When priority inheritance was added back in 2.6.18 to sched_setscheduler(), it
added a path to taking an rt-mutex wait_lock, which is not IRQ safe. As PI
is not a common occurrence, lockdep will likely never trigger if
sched_setscheduler was called from interrupt context. A BUG_ON() was added
to trigger if __sched_setscheduler() was ever called from interrupt context
because there was a possibility to take the wait_lock.

Today the wait_lock is irq safe, but the path to taking it in
sched_setscheduler() is the same as the path to taking it from normal
context. The wait_lock is taken with raw_spin_lock_irq() and released with
raw_spin_unlock_irq() which will indiscriminately enable interrupts,
which would be bad in interrupt context.

The problem is that normalize_rt_tasks, which is called by triggering the
sysrq nice-all-RT-tasks was changed to call __sched_setscheduler(), and this
is done from interrupt context!

Now __sched_setscheduler() takes a "pi" parameter that is used to know if
the priority inheritance should be called or not. As the BUG_ON() only cares
about calling the PI code, it should only bug if called from interrupt
context with the "pi" parameter set to true.
Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dbc7f069 ("sched: Use replace normalize_task() with __sched_setscheduler()")
Link: http://lkml.kernel.org/r/20170308124654.10e598f2@gandalf.local.homeSigned-off-by: Ingo Molnar <mingo@kernel.org>

pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task))
when it returns a task other than NULL, which means that task_cpu(task)
must be rq->cpu. So if task == next_task, then task_cpu(next_task) must
be rq->cpu as well. Remove the redundant condition and make the code simpler.

This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

pick_next_pushable_task(rq) has BUG_ON(rq_cpu != task_cpu(task)) when
it returns a task other than NULL, which means that task_cpu(task) must
be rq->cpu. So if task == next_task, then task_cpu(next_task) must be
rq->cpu as well. Remove the redundant condition and make the code simpler.

This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551143-22219-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Now that we've added llist_for_each_entry_safe(), use it to simplify
an open coded version of it in sched_ttwu_pending().
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494549584-11730-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Sometimes we have to dereference next field of llist node before entering
loop becasue the node might be deleted or the next field might be
modified within the loop. So this adds the safe version of llist_for_each(),
that is, llist_for_each_safe().
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Huang, Ying <ying.huang@intel.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494549416-10539-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The cpumasks in smp_call_function_many() are private and not subject
to concurrency, atomic bitops are pointless and expensive.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Inter-Processor-Interrupt(IPI) is needed when a page is unmapped and the
process' mm_cpumask() shows the process has ever run on other CPUs. page
migration, page reclaim all need IPIs. The number of IPI needed to send
to different CPUs is especially large for multi-threaded workload since
mm_cpumask() is per process.

For smp_call_function_many(), whenever a CPU queues a CSD to a target
CPU, it will send an IPI to let the target CPU to handle the work.
This isn't necessary - we need only send IPI when queueing a CSD
to an empty call_single_queue.

The reason:

flush_smp_call_function_queue() that is called upon a CPU receiving an
IPI will empty the queue and then handle all of the CSDs there. So if
the target CPU's call_single_queue is not empty, we know that:
i.  An IPI for the target CPU has already been sent by 'previous queuers';
ii. flush_smp_call_function_queue() hasn't emptied that CPU's queue yet.
Thus, it's safe for us to just queue our CSD there without sending an
addtional IPI. And for the 'previous queuers', we can limit it to the
first queuer.

To demonstrate the effect of this patch, a multi-thread workload that
spawns 80 threads to equally consume 100G memory is used. This is tested
on a 2 node broadwell-EP which has 44cores/88threads and 32G memory. So
after 32G memory is used up, page reclaiming starts to happen a lot.

With this patch, IPI number dropped 88% and throughput increased about
15% for the above workload.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20170519075331.GE2084@aaronlu.sh.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull crypto fix from Herbert Xu:
 "This fixes a regression in the skcipher interface that allows bogus
  key parameters to hit underlying implementations which can cause
  crashes"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: skcipher - Add missing API setkey checks

Pull pstore fix from Kees Cook:
 "Marta noticed another misbehavior in EFI pstore, which this fixes.

  Hopefully this is the last of the v4.12 fixes for pstore!"

* tag 'pstore-v4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  efi-pstore: Fix write/erase id tracking

Pull ACPI fixes from Rafael Wysocki:
 "These revert a 4.11 change that turned out to be problematic and add a
  .gitignore file.

  Specifics:

   - Revert a 4.11 commit related to the ACPI-based handling of laptop
     lids that made changes incompatible with existing user space stacks
     and broke things there (Lv Zheng).

   - Add .gitignore to the ACPI tools directory (Prarit Bhargava)"

* tag 'acpi-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPI / button: Remove lid_init_state=method mode"
  tools/power/acpi: Add .gitignore file

Pull power management fixes from Rafael Wysocki:
 "These fix RTC wakeup from suspend-to-idle broken recently, fix CPU
  idleness detection condition in the schedutil cpufreq governor, fix a
  cpufreq driver build failure, fix an error code path in the power
  capping framework, clean up the hibernate core and update the
  intel_pstate documentation.

  Specifics:

   - Fix RTC wakeup from suspend-to-idle broken by the recent rework of
     ACPI wakeup handling (Rafael Wysocki).

   - Update intel_pstate driver documentation to reflect the current
     code and explain how it works in more detail (Rafael Wysocki).

   - Fix an issue related to CPU idleness detection on systems with
     shared cpufreq policies in the schedutil governor (Juri Lelli).

   - Fix a possible build issue in the dbx500 cpufreq driver (Arnd
     Bergmann).

   - Fix a function in the power capping framework core to return an
     error code instead of 0 when there's an error (Dan Carpenter).

   - Clean up variable definition in the hibernation core (Pushkar
     Jambhlekar)"

* tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: dbx500: add a Kconfig symbol
  PM / hibernate: Declare variables as static
  PowerCap: Fix an error code in powercap_register_zone()
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()
  cpufreq: intel_pstate: Document the current behavior and user interface
  cpufreq: schedutil: use now as reference when aggregating shared policy requests

We need to initializes those variables to 0 for platforms that do not
provide ACPI parameters. Otherwise, we set sda_hold_time to random
values, breaking e.g. Galileo and IOT2000 boards.
Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Fixes: 9d640843 ("i2c: designware: don't infer timings described by ACPI from clock rate")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Prior to the pstore interface refactoring, the "id" generated during
a backend pstore_write() was only retained by the internal pstore
inode tracking list. Additionally the "part" was ignored, so EFI
would encode this in the id. This corrects the misunderstandings
and correctly sets "id" during pstore_write(), and uses "part"
directly during pstore_erase().
Reported-by: Marta Lofstedt <marta.lofstedt@intel.com>
Fixes: 76cc9580 ("pstore: Replace arguments for write() API")
Fixes: a61072aa ("pstore: Replace arguments for erase() API")
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Marta Lofstedt <marta.lofstedt@intel.com>

Pull networking fixes from David Miller:
 "Mostly netfilter bug fixes in here, but we have some bits elsewhere as
  well.

   1) Don't do SNAT replies for non-NATed connections in IPVS, from
      Julian Anastasov.

   2) Don't delete conntrack helpers while they are still in use, from
      Liping Zhang.

   3) Fix zero padding in xtables's xt_data_to_user(), from Willem de
      Bruijn.

   4) Add proper RCU protection to nf_tables_dump_set() because we
      cannot guarantee that we hold the NFNL_SUBSYS_NFTABLES lock. From
      Liping Zhang.

   5) Initialize rcv_mss in tcp_disconnect(), from Wei Wang.

   6) smsc95xx devices can't handle IPV6 checksums fully, so don't
      advertise support for offloading them. From Nisar Sayed.

   7) Fix out-of-bounds access in __ip6_append_data(), from Eric
      Dumazet.

   8) Make atl2_probe() propagate the error code properly on failures,
      from Alexey Khoroshilov.

   9) arp_target[] in bond_check_params() is used uninitialized. This
      got changes from a global static to a local variable, which is how
      this mistake happened. Fix from Jarod Wilson.

  10) Fix fallout from unnecessary NULL check removal in cls_matchall,
      from Jiri Pirko. This is definitely brown paper bag territory..."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  net: sched: cls_matchall: fix null pointer dereference
  vsock: use new wait API for vsock_stream_sendmsg()
  bonding: fix randomly populated arp target array
  net: Make IP alignment calulations clearer.
  bonding: fix accounting of active ports in 3ad
  net: atheros: atl2: don't return zero on failure path in atl2_probe()
  ipv6: fix out of bound writes in __ip6_append_data()
  bridge: start hello_timer when enabling KERNEL_STP in br_stp_start
  smsc95xx: Support only IPv4 TCP/UDP csum offload
  arp: always override existing neigh entries with gratuitous ARP
  arp: postpone addr_type calculation to as late as possible
  arp: decompose is_garp logic into a separate function
  arp: fixed error in a comment
  tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
  netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT
  ebtables: arpreply: Add the standard target sanity check
  netfilter: nf_tables: revisit chain/object refcounting from elements
  netfilter: nf_tables: missing sanitization in data from userspace
  netfilter: nf_tables: can't assume lock is acquired when dumping set elems
  netfilter: synproxy: fix conntrackd interaction
  ...

Since the head is guaranteed by the check above to be null, the call_rcu
would explode. Remove the previously logically dead code that was made
logically very much alive and kicking.

Fixes: 985538ee ("net/sched: remove redundant null check on head")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As reported by Michal, vsock_stream_sendmsg() could still
sleep at vsock_stream_has_space() after prepare_to_wait():

  vsock_stream_has_space
    vmci_transport_stream_has_space
      vmci_qpair_produce_free_space
        qp_lock
          qp_acquire_queue_mutex
            mutex_lock

Just switch to the new wait API like we did for commit
d9dc8b0f ("net: fix sleeping for sk_wait_event()").
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit dc9c4d0f, the arp_target array moved from a static global
to a local variable. By the nature of static globals, the array used to
be initialized to all 0. At present, it's full of random data, which
that gets interpreted as arp_target values, when none have actually been
specified. Systems end up booting with spew along these lines:

[   32.161783] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.168475] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.175089] 8021q: adding VLAN 0 to HW filter on device lacp0
[   32.193091] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.204892] lacp0: Setting MII monitoring interval to 100
[   32.211071] lacp0: Removing ARP target 216.124.228.17
[   32.216824] lacp0: Removing ARP target 218.160.255.255
[   32.222646] lacp0: Removing ARP target 185.170.136.184
[   32.228496] lacp0: invalid ARP target 255.255.255.255 specified for removal
[   32.236294] lacp0: option arp_ip_target: invalid value (-255.255.255.255)
[   32.243987] lacp0: Removing ARP target 56.125.228.17
[   32.249625] lacp0: Removing ARP target 218.160.255.255
[   32.255432] lacp0: Removing ARP target 15.157.233.184
[   32.261165] lacp0: invalid ARP target 255.255.255.255 specified for removal
[   32.268939] lacp0: option arp_ip_target: invalid value (-255.255.255.255)
[   32.276632] lacp0: Removing ARP target 16.0.0.0
[   32.281755] lacp0: Removing ARP target 218.160.255.255
[   32.287567] lacp0: Removing ARP target 72.125.228.17
[   32.293165] lacp0: Removing ARP target 218.160.255.255
[   32.298970] lacp0: Removing ARP target 8.125.228.17
[   32.304458] lacp0: Removing ARP target 218.160.255.255

None of these were actually specified as ARP targets, and the driver does
seem to clean up the mess okay, but it's rather noisy and confusing, leaks
values to userspace, and the 255.255.255.255 spew shows up even when debug
prints are disabled.

The fix: just zero out arp_target at init time.

While we're in here, init arp_all_targets_value in the right place.

Fixes: dc9c4d0f ("bonding: reduce scope of some global variables")
CC: Mahesh Bandewar <maheshb@google.com>
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: netdev@vger.kernel.org
CC: stable@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

* pm-sleep:
  PM / hibernate: Declare variables as static
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()

* powercap:
  PowerCap: Fix an error code in powercap_register_zone()

* acpi-button:
  Revert "ACPI / button: Remove lid_init_state=method mode"

* acpi-tools:
  tools/power/acpi: Add .gitignore file

* intel_pstate:
  cpufreq: intel_pstate: Document the current behavior and user interface

* pm-cpufreq:
  cpufreq: dbx500: add a Kconfig symbol

* pm-cpufreq-sched:
  cpufreq: schedutil: use now as reference when aggregating shared policy requests

The assignmnet:

	ip_align = strict ? 2 : NET_IP_ALIGN;

in compare_pkt_ptr_alignment() trips up Coverity because we can only
get to this code when strict is true, therefore ip_align will always
be 2 regardless of NET_IP_ALIGN's value.

So just assign directly to '2' and explain the situation in the
comment above.
Reported-by: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As of 7bb11dc9 and 0622cab0, bond slaves in a 3ad bond are not
removed from the aggregator when they are down, and the active slave count
is NOT equal to number of ports in the aggregator, but rather the number
of ports in the aggregator that are still enabled. The sysfs spew for
bonding_show_ad_num_ports() has a comment that says "Show number of active
802.3ad ports.", but it's currently showing total number of ports, both
active and inactive. Remedy it by using the same logic introduced in
0622cab0 in __bond_3ad_get_active_agg_info(), so sysfs, procfs and
netlink all report the number of active ports. Note that this means that
IFLA_BOND_AD_INFO_NUM_PORTS really means NUM_ACTIVE_PORTS instead of
NUM_PORTS, and thus perhaps should be renamed for clarity.

Lightly tested on a dual i40e lacp bond, simulating link downs with an ip
link set dev <slave2> down, was able to produce the state where I could
see both in the same aggregator, but a number of ports count of 1.

MII Status: up
Active Aggregator Info:
        Aggregator ID: 1
        Number of ports: 2 <---
Slave Interface: ens10
MII Status: up <---
Aggregator ID: 1
Slave Interface: ens11
MII Status: up
Aggregator ID: 1

MII Status: up
Active Aggregator Info:
        Aggregator ID: 1
        Number of ports: 1 <---
Slave Interface: ens10
MII Status: down <---
Aggregator ID: 1
Slave Interface: ens11
MII Status: up
Aggregator ID: 1

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If dma mask checks fail in atl2_probe(), it breaks off initialization,
deallocates all resources, but returns zero.

The patch adds proper error code return value and
make error code setup unified.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrey Konovalov and idaifish@gmail.com reported crashes caused by
one skb shared_info being overwritten from __ip6_append_data()

Andrey program lead to following state :

copy -4200 datalen 2000 fraglen 2040
maxfraglen 2040 alloclen 2048 transhdrlen 0 offset 0 fraggap 6200

The skb_copy_and_csum_bits(skb_prev, maxfraglen, data + transhdrlen,
fraggap, 0); is overwriting skb->head and skb_shared_info

Since we apparently detect this rare condition too late, move the
code earlier to even avoid allocating skb and risking crashes.

Once again, many thanks to Andrey and syzkaller team.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: <idaifish@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code to fetch a 64-bit value from user space was entirely buggered,
and has been since the code was merged in early 2016 in commit
b2f68038 ("x86/mm/32: Add support for 64-bit __get_user() on 32-bit
kernels").

Happily the buggered routine is almost certainly entirely unused, since
the normal way to access user space memory is just with the non-inlined
"get_user()", and the inlined version didn't even historically exist.

The normal "get_user()" case is handled by external hand-written asm in
arch/x86/lib/getuser.S that doesn't have either of these issues.

There were two independent bugs in __get_user_asm_u64():

 - it still did the STAC/CLAC user space access marking, even though
   that is now done by the wrapper macros, see commit 11f1a4b9
   ("x86: reorganize SMAP handling in user space accesses").

   This didn't result in a semantic error, it just means that the
   inlined optimized version was hugely less efficient than the
   allegedly slower standard version, since the CLAC/STAC overhead is
   quite high on modern Intel CPU's.

 - the double register %eax/%edx was marked as an output, but the %eax
   part of it was touched early in the asm, and could thus clobber other
   inputs to the asm that gcc didn't expect it to touch.

   In particular, that meant that the generated code could look like
   this:

        mov    (%eax),%eax
        mov    0x4(%eax),%edx

   where the load of %edx obviously was _supposed_ to be from the 32-bit
   word that followed the source of %eax, but because %eax was
   overwritten by the first instruction, the source of %edx was
   basically random garbage.

The fixes are trivial: remove the extraneous STAC/CLAC entries, and mark
the 64-bit output as early-clobber to let gcc know that no inputs should
alias with the output register.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@kernel.org   # v4.8+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Al noticed that unsafe_put_user() had type problems, and fixed them in
commit a7cc722f ("fix unsafe_put_user()"), which made me look more
at those functions.

It turns out that unsafe_get_user() had a type issue too: it limited the
largest size of the type it could handle to "unsigned long".  Which is
fine with the current users, but doesn't match our existing normal
get_user() semantics, which can also handle "u64" even when that does
not fit in a long.

While at it, also clean up the type cast in unsafe_put_user().  We
actually want to just make it an assignment to the expected type of the
pointer, because we actually do want warnings from types that don't
convert silently.  And it makes the code more readable by not having
that one very long and complex line.

[ This patch might become stable material if we ever end up back-porting
  any new users of the unsafe uaccess code, but as things stand now this
  doesn't matter for any current existing uses. ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull misc uaccess fixes from Al Viro:
 "Fix for unsafe_put_user() (no callers currently in mainline, but
  anyone starting to use it will step into that) + alpha osf_wait4()
  infoleak fix"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  osf_wait4(): fix infoleak
  fix unsafe_put_user()

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix:

  Prevent idle task from ever being preempted. That makes sure that
  synchronize_rcu_tasks() which is ignoring idle task does not pretend
  that no task is stuck in preempted state. If that happens and idle was
  preempted on a ftrace trampoline the machine crashes due to
  inconsistent state"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Call __schedule() from do_idle() without enabling preemption

Pull irq fixes from Thomas Gleixner:
 "A set of small fixes for the irq subsystem:

   - Cure a data ordering problem with chained interrupts

   - Three small fixlets for the mbigen irq chip"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Fix chained interrupt data ordering
  irqchip/mbigen: Fix the clear register offset calculation
  irqchip/mbigen: Fix potential NULL dereferencing
  irqchip/mbigen: Fix memory mapping code

Since commit 76b91c32 ("bridge: stp: when using userspace stp stop
kernel hello and hold timers"), bridge would not start hello_timer if
stp_enabled is not KERNEL_STP when br_dev_open.

The problem is even if users set stp_enabled with KERNEL_STP later,
the timer will still not be started. It causes that KERNEL_STP can
not really work. Users have to re-ifup the bridge to avoid this.

This patch is to fix it by starting br->hello_timer when enabling
KERNEL_STP in br_stp_start.

As an improvement, it's also to start hello_timer again only when
br->stp_enabled is KERNEL_STP in br_hello_timer_expired, there is
no reason to start the timer again when it's NO_STP.

Fixes: 76b91c32 ("bridge: stp: when using userspace stp stop kernel hello and hold timers")
Reported-by: Haidong Li <haili@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Ivan Vecera <cera@cera.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

When TX checksum offload is used, if the computed checksum is 0 the
LAN95xx device do not alter the checksum to 0xffff.  In the case of ipv4
UDP checksum, it indicates to receiver that no checksum is calculated.
Under ipv6, UDP checksum yields a result of zero must be changed to
0xffff. Hence disabling checksum offload for ipv6 packets.
Signed-off-by: Nisar Sayed <Nisar.Sayed@microchip.com>
Reported-by: popcorn mix <popcornmix@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ihar Hrachyshka says:

====================
arp: always override existing neigh entries with gratuitous ARP

This patchset is spurred by discussion started at
https://patchwork.ozlabs.org/patch/760372/ where we figured that there is no
real reason for enforcing override by gratuitous ARP packets only when
arp_accept is 1. Same should happen when it's 0 (the default value).

changelog v2: handled review comments by Julian Anastasov
- fixed a mistake in a comment;
- postponed addr_type calculation to as late as possible.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, when arp_accept is 1, we always override existing neigh
entries with incoming gratuitous ARP replies. Otherwise, we override
them only if new replies satisfy _locktime_ conditional (packets arrive
not earlier than _locktime_ seconds since the last update to the neigh
entry).

The idea behind locktime is to pick the very first (=> close) reply
received in a unicast burst when ARP proxies are used. This helps to
avoid ARP thrashing where Linux would switch back and forth from one
proxy to another.

This logic has nothing to do with gratuitous ARP replies that are
generally not aligned in time when multiple IP address carriers send
them into network.

This patch enforces overriding of existing neigh entries by all incoming
gratuitous ARP packets, irrespective of their time of arrival. This will
make the kernel honour all incoming gratuitous ARP packets.
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The addr_type retrieval can be costly, so it's worth trying to avoid its
calculation as much as possible. This patch makes it calculated only
for gratuitous ARP packets. This is especially important since later we
may want to move is_garp calculation outside of arp_accept block, at
which point the costly operation will be executed for all setups.

The patch is the result of a discussion in net-dev:
http://marc.info/?l=linux-netdev&m=149506354216994Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code is quite involving already to earn a separate function for
itself. If anything, it helps arp_process readability.
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

the is_garp code deals just with gratuitous ARP packets, not every
unsolicited packet.

This patch is a result of a discussion in netdev:
http://marc.info/?l=linux-netdev&m=149506354216994Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When tcp_disconnect() is called, inet_csk_delack_init() sets
icsk->icsk_ack.rcv_mss to 0.
This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() =>
__tcp_select_window() call path to have division by 0 issue.
So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0.
Reported-by: Andrey Konovalov  <andreyknvl@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

failing sys_wait4() won't fill struct rusage...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>