1. 12 Nov, 2014 9 commits
  2. 10 Nov, 2014 7 commits
    • Maurizio Lombardi's avatar
      bnx2fc: fix tgt spinlock locking · dc6311dd
      Maurizio Lombardi authored
      bnx2fc_queuecommand(): when allocating a new io_req, the tgt_lock
      spinlock must be locked before calling bnx2fc_cmd_alloc().
      
      The spinlock should also be kept locked until bnx2fc_post_io_req() has
      been completed.
      If not, a kernel thread may call bnx2fc_process_cq_compl() that extracts
      the newly allocated io_req from hba->cmd_mgr->cmds and destroys it while
      it is still being used by bnx2fc_post_io_req().
      
      BUG: unable to handle kernel NULL pointer dereference at 000000000000004c
      IP: [<ffffffffa03130da>] bnx2fc_init_task+0x6a/0x230 [bnx2fc]
      PGD 0
      Oops: 0000 [#1] SMP
      last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:04:00.3/net/eth3/type
      CPU 33
      Modules linked in: autofs4 target_core_iblock target_core_file target_core_pscsi target_core_mod configfs bnx2fc cnic uio fcoe libfcoe libfc scsi_transport_fc 8021q garp scsi_tgt stp llc cpufreq_ondemand freq_table pcc_cpufreq ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 power_meter microcode iTCO_wdt iTCO_vendor_support hpilo hpwdt sg bnx2x libcrc32c mdio serio_raw lpc_ich mfd_core shpchp ext4 jbd2 mbcache sd_mod crc_t10dif hpsa video output dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
      
      Pid: 7355, comm: bnx2fc_thread/3 Not tainted 2.6.32-431.el6.x86_64 #1 HP ProLiant BL460c Gen8
      RIP: 0010:[<ffffffffa03130da>]  [<ffffffffa03130da>] bnx2fc_init_task+0x6a/0x230 [bnx2fc]
      RSP: 0018:ffff8820b0da3b68  EFLAGS: 00010246
      RAX: 0000000000000000 RBX: ffff882003801080 RCX: 0000000000000000
      RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff882003801100
      RBP: ffff8820b0da3bc8 R08: ffffffff8160d4e8 R09: 0000000000000040
      R10: 0000000000000000 R11: 0000000000000000 R12: ffff88400e600e00
      R13: ffff8840108fbe40 R14: ffff88200ffe5400 R15: 0000000000000000
      FS:  0000000000000000(0000) GS:ffff8820b0da0000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
      CR2: 000000000000004c CR3: 0000002010b67000 CR4: 00000000001407e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
      Process bnx2fc_thread/3 (pid: 7355, threadinfo ffff88401f940000, task ffff884012f5f540)
      Stack:
       ffff8820b0da3bc8 ffffffff81527303 ffff884000000020 ffff8820b0da3bd8
      <d> ffff8820b0da3b98 000000028138931a ffff88400f506078 ffff88400e600e00
      <d> ffff88200ffe5400 ffff88200ffe5590 0000000000000021 0000000000000002
      Call Trace:
       <IRQ>
       [<ffffffff81527303>] ? printk+0x41/0x46
       [<ffffffffa03169bc>] bnx2fc_post_io_req+0x11c/0x440 [bnx2fc]
       [<ffffffff812825b9>] ? cpumask_next_and+0x29/0x50
       [<ffffffff8137ffd0>] ? scsi_done+0x0/0x60
       [<ffffffffa0316df7>] bnx2fc_queuecommand+0x117/0x140 [bnx2fc]
       [<ffffffff81380245>] scsi_dispatch_cmd+0xe5/0x310
       [<ffffffff81388b9e>] scsi_request_fn+0x5ee/0x7a0
       [<ffffffff812658f1>] __blk_run_queue+0x31/0x40
       [<ffffffff81265a40>] blk_run_queue+0x30/0x50
       [<ffffffff81387da6>] scsi_run_queue+0xc6/0x270
       [<ffffffff81260f92>] ? elv_requeue_request+0x52/0xa0
       [<ffffffff813897a0>] scsi_requeue_command+0x90/0xb0
       [<ffffffff81389b84>] scsi_io_completion+0x154/0x6c0
       [<ffffffff8137ff62>] scsi_finish_command+0xc2/0x130
       [<ffffffff8138a255>] scsi_softirq_done+0x145/0x170
       [<ffffffff8126e865>] blk_done_softirq+0x85/0xa0
       [<ffffffff8107a8e1>] __do_softirq+0xc1/0x1e0
       [<ffffffff8100c30c>] ? call_softirq+0x1c/0x30
       [<ffffffff8100c30c>] call_softirq+0x1c/0x30
       <EOI>
       [<ffffffff8100fa75>] ? do_softirq+0x65/0xa0
       [<ffffffff8107a40a>] local_bh_enable_ip+0x9a/0xb0
       [<ffffffff8152a4eb>] _spin_unlock_bh+0x1b/0x20
       [<ffffffffa0313937>] bnx2fc_process_cq_compl+0x257/0x2b0 [bnx2fc]
       [<ffffffffa03114ea>] bnx2fc_percpu_io_thread+0xea/0x160 [bnx2fc]
       [<ffffffffa0311400>] ? bnx2fc_percpu_io_thread+0x0/0x160 [bnx2fc]
       [<ffffffff8109aef6>] kthread+0x96/0xa0
       [<ffffffff8100c20a>] child_rip+0xa/0x20
       [<ffffffff8109ae60>] ? kthread+0x0/0xa0
       [<ffffffff8100c200>] ? child_rip+0x0/0x20
      Code: 89 df 45 8b 7e 30 0f 85 75 01 00 00 89 d1 31 c0 c1 e9 03 83 e2 04 89 c9 f3 48 ab 74 06 c7 07 00 00 00 00 49 89 9c 24 88 01 00 00 <83> 7e 4c 01 b8 01 00 00 00 0f 84 e7 00 00 00 89 c2 0a 53 38 41
      RIP  [<ffffffffa03130da>] bnx2fc_init_task+0x6a/0x230 [bnx2fc]
       RSP <ffff8820b0da3b68>
      CR2: 000000000000004c
      Signed-off-by: default avatarMaurizio Lombardi <mlombard@redhat.com>
      Acked-by: default avatarChad Dupuis <chad.dupuis@qlogic.com>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      dc6311dd
    • Jiang Liu's avatar
      megaraid_sas: fix bug in handling return value of pci_enable_msix_range() · c12de882
      Jiang Liu authored
      Function pci_enable_msix_range() may return negative values for error
      conditions. So it's a bug by checking (pci_enable_msix_range() != 0)
      for success and causes failure to megaraid driver when MSI is disabled.
      [   16.487267] megaraid_sas 0000:02:00.0: Controller type: iMR
      [   16.487275] genirq: Flags mismatch irq 0. 00000000 (megasas) vs. 00015a00 (tii
      mer)
      [   16.487347] megasas: Failed to register IRQ for vector 0.
      
      Fixes: 8ae80ed1 "megaraid: Use pci_enable_msix_range() instead of pci_enable_msix()"
      Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
      Acked-by: default avatarSumit Saxena <sumit.saxena@avagotech.com>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: <stable@vger.kernel.org> # 3.17
      c12de882
    • Anish Bhatt's avatar
      cxgb4i: send abort_rpl correctly · 7b07bf24
      Anish Bhatt authored
      Connection retries were not being cleaned up correctly if they failed as a
      result of link down. Applies on top of drivers-for-3.18.
      Signed-off-by: default avatarAnish Bhatt <anish@chelsio.com>
      Signed-off-by: default avatarKaren Xie <kxie@chelsio.com>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      7b07bf24
    • Anish Bhatt's avatar
      cxgbi: add maintainer for cxgb3i/cxgb4i · d8ae3c33
      Anish Bhatt authored
      Signed-off-by: default avatarAnish Bhatt <anish@chelsio.com>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      d8ae3c33
    • wenxiong@linux.vnet.ibm.com's avatar
      scsi: TUR path is down after adapter gets reset with multipath · 333b2448
      wenxiong@linux.vnet.ibm.com authored
      This patch fixes an issue with multipath ipr SAS devices which require a
      start unit command to be issued following an adapter reset. Without this
      patch, paths get marked failed following an adapter reset and since the
      error handler never gets invoked to issue the start unit, the paths are
      never recovered. Returning FAILED for this case ensures the error
      handler wakes up to issue the start unit.
      Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
      Tested-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      333b2448
    • Christoph Hellwig's avatar
      scsi: call device handler for failed TUR command · e925cc43
      Christoph Hellwig authored
      Multipath devices using the TUR path checker need to see the sense
      code for a failed TUR command in their device handler.  Since commit
      14216561 we always return success for mid
      layer issued TUR commands before calling the device handler, which
      stopped the TUR path checker from working.
      
      Move the call to the device handler check sense method before the early
      return for TUR commands to give the device handler a chance to intercept
      them.
      Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
      Tested-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      e925cc43
    • Christoph Hellwig's avatar
      scsi: only re-lock door after EH on devices that were reset · 48379270
      Christoph Hellwig authored
      Setups that use the blk-mq I/O path can lock up if a host with a single
      device that has its door locked enters EH.  Make sure to only send the
      command to re-lock the door to devices that actually were reset and thus
      might have lost their state.  Otherwise the EH code might be get blocked
      on blk_get_request as all requests for non-reset devices might be in use.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reported-by: default avatarMeelis Roos <meelis.roos@ut.ee>
      Tested-by: default avatarMeelis Roos <meelis.roos@ut.ee>
      Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      48379270
  3. 09 Nov, 2014 10 commits
  4. 08 Nov, 2014 4 commits
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · fe606dff
      Linus Torvalds authored
      Pull i2c bugfixes from Wolfram Sang:
       "One bigger cleanup (FSF address removal) and two bugfixes for I2C"
      
      * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: core: Dispose OF IRQ mapping at client removal time
        i2c: at91: don't account as iowait
        i2c: remove FSF address
      fe606dff
    • Linus Torvalds's avatar
      Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · a50d7156
      Linus Torvalds authored
      Pull irq fixes from Thomas Gleixner:
       "Two fixlets for the armada SoC interrupt controller"
      
      * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        irqchip: armada-370-xp: Fix MPIC interrupt handling
        irqchip: armada-370-xp: Fix MSI interrupt handling
      a50d7156
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media · ae04e1ca
      Linus Torvalds authored
      Pull media fixes from Mauro Carvalho Chehab:
       "For:
         - some regression fixes at the Remote Controller core and imon driver
         - a build fix for certain randconfigs with ir-hix5hd2
         - don't feed power to satellite system at ds3000 driver init
      
        It also contains some fixes for drivers added for Kernel 3.18:
         - some fixes at the new ISDB-S driver, and the corresponding bits to
           fix some descriptors for this Japanese TV standard at the DVB core
         - two warning cleanups for sp2 driver if PM is disabled
         - change the default mode for the new vivid driver"
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
        [media] sp2: sp2_init() can be static
        [media] dvb:tc90522: fix always-false expression
        [media] dvb-core: set default properties of ISDB-S
        [media] dvb:tc90522: fix stats report
        [media] vivid: default to single planar device instances
        [media] imon: fix other RC type protocol support
        [media] ir-hix5hd2 fix build warning
        [media] ds3000: fix LNB supply voltage on Tevii S480 on initialization
        [media] rc5-decoder: BZ#85721: Fix RC5-SZ decoding
        [media] rc-core: fix protocol_change regression in ir_raw_event_register
      ae04e1ca
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus · 6ac94d3a
      Linus Torvalds authored
      Pull MIPS updates from Ralf Baechle:
       "This weeks' round of MIPS bug fixes for 3.18:
      
         - wire up the bpf syscall
         - fix TLB dump output for R3000 class TLBs
         - fix strnlen_user return value if no NUL character was found.
         - fix build with binutils 2.24.51+.  While there is no binutils 2.25
           release yet, toolchains derived from binutils 2.24.51+ are already
           in common use.
         - the Octeon GPIO code forgot to offline GPIO IRQs.
         - fix build error for XLP.
         - fix possible BUG assertion with EVA for CMA"
      
      * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
        MIPS: Fix build with binutils 2.24.51+
        MIPS: R3000: Fix debug output for Virtual page number
        MIPS: Fix strnlen_user() return value in case of overlong strings.
        MIPS: CMA: Do not reserve memory if not required
        MIPS: Wire up bpf syscall.
        MIPS/Xlp: Remove the dead function destroy_irq() to fix build error
        MIPS: Octeon: Make Octeon GPIO IRQ chip CPU hotplug-aware
      6ac94d3a
  5. 07 Nov, 2014 10 commits
    • Linus Torvalds's avatar
      Merge tag 'xfs-for-linus-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs · 661b99e9
      Linus Torvalds authored
      Pull xfs fixes from Dave Chinner:
       "This update fixes a warning in the new pagecache_isize_extended() and
        updates some related comments, another fix for zero-range
        misbehaviour, and an unforntuately large set of fixes for regressions
        in the bulkstat code.
      
        The bulkstat fixes are large but necessary.  I wouldn't normally push
        such a rework for a -rcX update, but right now xfsdump can silently
        create incomplete dumps on 3.17 and it's possible that even xfsrestore
        won't notice that the dumps were incomplete.  Hence we need to get
        this update into 3.17-stable kernels ASAP.
      
        In more detail, the refactoring work I committed in 3.17 has exposed a
        major hole in our QA coverage.  With both xfsdump (the major user of
        bulkstat) and xfsrestore silently ignoring missing files in the
        dump/restore process, incomplete dumps were going unnoticed if they
        were being triggered.  Many of the dump/restore filesets were so small
        that they didn't evenhave a chance of triggering the loop iteration
        bugs we introduced in 3.17, so we didn't exercise the code
        sufficiently, either.
      
        We have already taken steps to improve QA coverage in xfstests to
        avoid this happening again, and I've done a lot of manual verification
        of dump/restore on very large data sets (tens of millions of inodes)
        of the past week to verify this patch set results in bulkstat behaving
        the same way as it does on 3.16.
      
        Unfortunately, the fixes are not exactly simple - in tracking down the
        problem historic API warts were discovered (e.g xfsdump has been
        working around a 20 year old bug in the bulkstat API for the past 10
        years) and so that complicated the process of diagnosing and fixing
        the problems.  i.e. we had to fix bugs in the code as well as
        discover and re-introduce the userspace visible API bugs that we
        unwittingly "fixed" in 3.17 that xfsdump relied on to work correctly.
      
        Summary:
      
         - incorrect warnings about i_mutex locking in pagecache_isize_extended()
           and updates comments to match expected locking
         - another zero-range bug fix for stray file size updates
         - a bunch of fixes for regression in the bulkstat code introduced in
           3.17"
      
      * tag 'xfs-for-linus-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
        xfs: track bulkstat progress by agino
        xfs: bulkstat error handling is broken
        xfs: bulkstat main loop logic is a mess
        xfs: bulkstat chunk-formatter has issues
        xfs: bulkstat chunk formatting cursor is broken
        xfs: bulkstat btree walk doesn't terminate
        mm: Fix comment before truncate_setsize()
        xfs: rework zero range to prevent invalid i_size updates
        mm: Remove false WARN_ON from pagecache_isize_extended()
        xfs: Check error during inode btree iteration in xfs_bulkstat()
        xfs: bulkstat doesn't release AGI buffer on error
      661b99e9
    • Linus Torvalds's avatar
      Merge tag 'regulator-v3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator · 51f83ef0
      Linus Torvalds authored
      Pull regulator fixes from Mark Brown:
       "More changes than I'd like here, most of them for a single bug
        repeated in a bunch of drivers with data not being initialized
        correctly, plus a fix to lower the severity of a warning introduced in
        the last merge window which can legitimately go off so we don't want
        to alarm users excessively"
      
      * tag 'regulator-v3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
        regulator: s2mpa01: zero-initialize regulator match table array
        regulator: max8660: zero-initialize regulator match table array
        regulator: max77802: zero-initialize regulator match table
        regulator: max77686: zero-initialize regulator match table
        regulator: max1586: zero-initialize regulator match table array
        regulator: max77693: Fix use of uninitialized regulator config
        regulator: of: Lower the severity of the error with no container
      51f83ef0
    • Linus Torvalds's avatar
      Merge tag 'spi-v3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi · 1395b9cf
      Linus Torvalds authored
      Pull spi bugfixes from Mark Brown:
       "A couple of small driver fixes for v3.18, both quite problematic if
        you hit a use case that's affected"
      
      * tag 'spi-v3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
        spi: pxa2xx: toggle clocks on suspend if not disabled by runtime PM
        spi: fsl-dspi: Fix CTAR selection
      1395b9cf
    • Johannes Berg's avatar
      tiny: rename ENABLE_DEV_COREDUMP to ALLOW_DEV_COREDUMP · cd3d9ea1
      Johannes Berg authored
      The ENABLE_DEV_COREDUMP option is misleading as it implies that
      it gets the framework enabled, this isn't true it just allows it
      to get enabled if a driver needs it.
      
      Rename it to ALLOW_DEV_COREDUMP to better capture its semantics.
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Acked-by: default avatarAristeu Rozanski <aris@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cd3d9ea1
    • Aristeu Rozanski's avatar
      tiny: reverse logic for DISABLE_DEV_COREDUMP · 9c602699
      Aristeu Rozanski authored
      It's desirable for allnconfig and tinyconfig targets to result in the
      least amount of code possible. DISABLE_DEV_COREDUMP exists as a way to
      switch off DEV_COREDUMP regardless if any drivers select
      WANT_DEV_COREDUMP.
      
      This patch renames the option to ENABLE_DEV_COREDUMP and setting it to
      'n' (as in allnconfig or tinyconfig) will effectively disable device
      coredump.
      
      Cc: Josh Triplett <josh@joshtriplett.org>
      Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Signed-off-by: default avatarAristeu Rozanski <arozansk@redhat.com>
      Reviewed-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Acked-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9c602699
    • Laurent Pinchart's avatar
      i2c: core: Dispose OF IRQ mapping at client removal time · e4df3a0b
      Laurent Pinchart authored
      Clients instantiated from OF get an IRQ mapping created at device
      registration time. Dispose the mapping when the client is removed.
      Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
      Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      Cc: stable@kernel.org
      e4df3a0b
    • Wolfram Sang's avatar
      i2c: at91: don't account as iowait · 11cfbfb0
      Wolfram Sang authored
      iowait is for blkio [1]. I2C shouldn't use it.
      
      [1] https://lkml.org/lkml/2014/11/3/317Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      Acked-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
      Cc: stable@kernel.org
      11cfbfb0
    • Wolfram Sang's avatar
      i2c: remove FSF address · ca1f8da9
      Wolfram Sang authored
      We have a central copy of the GPL for that. Some addresses were already
      outdated.
      Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
      ca1f8da9
    • Mark Knibbs's avatar
      USB: Update default usb-storage delay_use value in kernel-parameters.txt · 19101954
      Mark Knibbs authored
      Back in 2010 the default usb-storage delay_use time was reduced from 5 to 1
      second (commit a4a47bc0), but
      kernel-parameters.txt wasn't updated to reflect that.
      Signed-off-by: default avatarMark Knibbs <markk@clara.co.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      19101954
    • Yijing Wang's avatar
      sysfs: driver core: Fix glue dir race condition by gdp_mutex · e4a60d13
      Yijing Wang authored
      There is a race condition when removing glue directory.
      It can be reproduced in following test:
      
      path 1: Add first child device
      device_add()
          get_device_parent()
                  /*find parent from glue_dirs.list*/
                  list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
                          if (k->parent == parent_kobj) {
                                  kobj = kobject_get(k);
                                  break;
                          }
                  ....
                  class_dir_create_and_add()
      
      path2: Remove last child device under glue dir
      device_del()
          cleanup_device_parent()
                  cleanup_glue_dir()
                          kobject_put(glue_dir);
      
      If path2 has been called cleanup_glue_dir(), but not
      call kobject_put(glue_dir), the glue dir is still
      in parent's kset list. Meanwhile, path1 find the glue
      dir from the glue_dirs.list. Path2 may release glue dir
      before path1 call kobject_get(). So kernel will report
      the warning and bug_on.
      
      This is a "classic" problem we have of a kref in a list
      that can be found while the last instance could be removed
      at the same time.
      
      This patch reuse gdp_mutex to fix this race condition.
      
      The following calltrace is captured in kernel 3.4, but
      the latest kernel still has this bug.
      
      -----------------------------------------------------
      <4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40()
      <4>[ 3965.441474] Hardware name: Romley
      <4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)...
      ...
      <4>[ 3965.441605] Call Trace:
      <4>[ 3965.441611]  [<ffffffff8103717a>] warn_slowpath_common+0x7a/0xb0
      <4>[ 3965.441615]  [<ffffffff810371c5>] warn_slowpath_null+0x15/0x20
      <4>[ 3965.441618]  [<ffffffff81215963>] kobject_get+0x33/0x40
      <4>[ 3965.441624]  [<ffffffff812d1e45>] get_device_parent.isra.11+0x135/0x1f0
      <4>[ 3965.441627]  [<ffffffff812d22d4>] device_add+0xd4/0x6d0
      <4>[ 3965.441631]  [<ffffffff812d0dbc>] ? dev_set_name+0x3c/0x40
      ....
      <2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65!
      <4>[ 3965.441915] invalid opcode: 0000 [#1] SMP
      ...
      <4>[ 3965.686743]  [<ffffffff811a677e>] sysfs_create_group+0xe/0x10
      <4>[ 3965.686748]  [<ffffffff810cfb04>] blk_trace_init_sysfs+0x14/0x20
      <4>[ 3965.686753]  [<ffffffff811fcabb>] blk_register_queue+0x3b/0x120
      <4>[ 3965.686756]  [<ffffffff812030bc>] add_disk+0x1cc/0x490
      ....
      -------------------------------------------------------
      Signed-off-by: default avatarYijing Wang <wangyijing@huawei.com>
      Signed-off-by: default avatarWeng Meiling <wengmeiling.weng@huawei.com>
      Cc: <stable@vger.kernel.org> #3.4+
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e4a60d13