linux.git/include, branch v4.12-rc7

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-06-25T18:59:19+00:00

Pull timer fixes from Thomas Gleixner:
 "A few fixes for timekeeping and timers:

   - Plug a subtle race due to a missing READ_ONCE() in the timekeeping
     code where reloading of a pointer results in an inconsistent
     callback argument being supplied to the clocksource->read function.

   - Correct the CLOCK_MONOTONIC_RAW sub-nanosecond accounting in the
     time keeping core code, to prevent a possible discontuity.

   - Apply a similar fix to the arm64 vdso clock_gettime()
     implementation

   - Add missing includes to clocksource drivers, which relied on
     indirect includes which fails in certain configs.

   - Use the proper iomem pointer for read/iounmap in a probe function"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW
  time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
  time: Fix clock->read(clock) race around clocksource changes
  clocksource: Explicitly include linux/clocksource.h when needed
  clocksource/drivers/arm_arch_timer: Fix read and iounmap of incorrect variable

Merge tag 'acpi-4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2017-06-24T00:49:12+00:00

Pull ACPI fix from Rafael Wysocki:
 "This fixes the ACPI-based enumeration of some I2C and SPI devices
  broken in 4.11.

  Specifics:

   - I2C and SPI devices are expected to be enumerated by the I2C and
     SPI subsystems, respectively, but due to a change made during the
     4.11 cycle, in some cases the ACPI core marks them as already
     enumerated which causes the I2C and SPI subsystems to overlook
     them, so fix that (Jarkko Nikula)"

* tag 'acpi-4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / scan: Fix enumeration for special SPI and I2C devices

slub: make sysfs file removal asynchronous

2017-06-23T23:15:55+00:00

Commit bf5eb3de3847 ("slub: separate out sysfs_slab_release() from
sysfs_slab_remove()") made slub sysfs file removals synchronous to
kmem_cache shutdown.

Unfortunately, this created a possible ABBA deadlock between slab_mutex
and sysfs draining mechanism triggering the following lockdep warning.

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  4.10.0-test+ #48 Not tainted
  -------------------------------------------------------
  rmmod/1211 is trying to acquire lock:
   (s_active#120){++++.+}, at: [] kernfs_remove+0x23/0x40

  but task is already holding lock:
   (slab_mutex){+.+.+.}, at: [] kmem_cache_destroy+0x41/0x2d0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (slab_mutex){+.+.+.}:
	 lock_acquire+0xf6/0x1f0
	 __mutex_lock+0x75/0x950
	 mutex_lock_nested+0x1b/0x20
	 slab_attr_store+0x75/0xd0
	 sysfs_kf_write+0x45/0x60
	 kernfs_fop_write+0x13c/0x1c0
	 __vfs_write+0x28/0x120
	 vfs_write+0xc8/0x1e0
	 SyS_write+0x49/0xa0
	 entry_SYSCALL_64_fastpath+0x1f/0xc2

  -> #0 (s_active#120){++++.+}:
	 __lock_acquire+0x10ed/0x1260
	 lock_acquire+0xf6/0x1f0
	 __kernfs_remove+0x254/0x320
	 kernfs_remove+0x23/0x40
	 sysfs_remove_dir+0x51/0x80
	 kobject_del+0x18/0x50
	 __kmem_cache_shutdown+0x3e6/0x460
	 kmem_cache_destroy+0x1fb/0x2d0
	 kvm_exit+0x2d/0x80 [kvm]
	 vmx_exit+0x19/0xa1b [kvm_intel]
	 SyS_delete_module+0x198/0x1f0
	 entry_SYSCALL_64_fastpath+0x1f/0xc2

  other info that might help us debug this:

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(slab_mutex);
				 lock(s_active#120);
				 lock(slab_mutex);
    lock(s_active#120);

   *** DEADLOCK ***

  2 locks held by rmmod/1211:
   #0:  (cpu_hotplug.dep_map){++++++}, at: [] get_online_cpus+0x37/0x80
   #1:  (slab_mutex){+.+.+.}, at: [] kmem_cache_destroy+0x41/0x2d0

  stack backtrace:
  CPU: 3 PID: 1211 Comm: rmmod Not tainted 4.10.0-test+ #48
  Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
  Call Trace:
   print_circular_bug+0x1be/0x210
   __lock_acquire+0x10ed/0x1260
   lock_acquire+0xf6/0x1f0
   __kernfs_remove+0x254/0x320
   kernfs_remove+0x23/0x40
   sysfs_remove_dir+0x51/0x80
   kobject_del+0x18/0x50
   __kmem_cache_shutdown+0x3e6/0x460
   kmem_cache_destroy+0x1fb/0x2d0
   kvm_exit+0x2d/0x80 [kvm]
   vmx_exit+0x19/0xa1b [kvm_intel]
   SyS_delete_module+0x198/0x1f0
   ? SyS_delete_module+0x5/0x1f0
   entry_SYSCALL_64_fastpath+0x1f/0xc2

It'd be the cleanest to deal with the issue by removing sysfs files
without holding slab_mutex before the rest of shutdown; however, given
the current code structure, it is pretty difficult to do so.

This patch punts sysfs file removal to a work item.  Before commit
bf5eb3de3847, the removal was punted to a RCU delayed work item which is
executed after release.  Now, we're punting to a different work item on
shutdown which still maintains the goal removing the sysfs files earlier
when destroying kmem_caches.

Link: http://lkml.kernel.org/r/20170620204512.GI21326@htj.duckdns.org
Fixes: bf5eb3de3847 ("slub: separate out sysfs_slab_release() from sysfs_slab_remove()")
Signed-off-by: Tejun Heo 
Reported-by: Steven Rostedt (VMware) 
Tested-by: Steven Rostedt (VMware) 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2017-06-22T05:15:00+00:00

Pull block fixes from Jens Axboe:
 "This contains a set of fixes for xen-blkback by way of Konrad, and a
  performance regression fix for blk-mq for shared tags.

  The latter could account for as much as a 50x reduction in
  performance, with the test case from the user with 500 name spaces. A
  more realistic setup on my end with 32 drives showed a 3.5x drop. The
  fix has been thoroughly tested before being committed"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: fix performance regression with shared tags
  xen-blkback: don't leak stack data via response ring
  xen/blkback: don't use xen_blkif_get() in xen-blkback kthread
  xen/blkback: don't free be structure too early
  xen/blkback: fix disconnect while I/Os in flight

ACPI / scan: Fix enumeration for special SPI and I2C devices

2017-06-21T21:14:55+00:00

Commit f406270bf73d ("ACPI / scan: Set the visited flag for all
enumerated devices") caused that two group of special SPI or I2C
devices do not enumerate. SPI and I2C devices are expected to be
enumerated by the SPI and I2C subsystems but change caused that
acpi_bus_attach() marks those devices with acpi_device_set_enumerated().

First group of devices are matched using Device Tree compatible property
with special _HID "PRP0001". Those devices have matched scan handler,
acpi_scan_attach_handler() retuns 1 and acpi_bus_attach() marks them
with acpi_device_set_enumerated().

Second group of devices without valid _HID such as "LNXVIDEO" have
device->pnp.type.platform_id set to zero and change again marks them
with acpi_device_set_enumerated().

Fix this by flagging the SPI and I2C devices during struct acpi_device
object initialization time and let the code in acpi_bus_attach() to go
through the device_attach() and acpi_default_enumeration() path for all
SPI and I2C devices.

Fixes: f406270bf73d (ACPI / scan: Set the visited flag for all enumerated devices)
Signed-off-by: Jarkko Nikula 
Acked-by: Mika Westerberg 
Cc: 4.11+  # 4.11+
Signed-off-by: Rafael J. Wysocki

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-06-21T19:40:20+00:00

Pull networking fixes from David Miller:

 1) Fix refcounting wrt timers which hold onto inet6 address objects,
    from Xin Long.

 2) Fix an ancient bug in wireless wext ioctls, from Johannes Berg.

 3) Firmware handling fixes in brcm80211 driver, from Arend Van Spriel.

 4) Several mlx5 driver fixes (firmware readiness, timestamp cap
    reporting, devlink command validity checking, tc offloading, etc.)
    From Eli Cohen, Maor Dickman, Chris Mi, and Or Gerlitz.

 5) Fix dst leak in IP/IP6 tunnels, from Haishuang Yan.

 6) Fix dst refcount bug in decnet, from Wei Wang.

 7) Netdev can be double freed in register_vlan_device(). Fix from Gao
    Feng.

 8) Don't allow object to be destroyed while it is being dumped in SCTP,
    from Xin Long.

 9) Fix dpaa_eth build when modular, from Madalin Bucur.

10) Fix throw route leaks, from Serhey Popovych.

11) IFLA_GROUP missing from if_nlmsg_size() and ifla_policy[] table,
    also from Serhey Popovych.

12) Fix premature TX SKB free in stmmac, from Niklas Cassel.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (36 commits)
  igmp: add a missing spin_lock_init()
  net: stmmac: free an skb first when there are no longer any descriptors using it
  sfc: remove duplicate up_write on VF filter_sem
  rtnetlink: add IFLA_GROUP to ifla_policy
  ipv6: Do not leak throw route references
  dt-bindings: net: sms911x: Add missing optional VDD regulators
  dpaa_eth: reuse the dma_ops provided by the FMan MAC device
  fsl/fman: propagate dma_ops
  net/core: remove explicit do_softirq() from busy_poll_stop()
  fib_rules: Resolve goto rules target on delete
  sctp: ensure ep is not destroyed before doing the dump
  net/hns:bugfix of ethtool -t phy self_test
  net: 8021q: Fix one possible panic caused by BUG_ON in free_netdev
  cxgb4: notify uP to route ctrlq compl to rdma rspq
  ip6_tunnel: Correct tos value in collect_md mode
  decnet: always not take dst->__refcnt when inserting dst into hash table
  ip6_tunnel: fix potential issue in __ip6_tnl_rcv
  ip_tunnel: fix potential issue in ip_tunnel_rcv
  brcmfmac: fix uninitialized warning in brcmf_usb_probe_phase2()
  net/mlx5e: Avoid doing a cleanup call if the profile doesn't have it
  ...

blk-mq: fix performance regression with shared tags

2017-06-21T16:17:49+00:00

If we have shared tags enabled, then every IO completion will trigger
a full loop of every queue belonging to a tag set, and every hardware
queue for each of those queues, even if nothing needs to be done.
This causes a massive performance regression if you have a lot of
shared devices.

Instead of doing this huge full scan on every IO, add an atomic
counter to the main queue that tracks how many hardware queues have
been marked as needing a restart. With that, we can avoid looking for
restartable queues, if we don't have to.

Max reports that this restores performance. Before this patch, 4K
IOPS was limited to 22-23K IOPS. With the patch, we are running at
950-970K IOPS.

Fixes: 6d8c6c0f97ad ("blk-mq: Restart a single queue if tag sets are shared")
Reported-by: Max Gurtovoy 
Tested-by: Max Gurtovoy 
Reviewed-by: Bart Van Assche 
Tested-by: Bart Van Assche 
Signed-off-by: Jens Axboe

time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting

2017-06-20T08:41:50+00:00

Due to how the MONOTONIC_RAW accumulation logic was handled,
there is the potential for a 1ns discontinuity when we do
accumulations. This small discontinuity has for the most part
gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
in their vDSO clock_gettime implementation, we've seen failures
with the inconsistency-check test in kselftest.

This patch addresses the issue by using the same sub-ns
accumulation handling that CLOCK_MONOTONIC uses, which avoids
the issue for in-kernel users.

Since the ARM64 vDSO implementation has its own clock_gettime
calculation logic, this patch reduces the frequency of errors,
but failures are still seen. The ARM64 vDSO will need to be
updated to include the sub-nanosecond xtime_nsec values in its
calculation for this issue to be completely fixed.

Signed-off-by: John Stultz 
Tested-by: Daniel Mentz 
Cc: Prarit Bhargava 
Cc: Kevin Brodsky 
Cc: Richard Cochran 
Cc: Stephen Boyd 
Cc: Will Deacon 
Cc: "stable #4 . 8+" 
Cc: Miroslav Lichvar 
Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner

time: Fix clock->read(clock) race around clocksource changes

2017-06-20T08:41:50+00:00

In tests, which excercise switching of clocksources, a NULL
pointer dereference can be observed on AMR64 platforms in the
clocksource read() function:

u64 clocksource_mmio_readl_down(struct clocksource *c)
{
	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
}

This is called from the core timekeeping code via:

	cycle_now = tkr->read(tkr->clock);

tkr->read is the cached tkr->clock->read() function pointer.
When the clocksource is changed then tkr->clock and tkr->read
are updated sequentially. The code above results in a sequential
load operation of tkr->read and tkr->clock as well.

If the store to tkr->clock hits between the loads of tkr->read
and tkr->clock, then the old read() function is called with the
new clock pointer. As a consequence the read() function
dereferences a different data structure and the resulting 'reg'
pointer can point anywhere including NULL.

This problem was introduced when the timekeeping code was
switched over to use struct tk_read_base. Before that, it was
theoretically possible as well when the compiler decided to
reload clock in the code sequence:

     now = tk->clock->read(tk->clock);

Add a helper function which avoids the issue by reading
tk_read_base->clock once into a local variable clk and then issue
the read function via clk->read(clk). This guarantees that the
read() function always gets the proper clocksource pointer handed
in.

Since there is now no use for the tkr.read pointer, this patch
also removes it, and to address stopping the fast timekeeper
during suspend/resume, it introduces a dummy clocksource to use
rather then just a dummy read function.

Signed-off-by: John Stultz 
Acked-by: Ingo Molnar 
Cc: Prarit Bhargava 
Cc: Richard Cochran 
Cc: Stephen Boyd 
Cc: stable 
Cc: Miroslav Lichvar 
Cc: Daniel Mentz 
Link: http://lkml.kernel.org/r/1496965462-20003-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner

Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

2017-06-20T03:02:29+00:00

Pull clk fixes from Stephen Boyd:
 "One build fix for an Amlogic clk driver and a handful of Allwinner clk
  driver fixes for some DT bindings and a randconfig build error that
  all came in this merge window"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sunxi-ng: a64: Export PLL_PERIPH0 clock for the PRCM
  clk: sunxi-ng: h3: Export PLL_PERIPH0 clock for the PRCM
  dt-bindings: clock: sunxi-ccu: Add pll-periph to PRCM's needed clocks
  clk: sunxi-ng: sun5i: Fix ahb_bist_clk definition
  clk: sunxi-ng: enable SUNXI_CCU_MP for PRCM
  clk: meson: gxbb: fix build error without RESET_CONTROLLER
  clk: sunxi-ng: v3s: Fix usb otg device reset bit
  clk: sunxi-ng: a31: Correct lcd1-ch1 clock register offset