1. 05 Jan, 2017 3 commits
    • Takashi Sakamoto's avatar
      Revert "ALSA: firewire-lib: change structure member with proper type" · e4f34cf6
      Takashi Sakamoto authored
      This reverts commit 6b7e95d1
      
      . This commit
      is based on a concern about value of the given parameter. It's expected
      to be ORed value with some enumeration-constants, thus often it can not be
      one of the enumeration-constants. I understood that this is out of
      specification and causes implementation-dependent issues.
      
      In C language specification, enumerated type can be interpreted as an
      integer type, in which all of enumeration-constants in corresponding
      enumerator-list can be stored. Implementations can select one of char,
      signed int and unsigned int as its type, and this selection is
      implementation-dependent.
      
      In GCC, a signed integer is selected when at least one of
      enumeration-constants has negative value, else an unsigned integer is
      selected. This behaviour can be switched by -fshort-enums to short type.
      Anyway, the type can be decided after scanning all of
      enumeration-constants.
      
      Totally, there's no rules to constrain the value of enumerated type to
      be one of enumeration-constants. In short, in enumerated type, decision
      of actual type for the type is the most important and
      enumeration-constants are just used for the decision, thus it's permitted
      to have an integer value in a range of enumeration-constants. In our case,
      actual type for the type is currently deterministic to be either char or
      unsigned int. Under GCC, it's unsigned int.
      Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      e4f34cf6
    • Ioan-Adrian Ratiu's avatar
      ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion · 13a6c832
      Ioan-Adrian Ratiu authored
      
      
      Testing EP_FLAG_RUNNING in snd_complete_urb() before running the completion
      logic allows us to save a few cpu cycles by returning early, skipping the
      pending urb in case the stream was stopped; the stop logic handles the urb
      and sets the completion callbacks to NULL.
      Signed-off-by: default avatarIoan-Adrian Ratiu <adi@adirat.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      13a6c832
    • Ioan-Adrian Ratiu's avatar
      ALSA: usb-audio: Fix irq/process data synchronization · 1d0f9530
      Ioan-Adrian Ratiu authored
      Commit 16200948 ("ALSA: usb-audio: Fix race at stopping the stream") was
      incomplete causing another more severe kernel panic, so it got reverted.
      This fixes both the original problem and its fallout kernel race/crash.
      
      The original fix is to move the endpoint member NULL clearing logic inside
      wait_clear_urbs() so the irq triggering the urb completion doesn't call
      retire_capture/playback_urb() after the NULL clearing and generate a panic.
      
      However this creates a new race between snd_usb_endpoint_start()'s call
      to wait_clear_urbs() and the irq urb completion handler which again calls
      retire_capture/playback_urb() leading to a new NULL dereference.
      
      We keep the EP deactivation code in snd_usb_endpoint_start() because
      removing it will break the EP reference counting (see [1] [2] for info),
      however we don't need the "can_sleep" mechanism anymore because a new
      function was introduced (snd_usb_endpoint_sync_pending_stop()) which
      synchronizes pending stops and gets called inside the pcm prepare callback.
      
      It also makes sense to remove can_sleep because it was also removed from
      deactivate_urbs() signature in [3] so we benefit from more simplification.
      
      [1] commit 015618b9 ("ALSA: snd-usb: Fix URB cancellation at stream start")
      [2] commit e9ba389c ("ALSA: usb-audio: Fix scheduling-while-atomic bug in PCM capture stream")
      [3] commit ccc1696d ("ALSA: usb-audio: simplify endpoint deactivation code")
      
      Fixes: f8114f85
      
       ("Revert "ALSA: usb-audio: Fix race at stopping the stream"")
      Signed-off-by: default avatarIoan-Adrian Ratiu <adi@adirat.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      1d0f9530
  2. 04 Jan, 2017 2 commits
  3. 03 Jan, 2017 3 commits
  4. 01 Jan, 2017 2 commits
    • Linus Torvalds's avatar
      Linux 4.10-rc2 · 0c744ea4
      Linus Torvalds authored
      0c744ea4
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 4759d386
      Linus Torvalds authored
      Pull DAX updates from Dan Williams:
       "The completion of Jan's DAX work for 4.10.
      
        As I mentioned in the libnvdimm-for-4.10 pull request, these are some
        final fixes for the DAX dirty-cacheline-tracking invalidation work
        that was merged through the -mm, ext4, and xfs trees in -rc1. These
        patches were prepared prior to the merge window, but we waited for
        4.10-rc1 to have a stable merge base after all the prerequisites were
        merged.
      
        Quoting Jan on the overall changes in these patches:
      
           "So I'd like all these 6 patches to go for rc2. The first three
            patches fix invalidation of exceptional DAX entries (a bug which
            is there for a long time) - without these patches data loss can
            occur on power failure even though user called fsync(2). The other
            three patches change locking of DAX faults so that ->iomap_begin()
            is called in a more relaxed locking context and we are safe to
            start a transaction there for ext4"
      
        These have received a build success notification from the kbuild
        robot, and pass the latest libnvdimm unit tests. There have not been
        any -next releases since -rc1, so they have not appeared there"
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        ext4: Simplify DAX fault path
        dax: Call ->iomap_begin without entry lock during dax fault
        dax: Finish fault completely when loading holes
        dax: Avoid page invalidation races and unnecessary radix tree traversals
        mm: Invalidate DAX radix tree entries only if appropriate
        ext2: Return BH_New buffers for zeroed blocks
      4759d386
  5. 30 Dec, 2016 2 commits
  6. 29 Dec, 2016 2 commits
    • Olof Johansson's avatar
      mm/filemap: fix parameters to test_bit() · 98473f9f
      Olof Johansson authored
       mm/filemap.c: In function 'clear_bit_unlock_is_negative_byte':
        mm/filemap.c:933:9: error: too few arguments to function 'test_bit'
          return test_bit(PG_waiters);
               ^~~~~~~~
      
      Fixes: b91e1302
      
       ('mm: optimize PageWaiters bit use for unlock_page()')
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      Brown-paper-bag-by: default avatarLinus Torvalds <dummy@duh.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      98473f9f
    • Linus Torvalds's avatar
      mm: optimize PageWaiters bit use for unlock_page() · b91e1302
      Linus Torvalds authored
      In commit 62906027
      
       ("mm: add PageWaiters indicating tasks are
      waiting for a page bit") Nick Piggin made our page locking no longer
      unconditionally touch the hashed page waitqueue, which not only helps
      performance in general, but is particularly helpful on NUMA machines
      where the hashed wait queues can bounce around a lot.
      
      However, the "clear lock bit atomically and then test the waiters bit"
      sequence turns out to be much more expensive than it needs to be,
      because you get a nasty stall when trying to access the same word that
      just got updated atomically.
      
      On architectures where locking is done with LL/SC, this would be trivial
      to fix with a new primitive that clears one bit and tests another
      atomically, but that ends up not working on x86, where the only atomic
      operations that return the result end up being cmpxchg and xadd.  The
      atomic bit operations return the old value of the same bit we changed,
      not the value of an unrelated bit.
      
      On x86, we could put the lock bit in the high bit of the byte, and use
      "xadd" with that bit (where the overflow ends up not touching other
      bits), and look at the other bits of the result.  However, an even
      simpler model is to just use a regular atomic "and" to clear the lock
      bit, and then the sign bit in eflags will indicate the resulting state
      of the unrelated bit #7.
      
      So by moving the PageWaiters bit up to bit #7, we can atomically clear
      the lock bit and test the waiters bit on x86 too.  And architectures
      with LL/SC (which is all the usual RISC suspects), the particular bit
      doesn't matter, so they are fine with this approach too.
      
      This avoids the extra access to the same atomic word, and thus avoids
      the costly stall at page unlock time.
      
      The only downside is that the interface ends up being a bit odd and
      specialized: clear a bit in a byte, and test the sign bit.  Nick doesn't
      love the resulting name of the new primitive, but I'd rather make the
      name be descriptive and very clear about the limitation imposed by
      trying to work across all relevant architectures than make it be some
      generic thing that doesn't make the odd semantics explicit.
      
      So this introduces the new architecture primitive
      
          clear_bit_unlock_is_negative_byte();
      
      and adds the trivial implementation for x86.  We have a generic
      non-optimized fallback (that just does a "clear_bit()"+"test_bit(7)"
      combination) which can be overridden by any architecture that can do
      better.  According to Nick, Power has the same hickup x86 has, for
      example, but some other architectures may not even care.
      
      All these optimizations mean that my page locking stress-test (which is
      just executing a lot of small short-lived shell scripts: "make test" in
      the git source tree) no longer makes our page locking look horribly bad.
      Before all these optimizations, just the unlock_page() costs were just
      over 3% of all CPU overhead on "make test".  After this, it's down to
      0.66%, so just a quarter of the cost it used to be.
      
      (The difference on NUMA is bigger, but there this micro-optimization is
      likely less noticeable, since the big issue on NUMA was not the accesses
      to 'struct page', but the waitqueue accesses that were already removed
      by Nick's earlier commit).
      Acked-by: default avatarNick Piggin <npiggin@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Bob Peterson <rpeterso@redhat.com>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Andrew Lutomirski <luto@kernel.org>
      Cc: Andreas Gruenbacher <agruenba@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b91e1302
  7. 28 Dec, 2016 2 commits
    • Linus Torvalds's avatar
      Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · 2d706e79
      Linus Torvalds authored
      Pull crypto fix from Herbert Xu:
       "This fixes a hash corruption bug in the marvell driver"
      
      * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
        crypto: marvell - Copy IVDIG before launching partial DMA ahash requests
      2d706e79
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 8f18e4d0
      Linus Torvalds authored
      Pull networking fixes from David Miller:
      
       1) Various ipvlan fixes from Eric Dumazet and Mahesh Bandewar.
      
          The most important is to not assume the packet is RX just because
          the destination address matches that of the device. Such an
          assumption causes problems when an interface is put into loopback
          mode.
      
       2) If we retry when creating a new tc entry (because we dropped the
          RTNL mutex in order to load a module, for example) we end up with
          -EAGAIN and then loop trying to replay the request. But we didn't
          reset some state when looping back to the top like this, and if
          another thread meanwhile inserted the same tc entry we were trying
          to, we re-link it creating an enless loop in the tc chain. Fix from
          Daniel Borkmann.
      
       3) There are two different WRITE bits in the MDIO address register for
          the stmmac chip, depending upon the chip variant. Due to a bug we
          could set them both, fix from Hock Leong Kweh.
      
       4) Fix mlx4 bug in XDP_TX handling, from Tariq Toukan.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
        net: stmmac: fix incorrect bit set in gmac4 mdio addr register
        r8169: add support for RTL8168 series add-on card.
        net: xdp: remove unused bfp_warn_invalid_xdp_buffer()
        openvswitch: upcall: Fix vlan handling.
        ipv4: Namespaceify tcp_tw_reuse knob
        net: korina: Fix NAPI versus resources freeing
        net, sched: fix soft lockup in tc_classify
        net/mlx4_en: Fix user prio field in XDP forward
        tipc: don't send FIN message from connectionless socket
        ipvlan: fix multicast processing
        ipvlan: fix various issues in ipvlan_process_multicast()
      8f18e4d0
  8. 27 Dec, 2016 17 commits
  9. 26 Dec, 2016 5 commits
    • Al Viro's avatar
      arm64: don't pull uaccess.h into *.S · b4b8664d
      Al Viro authored
      
      
      Split asm-only parts of arm64 uaccess.h into a new header and use that
      from *.S.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      b4b8664d
    • Florian Fainelli's avatar
      net: korina: Fix NAPI versus resources freeing · e6afb1ad
      Florian Fainelli authored
      Commit beb0babf ("korina: disable napi on close and restart")
      introduced calls to napi_disable() that were missing before,
      unfortunately this leaves a small window during which NAPI has a chance
      to run, yet we just freed resources since korina_free_ring() has been
      called:
      
      Fix this by disabling NAPI first then freeing resource, and make sure
      that we also cancel the restart task before doing the resource freeing.
      
      Fixes: beb0babf
      
       ("korina: disable napi on close and restart")
      Reported-by: default avatarAlexandros C. Couloumbis <alex@ozo.com>
      Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e6afb1ad
    • Daniel Borkmann's avatar
      net, sched: fix soft lockup in tc_classify · 628185cf
      Daniel Borkmann authored
      Shahar reported a soft lockup in tc_classify(), where we run into an
      endless loop when walking the classifier chain due to tp->next == tp
      which is a state we should never run into. The issue only seems to
      trigger under load in the tc control path.
      
      What happens is that in tc_ctl_tfilter(), thread A allocates a new
      tp, initializes it, sets tp_created to 1, and calls into tp->ops->change()
      with it. In that classifier callback we had to unlock/lock the rtnl
      mutex and returned with -EAGAIN. One reason why we need to drop there
      is, for example, that we need to request an action module to be loaded.
      
      This happens via tcf_exts_validate() -> tcf_action_init/_1() meaning
      after we loaded and found the requested action, we need to redo the
      whole request so we don't race against others. While we had to unlock
      rtnl in that time, thread B's request was processed next on that CPU.
      Thread B added a new tp instance successfully to the classifier chain.
      When thread A returned grabbing the rtnl mutex again, propagating -EAGAIN
      and destroying its tp instance which never got linked, we goto replay
      and redo A's request.
      
      This time when walking the classifier chain in tc_ctl_tfilter() for
      checking for existing tp instances we had a priority match and found
      the tp instance that was created and linked by thread B. Now calling
      again into tp->ops->change() with that tp was successful and returned
      without error.
      
      tp_created was never cleared in the second round, thus kernel thinks
      that we need to link it into the classifier chain (once again). tp and
      *back point to the same object due to the match we had earlier on. Thus
      for thread B's already public tp, we reset tp->next to tp itself and
      link it into the chain, which eventually causes the mentioned endless
      loop in tc_classify() once a packet hits the data path.
      
      Fix is to clear tp_created at the beginning of each request, also when
      we replay it. On the paths that can cause -EAGAIN we already destroy
      the original tp instance we had and on replay we really need to start
      from scratch. It seems that this issue was first introduced in commit
      12186be7 ("net_cls: fix unconfigured struct tcf_proto keeps chaining
      and avoid kernel panic when we use cls_cgroup").
      
      Fixes: 12186be7
      
       ("net_cls: fix unconfigured struct tcf_proto keeps chaining and avoid kernel panic when we use cls_cgroup")
      Reported-by: default avatarShahar Klein <shahark@mellanox.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Cc: Cong Wang <xiyou.wangcong@gmail.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Tested-by: default avatarShahar Klein <shahark@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      628185cf
    • Linus Torvalds's avatar
      Linux 4.10-rc1 · 7ce7d89f
      Linus Torvalds authored
      7ce7d89f
    • Larry Finger's avatar
      powerpc: Fix build warning on 32-bit PPC · 8ae679c4
      Larry Finger authored
      I am getting the following warning when I build kernel 4.9-git on my
      PowerBook G4 with a 32-bit PPC processor:
      
          AS      arch/powerpc/kernel/misc_32.o
        arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined [-Wundef]
      
      This problem is evident after commit 989cea5c ("kbuild: prevent
      lib-ksyms.o rebuilds"); however, this change in kbuild only exposes an
      error that has been in the code since 2005 when this source file was
      created.  That was with commit 9994a338 ("powerpc: Introduce
      entry_{32,64}.S, misc_{32,64}.S, systbl.S").
      
      The offending line does not make a lot of sense.  This error does not
      seem to cause any errors in the executable, thus I am not recommending
      that it be applied to any stable versions.
      
      Thanks to Nicholas Piggin for suggesting this solution.
      
      Fixes: 9994a338
      
       ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S")
      Signed-off-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: linuxppc-dev@lists.ozlabs.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8ae679c4
  10. 25 Dec, 2016 2 commits
    • Linus Torvalds's avatar
      avoid spurious "may be used uninitialized" warning · d33d5a6c
      Linus Torvalds authored
      
      
      The timer type simplifications caused a new gcc warning:
      
        drivers/base/power/domain.c: In function ‘genpd_runtime_suspend’:
        drivers/base/power/domain.c:562:14: warning: ‘time_start’ may be used uninitialized in this function [-Wmaybe-uninitialized]
           elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
      
      despite the actual use of "time_start" not having changed in any way.
      It appears that simply changing the type of ktime_t from a union to a
      plain scalar type made gcc check the use.
      
      The variable wasn't actually used uninitialized, but gcc apparently
      failed to notice that the conditional around the use was exactly the
      same as the conditional around the initialization of that variable.
      
      Add an unnecessary initialization just to shut up the compiler.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d33d5a6c
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 3ddc76df
      Linus Torvalds authored
      Pull timer type cleanups from Thomas Gleixner:
       "This series does a tree wide cleanup of types related to
        timers/timekeeping.
      
         - Get rid of cycles_t and use a plain u64. The type is not really
           helpful and caused more confusion than clarity
      
         - Get rid of the ktime union. The union has become useless as we use
           the scalar nanoseconds storage unconditionally now. The 32bit
           timespec alike storage got removed due to the Y2038 limitations
           some time ago.
      
           That leaves the odd union access around for no reason. Clean it up.
      
        Both changes have been done with coccinelle and a small amount of
        manual mopping up"
      
      * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        ktime: Get rid of ktime_equal()
        ktime: Cleanup ktime_set() usage
        ktime: Get rid of the union
        clocksource: Use a plain u64 instead of cycle_t
      3ddc76df