforts.
      
      To avoid loss of useful debug information, for architectures which
      support NMI, this patch makes it possible to improve soft lockup
      reporting.  This is accomplished by issuing an NMI to each cpu to obtain
      a stack trace.
      
      If NMI is not supported we just revert back to the old method.  A sysctl
      and boot-time parameter is available to toggle this feature.
      
      [dzickus@redhat.com: add CONFIG_SMP in certain areas]
      [akpm@linux-foundation.org: additional CONFIG_SMP=n optimisations]
      [mq@suse.cz: fix warning]
      Signed-off-by: default avatarAaron Tomlin <atomlin@redhat.com>
      Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Mateusz Guzik <mguzik@redhat.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarJan Moskyto Matejka <mq@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ed235875
    • Aaron Tomlin's avatar
      nmi: provide the option to issue an NMI back trace to every cpu but current · f3aca3d0
      Aaron Tomlin authored
      
      
      Sometimes it is preferred not to use the trigger_all_cpu_backtrace()
      routine when one wants to avoid capturing a back trace for current.  For
      instance if one was previously captured recently.
      
      This patch provides a new routine namely
      trigger_allbutself_cpu_backtrace() which offers the flexibility to issue
      an NMI to every cpu but current and capture a back trace accordingly.
      
      Patch x86 and sparc to support new routine.
      
      [dzickus@redhat.com: add stub in #else clause]
      [dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion]
      [sfr@canb.auug.org.au: undo C99ism]
      Signed-off-by: default avatarAaron Tomlin <atomlin@redhat.com>
      Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
      Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
      Cc: Mateusz Guzik <mguzik@redhat.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f3aca3d0
    • Rickard Strandqvist's avatar
      Documentation/accounting/getdelays.c: add missing null-terminate after strncpy call · 88e15ce4
      Rickard Strandqvist authored
      
      
      Added a guaranteed null-terminate after call to strncpy.
      
      This was partly found using a static code analysis program called
      cppcheck.
      Signed-off-by: default avatarRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      88e15ce4
    • Micky Ching's avatar
      drivers/memstick/host/rtsx_pci_ms.c: add cancel_work when remove driver · b6226b45
      Micky Ching authored
      
      
      Add cancel_work_sync() in rtsx_pci_ms_drv_remove() to cancel pending
      request work when removing the driver.
      Signed-off-by: default avatarMicky Ching <micky_ching@realsil.com.cn>
      Cc: Samuel Ortiz <sameo@linux.intel.com> says:
      Cc: Maxim Levitsky <maximlevitsky@gmail.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Alex Dubov <oakad@yahoo.com>
      Cc: Roger Tseng <rogerable@realtek.com>
      Cc: Wei WANG <wei_wang@realsil.com.cn>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b6226b45
    • David Rientjes's avatar
      mm, pcp: allow restoring percpu_pagelist_fraction default · 7cd2b0a3
      David Rientjes authored
      
      
      Oleg reports a division by zero error on zero-length write() to the
      percpu_pagelist_fraction sysctl:
      
          divide error: 0000 [#1] SMP DEBUG_PAGEALLOC
          CPU: 1 PID: 9142 Comm: badarea_io Not tainted 3.15.0-rc2-vm-nfs+ #19
          Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
          task: ffff8800d5aeb6e0 ti: ffff8800d87a2000 task.ti: ffff8800d87a2000
          RIP: 0010: percpu_pagelist_fraction_sysctl_handler+0x84/0x120
          RSP: 0018:ffff8800d87a3e78  EFLAGS: 00010246
          RAX: 0000000000000f89 RBX: ffff88011f7fd000 RCX: 0000000000000000
          RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000010
          RBP: ffff8800d87a3e98 R08: ffffffff81d002c8 R09: ffff8800d87a3f50
          R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000060
          R13: ffffffff81c3c3e0 R14: ffffffff81cfddf8 R15: ffff8801193b0800
          FS:  00007f614f1e9740(0000) GS:ffff88011f440000(0000) knlGS:0000000000000000
          CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
          CR2: 00007f614f1fa000 CR3: 00000000d9291000 CR4: 00000000000006e0
          Call Trace:
            proc_sys_call_handler+0xb3/0xc0
            proc_sys_write+0x14/0x20
            vfs_write+0xba/0x1e0
            SyS_write+0x46/0xb0
            tracesys+0xe1/0xe6
      
      However, if the percpu_pagelist_fraction sysctl is set by the user, it
      is also impossible to restore it to the kernel default since the user
      cannot write 0 to the sysctl.
      
      This patch allows the user to write 0 to restore the default behavior.
      It still requires a fraction equal to or larger than 8, however, as
      stated by the documentation for sanity.  If a value in the range [1, 7]
      is written, the sysctl will return EINVAL.
      
      This successfully solves the divide by zero issue at the same time.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Reported-by: default avatarOleg Drokin <green@linuxhacker.ru>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7cd2b0a3
    • Chen Gang's avatar
      lib/Kconfig.debug: let FRAME_POINTER exclude SCORE, just like exclude most of other architectures · df2e1ef6
      Chen Gang authored
      
      
      The related warning:
      
        scripts/kconfig/conf --allmodconfig Kconfig
        warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && LOCKDEP) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS)
      Signed-off-by: default avatarChen Gang <gang.chen.5i5j@gmail.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      df2e1ef6
    • Don Zickus's avatar
      kernel/watchdog.c: remove preemption restrictions when restarting lockup detector · bde92cf4
      Don Zickus authored
      
      
      Peter Wu noticed the following splat on his machine when updating
      /proc/sys/kernel/watchdog_thresh:
      
        BUG: sleeping function called from invalid context at mm/slub.c:965
        in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: init
        3 locks held by init/1:
         #0:  (sb_writers#3){.+.+.+}, at: [<ffffffff8117b663>] vfs_write+0x143/0x180
         #1:  (watchdog_proc_mutex){+.+.+.}, at: [<ffffffff810e02d3>] proc_dowatchdog+0x33/0x110
         #2:  (cpu_hotplug.lock){.+.+.+}, at: [<ffffffff810589c2>] get_online_cpus+0x32/0x80
        Preemption disabled at:[<ffffffff810e0384>] proc_dowatchdog+0xe4/0x110
      
        CPU: 0 PID: 1 Comm: init Not tainted 3.16.0-rc1-testing #34
        Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
        Call Trace:
          dump_stack+0x4e/0x7a
          __might_sleep+0x11d/0x190
          kmem_cache_alloc_trace+0x4e/0x1e0
          perf_event_alloc+0x55/0x440
          perf_event_create_kernel_counter+0x26/0xe0
          watchdog_nmi_enable+0x75/0x140
          update_timers_all_cpus+0x53/0xa0
          proc_dowatchdog+0xe4/0x110
          proc_sys_call_handler+0xb3/0xc0
          proc_sys_write+0x14/0x20
          vfs_write+0xad/0x180
          SyS_write+0x49/0xb0
          system_call_fastpath+0x16/0x1b
        NMI watchdog: disabled (cpu0): hardware events not enabled
      
      What happened is after updating the watchdog_thresh, the lockup detector
      is restarted to utilize the new value.  Part of this process involved
      disabling preemption.  Once preemption was disabled, perf tried to
      allocate a new event (as part of the restart).  This caused the above
      BUG_ON as you can't sleep with preemption disabled.
      
      The preemption restriction seemed agressive as we are not doing anything
      on that particular cpu, but with all the online cpus (which are
      protected by the get_online_cpus lock).  Remove the restriction and the
      BUG_ON goes away.
      Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
      Reported-by: default avatarPeter Wu <peter@lekensteyn.nl>
      Tested-by: default avatarPeter Wu <peter@lekensteyn.nl>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: <stable@vger.kernel.org>		[3.13+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bde92cf4
    • Christoph Lameter's avatar
      MAINTAINERS: SLAB maintainer update · 16e943bf
      Christoph Lameter authored
      
      
      As discussed in various threads on the side:
      
      Remove one inactive maintainer, add two new ones and update my email
      address.  Plus add Andrew.  And fix the glob to include files like
      mm/slab_common.c
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: default avatarPekka Enberg <penberg@kernel.org>
      Cc: Matt Mackall <mpm@selenic.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      16e943bf
    • Naoya Horiguchi's avatar
      hugetlb: fix copy_hugetlb_page_range() to handle migration/hwpoisoned entry · 4a705fef
      Naoya Horiguchi authored
      
      
      There's a race between fork() and hugepage migration, as a result we try
      to "dereference" a swap entry as a normal pte, causing kernel panic.
      The cause of the problem is that copy_hugetlb_page_range() can't handle
      "swap entry" family (migration entry and hwpoisoned entry) so let's fix
      it.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHugh Dickins <hughd@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: <stable@vger.kernel.org>	[2.6.37+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4a705fef
    • Hugh Dickins's avatar
      tmpfs: ZERO_RANGE and COLLAPSE_RANGE not currently supported · 13ace4d0
      Hugh Dickins authored
      
      
      I was well aware of FALLOC_FL_ZERO_RANGE and FALLOC_FL_COLLAPSE_RANGE
      support being added to fallocate(); but didn't realize until now that I
      had been too stupid to future-proof shmem_fallocate() against new
      additions.  -EOPNOTSUPP instead of going on to ordinary fallocation.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Reviewed-by: default avatarLukas Czerner <lczerner@redhat.com>
      Cc: <stable@vger.kernel.org>	[3.15]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      13ace4d0
    • David Rientjes's avatar
      mm, hotplug: probe interface is available on several platforms · 7cdb0d25
      David Rientjes authored
      
      
      Documentation/memory-hotplug.txt incorrectly states that the memory
      driver "probe" interface is only supported on powerpc and is vague about
      its application on x86.  Clarify the platforms that make this interface
      available if memory hotplug is enabled.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7cdb0d25
    • Petr Tesarik's avatar
      kexec: save PG_head_mask in VMCOREINFO · b3acc56b
      Petr Tesarik authored
      To allow filtering of huge pages, makedumpfile must be able to identify
      them in the dump.  This can be done by checking the appropriate page
      flag, so communicate its value to makedumpfile through the VMCOREINFO
      interface.
      
      There's only one small catch.  Depending on how many page flags are
      available on a given architecture, this bit can be called PG_head or
      PG_compound.
      
      I sent a similar patch back in 2012, but Eric Biederman did not like
      using an #ifdef.  So, this time I'm adding a common symbol
      (PG_head_mask) instead.
      
      See https://lkml.org/lkml/2012/11/28/91
      
       for the previous version.
      Signed-off-by: default avatarPetr Tesarik <ptesarik@suse.cz>
      Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Shaohua Li <shli@kernel.org>
      Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b3acc56b
    • Srivatsa S. Bhat's avatar
      CPU hotplug, smp: flush any pending IPI callbacks before CPU offline · 8d056c48
      Srivatsa S. Bhat authored
      
      
      There is a race between the CPU offline code (within stop-machine) and
      the smp-call-function code, which can lead to getting IPIs on the
      outgoing CPU, *after* it has gone offline.
      
      Specifically, this can happen when using
      smp_call_function_single_async() to send the IPI, since this API allows
      sending asynchronous IPIs from IRQ disabled contexts.  The exact race
      condition is described below.
      
      During CPU offline, in stop-machine, we don't enforce any rule in the
      _DISABLE_IRQ stage, regarding the order in which the outgoing CPU and
      the other CPUs disable their local interrupts.  Due to this, we can
      encounter a situation in which an IPI is sent by one of the other CPUs
      to the outgoing CPU (while it is *still* online), but the outgoing CPU
      ends up noticing it only *after* it has gone offline.
      
                    CPU 1                                         CPU 2
                (Online CPU)                               (CPU going offline)
      
             Enter _PREPARE stage                          Enter _PREPARE stage
      
                                                           Enter _DISABLE_IRQ stage
      
                                                         =
             Got a device interrupt, and                 | Didn't notice the IPI
             the interrupt handler sent an               | since interrupts were
             IPI to CPU 2 using                          | disabled on this CPU.
             smp_call_function_single_async()            |
                                                         =
      
             Enter _DISABLE_IRQ stage
      
             Enter _RUN stage                              Enter _RUN stage
      
                                        =
             Busy loop with interrupts  |                  Invoke take_cpu_down()
             disabled.                  |                  and take CPU 2 offline
                                        =
      
             Enter _EXIT stage                             Enter _EXIT stage
      
             Re-enable interrupts                          Re-enable interrupts
      
                                                           The pending IPI is noted
                                                           immediately, but alas,
                                                           the CPU is offline at
                                                           this point.
      
      This of course, makes the smp-call-function IPI handler code running on
      CPU 2 unhappy and it complains about "receiving an IPI on an offline
      CPU".
      
      One real example of the scenario on CPU 1 is the block layer's
      complete-request call-path:
      
      	__blk_complete_request() [interrupt-handler]
      	    raise_blk_irq()
      	        smp_call_function_single_async()
      
      However, if we look closely, the block layer does check that the target
      CPU is online before firing the IPI.  So in this case, it is actually
      the unfortunate ordering/timing of events in the stop-machine phase that
      leads to receiving IPIs after the target CPU has gone offline.
      
      In reality, getting a late IPI on an offline CPU is not too bad by
      itself (this can happen even due to hardware latencies in IPI
      send-receive).  It is a bug only if the target CPU really went offline
      without executing all the callbacks queued on its list.  (Note that a
      CPU is free to execute its pending smp-call-function callbacks in a
      batch, without waiting for the corresponding IPIs to arrive for each one
      of those callbacks).
      
      So, fixing this issue can be broken up into two parts:
      
      1. Ensure that a CPU goes offline only after executing all the
         callbacks queued on it.
      
      2. Modify the warning condition in the smp-call-function IPI handler
         code such that it warns only if an offline CPU got an IPI *and* that
         CPU had gone offline with callbacks still pending in its queue.
      
      Achieving part 1 is straight-forward - just flush (execute) all the
      queued callbacks on the outgoing CPU in the CPU_DYING stage[1],
      including those callbacks for which the source CPU's IPIs might not have
      been received on the outgoing CPU yet.  Once we do this, an IPI that
      arrives late on the CPU going offline (either due to the race mentioned
      above, or due to hardware latencies) will be completely harmless, since
      the outgoing CPU would have executed all the queued callbacks before
      going offline.
      
      Overall, this fix (parts 1 and 2 put together) additionally guarantees
      that we will see a warning only when the *IPI-sender code* is buggy -
      that is, if it queues the callback _after_ the target CPU has gone
      offline.
      
      [1].  The CPU_DYING part needs a little more explanation: by the time we
      execute the CPU_DYING notifier callbacks, the CPU would have already
      been marked offline.  But we want to flush out the pending callbacks at
      this stage, ignoring the fact that the CPU is offline.  So restructure
      the IPI handler code so that we can by-pass the "is-cpu-offline?" check
      in this particular case.  (Of course, the right solution here is to fix
      CPU hotplug to mark the CPU offline _after_ invoking the CPU_DYING
      notifiers, but this requires a lot of audit to ensure that this change
      doesn't break any existing code; hence lets go with the solution
      proposed above until that is done).
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
      Suggested-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Mike Galbraith <mgalbraith@suse.de>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarSachin Kamat <sachin.kamat@samsung.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8d056c48
    • Steven Miao's avatar
      mm: nommu: per-thread vma cache fix · e020d5bd
      Steven Miao authored
      
      
      mm could be removed from current task struct, using previous vma->vm_mm
      
      It will crash on blackfin after updated to Linux 3.15.  The commit "mm:
      per-thread vma caching" caused the crash.  mm could be removed from
      current task struct before
      
        mmput()->
          exit_mmap()->
            delete_vma_from_mm()
      
      the detailed fault information:
      
          NULL pointer access
          Kernel OOPS in progress
          Deferred Exception context
          CURRENT PROCESS:
          COMM=modprobe PID=278  CPU=0
          invalid mm
          return address: [0x000531de]; contents of:
          0x000531b0:  c727  acea  0c42  181d  0000  0000  0000  a0a8
          0x000531c0:  b090  acaa  0c42  1806  0000  0000  0000  a0e8
          0x000531d0:  b0d0  e801  0000  05b3  0010  e522  0046 [a090]
          0x000531e0:  6408  b090  0c00  17cc  3042  e3ff  f37b  2fc8
      
          CPU: 0 PID: 278 Comm: modprobe Not tainted 3.15.0-ADI-2014R1-pre-00345-gea9f446 #25
          task: 0572b720 ti: 0569e000 task.ti: 0569e000
          Compiled for cpu family 0x27fe (Rev 0), but running on:0x0000 (Rev 0)
          ADSP-BF609-0.0 500(MHz CCLK) 125(MHz SCLK) (mpu off)
          Linux version 3.15.0-ADI-2014R1-pre-00345-gea9f446 (steven@steven-OptiPlex-390) (gcc version 4.3.5 (ADI-trunk/svn-5962) ) #25 Tue Jun 10 17:47:46 CST 2014
      
          SEQUENCER STATUS:		Not tainted
           SEQSTAT: 00000027  IPEND: 8008  IMASK: ffff  SYSCFG: 2806
            EXCAUSE   : 0x27
            physical IVG3 asserted : <0xffa00744> { _trap + 0x0 }
            physical IVG15 asserted : <0xffa00d68> { _evt_system_call + 0x0 }
            logical irq   6 mapped  : <0xffa003bc> { _bfin_coretmr_interrupt + 0x0 }
            logical irq   7 mapped  : <0x00008828> { _bfin_fault_routine + 0x0 }
            logical irq  11 mapped  : <0x00007724> { _l2_ecc_err + 0x0 }
            logical irq  13 mapped  : <0x00008828> { _bfin_fault_routine + 0x0 }
            logical irq  39 mapped  : <0x00150788> { _bfin_twi_interrupt_entry + 0x0 }
            logical irq  40 mapped  : <0x00150788> { _bfin_twi_interrupt_entry + 0x0 }
           RETE: <0x00000000> /* Maybe null pointer? */
           RETN: <0x0569fe50> /* kernel dynamic memory (maybe user-space) */
           RETX: <0x00000480> /* Maybe fixed code section */
           RETS: <0x00053384> { _exit_mmap + 0x28 }
           PC  : <0x000531de> { _delete_vma_from_mm + 0x92 }
          DCPLB_FAULT_ADDR: <0x00000008> /* Maybe null pointer? */
          ICPLB_FAULT_ADDR: <0x000531de> { _delete_vma_from_mm + 0x92 }
          PROCESSOR STATE:
           R0 : 00000004    R1 : 0569e000    R2 : 00bf3db4    R3 : 00000000
           R4 : 057f9800    R5 : 00000001    R6 : 0569ddd0    R7 : 0572b720
           P0 : 0572b854    P1 : 00000004    P2 : 00000000    P3 : 0569dda0
           P4 : 0572b720    P5 : 0566c368    FP : 0569fe5c    SP : 0569fd74
           LB0: 057f523f    LT0: 057f523e    LC0: 00000000
           LB1: 0005317c    LT1: 00053172    LC1: 00000002
           B0 : 00000000    L0 : 00000000    M0 : 0566f5bc    I0 : 00000000
           B1 : 00000000    L1 : 00000000    M1 : 00000000    I1 : ffffffff
           B2 : 00000001    L2 : 00000000    M2 : 00000000    I2 : 00000000
           B3 : 00000000    L3 : 00000000    M3 : 00000000    I3 : 057f8000
          A0.w: 00000000   A0.x: 00000000   A1.w: 00000000   A1.x: 00000000
          USP : 056ffcf8  ASTAT: 02003024
      
          Hardware Trace:
             0 Target : <0x00003fb8> { _trap_c + 0x0 }
               Source : <0xffa006d8> { _exception_to_level5 + 0xa0 } JUMP.L
             1 Target : <0xffa00638> { _exception_to_level5 + 0x0 }
               Source : <0xffa004f2> { _bfin_return_from_exception + 0x6 } RTX
             2 Target : <0xffa004ec> { _bfin_return_from_exception + 0x0 }
               Source : <0xffa00590> { _ex_trap_c + 0x70 } JUMP.S
             3 Target : <0xffa00520> { _ex_trap_c + 0x0 }
               Source : <0xffa0076e> { _trap + 0x2a } JUMP (P4)
             4 Target : <0xffa00744> { _trap + 0x0 }
                FAULT : <0x000531de> { _delete_vma_from_mm + 0x92 } P0 = W[P2 + 2]
               Source : <0x000531da> { _delete_vma_from_mm + 0x8e } P2 = [P4 + 0x18]
             5 Target : <0x000531da> { _delete_vma_from_mm + 0x8e }
               Source : <0x00053176> { _delete_vma_from_mm + 0x2a } IF CC JUMP pcrel
             6 Target : <0x0005314c> { _delete_vma_from_mm + 0x0 }
               Source : <0x00053380> { _exit_mmap + 0x24 } JUMP.L
             7 Target : <0x00053378> { _exit_mmap + 0x1c }
               Source : <0x00053394> { _exit_mmap + 0x38 } IF !CC JUMP pcrel (BP)
             8 Target : <0x00053390> { _exit_mmap + 0x34 }
               Source : <0xffa020e0> { __cond_resched + 0x20 } RTS
             9 Target : <0xffa020c0> { __cond_resched + 0x0 }
               Source : <0x0005338c> { _exit_mmap + 0x30 } JUMP.L
            10 Target : <0x0005338c> { _exit_mmap + 0x30 }
               Source : <0x0005333a> { _delete_vma + 0xb2 } RTS
            11 Target : <0x00053334> { _delete_vma + 0xac }
               Source : <0x0005507a> { _kmem_cache_free + 0xba } RTS
            12 Target : <0x00055068> { _kmem_cache_free + 0xa8 }
               Source : <0x0005505e> { _kmem_cache_free + 0x9e } IF !CC JUMP pcrel (BP)
            13 Target : <0x00055052> { _kmem_cache_free + 0x92 }
               Source : <0x0005501a> { _kmem_cache_free + 0x5a } IF CC JUMP pcrel
            14 Target : <0x00054ff4> { _kmem_cache_free + 0x34 }
               Source : <0x00054fce> { _kmem_cache_free + 0xe } IF CC JUMP pcrel (BP)
            15 Target : <0x00054fc0> { _kmem_cache_free + 0x0 }
               Source : <0x00053330> { _delete_vma + 0xa8 } JUMP.L
          Kernel Stack
          Stack info:
           SP: [0x0569ff24] <0x0569ff24> /* kernel dynamic memory (maybe user-space) */
           Memory from 0x0569ff20 to 056a0000
          0569ff20: 00000001 [04e8da5a] 00008000  00000000  00000000  056a0000  04e8da5a  04e8da5a
          0569ff40: 04eb9eea  ffa00dce  02003025  04ea09c5  057f523f  04ea09c4  057f523e  00000000
          0569ff60: 00000000  00000000  00000000  00000000  00000000  00000000  00000001  00000000
          0569ff80: 00000000  00000000  00000000  00000000  00000000  00000000  00000000  00000000
          0569ffa0: 0566f5bc  057f8000  057f8000  00000001  04ec0170  056ffcf8  056ffd04  057f9800
          0569ffc0: 04d1d498  057f9800  057f8fe4  057f8ef0  00000001  057f928c  00000001  00000001
          0569ffe0: 057f9800  00000000  00000008  00000007  00000001  00000001  00000001 <00002806>
          Return addresses in stack:
              address : <0x00002806> { _show_cpuinfo + 0x2d2 }
          Modules linked in:
          Kernel panic - not syncing: Kernel exception
          [ end Kernel panic - not syncing: Kernel exception
      Signed-off-by: default avatarSteven Miao <realmz6@gmail.com>
      Acked-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: <stable@vger.kernel.org>	[3.15.x]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e020d5bd
    • Greg Kroah-Hartman's avatar
      lz4: ensure length does not wrap · 206204a1
      Greg Kroah-Hartman authored
      
      
      Given some pathologically compressed data, lz4 could possibly decide to
      wrap a few internal variables, causing unknown things to happen.  Catch
      this before the wrapping happens and abort the decompression.
      Reported-by: default avatar"Don A. Bailey" <donb@securitymouse.com>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      206204a1
    • Greg Kroah-Hartman's avatar
      lzo: properly check for overruns · 206a81c1
      Greg Kroah-Hartman authored
      
      
      The lzo decompressor can, if given some really crazy data, possibly
      overrun some variable types.  Modify the checking logic to properly
      detect overruns before they happen.
      Reported-by: default avatar"Don A. Bailey" <donb@securitymouse.com>
      Tested-by: default avatar"Don A. Bailey" <donb@securitymouse.com>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      206a81c1
  3. 22 Jun, 2014 4 commits
    • Linus Torvalds's avatar
      Linux 3.16-rc2 · a497c3ba
      Linus Torvalds authored
      a497c3ba
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · 8f5d2708
      Linus Torvalds authored
      Pull i2c new drivers from Wolfram Sang:
       "Here is a pull request from i2c hoping for the "new driver" rule.
      
        Originally, I wanted to send this request during the merge window, but
        code checkers with very recent additions complained, so a few fixups
        were needed.  So, some more time went by and I merged rc1 to get a
        stable base"
      
      So the "new driver" rule is really about drivers that people absolutely
      need for the kernel to work on new hardware, which is not so much the
      case for i2c.  So I considered not pulling this, but eventually
      relented.
      
      Just for FYI: the whole (and only) point of "new drivers" is not that
      new drivers cannot regress things (they can, and they have - by
      triggering badly tested code on machines that never triggered that code
      before), but because they can bring to life machines that otherwise
      wouldn't be useful at all without the drivers.
      
      So the new driver rule is for essential things that actual consumers
      would care about, ie devices like networking or disk drivers that matter
      to normal people (not server people - they run old kernels anyway, so
      mainlining new drivers is irrelevant for them).
      
      * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: sun6-p2wi: fix call to snprintf
        i2c: rk3x: add NULL entry to the end of_device_id array
        i2c: sun6i-p2wi: use proper return value in probe
        i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support
        i2c: sunxi: add P2WI DT bindings documentation
        i2c: rk3x: add driver for Rockchip RK3xxx SoC I2C adapter
      8f5d2708
    • Linus Torvalds's avatar
      Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux · 2dfded82
      Linus Torvalds authored
      Pull file locking fixes from Jeff Layton:
       "File locking related bugfixes
      
        Nothing too earth-shattering here.  A fix for a potential regression
        due to a patch in pile #1, and the addition of a memory barrier to
        prevent a race condition between break_deleg and generic_add_lease"
      
      * tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux:
        locks: set fl_owner for leases back to current->files
        locks: add missing memory barrier in break_deleg
      2dfded82
    • Linus Torvalds's avatar
      Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild · 532f5138
      Linus Torvalds authored
      Pull kbuild fixes from Michal Marek:
       "There are three fixes for regressions caused by the relative paths
        series: deb-pkg, tar-pkg and *docs did not work with O=.
      
        Plus, there is a fix for the linux-headers deb package and a fixed
        typo.  These are not regression fixes but are safe enough"
      
      * 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
        kbuild: fix a typo in a kbuild document
        builddeb: fix missing headers in linux-headers package
        Documentation: Fix DocBook build with relative $(srctree)
        kbuild: Fix tar-pkg with relative $(objtree)
        deb-pkg: Fix for relative paths
      532f5138