git.stricted.de - GitHub/LineageOS/android_kernel_motorola

net: Fix RCU splat in af_key

Hit the following splat testing VRF change for ipsec:

[  113.475692] ===============================
[  113.476194] [ INFO: suspicious RCU usage. ]
[  113.476667] 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED Not tainted
[  113.477545] -------------------------------
[  113.478013] /work/monster-14/dsa/kernel.git/include/linux/rcupdate.h:568 Illegal context switch in RCU read-side critical section!
[  113.479288]
[  113.479288] other info that might help us debug this:
[  113.479288]
[  113.480207]
[  113.480207] rcu_scheduler_active = 1, debug_locks = 1
[  113.480931] 2 locks held by setkey/6829:
[  113.481371]  #0:  (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff814e9887>] pfkey_sendmsg+0xfb/0x213
[  113.482509]  #1:  (rcu_read_lock){......}, at: [<ffffffff814e767f>] rcu_read_lock+0x0/0x6e
[  113.483509]
[  113.483509] stack backtrace:
[  113.484041] CPU: 0 PID: 6829 Comm: setkey Not tainted 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED
[  113.485422] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[  113.486845]  0000000000000001 ffff88001d4c7a98 ffffffff81518af2 ffffffff81086962
[  113.487732]  ffff88001d538480 ffff88001d4c7ac8 ffffffff8107ae75 ffffffff8180a154
[  113.488628]  0000000000000b30 0000000000000000 00000000000000d0 ffff88001d4c7ad8
[  113.489525] Call Trace:
[  113.489813]  [<ffffffff81518af2>] dump_stack+0x4c/0x65
[  113.490389]  [<ffffffff81086962>] ? console_unlock+0x3d6/0x405
[  113.491039]  [<ffffffff8107ae75>] lockdep_rcu_suspicious+0xfa/0x103
[  113.491735]  [<ffffffff81064032>] rcu_preempt_sleep_check+0x45/0x47
[  113.492442]  [<ffffffff8106404d>] ___might_sleep+0x19/0x1c8
[  113.493077]  [<ffffffff81064268>] __might_sleep+0x6c/0x82
[  113.493681]  [<ffffffff81133190>] cache_alloc_debugcheck_before.isra.50+0x1d/0x24
[  113.494508]  [<ffffffff81134876>] kmem_cache_alloc+0x31/0x18f
[  113.495149]  [<ffffffff814012b5>] skb_clone+0x64/0x80
[  113.495712]  [<ffffffff814e6f71>] pfkey_broadcast_one+0x3d/0xff
[  113.496380]  [<ffffffff814e7b84>] pfkey_broadcast+0xb5/0x11e
[  113.497024]  [<ffffffff814e82d1>] pfkey_register+0x191/0x1b1
[  113.497653]  [<ffffffff814e9770>] pfkey_process+0x162/0x17e
[  113.498274]  [<ffffffff814e9895>] pfkey_sendmsg+0x109/0x213

In pfkey_sendmsg the net mutex is taken and then pfkey_broadcast takes
the RCU lock.

Since pfkey_broadcast takes the RCU lock the allocation argument is
pointless since GFP_ATOMIC must be used between the rcu_read_{,un}lock.
The one call outside of rcu can be done with GFP_KERNEL.

Fixes: 7f6b9dbd5afbd ("af_key: locking change")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bcmgenet: fix uncleaned dma flags

Clean the dma flags of multiq ring buffer int the interface stop
process. This patch fixes that the genet is not running while the
interface is re-enabled.

$ ifup eth0 - running after booting
$ ifdown eth0
$ ifup eth0 - not running and occur tx_timeout

The bcmgenet_dma_disable() in bcmgenet_open() do clean ring16 dma flag
only. If the genet has multiq, the dma register is not cleaned. and
bcmgenet_init_dma() is not done correctly. in case
GENET_V2(tx_queues=4), tdma_ctrl has 0x1e after running
bcmgenet_dma_disable().

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bcmgenet: Avoid sleeping in bcmgenet_timeout

bcmgenet_timeout() executes in atomic context, yet we will invoke
napi_disable() which does sleep. Looking back at the changes, disabling
TX napi and re-enabling it is completely useless, since we reclaim all
TX buffers and re-enable interrupts, and wake up the TX queues.

Fixes: 13ea657806cf ("net: bcmgenet: improve TX timeout")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: mmap: fix tx type check

I can't send netlink message via mmaped netlink socket since

    commit: a8866ff6a5bce7d0ec465a63bc482a85c09b0d39
    netlink: make the check for "send from tx_ring" deterministic

msg->msg_iter.type is set to WRITE (1) at

    SYSCALL_DEFINE6(sendto, ...
        import_single_range(WRITE, ...
            iov_iter_init(1, WRITE, ...

call path, so that we need to check the type by iter_is_iovec()
to accept the WRITE.

Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'pm+acpi-4.2-rc8' of git://git./linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
"These fix a recent regression in the ACPI backlight code and a memory
  leak in the Exynos cpufreq driver.

  Specifics:

   - Fix a recently introduced issue in the ACPI backlight code which
     causes lockdep to complain about a circular lock dependency during
     initialization (Hans de Goede).

   - Fix a possible memory during initialization in the Exynos cpufreq
     driver (Shailendra Verma)"

* tag 'pm+acpi-4.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: exynos: Fix for memory leak in case SoC name does not match
  ACPI / video: Fix circular lock dependency issue in the video-detect code

Merge branches 'acpi-video' and 'cpufreq-fixes'

* acpi-video:
ACPI / video: Fix circular lock dependency issue in the video-detect code

* cpufreq-fixes:
cpufreq: exynos: Fix for memory leak in case SoC name does not match

Merge git://git./linux/kernel/git/davem/net

Pull networking fixes from David Miller:

1) Out of bounds array access in 802.11 minstrel code, from Adrien
    Schildknecht.

2) Don't use skb_get() in IGMP/MLD code paths, as this makes
    pskb_may_pull() BUG.  From Linus Luessing.

3) Fix off by one in ipv4 route dumping code, from Andy Whitcroft.

4) Fix deadlock in reqsk_queue_unlink(), from Eric Dumazet.

5) Fix ppp device deregistration wrt.  netns deletion, from Guillaume
    Nault.

6) Fix deadlock when creating per-cpu ipv6 routes, from Martin KaFai
    Lau.

7) Fix memory leak in batman-adv code, from Sven Eckelmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  batman-adv: Fix memory leak on tt add with invalid vlan
  net: phy: fix semicolon.cocci warnings
  net: qmi_wwan: add HP lt4111 LTE/EV-DO/HSPA+ Gobi 4G Module
  be2net: avoid vxlan offloading on multichannel configs
  ipv6: Fix a potential deadlock when creating pcpu rt
  ipv6: Add rt6_make_pcpu_route()
  ipv6: Remove un-used argument from ip6_dst_alloc()
  net: phy: workaround for buggy cable detection by LAN8700 after cable plugging
  net: ethernet: micrel: fix an error code
  ppp: fix device unregistration upon netns deletion
  net: phy: fix PHY_RUNNING in phy_state_machine
  Revert "net: limit tcp/udp rmem/wmem to SOCK_{RCV,SND}BUF_MIN"
  inet: fix potential deadlock in reqsk_queue_unlink()
  gianfar: Restore link state settings after MAC reset
  ipv4: off-by-one in continuation handling in /proc/net/route
  net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code
  mac80211: fix invalid read in minstrel_sort_best_tp_rates()

Merge tag 'for-linus-4.2-rc7-tag' of git://git./linux/kernel/git/xen/tip

Pull xen build fix from David Vrabel:
"Fix i386 build with an (uncommon) configuration"

* tag 'for-linus-4.2-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: make CONFIG_XEN depend on CONFIG_X86_LOCAL_APIC

Merge tag 'sound-4.2' of git://git./linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
"Here are a small collecton of sound fix patches.

  The most significant one is the disablement of newly introduced
  topology API.  Its ABI couldn't be stabilized enough, so we decided to
  delay for 4.3 in the end.  Other than that, all oneliner fixes: a
  USB-audio runtime PM fix and a couple of HD-audio quirks"

* tag 'sound-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Add dock support for Thinkpad W541 (17aa:2211)
  ALSA: usb-audio: Fix runtime PM unbalance
  ASoC: topology: Disable use from userspace
  ASoC: topology: Add Kconfig option for topology
  ALSA: hda - Fix the white noise on Dell laptop

Merge git://git./linux/kernel/git/nab/target-pending

Pull SCSI target fixes from Nicholas Bellinger:
"This contains a v4.2-rc specific RCU module unload regression bug-fix,
  a long-standing iscsi-target bug-fix for duplicate target_xfer_tags
  during NOP processing from Alexei, and two more small REPORT_LUNs
  emulation related patches to make Solaris FC host LUN scanning happy
  from Roland.

  There is also one patch not included that allows target-core to limit
  the number of fabric driver SGLs per I/O request using residuals, that
  is currently required as a work-around for FC hosts which don't honor
  EVPD block-limits settings.  At this point, it will most likely become
  for-next material"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: Fix handling of small allocation lengths in REPORT LUNS
  target: REPORT LUNS should return LUN 0 even for dynamic ACLs
  target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT
  target: Perform RCU callback barrier before backend/fabric unload

Merge branch 'fixes' of git://git./linux/kernel/git/evalenti/linux-soc-thermal

Pull thermal fixes from Eduardo Valentin:
"Last minute fixes on the thermal-soc tree.  There is a fix of a long
  lasting bug in cpu cooling device, thanks for RMK for being pushing
  this"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  thermal/cpu_cooling: update policy limits if clipped_freq < policy->max
  thermal/cpu_cooling: rename max_freq as clipped_freq in notifier
  thermal/cpu_cooling: rename cpufreq_val as clipped_freq
  thermal/cpu_cooling: convert 'switch' block to 'if' block in notifier
  thermal/cpu_cooling: quit early after updating policy
  thermal/cpu_cooling: No need to initialize max_freq to 0
  thermal: cpu_cooling: fix lockdep problems in cpu_cooling
  thermal: power_allocator: do not use devm* interfaces

x86/xen: make CONFIG_XEN depend on CONFIG_X86_LOCAL_APIC

Since commit feb44f1f7a4ac299d1ab1c3606860e70b9b89d69 (x86/xen:
Provide a "Xen PV" APIC driver to support >255 VCPUs) Xen guests need
a full APIC driver and thus should depend on X86_LOCAL_APIC.

This fixes an i386 build failure with !SMP && !CONFIG_X86_UP_APIC by
disabling Xen support in this configuration.

Users needing Xen support in a non-SMP i386 kernel will need to enable
CONFIG_X86_UP_APIC.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org>

Merge tag 'asoc-v4.2-disable-topology' of git://git./linux/kernel/git/broonie/sound into for-linus

ASoC: Disable topology support for v4.2

The topology code merged in the v4.2 merge window introduced a new ABI
which was believed to be suitable for use but subsequently additional
work by the developers of this feature have revealed some problems that
need to be addressed. In order to allow this to be done without having
to support the initial ABI add Kconfig to disable the build and also add
some #error statements to the UAPI header so users can't use them.

ALSA: hda - Add dock support for Thinkpad W541 (17aa:2211)

Tested with W541 and Ultra Dock 170w

Signed-off-by: Rick Sherman <rick@shermdog.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: usb-audio: Fix runtime PM unbalance

The fix for deadlock in PM in commit [1ee23fe07ee8: ALSA: usb-audio:
Fix deadlocks at resuming] introduced a new check of in_pm flag.
However, the brainless patch author evaluated it in a wrong way
(logical AND instead of logical OR), thus usb_autopm_get_interface()
is wrongly called at probing, leading to unbalance of runtime PM
refcount.

This patch fixes it by correcting the logic.

Reported-by: Hans Yang <hansy@nvidia.com>
Fixes: 1ee23fe07ee8 ('ALSA: usb-audio: Fix deadlocks at resuming')
Cc: <stable@vger.kernel.org> [v3.15+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>

target: Fix handling of small allocation lengths in REPORT LUNS

REPORT LUNS should not fail just because the allocation length is less
than 16.  The relevant section of SPC-4 is:

  4.2.5.6 Allocation length

  The ALLOCATION LENGTH field specifies the maximum number of bytes or
  blocks that an application client has allocated in the Data-In
  Buffer. The ALLOCATION LENGTH field specifies bytes unless a
  different requirement is stated in the command definition.

  An allocation length of zero specifies that no data shall be
  transferred. This condition shall not be considered an error.

So we should just truncate our response rather than return an error.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

batman-adv: Fix memory leak on tt add with invalid vlan

The object tt_local is allocated with kmalloc and not initialized when the
function batadv_tt_local_add checks for the vlan. But this function can
only cleanup the object when the (not yet initialized) reference counter of
the object is 1. This is unlikely and thus the object would leak when the
vlan could not be found.

Instead the uninitialized object tt_local has to be freed manually and the
pointer has to set to NULL to avoid calling the function which would try to
decrement the reference counter of the not existing object.

CID: 1316518
Fixes: 354136bcc3c4 ("batman-adv: fix kernel crash due to missing NULL checks")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'dmaengine-fix-4.2-rc8' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fix from Vinod Koul:
"We recently found issue with dma_request_slave_channel() API causing
privatecnt value to go bad. This is fixed by balancing the privatecnt"

* tag 'dmaengine-fix-4.2-rc8' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: fix balance of privatecnt inc/dec operations

ASoC: topology: Disable use from userspace

Since the topology API is still in sufficient flux for changes to be
identified disable the use of the userspace ABI by adding #error
statements to the code, ensuring that nobody relies on the headers as
currently defined. It is expected that this change will be reverted for
v4.3.

Signed-off-by: Mark Brown <broonie@kernel.org>

Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
"These came in late last week, I wanted to look over the mst one before
  forwarding, but it seems good.

  Just three i915 and one MST fix"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Commit planes on each crtc separately.
  drm/i915: calculate primary visibility changes instead of calling from set_config
  drm/i915: Only dither on 6bpc panels
  drm/dp/mst: Remove port after removing connector.

ASoC: topology: Add Kconfig option for topology

Allow the topology code to be compiled out so that users who don't need
topology don't need to havve the code compiled in, saving them some
memory.

Some more configuration could be added to remove some of the hooks into
the core data structures but that is probably best done with some
refactoring to use functions to do the updates of the data structures
rather than ifdefing in the code as we'd need to do at the minute.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

Merge tag 'for-linus' of git://git./linux/kernel/git/dledford/rdma

Pull rdma bugfix from Doug Ledford:
"Bugfix in iw_cxgb4"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
iw_cxgb4: gracefully handle unknown CQE status errors

Merge branch 'for-4.2-fixes' of git://git./linux/kernel/git/tj/libata

Pull libata fixes from Tejun Heo:
"Three minor device-specific fixes and revert of NCQ autosense added
  during this -rc1.

  It turned out that NCQ autosense as currently implemented interferes
  with the usual error handling behavior.  It will be revisited in the
  near future"

* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ata: ahci_brcmstb: Fix misuse of IS_ENABLED
  sata_sx4: Check return code from pdc20621_i2c_read()
  Revert "libata: Implement NCQ autosense"
  Revert "libata: Implement support for sense data reporting"
  Revert "libata-eh: Set 'information' field for autosense"
  ata: ahci_brcmstb: Fix warnings with CONFIG_PM_SLEEP=n

Merge branch 'for-4.2-fixes' of git://git./linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:
"A fix for a subtle bug introduced back during 3.17 cycle which
interferes with setting configurations under specific conditions"

* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: use trialcs->mems_allowed as a temp variable

net: phy: fix semicolon.cocci warnings

drivers/net/phy/smsc.c:127:3-4: Unneeded semicolon

Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

CC: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qmi_wwan: add HP lt4111 LTE/EV-DO/HSPA+ Gobi 4G Module

This is an HP-branded Sierra Wireless EM7355:
https://bugzilla.redhat.com/show_bug.cgi?id=1223646#c2

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

be2net: avoid vxlan offloading on multichannel configs

VxLAN offloading is not functional if the NIC is running in multichannel
mode (UMC, FLEX-10, VNIC...). Enabling this additionally kills whole
connectivity through the NIC and the device needs to be down and up to
restore it. The firmware should take care about it and does not allow
the conversion of interface to tunnel type (be_cmd_manage_iface) or should
support VxLAN offloading if multichannel config is enabled.
I have tested this on the latest available firmware (10.6.144.21).

Result:
[root@sm-04 ~]# ip link set enp5s0f0 up[root@sm-04 ~]# ip addr add 172.30.10.50/24 dev enp5s0f0
[root@sm-04 ~]# ping -c 3 172.30.10.254PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
64 bytes from 172.30.10.254: icmp_seq=1 ttl=64 time=0.317 ms
64 bytes from 172.30.10.254: icmp_seq=2 ttl=64 time=0.187 ms
64 bytes from 172.30.10.254: icmp_seq=3 ttl=64 time=0.188 ms

--- 172.30.10.254 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.187/0.230/0.317/0.063 ms
[root@sm-04 ~]# ip link add link enp5s0f0 vxlan10 type vxlan id 10 remote 172.30.10.60 dstport 4789
[root@sm-04 ~]# ip link set vxlan10 up
[ 7900.442811] be2net 0000:05:00.0: Enabled VxLAN offloads for UDP port 4789
[ 7900.455722] be2net 0000:05:00.1: Enabled VxLAN offloads for UDP port 4789
[ 7900.468635] be2net 0000:05:00.2: Enabled VxLAN offloads for UDP port 4789
[ 7900.481553] be2net 0000:05:00.3: Enabled VxLAN offloads for UDP port 4789
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.

--- 172.30.10.254 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

[root@sm-04 ~]# ip link set vxlan10 down
[ 7959.434093] be2net 0000:05:00.0: Disabled VxLAN offloads for UDP port 4789
[ 7959.444792] be2net 0000:05:00.1: Disabled VxLAN offloads for UDP port 4789
[ 7959.455592] be2net 0000:05:00.2: Disabled VxLAN offloads for UDP port 4789
[ 7959.466416] be2net 0000:05:00.3: Disabled VxLAN offloads for UDP port 4789
[root@sm-04 ~]# ip link del vxlan10
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.

--- 172.30.10.254 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

[root@sm-04 ~]# ip link set enp5s0f0 down
[root@sm-04 ~]# ip link set enp5s0f0 up
[ 8071.019003] be2net 0000:05:00.0 enp5s0f0: Link is Up
[root@sm-04 ~]# ping -c 3 172.30.10.254
PING 172.30.10.254 (172.30.10.254) 56(84) bytes of data.
64 bytes from 172.30.10.254: icmp_seq=1 ttl=64 time=0.318 ms
64 bytes from 172.30.10.254: icmp_seq=2 ttl=64 time=0.196 ms
64 bytes from 172.30.10.254: icmp_seq=3 ttl=64 time=0.194 ms

--- 172.30.10.254 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.194/0.236/0.318/0.057 ms

Cc: Sathya Perla <sathya.perla@avagotech.com>
Cc: Ajit Khaparde <ajit.khaparde@avagotech.com>
Cc: Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Cc: Sriharsha Basavapatna <sriharsha.basavapatna@avagotech.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Ajit Khaparde <ajit.khaparde@avagotech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'ipv6_percpu_rt_deadlock'

Martin KaFai Lau says:

====================
ipv6: Fix a potential deadlock when creating pcpu rt

v1 -> v2:
A minor change in the commit message of patch 2.

This patch series fixes a potential deadlock when creating a pcpu rt.
It happens when dst_alloc() decided to run gc. Something like this:

read_lock(&table->tb6_lock);
ip6_rt_pcpu_alloc()
=> dst_alloc()
=> ip6_dst_gc()
=> write_lock(&table->tb6_lock); /* oops */

Patch 1 and 2 are some prep works.
Patch 3 is the fix.

Original report: https://bugzilla.kernel.org/show_bug.cgi?id=102291
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: Fix a potential deadlock when creating pcpu rt

rt6_make_pcpu_route() is called under read_lock(&table->tb6_lock).
rt6_make_pcpu_route() calls ip6_rt_pcpu_alloc(rt) which then
calls dst_alloc().  dst_alloc() _may_ call ip6_dst_gc() which takes
the write_lock(&tabl->tb6_lock).  A visualized version:

read_lock(&table->tb6_lock);
rt6_make_pcpu_route();
=> ip6_rt_pcpu_alloc();
=> dst_alloc();
=> ip6_dst_gc();
=> write_lock(&table->tb6_lock); /* oops */

The fix is to do a read_unlock first before calling ip6_rt_pcpu_alloc().

A reported stack:

[141625.537638] INFO: rcu_sched self-detected stall on CPU { 27}  (t=60000 jiffies g=4159086 c=4159085 q=2139)
[141625.547469] Task dump for CPU 27:
[141625.550881] mtr             R  running task        0 22121  22081 0x00000008
[141625.558069]  0000000000000000 ffff88103f363d98 ffffffff8106e488 000000000000001b
[141625.565641]  ffffffff81684900 ffff88103f363db8 ffffffff810702b0 0000000008000000
[141625.573220]  ffffffff81684900 ffff88103f363de8 ffffffff8108df9f ffff88103f375a00
[141625.580803] Call Trace:
[141625.583345]  <IRQ>  [<ffffffff8106e488>] sched_show_task+0xc1/0xc6
[141625.589650]  [<ffffffff810702b0>] dump_cpu_task+0x35/0x39
[141625.595144]  [<ffffffff8108df9f>] rcu_dump_cpu_stacks+0x6a/0x8c
[141625.601320]  [<ffffffff81090606>] rcu_check_callbacks+0x1f6/0x5d4
[141625.607669]  [<ffffffff810940c8>] update_process_times+0x2a/0x4f
[141625.613925]  [<ffffffff8109fbee>] tick_sched_handle+0x32/0x3e
[141625.619923]  [<ffffffff8109fc2f>] tick_sched_timer+0x35/0x5c
[141625.625830]  [<ffffffff81094a1f>] __hrtimer_run_queues+0x8f/0x18d
[141625.632171]  [<ffffffff81094c9e>] hrtimer_interrupt+0xa0/0x166
[141625.638258]  [<ffffffff8102bf2a>] local_apic_timer_interrupt+0x4e/0x52
[141625.645036]  [<ffffffff8102c36f>] smp_apic_timer_interrupt+0x39/0x4a
[141625.651643]  [<ffffffff8140b9e8>] apic_timer_interrupt+0x68/0x70
[141625.657895]  <EOI>  [<ffffffff81346ee8>] ? dst_destroy+0x7c/0xb5
[141625.664188]  [<ffffffff813d45b5>] ? fib6_flush_trees+0x20/0x20
[141625.670272]  [<ffffffff81082b45>] ? queue_write_lock_slowpath+0x60/0x6f
[141625.677140]  [<ffffffff8140aa33>] _raw_write_lock_bh+0x23/0x25
[141625.683218]  [<ffffffff813d4553>] __fib6_clean_all+0x40/0x82
[141625.689124]  [<ffffffff813d45b5>] ? fib6_flush_trees+0x20/0x20
[141625.695207]  [<ffffffff813d6058>] fib6_clean_all+0xe/0x10
[141625.700854]  [<ffffffff813d60d3>] fib6_run_gc+0x79/0xc8
[141625.706329]  [<ffffffff813d0510>] ip6_dst_gc+0x85/0xf9
[141625.711718]  [<ffffffff81346d68>] dst_alloc+0x55/0x159
[141625.717105]  [<ffffffff813d09b5>] __ip6_dst_alloc.isra.32+0x19/0x63
[141625.723620]  [<ffffffff813d1830>] ip6_pol_route+0x36a/0x3e8
[141625.729441]  [<ffffffff813d18d6>] ip6_pol_route_output+0x11/0x13
[141625.735700]  [<ffffffff813f02c8>] fib6_rule_action+0xa7/0x1bf
[141625.741698]  [<ffffffff813d18c5>] ? ip6_pol_route_input+0x17/0x17
[141625.748043]  [<ffffffff81357c48>] fib_rules_lookup+0xb5/0x12a
[141625.754050]  [<ffffffff81141628>] ? poll_select_copy_remaining+0xf9/0xf9
[141625.761002]  [<ffffffff813f0535>] fib6_rule_lookup+0x37/0x5c
[141625.766914]  [<ffffffff813d18c5>] ? ip6_pol_route_input+0x17/0x17
[141625.773260]  [<ffffffff813d008c>] ip6_route_output+0x7a/0x82
[141625.779177]  [<ffffffff813c44c8>] ip6_dst_lookup_tail+0x53/0x112
[141625.785437]  [<ffffffff813c45c3>] ip6_dst_lookup_flow+0x2a/0x6b
[141625.791604]  [<ffffffff813ddaab>] rawv6_sendmsg+0x407/0x9b6
[141625.797423]  [<ffffffff813d7914>] ? do_ipv6_setsockopt.isra.8+0xd87/0xde2
[141625.804464]  [<ffffffff8139d4b4>] inet_sendmsg+0x57/0x8e
[141625.810028]  [<ffffffff81329ba3>] sock_sendmsg+0x2e/0x3c
[141625.815588]  [<ffffffff8132be57>] SyS_sendto+0xfe/0x143
[141625.821063]  [<ffffffff813dd551>] ? rawv6_setsockopt+0x5e/0x67
[141625.827146]  [<ffffffff8132c9f8>] ? sock_common_setsockopt+0xf/0x11
[141625.833660]  [<ffffffff8132c08c>] ? SyS_setsockopt+0x81/0xa2
[141625.839565]  [<ffffffff8140ac17>] entry_SYSCALL_64_fastpath+0x12/0x6a

Fixes: d52d3997f843 ("pv6: Create percpu rt6_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: Add rt6_make_pcpu_route()

It is a prep work for fixing a potential deadlock when creating
a pcpu rt.

The current rt6_get_pcpu_route() will also create a pcpu rt if one does not
exist. This patch moves the pcpu rt creation logic into another function,
rt6_make_pcpu_route().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: Remove un-used argument from ip6_dst_alloc()

After 4b32b5ad31a6 ("ipv6: Stop rt6_info from using inet_peer's metrics"),
ip6_dst_alloc() does not need the 'table' argument. This patch
cleans it up.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: workaround for buggy cable detection by LAN8700 after cable plugging

* Due to HW bug, LAN8700 sometimes does not detect presence of energy in the
  Ethernet cable in Energy Detect Power-Down mode (e.g while EDPWRDOWN bit is
  set, the ENERGYON bit does not asserted sometimes). This is a common bug of
  LAN87xx family of PHY chips.
* The lan87xx_read_status() was improved to acquire ENERGYON bit. Its previous
  algorythm still not reliable on 100 % and sometimes skip cable plugging.

Signed-off-by: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2015-08-14' of git://git./linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
We have a single bugfix for an invalid memory read.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethernet: micrel: fix an error code

The dma_mapping_error() function returns true or false. We should
return -ENOMEM if it there is a dma mapping error.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ppp: fix device unregistration upon netns deletion

PPP devices may get automatically unregistered when their network
namespace is getting removed. This happens if the ppp control plane
daemon (e.g. pppd) exits while it is the last user of this namespace.

This leads to several races:

  * ppp_exit_net() may destroy the per namespace idr (pn->units_idr)
    before all file descriptors were released. Successive ppp_release()
    calls may then cleanup PPP devices with ppp_shutdown_interface() and
    try to use the already destroyed idr.

  * Automatic device unregistration may also happen before the
    ppp_release() call for that device gets executed. Once called on
    the file owning the device, ppp_release() will then clean it up and
    try to unregister it a second time.

To fix these issues, operations defined in ppp_shutdown_interface() are
moved to the PPP device's ndo_uninit() callback. This allows PPP
devices to be properly cleaned up by unregister_netdev() and friends.
So checking for ppp->owner is now an accurate test to decide if a PPP
device should be unregistered.

Setting ppp->owner is done in ppp_create_interface(), before device
registration, in order to avoid unprotected modification of this field.

Finally, ppp_exit_net() now starts by unregistering all remaining PPP
devices to ensure that none will get unregistered after the call to
idr_destroy().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: fix PHY_RUNNING in phy_state_machine

Currently, if phy state is PHY_RUNNING, we always register a CHANGE
when phy works in polling or interrupt ignored, this will make the
adjust_link being called even the phy link did Not changed.

checking the phy link to make sure the link did changed before we
register a CHANGE, if link did not changed, we do nothing.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "net: limit tcp/udp rmem/wmem to SOCK_{RCV,SND}BUF_MIN"

Commit 8133534c760d4083 ("net: limit tcp/udp rmem/wmem to
SOCK_{RCV,SND}BUF_MIN") modified four sysctls to enforce that the values
written to them are not less than SOCK_MIN_{RCV,SND}BUF.

That change causes 4096 to no longer be accepted as a valid value for
'min' in tcp_wmem and udp_wmem_min. 4096 has been the default for both
of those sysctls for a long time, and unfortunately seems to be an
extremely popular setting. This change breaks a large number of sysctl
configurations at Facebook.

That commit referred to b1cb59cf2efe7971 ("net: sysctl_net_core: check
SNDBUF and RCVBUF for min length"), which choose to use the SOCK_MIN
constants as the lower limits to avoid nasty bugs. But AFAICS, a limit
of SOCK_MIN_SNDBUF isn't necessary to do that: the BUG_ON cited in the
commit message seems to have happened because unix_stream_sendmsg()
expects a minimum of a full page (ie SK_MEM_QUANTUM) and the math broke,
not because it had less than SOCK_MIN_SNDBUF allocated.

This particular issue doesn't seem to affect TCP however: using a
setting of "1 1 1" for tcp_{r,w}mem works, although it's obviously
suboptimal. SK_MEM_QUANTUM would be a nice minimum, but it's 64K on
some archs, so there would still be breakage.

Since a value of one doesn't seem to cause any problems, we can drop the
minimum 8133534c added to fix this.

This reverts commit 8133534c760d4083f79d2cde42c636ccc0b2792e.

Fixes: 8133534c760d4083 ("net: limit tcp/udp rmem/wmem to SOCK_MIN...")
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sorin Dumitru <sorin@returnze.ro>
Signed-off-by: Calvin Owens <calvinowens@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dmaengine: fix balance of privatecnt inc/dec operations

This patch increments privatecnt value and set DMA_PRIVATE in device
caps in dma_request_slave_channel() function. This is needed to keep
privatecnt increment/decrement balance.

As function dma_release_channel() decrements privatecnt counter, we need
to increment it when channel is requested. Otherwise privatecnt drops
into negatives after few dma_release_channel() calls.

Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Merge git://git./linux/kernel/git/herbert/crypto-2.6

Pull crypto fixes from Herbert Xu:
"This fixes the following issues:

   - a regression caused by the conversion of IPsec ESP to the new AEAD
     interface: ESN with authencesn no longer works because it relied on
     the AD input SG list having a specific layout which is no longer
     the case.  In linux-next authencesn is fixed properly and no longer
     assumes anything about the SG list format.  While for this release
     a minimal fix is applied to authencesn so that it works with the
     new linear layout.

   - fix memory corruption caused by bogus index in the caam hash code.

   - fix powerpc nx SHA hashing which could cause module load failures
     if module signature verification is enabled"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: caam - fix memory corruption in ahash_final_ctx
  crypto: nx - respect sg limit bounds when building sg lists for SHA
  crypto: authencesn - Fix breakage with new ESP code

Linux 4.2-rc7

Merge tag 'armsoc-for-linus' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:
"A smallish batch of fixes, a little more than expected this late, but
  all fixes are contained to their platforms and seem reasonably low
  risk:

   - a somewhat large SMP fix for ux500 that still seemed warranted to
     include here
   - OMAP DT fixes for pbias regulator specification that broke due to
     some DT reshuffling
   - PCIe IRQ routing bugfix for i.MX
   - networking fixes for keystone
   - runtime PM for OMAP GPMC
   - a couple of error path bug fixes for exynos"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
  ARM: dts: keystone: fix the clock node for mdio
  memory: omap-gpmc: Don't try to save uninitialized GPMC context
  ARM: imx6: correct i.MX6 PCIe interrupt routing
  ARM: ux500: add an SMP enablement type and move cpu nodes
  ARM: dts: dra7: Fix broken pbias device creation
  ARM: dts: OMAP5: Fix broken pbias device creation
  ARM: dts: OMAP4: Fix broken pbias device creation
  ARM: dts: omap243x: Fix broken pbias device creation
  ARM: EXYNOS: fix double of_node_put() on error path
  ARM: EXYNOS: Fix potentian kfree() of ro memory

Merge branch 'upstream' of git://git.linux-mips.org/ralf/upstream-linus

Pull MIPS bugfix from Ralf Baechle:
"Only a single MIPS fix - the math when invoking syscall_trace_enter
was wrong"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Fix seccomp syscall argument for MIPS64

Merge branch 'x86-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Merge x86 fixes from Ingo Molnar:
"Two followup fixes related to the previous LDT fix"

Also applied a further FPU emulation fix from Andy Lutomirski to the
branch before actually merging it.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
  x86/ldt: Further fix FPU emulation
  x86/ldt: Correct FPU emulation access to LDT
  x86/ldt: Correct LDT access in single stepping logic

x86/ldt: Further fix FPU emulation

The previous fix confused a selector with a segment prefix. Fix it.

Compile-tested only.

Cc: stable@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 4809146b86c3 ("x86/ldt: Correct FPU emulation access to LDT")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fuse: fix ioctl type confusion

fuse_dev_ioctl() performed fuse_get_dev() on a user-supplied fd,
leading to a type confusion issue. Fix it by checking file->f_op.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'keystone-dts-late-fixes-v2' of git://git./linux/kernel/git/ssantosh/linux-keystone into fixes

ARM: Couple of Keysyone MDIO DTS fixes for 4.2-rc6+

These are necessary to get the NIC card working on all Keystone
EVMs. Couple of boards are broken without these two fixes.

* tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone:
ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
ARM: dts: keystone: fix the clock node for mdio

Signed-off-by: Olof Johansson <olof@lixom.net>

MIPS: Fix seccomp syscall argument for MIPS64

Commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
fixed indirect system calls on O32 but it also introduced a bug for MIPS64
where it erroneously modified the v0 (syscall) register with the assumption
that the sycall offset hasn't been taken into consideration. This breaks
seccomp on MIPS64 n64 and n32 ABIs. We fix this by replacing the addition
with a move instruction.

Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
Cc: <stable@vger.kernel.org> # 3.15+
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10951/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Merge tag 'scsi-fixes' of git://git./linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
"This has two libfc fixes for bugs causing rare crashes, one iscsi fix
  for a potential hang on shutdown, and a fix for an I/O blocksize issue
  which caused a regression"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix maximum I/O size for BLOCK_PC requests
  libfc: Fix fc_fcp_cleanup_each_cmd()
  libfc: Fix fc_exch_recv_req() error path
  libiscsi: Fix host busy blocking during connection teardown

Merge tag 'topic/drm-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel into drm-next

single MST fixes from Maarten.

* tag 'topic/drm-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel:
drm/dp/mst: Remove port after removing connector.

Merge tag 'drm-intel-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel into drm-next

three display fixes for Intel.

* tag 'drm-intel-fixes-2015-08-14' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Commit planes on each crtc separately.
  drm/i915: calculate primary visibility changes instead of calling from set_config
  drm/i915: Only dither on 6bpc panels

thermal/cpu_cooling: update policy limits if clipped_freq < policy->max

policy->max is the maximum allowed frequency defined by user and
clipped_freq is the maximum that thermal constraints allow.

If clipped_freq is lower than policy->max, then we need to readjust
policy->max.

But, if clipped_freq is greater than policy->max, we don't need to do
anything. We used to call cpufreq_verify_within_limits() in this case,
but it doesn't change anything in this case.

Lets skip this unnecessary call and write a comment that explains this.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal/cpu_cooling: rename max_freq as clipped_freq in notifier

That's what it is for, lets name it properly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal/cpu_cooling: rename cpufreq_val as clipped_freq

That's what it is for, lets name it properly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal/cpu_cooling: convert 'switch' block to 'if' block in notifier

We just need to take care of single event here and there is no need to
increase indentation level of most of the code (which causes lines
longer that 80 columns to break).

Kill the switch block.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal/cpu_cooling: quit early after updating policy

If a valid cpufreq_dev is found for policy->cpu, we should update the
policy and quit the for loop. There is no need to keep traversing the
list of cpufreq_dev's.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal/cpu_cooling: No need to initialize max_freq to 0

Its always set before getting used, don't initialize it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: cpu_cooling: fix lockdep problems in cpu_cooling

A recent change to the cpu_cooling code introduced a AB-BA deadlock
scenario between the cpufreq_policy_notifier_list rwsem and the
cooling_cpufreq_lock.  This is caused by cooling_cpufreq_lock being held
before the registration/removal of the notifier block (an operation
which takes the rwsem), and the notifier code itself which takes the
locks in the reverse order:

======================================================
[ INFO: possible circular locking dependency detected ]
3.18.0+ #1453 Not tainted
-------------------------------------------------------
rc.local/770 is trying to acquire lock:
(cooling_cpufreq_lock){+.+.+.}, at: [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc

but task is already holding lock:
((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>]  __blocking_notifier_call_chain+0x34/0x68

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 ((cpufreq_policy_notifier_list).rwsem){++++.+}:
       [<c06bc3b0>] down_write+0x44/0x9c
       [<c0043444>] blocking_notifier_chain_register+0x28/0xd8
       [<c04ad610>] cpufreq_register_notifier+0x68/0x90
       [<c04abe4c>] __cpufreq_cooling_register.part.1+0x120/0x180
       [<c04abf44>] __cpufreq_cooling_register+0x98/0xa4
       [<c04abf8c>] cpufreq_cooling_register+0x18/0x1c
       [<bf0046f8>] imx_thermal_probe+0x1c0/0x470 [imx_thermal]
       [<c037cef8>] platform_drv_probe+0x50/0xac
       [<c037b710>] driver_probe_device+0x114/0x234
       [<c037b8cc>] __driver_attach+0x9c/0xa0
       [<c0379d68>] bus_for_each_dev+0x5c/0x90
       [<c037b204>] driver_attach+0x24/0x28
       [<c037ae7c>] bus_add_driver+0xe0/0x1d8
       [<c037c0cc>] driver_register+0x80/0xfc
       [<c037cd80>] __platform_driver_register+0x50/0x64
       [<bf007018>] 0xbf007018
       [<c0008a5c>] do_one_initcall+0x88/0x1d8
       [<c0095da4>] load_module+0x1768/0x1ef8
       [<c0096614>] SyS_init_module+0xe0/0xf4
       [<c000ec00>] ret_fast_syscall+0x0/0x48

-> #0 (cooling_cpufreq_lock){+.+.+.}:
       [<c00619f8>] lock_acquire+0xb0/0x124
       [<c06ba3b4>] mutex_lock_nested+0x5c/0x3d8
       [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc
       [<c0042bf4>] notifier_call_chain+0x4c/0x8c
       [<c0042f20>] __blocking_notifier_call_chain+0x50/0x68
       [<c0042f58>] blocking_notifier_call_chain+0x20/0x28
       [<c04ae62c>] cpufreq_set_policy+0x7c/0x1d0
       [<c04af3cc>] store_scaling_governor+0x74/0x9c
       [<c04ad418>] store+0x90/0xc0
       [<c0175384>] sysfs_kf_write+0x54/0x58
       [<c01746b4>] kernfs_fop_write+0xdc/0x190
       [<c010dcc0>] vfs_write+0xac/0x1b4
       [<c010dfec>] SyS_write+0x44/0x90
       [<c000ec00>] ret_fast_syscall+0x0/0x48

other info that might help us debug this:

Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((cpufreq_policy_notifier_list).rwsem);
                               lock(cooling_cpufreq_lock);
                               lock((cpufreq_policy_notifier_list).rwsem);
  lock(cooling_cpufreq_lock);

*** DEADLOCK ***

7 locks held by rc.local/770:
#0:  (sb_writers#6){.+.+.+}, at: [<c010dda0>] vfs_write+0x18c/0x1b4
#1:  (&of->mutex){+.+.+.}, at: [<c0174678>] kernfs_fop_write+0xa0/0x190
#2:  (s_active#52){.+.+.+}, at: [<c0174680>] kernfs_fop_write+0xa8/0x190
#3:  (cpu_hotplug.lock){++++++}, at: [<c0026a60>] get_online_cpus+0x34/0x90
#4:  (cpufreq_rwsem){.+.+.+}, at: [<c04ad3e0>] store+0x58/0xc0
#5:  (&policy->rwsem){+.+.+.}, at: [<c04ad3f8>] store+0x70/0xc0
#6:  ((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>] __blocking_notifier_call_chain+0x34/0x68

stack backtrace:
CPU: 0 PID: 770 Comm: rc.local Not tainted 3.18.0+ #1453
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
[<c00121c8>] (dump_backtrace) from [<c0012360>] (show_stack+0x18/0x1c)
r6:c0b85a80 r5:c0b75630 r4:00000000 r3:00000000
[<c0012348>] (show_stack) from [<c06b6c48>] (dump_stack+0x7c/0x98)
[<c06b6bcc>] (dump_stack) from [<c06b42a4>] (print_circular_bug+0x28c/0x2d8)
r4:c0b85a80 r3:d0071d40
[<c06b4018>] (print_circular_bug) from [<c00613b0>] (__lock_acquire+0x1acc/0x1bb0)
r10:c0b50660 r8:c09e6d80 r7:d0071d40 r6:c11d0f0c r5:00000007 r4:d0072240
[<c005f8e4>] (__lock_acquire) from [<c00619f8>] (lock_acquire+0xb0/0x124)
r10:00000000 r9:c04abfc4 r8:00000000 r7:00000000 r6:00000000 r5:c0a06f0c
r4:00000000
[<c0061948>] (lock_acquire) from [<c06ba3b4>] (mutex_lock_nested+0x5c/0x3d8)
r10:ec853800 r9:c0a06ed4 r8:d0071d40 r7:c0a06ed4 r6:c11d0f0c r5:00000000
r4:c04abfc4
[<c06ba358>] (mutex_lock_nested) from [<c04abfc4>] (cpufreq_thermal_notifier+0x34/0xfc)
r10:ec853800 r9:ec85380c r8:d00d7d3c r7:c0a06ed4 r6:d00d7d3c r5:00000000
r4:fffffffe
[<c04abf90>] (cpufreq_thermal_notifier) from [<c0042bf4>] (notifier_call_chain+0x4c/0x8c)
r7:00000000 r6:00000000 r5:00000000 r4:fffffffe
[<c0042ba8>] (notifier_call_chain) from [<c0042f20>] (__blocking_notifier_call_chain+0x50/0x68)
r8:c0a072a4 r7:00000000 r6:d00d7d3c r5:ffffffff r4:c0a06fc8 r3:ffffffff
[<c0042ed0>] (__blocking_notifier_call_chain) from [<c0042f58>] (blocking_notifier_call_chain+0x20/0x28)
r7:ec98b540 r6:c13ebc80 r5:ed76e600 r4:d00d7d3c
[<c0042f38>] (blocking_notifier_call_chain) from [<c04ae62c>] (cpufreq_set_policy+0x7c/0x1d0)
[<c04ae5b0>] (cpufreq_set_policy) from [<c04af3cc>] (store_scaling_governor+0x74/0x9c)
r7:ec98b540 r6:0000000c r5:ec98b540 r4:ed76e600
[<c04af358>] (store_scaling_governor) from [<c04ad418>] (store+0x90/0xc0)
r6:0000000c r5:ed76e6d4 r4:ed76e600
[<c04ad388>] (store) from [<c0175384>] (sysfs_kf_write+0x54/0x58)
r8:0000000c r7:d00d7f78 r6:ec98b540 r5:0000000c r4:ec853800 r3:0000000c
[<c0175330>] (sysfs_kf_write) from [<c01746b4>] (kernfs_fop_write+0xdc/0x190)
r6:ec98b540 r5:00000000 r4:00000000 r3:c0175330
[<c01745d8>] (kernfs_fop_write) from [<c010dcc0>] (vfs_write+0xac/0x1b4)
r10:0162aa70 r9:d00d6000 r8:0000000c r7:d00d7f78 r6:0162aa70 r5:0000000c
r4:eccde500
[<c010dc14>] (vfs_write) from [<c010dfec>] (SyS_write+0x44/0x90)
r10:0162aa70 r8:0000000c r7:eccde500 r6:eccde500 r5:00000000 r4:00000000
[<c010dfa8>] (SyS_write) from [<c000ec00>] (ret_fast_syscall+0x0/0x48)
r10:00000000 r8:c000edc4 r7:00000004 r6:000216cc r5:0000000c r4:0162aa70

Solve this by moving to finer grained locking - use one mutex to protect
the cpufreq_dev_list as a whole, and a separate lock to ensure correct
ordering of cpufreq notifier registration and removal.

cooling_list_lock is taken within cooling_cpufreq_lock on
(un)registration to preserve the behavior of the code, i.e. to
atomically add/remove to the list and (un)register the notifier.

Fixes: 2dcd851fe4b4 ("thermal: cpu_cooling: Update always cpufreq policy with
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Merge tag 'for-linus' of git://git./virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
"Just two very small & simple patches"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST
KVM: x86: zero IDT limit on entry to SMM

Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
"11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  Update maintainers for DRM STI driver
  mm: cma: mark cma_bitmap_maxno() inline in header
  zram: fix pool name truncation
  memory-hotplug: fix wrong edge when hot add a new node
  .mailmap: Andrey Ryabinin has moved
  ipc/sem.c: update/correct memory barriers
  mm/hwpoison: fix panic due to split huge zero page
  ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
  ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits
  mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held
  mm/hwpoison: fix page refcount of unknown non LRU page

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

Pull clock fix from Stephen Boyd:
"A one-liner for a regression found in the PXA clock driver"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: pxa: pxa3xx: fix CKEN register access

Update maintainers for DRM STI driver

Add Vincent Abriou and myself as maintainers.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: cma: mark cma_bitmap_maxno() inline in header

cma_bitmap_maxno() was marked as static and not static inline, which can
cause warnings about this function not being used if this file is included
in a file that does not call that function, and violates the conventions
used elsewhere. The two options are to move the function implementation
back to mm/cma.c or make it inline here, and it's simple enough for the
latter to make sense.

Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: fix pool name truncation

zram_meta_alloc() constructs a pool name for zs_create_pool() call as

    snprintf(pool_name, sizeof(pool_name), "zram%d", device_id);

However, it defines pool name buffer to be only 8 bytes long (minus
trailing zero), which means that we can have only 1000 pool names: zram0
-- zram999.

With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device zram1000
can fail if device zram100 already exists, because snprintf() will
truncate new pool name to zram100 and pass it debugfs_create_dir(),
causing:

  debugfs dir <zram100> creation failed
  zram: Error creating memory pool

... and so on.

Fix it by passing zram->disk->disk_name to zram_meta_alloc() instead of
divice_id.  We construct zram%d name earlier and keep it as a ->disk_name,
no need to snprintf() it again.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: fix wrong edge when hot add a new node

When we add a new node, the edge of memory may be wrong.

e.g. system has 4 nodes, and node3 is movable, node3 mem:[24G-32G],

1. hotremove the node3,
2. then hotadd node3 with a part of memory, mem:[26G-30G],
3. call hotadd_new_pgdat()
free_area_init_node()
get_pfn_range_for_nid()
4. it will return wrong start_pfn and end_pfn, because we have not
update the memblock.

This patch also fixes a BUG_ON during hot-addition, please see
http://marc.info/?l=linux-kernel&m=142961156129456&w=2

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

.mailmap: Andrey Ryabinin has moved

Update my email address.

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem.c: update/correct memory barriers

sem_lock() did not properly pair memory barriers:

!spin_is_locked() and spin_unlock_wait() are both only control barriers.
The code needs an acquire barrier, otherwise the cpu might perform read
operations before the lock test.

As no primitive exists inside <include/spinlock.h> and since it seems
noone wants another primitive, the code creates a local primitive within
ipc/sem.c.

With regards to -stable:

The change of sem_wait_array() is a bugfix, the change to sem_lock() is a
nop (just a preprocessor redefinition to improve the readability). The
bugfix is necessary for all kernels that use sem_wait_array() (i.e.:
starting from 3.10).

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hwpoison: fix panic due to split huge zero page

Bug:

  ------------[ cut here ]------------
  kernel BUG at mm/huge_memory.c:1957!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: snd_hda_codec_hdmi i915 rpcsec_gss_krb5 snd_hda_codec_realtek snd_hda_codec_generic nfsv4 dns_re
  CPU: 2 PID: 2576 Comm: test_huge Not tainted 4.2.0-rc5-mm1+ #27
  Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015
  task: ffff880204e3d600 ti: ffff8800db16c000 task.ti: ffff8800db16c000
  RIP: split_huge_page_to_list+0xdb/0x120
  Call Trace:
    memory_failure+0x32e/0x7c0
    madvise_hwpoison+0x8b/0x160
    SyS_madvise+0x40/0x240
    ? do_page_fault+0x37/0x90
    entry_SYSCALL_64_fastpath+0x12/0x71
  Code: ff f0 41 ff 4c 24 30 74 0d 31 c0 48 83 c4 08 5b 41 5c 41 5d c9 c3 4c 89 e7 e8 e2 58 fd ff 48 83 c4 08 31 c0
  RIP  split_huge_page_to_list+0xdb/0x120
   RSP <ffff8800db16fde8>
  ---[ end trace aee7ce0df8e44076 ]---

Testcase:

    #define _GNU_SOURCE
    #include <stdlib.h>
    #include <stdio.h>
    #include <sys/mman.h>
    #include <unistd.h>
    #include <fcntl.h>
    #include <sys/types.h>
    #include <errno.h>
    #include <string.h>

    #define MB 1024*1024

    int main(void)
    {
            char *mem;

            posix_memalign((void **)&mem, 2 * MB, 200 * MB);

            madvise(mem, 200 * MB, MADV_HWPOISON);

            free(mem);

            return 0;
    }

Huge zero page is allocated if page fault w/o FAULT_FLAG_WRITE flag.
The get_user_pages_fast() which called in madvise_hwpoison() will get
huge zero page if the page is not allocated before.  Huge zero page is a
tranparent huge page, however, it is not an anonymous page.
memory_failure will split the huge zero page and trigger
BUG_ON(is_huge_zero_page(page));

After commit 98ed2b0052e6 ("mm/memory-failure: give up error handling
for non-tail-refcounted thp"), memory_failure will not catch non anon
thp from madvise_hwpoison path and this bug occur.

Fix it by catching non anon thp in memory_failure in order to not split
huge zero page in madvise_hwpoison path.

After this patch:

  Injecting memory failure for page 0x202800 at 0x7fd8ae800000
  MCE: 0x202800: non anonymous thp
  [...]

[akpm@linux-foundation.org: remove second split, per Wanpeng]
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()

After we acquire the sma->sem_perm lock in exit_sem(), we are protected
against a racing IPC_RMID operation. Also at that point, we are the last
user of sem_undo_list. Therefore it isn't required that we acquire or use
ulp->lock.

Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
CC: Aristeu Rozanski <aris@redhat.com>
Cc: David Jeffery <djeffery@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits

The current semaphore code allows a potential use after free: in
exit_sem we may free the task's sem_undo_list while there is still
another task looping through the same semaphore set and cleaning the
sem_undo list at freeary function (the task called IPC_RMID for the same
semaphore set).

For example, with a test program [1] running which keeps forking a lot
of processes (which then do a semop call with SEM_UNDO flag), and with
the parent right after removing the semaphore set with IPC_RMID, and a
kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and
CONFIG_DEBUG_SPINLOCK, you can easily see something like the following
in the kernel log:

   Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64
   000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b  kkkkkkkk.kkkkkkk
   010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff  ....kkkk........
   Prev obj: start=ffff88003b45c180, len=64
   000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a  .....N......ZZZZ
   010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff  ...........7....
   Next obj: start=ffff88003b45c200, len=64
   000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a  .....N......ZZZZ
   010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff  ........h).<....
   BUG: spinlock wrong CPU on CPU#2, test/18028
   general protection fault: 0000 [#1] SMP
   Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
   CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
   RIP: spin_dump+0x53/0xc0
   Call Trace:
     spin_bug+0x30/0x40
     do_raw_spin_unlock+0x71/0xa0
     _raw_spin_unlock+0xe/0x10
     freeary+0x82/0x2a0
     ? _raw_spin_lock+0xe/0x10
     semctl_down.clone.0+0xce/0x160
     ? __do_page_fault+0x19a/0x430
     ? __audit_syscall_entry+0xa8/0x100
     SyS_semctl+0x236/0x2c0
     ? syscall_trace_leave+0xde/0x130
     entry_SYSCALL_64_fastpath+0x12/0x71
   Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89
   RIP  [<ffffffff810d6053>] spin_dump+0x53/0xc0
    RSP <ffff88003750fd68>
   ---[ end trace 783ebb76612867a0 ]---
   NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053]
   Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
   CPU: 3 PID: 18053 Comm: test Tainted: G      D         4.2.0-rc5+ #1
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
   RIP: native_read_tsc+0x0/0x20
   Call Trace:
     ? delay_tsc+0x40/0x70
     __delay+0xf/0x20
     do_raw_spin_lock+0x96/0x140
     _raw_spin_lock+0xe/0x10
     sem_lock_and_putref+0x11/0x70
     SYSC_semtimedop+0x7bf/0x960
     ? handle_mm_fault+0xbf6/0x1880
     ? dequeue_task_fair+0x79/0x4a0
     ? __do_page_fault+0x19a/0x430
     ? kfree_debugcheck+0x16/0x40
     ? __do_page_fault+0x19a/0x430
     ? __audit_syscall_entry+0xa8/0x100
     ? do_audit_syscall_entry+0x66/0x70
     ? syscall_trace_enter_phase1+0x139/0x160
     SyS_semtimedop+0xe/0x10
     SyS_semop+0x10/0x20
     entry_SYSCALL_64_fastpath+0x12/0x71
   Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9
   Kernel panic - not syncing: softlockup: hung tasks

I wasn't able to trigger any badness on a recent kernel without the
proper config debugs enabled, however I have softlockup reports on some
kernel versions, in the semaphore code, which are similar as above (the
scenario is seen on some servers running IBM DB2 which uses semaphore
syscalls).

The patch here fixes the race against freeary, by acquiring or waiting
on the sem_undo_list lock as necessary (exit_sem can race with freeary,
while freeary sets un->semid to -1 and removes the same sem_undo from
list_proc or when it removes the last sem_undo).

After the patch I'm unable to reproduce the problem using the test case
[1].

[1] Test case used below:

    #include <stdio.h>
    #include <sys/types.h>
    #include <sys/ipc.h>
    #include <sys/sem.h>
    #include <sys/wait.h>
    #include <stdlib.h>
    #include <time.h>
    #include <unistd.h>
    #include <errno.h>

    #define NSEM 1
    #define NSET 5

    int sid[NSET];

    void thread()
    {
            struct sembuf op;
            int s;
            uid_t pid = getuid();

            s = rand() % NSET;
            op.sem_num = pid % NSEM;
            op.sem_op = 1;
            op.sem_flg = SEM_UNDO;

            semop(sid[s], &op, 1);
            exit(EXIT_SUCCESS);
    }

    void create_set()
    {
            int i, j;
            pid_t p;
            union {
                    int val;
                    struct semid_ds *buf;
                    unsigned short int *array;
                    struct seminfo *__buf;
            } un;

            /* Create and initialize semaphore set */
            for (i = 0; i < NSET; i++) {
                    sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT);
                    if (sid[i] < 0) {
                            perror("semget");
                            exit(EXIT_FAILURE);
                    }
            }
            un.val = 0;
            for (i = 0; i < NSET; i++) {
                    for (j = 0; j < NSEM; j++) {
                            if (semctl(sid[i], j, SETVAL, un) < 0)
                                    perror("semctl");
                    }
            }

            /* Launch threads that operate on semaphore set */
            for (i = 0; i < NSEM * NSET * NSET; i++) {
                    p = fork();
                    if (p < 0)
                            perror("fork");
                    if (p == 0)
                            thread();
            }

            /* Free semaphore set */
            for (i = 0; i < NSET; i++) {
                    if (semctl(sid[i], NSEM, IPC_RMID))
                            perror("IPC_RMID");
            }

            /* Wait for forked processes to exit */
            while (wait(NULL)) {
                    if (errno == ECHILD)
                            break;
            };
    }

    int main(int argc, char **argv)
    {
            pid_t p;

            srand(time(NULL));

            while (1) {
                    p = fork();
                    if (p < 0) {
                            perror("fork");
                            exit(EXIT_FAILURE);
                    }
                    if (p == 0) {
                            create_set();
                            goto end;
                    }

                    /* Wait for forked processes to exit */
                    while (wait(NULL)) {
                            if (errno == ECHILD)
                                    break;
                    };
            }
    end:
            return 0;
    }

[akpm@linux-foundation.org: use normal comment layout]
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
CC: Aristeu Rozanski <aris@redhat.com>
Cc: David Jeffery <djeffery@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held

Hugetlbfs pages will get a refcount in get_any_page() or
madvise_hwpoison() if soft offlining through madvise. The refcount which
is held by the soft offline path should be released if we fail to isolate
hugetlbfs pages.

Fix it by reducing the refcount for both isolation success and failure.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org> [3.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hwpoison: fix page refcount of unknown non LRU page

After trying to drain pages from pagevec/pageset, we try to get reference
count of the page again, however, the reference count of the page is not
reduced if the page is still not on LRU list.

Fix it by adding the put_page() to drop the page reference which is from
__get_any_page().

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org> [3.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

Pull timer fix from Ingo Molnar:
"A single clocksource driver suspend/resume fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clockevents/drivers/sh_cmt: Only perform clocksource suspend/resume if enabled

Merge branch 'perf-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
"Misc fixes: PMU driver corner cases, tooling fixes, and an 'AUX'
  (Intel PT) race related core fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/cqm: Do not access cpu_data() from CPU_UP_PREPARE handler
  perf/x86/intel: Fix memory leak on hot-plug allocation fail
  perf: Fix PERF_EVENT_IOC_PERIOD migration race
  perf: Fix double-free of the AUX buffer
  perf: Fix fasync handling on inherited events
  perf tools: Fix test build error when bindir contains double slash
  perf stat: Fix transaction lenght metrics
  perf: Fix running time accounting

Merge branch 'locking-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull locking fix from Ingo Molnar:
"A single fix for a locking self-test crash"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/pvqspinlock: Fix kernel panic in locking-selftest

Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
"Back from holidays, found these in the cracks: one nouveau revert, one
  vmwgfx locking fix and a bunch of exynos fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  Revert "drm/nouveau/fifo/gk104: kick channels when deactivating them"
  drm/vmwgfx: Fix execbuf locking issues
  drm/exynos/fimc: fix runtime pm support
  drm/exynos/mixer: always update INT_EN cache
  drm/exynos/mixer: correct vsync configuration sequence
  drm/exynos/mixer: fix interrupt clearing
  drm/exynos/hdmi: fix edid memory leak
  drm/exynos: gsc: fix wrong bitwise operation for swap detection

cpufreq: exynos: Fix for memory leak in case SoC name does not match

During probe free the memory allocated to "exynos_info" in case of
unknown SoC type.

Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
[k.kozlowski: Rebased the patch around if(of_machine_is_compatible)]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Fix circular lock dependency issue in the video-detect code

Before this commit, the following would happen:

a) acpi_video_get_backlight_type() gets called
b) acpi_video_get_backlight_type() calls acpi_video_init_backlight_type()
c) acpi_video_init_backlight_type() locks its function static init_mutex
d) acpi_video_init_backlight_type() calls backlight_register_notifier()
e) backlight_register_notifier() takes its notifier-chain lock

And when the backlight notifier chain gets called we've:

1) blocking_notifier_call_chain() gets called
2) blocking_notifier_call_chain() takes the notifier-chain lock
3) blocking_notifier_call_chain() calls acpi_video_backlight_notify()
4) acpi_video_backlight_notify() calls acpi_video_get_backlight_type()
5) acpi_video_get_backlight_type() calls acpi_video_init_backlight_type()
6) acpi_video_init_backlight_type() locks its function static init_mutex

So in the first call sequence we have:

a) init_mutex gets locked
b) notifier-chain gets locked

and in the second call sequence we have:

1) notifier-chain gets locked
2) init_mutex gets locked

And we've a circular locking dependency. This specific locking dependency
is fixable without using the big hammer otherwise known as a workqueue,
but further analysis shows a similar problem with the backlight notifier
chain lock vs register_count_mutex from drivers/acpi/acpi_video.c,
and fixing that becomes problematic.

So this commit simply fixes this with the big hammer, performance
wise this is a non issue as we expect the work to get scheduled
exactly zero or one times during normal system use.

Fixes: 93a291dfaf9c (ACPI / video: Move backlight notifier to video_detect.c)
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

inet: fix potential deadlock in reqsk_queue_unlink()

When replacing del_timer() with del_timer_sync(), I introduced
a deadlock condition :

reqsk_queue_unlink() is called from inet_csk_reqsk_queue_drop()

inet_csk_reqsk_queue_drop() can be called from many contexts,
one being the timer handler itself (reqsk_timer_handler()).

In this case, del_timer_sync() loops forever.

Simple fix is to test if timer is pending.

Fixes: 2235f2ac75fd ("inet: fix races with reqsk timers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

thermal: power_allocator: do not use devm* interfaces

The code in question is called outside of standard driver
probe()/remove() callbacks and thus will not benefit from use of devm*
infrastructure.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

gianfar: Restore link state settings after MAC reset

There are some MAC registers that need to be kept in sync
with the link state parameters, see adjust_link().
However, after a MAC soft reset default values for
these registers are assumed. In some cases (excepting
if down/ if up for example) adjust_link() does not see
that these values were reset to default because the
priv->old* link parameters were left unchanged.
So, reset the priv->old* link params as well during a
MAC reset to let adjust_link() restore the MAC link
settings to the actual link state values.

Fixes following case, for example:
Setting link to 100M, changing MTU (implies MAC reset),
link state remains unchanged to 100M but MAC registers
were reset to default (1G) breaking the connectivity w/
the PHY. Closing and re-opening the interface would
restore the MAC link parameters to the correct values.

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: off-by-one in continuation handling in /proc/net/route

When generating /proc/net/route we emit a header followed by a line for
each route.  When a short read is performed we will restart this process
based on the open file descriptor.  When calculating the start point we
fail to take into account that the 0th entry is the header.  This leads
us to skip the first entry when doing a continuation read.

This can be easily seen with the comparison below:

  while read l; do echo "$l"; done </proc/net/route >A
  cat /proc/net/route >B
  diff -bu A B | grep '^[+-]'

On my example machine I have approximatly 10KB of route output.  There we
see the very first non-title element is lost in the while read case,
and an entry around the 8K mark in the cat case:

  +wlan0 00000000 02021EAC 0003 0 0 400 00000000 0 0 0
  -tun1  00C0AC0A 00000000 0001 0 0 950 00C0FFFF 0 0 0

Fix up the off-by-one when reaquiring position on continuation.

Fixes: 8be33e955cb9 ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf")
BugLink: http://bugs.launchpad.net/bugs/1483440
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code

The recent refactoring of the IGMP and MLD parsing code into
ipv6_mc_check_mld() / ip_mc_check_igmp() introduced a potential crash /
BUG() invocation for bridges:

I wrongly assumed that skb_get() could be used as a simple reference
counter for an skb which is not the case. skb_get() bears additional
semantics, a user count. This leads to a BUG() invocation in
pskb_expand_head() / kernel panic if pskb_may_pull() is called on an skb
with a user count greater than one - unfortunately the refactoring did
just that.

Fixing this by removing the skb_get() call and changing the API: The
caller of ipv6_mc_check_mld() / ip_mc_check_igmp() now needs to
additionally check whether the returned skb_trimmed is a clone.

Fixes: 9afd85c9e455 ("net: Export IGMP/MLD message validation code")
Reported-by: Brenden Blanco <bblanco@plumgrid.com>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "drm/nouveau/fifo/gk104: kick channels when deactivating them"

This reverts commit 1addc1264852

This commit seems to cause crashes in gk104_fifo_intr_runlist() by
returning 0xbad0da00 when register 0x2a00 is read. Since this commit was
intended for GM20B which is not completely supported yet, let's revert
it for the time being.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Afzal Mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/vmwgfx: Fix execbuf locking issues

This addresses two issues that cause problems with viewperf maya-03 in
situation with memory pressure.

The first issue causes attempts to unreserve buffers if batched
reservation fails due to, for example, a signal pending. While previously
the ttm_eu api was resistant against this type of error, it is no longer
and the lockdep code will complain about attempting to unreserve buffers
that are not reserved. The issue is resolved by avoid calling
ttm_eu_backoff_reservation in the buffer reserve error path.

The second issue is that the binding_mutex may be held when user-space
fence objects are created and hence during memory reclaims. This may cause
recursive attempts to grab the binding mutex. The issue is resolved by not
holding the binding mutex across fence creation and submission.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge branch 'exynos-drm-fixes' of git://git./linux/kernel/git/daeinki/drm-exynos into drm-fixes

   This pull request fixes memory leak and some issues related to
   mixer and gscaler driver issues.

* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos/fimc: fix runtime pm support
  drm/exynos/mixer: always update INT_EN cache
  drm/exynos/mixer: correct vsync configuration sequence
  drm/exynos/mixer: fix interrupt clearing
  drm/exynos/hdmi: fix edid memory leak
  drm/exynos: gsc: fix wrong bitwise operation for swap detection

Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
"Another few small ARM fixes, mostly addressing some VDSO issues"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8410/1: VDSO: fix coarse clock monotonicity regression
  ARM: 8409/1: Mark ret_fast_syscall as a function
  ARM: 8408/1: Fix the secondary_startup function in Big Endian case
  ARM: 8405/1: VDSO: fix regression with toolchains lacking ld.bfd executable

x86: fix error handling for 32-bit compat out-of-range system call numbers

Commit 3f5159a9221f ("x86/asm/entry/32: Update -ENOSYS handling to match
the 64-bit logic") broke the ENOSYS handling for the 32-bit compat case.
The proper error return value was never loaded into %rax, except if
things just happened to go through the audit paths, which ended up
reloading the return value.

This moves the loading or %rax into the normal system call path, just to
make sure the error case triggers it. It's kind of sad, since it adds a
useless instruction to reload the register to the fast path, but it's
not like that single load from the stack is going to be noticeable.

Reported-by: David Drysdale <drysdale@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'dm-4.2-fixes-5' of git://git./linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

- two stable fixes for corruption seen in a snapshot of thinp metadata;
   metadata snapshots aren't widely used but help provide a consistent
   view of the metadata associated with an active thin-pool.

- a dm-cache fix for the 4.2 "default" policy switch from "mq" to "smq"

* tag 'dm-4.2-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache policy smq: move 'dm-cache-default' module alias to SMQ
  dm btree: add ref counting ops for the leaves of top level btrees
  dm thin metadata: delete btrees when releasing metadata snapshot

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

Pull xen block driver fixes from Jens Axboe:
"A few small bug fixes for xen-blk{front,back} that have been sitting
  over my vacation"

* 'for-linus' of git://git.kernel.dk/linux-block:
  xen-blkback: replace work_pending with work_busy in purge_persistent_gnt()
  xen-blkfront: don't add indirect pages to list when !feature_persistent
  xen-blkfront: introduce blkfront_gather_backend_features()

Merge tag 'for-linus-4.2-rc6-tag' of git://git./linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:

- revert a fix from 4.2-rc5 that was causing lots of WARNING spam.

- fix a memory leak affecting backends in HVM guests.

- fix PV domU hang with certain configurations.

* tag 'for-linus-4.2-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
  Revert "xen/events/fifo: Handle linked events when closing a port"
  x86/xen: build "Xen PV" APIC driver for domU as well

Revert x86 sigcontext cleanups

This reverts commits 9a036b93a344 ("x86/signal/64: Remove 'fs' and 'gs'
from sigcontext") and c6f2062935c8 ("x86/signal/64: Fix SS handling for
signals delivered to 64-bit programs").

They were cleanups, but they break dosemu by changing the signal return
behavior (and removing 'fs' and 'gs' from the sigcontext struct - while
not actually changing any behavior - causes build problems).

Reported-and-tested-by: Stas Sergeev <stsp@list.ru>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge git://git./linux/kernel/git/davem/net

Pull networking fixes from David Miller:

1) Workaround hw bug when acquiring PCI bos ownership of iwlwifi
    devices, from Emmanuel Grumbach.

2) Falling back to vmalloc in conntrack should not emit a warning, from
    Pablo Neira Ayuso.

3) Fix NULL deref when rtlwifi driver is used as an AP, from Luis
    Felipe Dominguez Vega.

4) Rocker doesn't free netdev on device removal, from Ido Schimmel.

5) UDP multicast early sock demux has route handling races, from Eric
    Dumazet.

6) Fix L4 checksum handling in openvswitch, from Glenn Griffin.

7) Fix use-after-free in skb_set_peeked, from Herbert Xu.

8) Don't advertize NETIF_F_FRAGLIST in virtio_net driver, this can lead
    to fraglists longer than the driver can support.  From Jason Wang.

9) Fix mlx5 on non-4k-pagesize systems, from Carol L Soto.

10) Fix interrupt storm in bna driver, from Ivan Vecera.

11) Don't propagate -EBUSY from netlink_insert(), from Daniel Borkmann.

12) Fix inet request sock leak, from Eric Dumazet.

13) Fix TX interrupt masking and marking in TX descriptors of fs_enet
    driver, from LEROY Christophe.

14) Get rid of rule optimizer in gianfar driver, it's buggy and unlikely
    to get fixed any time soon.  From Jakub Kicinski

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (61 commits)
  cosa: missing error code on failure in probe()
  gianfar: remove faulty filer optimizer
  gianfar: correct list membership accounting
  gianfar: correct filer table writing
  bonding: Gratuitous ARP gets dropped when first slave added
  net: dsa: Do not override PHY interface if already configured
  net: fs_enet: mask interrupts for TX partial frames.
  net: fs_enet: explicitly remove I flag on TX partial frames
  inet: fix possible request socket leak
  inet: fix races with reqsk timers
  mkiss: Fix error handling in mkiss_open()
  bnx2x: Free NVRAM lock at end of each page
  bnx2x: Prevent null pointer dereference on SKB release
  cxgb4: missing curly braces in t4_setup_debugfs()
  net-timestamp: Update skb_complete_tx_timestamp comment
  ipv6: don't reject link-local nexthop on other interface
  netlink: make sure -EBUSY won't escape from netlink_insert
  bna: fix interrupts storm caused by erroneous packets
  net: mvpp2: replace TX coalescing interrupts with hrtimer
  net: mvpp2: enable proper per-CPU TX buffers unmapping
  ...

Merge tag 'edac_fix_for_4.2' of git://git./linux/kernel/git/bp/bp

Pull EDAC fix from Borislav Petkov:
"A ppc4xx_edac fix for accessing ->csrows properly.  This driver was
  missed during the conversion a couple of years ago"

* tag 'edac_fix_for_4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC, ppc4xx: Access mci->csrows array elements properly

ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file

Currently mdio bindings are defined in keystone.dtsi and this results
in incorrect unit address for the node on K2E and K2L SoCs. Fix this
by moving them to SoC specific DTS file.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>

ARM: dts: keystone: fix the clock node for mdio

Currently the MDIO clock is pointing to clkpa instead of clkcpgmac.
MDIO is part of the ethss and the clock should be clkcpgmac.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>

Merge tag 'omap-for-v4.2/fixes-rc6' of git://git./linux/kernel/git/tmlind/linux-omap into fixes

Fix a NULL pointer exception for omap GPMC bus code if probe fails.

* tag 'omap-for-v4.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
memory: omap-gpmc: Don't try to save uninitialized GPMC context

Signed-off-by: Olof Johansson <olof@lixom.net>

mac80211: fix invalid read in minstrel_sort_best_tp_rates()

At the last iteration of the loop, j may equal zero and thus
tp_list[j - 1] causes an invalid read.
Change the logic of the loop so that j - 1 is always >= 0.

Cc: stable@vger.kernel.org
Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Merge tag 'imx-fixes-4.2-3' of git://git./linux/kernel/git/shawnguo/linux into fixes

The i.MX fixes for 4.2, 3rd round:
- Fix i.MX6 PCIe interrupt routing which gets missed from stacked IRQ
   domain conversion.  The PCIe wakeup support is currently broken
   because of this.

* tag 'imx-fixes-4.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  ARM: imx6: correct i.MX6 PCIe interrupt routing

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'samsung-mach-fixes-4.2' of https://github.com/krzk/linux into fixes

Two fixes for bugs in Exynos power domain error exit path:
1. kfree() of read-only memory (name of power domain returned
   by kstrdup_const()),
2. Doubled of_node_put() leading to invalid ref count for OF node.

* tag 'samsung-mach-fixes-4.2' of https://github.com/krzk/linux:
  ARM: EXYNOS: fix double of_node_put() on error path
  ARM: EXYNOS: Fix potentian kfree() of ro memory

Signed-off-by: Olof Johansson <olof@lixom.net>

drm/i915: Commit planes on each crtc separately.

This patch is based on the upstream commit 5ac1c4bcf073ad and amended
for v4.2 to make sure it works as intended.

Repeated calls to begin_crtc_commit can cause warnings like this:
[  169.127746] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616
[  169.127835] in_atomic(): 0, irqs_disabled(): 1, pid: 1947, name: kms_flip
[  169.127840] 3 locks held by kms_flip/1947:
[  169.127843]  #0:  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffff814774bc>] __drm_modeset_lock_all+0x9c/0x130
[  169.127860]  #1:  (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffff814774cd>] __drm_modeset_lock_all+0xad/0x130
[  169.127870]  #2:  (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffff81477178>] drm_modeset_lock+0x38/0x110
[  169.127879] irq event stamp: 665690
[  169.127882] hardirqs last  enabled at (665689): [<ffffffff817ffdb5>] _raw_spin_unlock_irqrestore+0x55/0x70
[  169.127889] hardirqs last disabled at (665690): [<ffffffffc0197a23>] intel_pipe_update_start+0x113/0x5c0 [i915]
[  169.127936] softirqs last  enabled at (665470): [<ffffffff8108a766>] __do_softirq+0x236/0x650
[  169.127942] softirqs last disabled at (665465): [<ffffffff8108ae75>] irq_exit+0xc5/0xd0
[  169.127951] CPU: 1 PID: 1947 Comm: kms_flip Not tainted 4.1.0-rc4-patser+ #4039
[  169.127954] Hardware name: LENOVO 2349AV8/2349AV8, BIOS G1ETA5WW (2.65 ) 04/15/2014
[  169.127957]  ffff8800c49036f0 ffff8800cde5fa28 ffffffff817f6907 0000000080000001
[  169.127964]  0000000000000000 ffff8800cde5fa58 ffffffff810aebed 0000000000000046
[  169.127970]  ffffffff81c5d518 0000000000000268 0000000000000000 ffff8800cde5fa88
[  169.127981] Call Trace:
[  169.127992]  [<ffffffff817f6907>] dump_stack+0x4f/0x7b
[  169.128001]  [<ffffffff810aebed>] ___might_sleep+0x16d/0x270
[  169.128008]  [<ffffffff810aed38>] __might_sleep+0x48/0x90
[  169.128017]  [<ffffffff817fc359>] mutex_lock_nested+0x29/0x410
[  169.128073]  [<ffffffffc01635f0>] ? vgpu_write64+0x220/0x220 [i915]
[  169.128138]  [<ffffffffc017fddf>] ? ironlake_update_primary_plane+0x2ff/0x410 [i915]
[  169.128198]  [<ffffffffc0190e75>] intel_frontbuffer_flush+0x25/0x70 [i915]
[  169.128253]  [<ffffffffc01831ac>] intel_finish_crtc_commit+0x4c/0x180 [i915]
[  169.128279]  [<ffffffffc00784ac>] drm_atomic_helper_commit_planes+0x12c/0x240 [drm_kms_helper]
[  169.128338]  [<ffffffffc0184264>] __intel_set_mode+0x684/0x830 [i915]
[  169.128378]  [<ffffffffc018a84a>] intel_crtc_set_config+0x49a/0x620 [i915]
[  169.128385]  [<ffffffff817fdd39>] ? mutex_unlock+0x9/0x10
[  169.128391]  [<ffffffff81467b69>] drm_mode_set_config_internal+0x69/0x120
[  169.128398]  [<ffffffff8119b547>] ? might_fault+0x57/0xb0
[  169.128403]  [<ffffffff8146bf93>] drm_mode_setcrtc+0x253/0x620
[  169.128409]  [<ffffffff8145c600>] drm_ioctl+0x1a0/0x6a0
[  169.128415]  [<ffffffff810b3b41>] ? get_parent_ip+0x11/0x50
[  169.128424]  [<ffffffff811e9ab8>] do_vfs_ioctl+0x2f8/0x530
[  169.128429]  [<ffffffff810d0fcd>] ? trace_hardirqs_on+0xd/0x10
[  169.128435]  [<ffffffff812e7676>] ? selinux_file_ioctl+0x56/0x100
[  169.128439]  [<ffffffff811e9d71>] SyS_ioctl+0x81/0xa0
[  169.128445]  [<ffffffff81800697>] system_call_fastpath+0x12/0x6f

Solve it by using the newly introduced drm_atomic_helper_commit_planes_on_crtc.

The problem here was that the drm_atomic_helper_commit_planes() helper
we were using was basically designed to do

    begin_crtc_commit(crtc #1)
    begin_crtc_commit(crtc #2)
    ...
    commit all planes
    finish_crtc_commit(crtc #1)
    finish_crtc_commit(crtc #2)

The problem here is that since our hardware relies on vblank evasion,
our CRTC 'begin' function waits until we're out of the danger zone in
which register writes might wind up straddling the vblank, then disables
interrupts; our 'finish' function re-enables interrupts after the
registers have been written.  The expectation is that the operations between
'begin' and 'end' must be performed without sleeping (since interrupts
are disabled) and should happen as quickly as possible.  By clumping all
of the 'begin' calls together, we introducing a couple problems:
* Subsequent 'begin' invocations might sleep (which is illegal)
* The first 'begin' ensured that we were far enough from the vblank that
   we could write our registers safely and ensure they all fell within
   the same frame.  Adding extra delay waiting for subsequent CRTC's
   wasn't accounted for and could put us back into the 'danger zone' for
   CRTC #1.

This commit solves the problem by using a new helper that allows an
order of operations like:

   for each crtc {
        begin_crtc_commit(crtc)  // sleep (maybe), then disable interrupts
        commit planes for this specific CRTC
        end_crtc_commit(crtc)    // reenable interrupts
   }

so that sleeps will only be performed while interrupts are enabled and
we can be sure that registers for a CRTC will be written immediately
once we know we're in the safe zone.

The crtc->config->base.crtc update may seem unrelated, but the helper
will use it to obtain the crtc for the state. Without the update it
will dereference NULL and crash.

Changes since v1:
- Use Matt Roper's commit message.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=90398
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>