1. 26 Apr, 2013 26 commits
  2. 17 Apr, 2013 14 commits
    • Greg Kroah-Hartman's avatar
      Linux 3.4.41 · 94402d16
      Greg Kroah-Hartman authored
      94402d16
    • David Woodhouse's avatar
      mtd: Disable mtdchar mmap on MMU systems · 06ce3e44
      David Woodhouse authored
      commit f5cf8f07 upstream.
      
      This code was broken because it assumed that all MTD devices were map-based.
      Disable it for now, until it can be fixed properly for the next merge window.
      Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      06ce3e44
    • Hayes Wang's avatar
      r8169: fix auto speed down issue · 880f56d9
      Hayes Wang authored
      commit e2409d83 upstream.
      
      It would cause no link after suspending or shutdowning when the
      nic changes the speed to 10M and connects to a link partner which
      forces the speed to 100M.
      
      Check the link partner ability to determine which speed to set.
      Signed-off-by: default avatarHayes Wang <hayeswang@realtek.com>
      Acked-by: default avatarFrancois Romieu <romieu@fr.zoreil.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      880f56d9
    • Linus Torvalds's avatar
      kobject: fix kset_find_obj() race with concurrent last kobject_put() · 2931b31f
      Linus Torvalds authored
      commit a49b7e82 upstream.
      
      Anatol Pomozov identified a race condition that hits module unloading
      and re-loading.  To quote Anatol:
      
       "This is a race codition that exists between kset_find_obj() and
        kobject_put().  kset_find_obj() might return kobject that has refcount
        equal to 0 if this kobject is freeing by kobject_put() in other
        thread.
      
        Here is timeline for the crash in case if kset_find_obj() searches for
        an object tht nobody holds and other thread is doing kobject_put() on
        the same kobject:
      
          THREAD A (calls kset_find_obj())     THREAD B (calls kobject_put())
          splin_lock()
                                               atomic_dec_return(kobj->kref), counter gets zero here
                                               ... starts kobject cleanup ....
                                               spin_lock() // WAIT thread A in kobj_kset_leave()
          iterate over kset->list
          atomic_inc(kobj->kref) (counter becomes 1)
          spin_unlock()
                                               spin_lock() // taken
                                               // it does not know that thread A increased counter so it
                                               remove obj from list
                                               spin_unlock()
                                               vfree(module) // frees module object with containing kobj
      
          // kobj points to freed memory area!!
          kobject_put(kobj) // OOPS!!!!
      
        The race above happens because module.c tries to use kset_find_obj()
        when somebody unloads module.  The module.c code was introduced in
        commit 6494a93d"
      
      Anatol supplied a patch specific for module.c that worked around the
      problem by simply not using kset_find_obj() at all, but rather than make
      a local band-aid, this just fixes kset_find_obj() to be thread-safe
      using the proper model of refusing the get a new reference if the
      refcount has already dropped to zero.
      
      See examples of this proper refcount handling not only in the kref
      documentation, but in various other equivalent uses of this pattern by
      grepping for atomic_inc_not_zero().
      
      [ Side note: the module race does indicate that module loading and
        unloading is not properly serialized wrt sysfs information using the
        module mutex.  That may require further thought, but this is the
        correct fix at the kobject layer regardless. ]
      Reported-analyzed-and-tested-by: default avatarAnatol Pomozov <anatol.pomozov@gmail.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2931b31f
    • Linus Torvalds's avatar
      mtdchar: fix offset overflow detection · a7d50720
      Linus Torvalds authored
      commit 9c603e53 upstream.
      
      Sasha Levin has been running trinity in a KVM tools guest, and was able
      to trigger the BUG_ON() at arch/x86/mm/pat.c:279 (verifying the range of
      the memory type).  The call trace showed that it was mtdchar_mmap() that
      created an invalid remap_pfn_range().
      
      The problem is that mtdchar_mmap() does various really odd and subtle
      things with the vma page offset etc, and uses the wrong types (and the
      wrong overflow) detection for it.
      
      For example, the page offset may well be 32-bit on a 32-bit
      architecture, but after shifting it up by PAGE_SHIFT, we need to use a
      potentially 64-bit resource_size_t to correctly hold the full value.
      
      Also, we need to check that the vma length plus offset doesn't overflow
      before we check that it is smaller than the length of the mtdmap region.
      
      This fixes things up and tries to make the code a bit easier to read.
      Reported-and-tested-by: default avatarSasha Levin <levinsasha928@gmail.com>
      Acked-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Acked-by: default avatarArtem Bityutskiy <dedekind1@gmail.com>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: linux-mtd@lists.infradead.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Brad Spengler <spender@grsecurity.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a7d50720
    • Boris Ostrovsky's avatar
      x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal · 7ad09085
      Boris Ostrovsky authored
      commit 511ba86e upstream.
      
      Invoking arch_flush_lazy_mmu_mode() results in calls to
      preempt_enable()/disable() which may have performance impact.
      
      Since lazy MMU is not used on bare metal we can patch away
      arch_flush_lazy_mmu_mode() so that it is never called in such
      environment.
      
      [ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU
        updates" may cause a minor performance regression on
        bare metal.  This patch resolves that performance regression.  It is
        somewhat unclear to me if this is a good -stable candidate. ]
      Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.comTested-by: default avatarJosh Boyer <jwboyer@redhat.com>
      Tested-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Acked-by: default avatarBorislav Petkov <bp@suse.de>
      Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7ad09085
    • Samu Kallio's avatar
      x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updates · e082a177
      Samu Kallio authored
      commit 1160c277 upstream.
      
      In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
      when lazy MMU updates are enabled, because set_pgd effects are being
      deferred.
      
      One instance of this problem is during process mm cleanup with memory
      cgroups enabled. The chain of events is as follows:
      
      - zap_pte_range enables lazy MMU updates
      - zap_pte_range eventually calls mem_cgroup_charge_statistics,
        which accesses the vmalloc'd mem_cgroup per-cpu stat area
      - vmalloc_fault is triggered which tries to sync the corresponding
        PGD entry with set_pgd, but the update is deferred
      - vmalloc_fault oopses due to a mismatch in the PUD entries
      
      The OOPs usually looks as so:
      
      ------------[ cut here ]------------
      kernel BUG at arch/x86/mm/fault.c:396!
      invalid opcode: 0000 [#1] SMP
      .. snip ..
      CPU 1
      Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
      RIP: e030:[<ffffffff816271bf>]  [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208
      .. snip ..
      Call Trace:
       [<ffffffff81627759>] do_page_fault+0x399/0x4b0
       [<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110
       [<ffffffff81624065>] page_fault+0x25/0x30
       [<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
       [<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350
       [<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60
       [<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150
       [<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80
       [<ffffffff81153e61>] unmap_single_vma+0x531/0x870
       [<ffffffff81154962>] unmap_vmas+0x52/0xa0
       [<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100
       [<ffffffff8115c8f8>] exit_mmap+0x98/0x170
       [<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
       [<ffffffff81059ce3>] mmput+0x83/0xf0
       [<ffffffff810624c4>] exit_mm+0x104/0x130
       [<ffffffff8106264a>] do_exit+0x15a/0x8c0
       [<ffffffff810630ff>] do_group_exit+0x3f/0xa0
       [<ffffffff81063177>] sys_exit_group+0x17/0x20
       [<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b
      
      Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
      changes visible to the consistency checks.
      
      RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737Tested-by: default avatarJosh Boyer <jwboyer@redhat.com>
      Reported-and-Tested-by: default avatarKrishna Raman <kraman@redhat.com>
      Signed-off-by: default avatarSamu Kallio <samu.kallio@aberdeencloud.com>
      Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.comTested-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e082a177
    • Thomas Gleixner's avatar
      sched_clock: Prevent 64bit inatomicity on 32bit systems · fdd9ce00
      Thomas Gleixner authored
      commit a1cbcaa9 upstream.
      
      The sched_clock_remote() implementation has the following inatomicity
      problem on 32bit systems when accessing the remote scd->clock, which
      is a 64bit value.
      
      CPU0			CPU1
      
      sched_clock_local()	sched_clock_remote(CPU0)
      ...
      			remote_clock = scd[CPU0]->clock
      			    read_low32bit(scd[CPU0]->clock)
      cmpxchg64(scd->clock,...)
      			    read_high32bit(scd[CPU0]->clock)
      
      While the update of scd->clock is using an atomic64 mechanism, the
      readout on the remote cpu is not, which can cause completely bogus
      readouts.
      
      It is a quite rare problem, because it requires the update to hit the
      narrow race window between the low/high readout and the update must go
      across the 32bit boundary.
      
      The resulting misbehaviour is, that CPU1 will see the sched_clock on
      CPU1 ~4 seconds ahead of it's own and update CPU1s sched_clock value
      to this bogus timestamp. This stays that way due to the clamping
      implementation for about 4 seconds until the synchronization with
      CLOCK_MONOTONIC undoes the problem.
      
      The issue is hard to observe, because it might only result in a less
      accurate SCHED_OTHER timeslicing behaviour. To create observable
      damage on realtime scheduling classes, it is necessary that the bogus
      update of CPU1 sched_clock happens in the context of an realtime
      thread, which then gets charged 4 seconds of RT runtime, which results
      in the RT throttler mechanism to trigger and prevent scheduling of RT
      tasks for a little less than 4 seconds. So this is quite unlikely as
      well.
      
      The issue was quite hard to decode as the reproduction time is between
      2 days and 3 weeks and intrusive tracing makes it less likely, but the
      following trace recorded with trace_clock=global, which uses
      sched_clock_local(), gave the final hint:
      
        <idle>-0   0d..30 400269.477150: hrtimer_cancel: hrtimer=0xf7061e80
        <idle>-0   0d..30 400269.477151: hrtimer_start:  hrtimer=0xf7061e80 ...
      irq/20-S-587 1d..32 400273.772118: sched_wakeup:   comm= ... target_cpu=0
        <idle>-0   0dN.30 400273.772118: hrtimer_cancel: hrtimer=0xf7061e80
      
      What happens is that CPU0 goes idle and invokes
      sched_clock_idle_sleep_event() which invokes sched_clock_local() and
      CPU1 runs a remote wakeup for CPU0 at the same time, which invokes
      sched_remote_clock(). The time jump gets propagated to CPU0 via
      sched_remote_clock() and stays stale on both cores for ~4 seconds.
      
      There are only two other possibilities, which could cause a stale
      sched clock:
      
      1) ktime_get() which reads out CLOCK_MONOTONIC returns a sporadic
         wrong value.
      
      2) sched_clock() which reads the TSC returns a sporadic wrong value.
      
      #1 can be excluded because sched_clock would continue to increase for
         one jiffy and then go stale.
      
      #2 can be excluded because it would not make the clock jump
         forward. It would just result in a stale sched_clock for one jiffy.
      
      After quite some brain twisting and finding the same pattern on other
      traces, sched_clock_remote() remained the only place which could cause
      such a problem and as explained above it's indeed racy on 32bit
      systems.
      
      So while on 64bit systems the readout is atomic, we need to verify the
      remote readout on 32bit machines. We need to protect the local->clock
      readout in sched_clock_remote() on 32bit as well because an NMI could
      hit between the low and the high readout, call sched_clock_local() and
      modify local->clock.
      
      Thanks to Siegfried Wulsch for bearing with my debug requests and
      going through the tedious tasks of running a bunch of reproducer
      systems to generate the debug information which let me decode the
      issue.
      Reported-by: default avatarSiegfried Wulsch <Siegfried.Wulsch@rovema.de>
      Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304051544160.21884@ionosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fdd9ce00
    • Dave Airlie's avatar
      udl: handle EDID failure properly. · bff66275
      Dave Airlie authored
      commit 1baee586 upstream.
      
      Don't oops seems proper.
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bff66275
    • Thomas Hellstrom's avatar
      kref: Implement kref_get_unless_zero v3 · e3a55052
      Thomas Hellstrom authored
      commit 4b20db3d upstream.
      
      This function is intended to simplify locking around refcounting for
      objects that can be looked up from a lookup structure, and which are
      removed from that lookup structure in the object destructor.
      Operations on such objects require at least a read lock around
      lookup + kref_get, and a write lock around kref_put + remove from lookup
      structure. Furthermore, RCU implementations become extremely tricky.
      With a lookup followed by a kref_get_unless_zero *with return value check*
      locking in the kref_put path can be deferred to the actual removal from
      the lookup structure and RCU lookups become trivial.
      
      v2: Formatting fixes.
      v3: Invert the return value.
      Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e3a55052
    • Suleiman Souhlal's avatar
      vfs: Revert spurious fix to spinning prevention in prune_icache_sb · 7077c66b
      Suleiman Souhlal authored
      commit 5b55d708 upstream.
      
      Revert commit 62a3ddef ("vfs: fix spinning prevention in prune_icache_sb").
      
      This commit doesn't look right: since we are looking at the tail of the
      list (sb->s_inode_lru.prev) if we want to skip an inode, we should put
      it back at the head of the list instead of the tail, otherwise we will
      keep spinning on it.
      
      Discovered when investigating why prune_icache_sb came top in perf
      reports of a swapping load.
      Signed-off-by: default avatarSuleiman Souhlal <suleiman@google.com>
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7077c66b
    • Nicholas Bellinger's avatar
      target: Fix incorrect fallthrough of ALUA Standby/Offline/Transition CDBs · eced4ec1
      Nicholas Bellinger authored
      commit 30f359a6 upstream.
      
      This patch fixes a bug where a handful of informational / control CDBs
      that should be allowed during ALUA access state Standby/Offline/Transition
      where incorrectly returning CHECK_CONDITION + ASCQ_04H_ALUA_TG_PT_*.
      
      This includes INQUIRY + REPORT_LUNS, which would end up preventing LUN
      registration when LUN scanning occured during these ALUA access states.
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Cc: Hannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eced4ec1
    • Sachin Prabhu's avatar
      cifs: Allow passwords which begin with a delimitor · e0b4cef3
      Sachin Prabhu authored
      commit c369c9a4 upstream.
      
      Fixes a regression in cifs_parse_mount_options where a password
      which begins with a delimitor is parsed incorrectly as being a blank
      password.
      Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
      Acked-by: default avatarJeff Layton <jlayton@redhat.com>
      Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e0b4cef3
    • Lukasz Dorau's avatar
      SCSI: libsas: fix handling vacant phy in sas_set_ex_phy() · b7dba0e4
      Lukasz Dorau authored
      commit d4a2618f upstream.
      
      If a result of the SMP discover function is PHY VACANT,
      the content of discover response structure (dr) is not valid.
      It sometimes happens that dr->attached_sas_addr can contain
      even SAS address of other phy. In such case an invalid phy
      is created, what causes NULL pointer dereference during
      destruction of expander's phys.
      
      So if a result of SMP function is PHY VACANT, the content of discover
      response structure (dr) must not be copied to phy structure.
      
      This patch fixes the following bug:
      
      BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
      IP: [<ffffffff811c9002>] sysfs_find_dirent+0x12/0x90
      Call Trace:
        [<ffffffff811c95f5>] sysfs_get_dirent+0x35/0x80
        [<ffffffff811cb55e>] sysfs_unmerge_group+0x1e/0xb0
        [<ffffffff813329f4>] dpm_sysfs_remove+0x24/0x90
        [<ffffffff8132b0f4>] device_del+0x44/0x1d0
        [<ffffffffa016fc59>] sas_rphy_delete+0x9/0x20 [scsi_transport_sas]
        [<ffffffffa01a16f6>] sas_destruct_devices+0xe6/0x110 [libsas]
        [<ffffffff8107ac7c>] process_one_work+0x16c/0x350
        [<ffffffff8107d84a>] worker_thread+0x17a/0x410
        [<ffffffff81081b76>] kthread+0x96/0xa0
        [<ffffffff81464944>] kernel_thread_helper+0x4/0x10
      Signed-off-by: default avatarLukasz Dorau <lukasz.dorau@intel.com>
      Signed-off-by: default avatarPawel Baldysiak <pawel.baldysiak@intel.com>
      Reviewed-by: default avatarMaciej Patelczyk <maciej.patelczyk@intel.com>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b7dba0e4