The sched_entity::avg collides with read-mostly sched_entity data.

The perf c2c tool showed many read HITM accesses across
many CPUs for sched_entity's cfs_rq and my_q, while having
at the same time tons of stores for avg.

After placing sched_entity::avg into separate cache line,
the perf bench sched pipe showed around 20 seconds speedup.

NOTE I cut out all perf events except for cycles and
instructions from following output.

Before:
  $ perf stat -r 5 perf bench sched pipe -l 10000000
  # Running 'sched/pipe' benchmark:
  # Executed 10000000 pipe operations between two processes

       Total time: 270.348 [sec]

        27.034805 usecs/op
            36989 ops/sec
   ...

     245,537,074,035      cycles                    #    1.433 GHz
     187,264,548,519      instructions              #    0.77  insns per cycle

       272.653840535 seconds time elapsed           ( +-  1.31% )

After:
  $ perf stat -r 5 perf bench sched pipe -l 10000000
  # Running 'sched/pipe' benchmark:
  # Executed 10000000 pipe operations between two processes

       Total time: 251.076 [sec]

        25.107678 usecs/op
            39828 ops/sec
  ...

     244,573,513,928      cycles                    #    1.572 GHz
     187,409,641,157      instructions              #    0.76  insns per cycle

       251.679315188 seconds time elapsed           ( +-  0.31% )
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449606239-28602-1-git-send-email-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) checks whether MEMBER
is last member of TYPE by evaluating:

  offsetof(TYPE::MEMBER) + sizeof(TYPE::MEMBER) == sizeof(TYPE)

and ensuring TYPE::MEMBER is the last member of the TYPE.

This condition breaks on structs that are padded to be
aligned. This patch ensures the TYPE alignment is taken
into account.

This bug was revealed after adding cacheline alignment into
struct sched_entity, which broke task_struct::thread check:

  CHECK_MEMBER_AT_END_OF(struct task_struct, thread);
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1450707930-3445-1-git-send-email-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

earliest_dl.next should cache deadline of the earliest ready task that
is also enqueued in the pushable rbtree, as pull algorithm uses this
information to find candidates for migration: if the earliest_dl.next
deadline of source rq is earlier than the earliest_dl.curr deadline of
destination rq, the task from the source rq can be pulled.

However, current implementation only guarantees that earliest_dl.next is
the deadline of the next ready task instead of the next pushable task;
which will result in potentially holding both rqs' lock and find nothing
to migrate because of affinity constraints. In addition, current logic
doesn't update the next candidate for pushing in pick_next_task_dl(),
even if the running task is never eligible.

This patch fixes both problems by updating earliest_dl.next when
pushable dl task is enqueued/dequeued, similar to what we already do for
RT.
Tested-by: NLuca Abeni <luca.abeni@unitn.it>
Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NJuri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449135730-27202-1-git-send-email-wanpeng.li@hotmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

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

In the following commit:

  76751049 ("sched: Implement lockless wake-queues")

we gained lockless wake-queues.

The -RT kernel managed to lockup itself with those. There could be multiple
attempts for task X to enqueue it for a wakeup _even_ if task X is already
running.

The reason is that task X could be runnable but not yet on CPU. The the
task performing the wakeup did not leave the CPU it could performe
multiple wakeups.

With the proper timming task X could be running and enqueued for a
wakeup. If this happens while X is performing a fork() then its its
child will have a !NULL `wake_q` member copied.

This is not a problem as long as the child task does not participate in
lockless wakeups :)
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 76751049 ("sched: Implement lockless wake-queues")
Link: http://lkml.kernel.org/r/20151221171710.GA5499@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some of the sched bitfieds (notably sched_reset_on_fork) can be set
on other than current, this can cause the r-m-w to race with other
updates.

Since all the sched bits are serialized by scheduler locks, pull them
in a separate word.
Reported-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: hannes@cmpxchg.org
Cc: mhocko@kernel.org
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/20151125150207.GM11639@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Our global init task can have sub-threads, so ->pid check is not reliable
enough for is_global_init(), we need to check tgid instead. This has been
spotted by Oleg and a fix was proposed by Richard a long time ago (see the
link below).

Oleg wrote:

  : Because is_global_init() is only true for the main thread of /sbin/init.
  :
  : Just look at oom_unkillable_task(). It tries to not kill init. But, say,
  : select_bad_process() can happily find a sub-thread of is_global_init()
  : and still kill it.

I recently hit the problem in question; re-sending the patch (to the
best of my knowledge it has never been submitted) with updated function
comment. Credit goes to Oleg and Richard.
Suggested-by: NRichard Guy Briggs <rgb@redhat.com>
Reported-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric W . Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge E . Hallyn <serge.hallyn@ubuntu.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://www.redhat.com/archives/linux-audit/2013-December/msg00086.htmlSigned-off-by: NIngo Molnar <mingo@kernel.org>

Make 'r' 64-bit type to avoid overflow in 'r * LOAD_AVG_MAX'
on 32-bit systems:

	UBSAN: Undefined behaviour in kernel/sched/fair.c:2785:18
	signed integer overflow:
	87950 * 47742 cannot be represented in type 'int'

The most likely effect of this bug are bad load average numbers
resulting in weird scheduling. It's also likely that this can
persist for a longer time - until the system goes idle for
a long time so that all load avg numbers get reset.

[ This is the CFS load average metric, not the procfs output, which
  is separate. ]
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 9d89c257 ("sched/fair: Rewrite runnable load and utilization average tracking")
Link: http://lkml.kernel.org/r/1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com
[ Improved the changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull tracing fixes from Steven Rostedt:
 "Two more fixes:

  1. The recordmcount change had an output that used sprintf()
     (incorrectly) when it should have been a fprintf() to stderr.

  2. The printk_formats file could crash if someone added a
     trace_printk() in the core kernel, and also added one in a module.
     This does not affect production kernels.  Only kernels where
     developers add trace_printk() for debugging can crash"

* tag 'trace-v4.4-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix setting of start_index in find_next()
  ftrace/scripts: Fix incorrect use of sprintf in recordmcount

Pull tile bugfix from Chris Metcalf:
 "This fixes a bug that Sudip's buildbot found for tilepro allmodconfig.

  I've tagged it for stable only back to 3.19, which was when most of
  the other affected architectures added their support for working
  around this issue"

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: provide CONFIG_PAGE_SIZE_64KB etc for tilepro

This allows the build system to know that it can't attempt to
configure the Lustre virtual block device, for example, when tilepro
is using 64KB pages (as it does by default).  The tilegx build
already provided those symbols.

Previously we required that the tilepro hypervisor be rebuilt with
a different hardcoded page size in its headers, and then Linux be
rebuilt using the updated hypervisor header.  Now we allow each of
the hypervisor and Linux to be built independently.  We still check
at boot time to ensure that the page size provided by the hypervisor
matches what Linux expects.
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>
Cc: stable@vger.kernel.org [3.19+]

When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel
panic at t_show.

general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 2957 Comm: sh Tainted: G W  O 3.14.55-x86_64-01062-gd4acdc7 #2
RIP: 0010:[<ffffffff811375b2>]
 [<ffffffff811375b2>] t_show+0x22/0xe0
RSP: 0000:ffff88002b4ebe80  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1
RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec
R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0
R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570
FS:  0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0
Call Trace:
 [<ffffffff811dc076>] seq_read+0x2f6/0x3e0
 [<ffffffff811b749b>] vfs_read+0x9b/0x160
 [<ffffffff811b7f69>] SyS_read+0x49/0xb0
 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13
 ---[ end trace 5bd9eb630614861e ]---
Kernel panic - not syncing: Fatal exception

When the first time find_next calls find_next_mod_format, it should
iterate the trace_bprintk_fmt_list to find the first print format of
the module. However in current code, start_index is smaller than *pos
at first, and code will not iterate the list. Latter container_of will
get the wrong address with former v, which will cause mod_fmt be a
meaningless object and so is the returned mod_fmt->fmt.

This patch will fix it by correcting the start_index. After fixed,
when the first time calls find_next_mod_format, start_index will be
equal to *pos, and code will iterate the trace_bprintk_fmt_list to
get the right module printk format, so is the returned mod_fmt->fmt.

Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com

Cc: stable@vger.kernel.org # 3.12+
Fixes: 102c9323 "tracing: Add __tracepoint_string() to export string pointers"
Signed-off-by: NQiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Fix build warning:

scripts/recordmcount.c:589:4: warning: format not a string
literal and no format arguments [-Wformat-security]
    sprintf("%s: failed\n", file);

Fixes: a50bd439 ("ftrace/scripts: Have recordmcount copy the object file")
Link: http://lkml.kernel.org/r/1451516801-16951-1-git-send-email-colin.king@canonical.com

Cc: Li Bin <huawei.libin@huawei.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org # 2.6.37+
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Pull MIPS build fix from Ralf Baechle:
 "Fix a makefile issue resulting in build breakage with older binutils.

  This has sat in -next for a few days, testers and buildbot are happy
  with it, too though if you are going for another -rc that'd certainly
  help ironing out a few more issues"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: VDSO: Fix build error with binutils 2.24 and earlier

Pull i915 drm fixes from Jani Nikula:
 "Two display fixes still for v4.4.

  The new year's resolution is to start using signed tags per Linus'
  request.  This one is still unsigned; I want to fix this up in our
  maintainer scripts instead of doing it one-off"

* tag 'drm-intel-fixes-2016-01-02' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: increase the tries for HDMI hotplug live status checking
  drm/i915: Unbreak check_digital_port_conflicts()

Pull PCI bugfix from Bjorn Helgaas:
 "Here's another fix for v4.4.

  This fixes 32-bit config reads for the HiSilicon driver.  Obviously
  the driver is completely broken without this fix (apparently it
  actually was tested internally, but got broken somehow in the process
  of upstreaming it).

  Summary:

  HiSilicon host bridge driver
    Fix 32-bit config reads (Dongdong Liu)"

* tag 'pci-v4.4-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: hisi: Fix hisi_pcie_cfg_read() 32-bit reads

Pull sparc fixes from David Miller:
 "Just some missing syscall wire ups"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Wire up mlock2 system call.
  sparc: Add all necessary direct socket system calls.

Pull networking fixes from David Miller:

 1) Prevent XFRM per-cpu counter updates for one namespace from being
    applied to another namespace.  Fix from DanS treetman.

 2) Fix RCU de-reference in iwl_mvm_get_key_sta_id(), from Johannes
    Berg.

 3) Remove ethernet header assumption in nft_do_chain_netdev(), from
    Pablo Neira Ayuso.

 4) Fix cpsw PHY ident with multiple slaves and fixed-phy, from Pascal
    Speck.

 5) Fix use after free in sixpack_close and mkiss_close.

 6) Fix VXLAN fw assertion on bnx2x, from Yuval Mintz.

 7) natsemi doesn't check for DMA mapping errors, from Alexey
    Khoroshilov.

 8) Fix inverted test in ip6addrlbl_get(), from ANdrey Ryabinin.

 9) Missing initialization of needed_headroom in geneve tunnel driver,
    from Paolo Abeni.

10) Fix conntrack template leak in openvswitch, from Joe Stringer.

11) Mission initialization of wq->flags in sock_alloc_inode(), from
    Nicolai Stange.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits)
  sctp: sctp should release assoc when sctp_make_abort_user return NULL in sctp_close
  net, socket, socket_wq: fix missing initialization of flags
  drivers: net: cpsw: fix error return code
  openvswitch: Fix template leak in error cases.
  sctp: label accepted/peeled off sockets
  sctp: use GFP_USER for user-controlled kmalloc
  qlcnic: fix a loop exit condition better
  net: cdc_ncm: avoid changing RX/TX buffers on MTU changes
  geneve: initialize needed_headroom
  ipv6: honor ifindex in case we receive ll addresses in router advertisements
  addrconf: always initialize sysctl table data
  ipv6/addrlabel: fix ip6addrlbl_get()
  switchdev: bridge: Pass ageing time as clock_t instead of jiffies
  sh_eth: fix 16-bit descriptor field access endianness too
  veth: don’t modify ip_summed; doing so treats packets with bad checksums as good.
  net: usb: cdc_ncm: Adding Dell DW5813 LTE AT&T Mobile Broadband Card
  net: usb: cdc_ncm: Adding Dell DW5812 LTE Verizon Mobile Broadband Card
  natsemi: add checks for dma mapping errors
  rhashtable: Kill harmless RCU warning in rhashtable_walk_init
  openvswitch: correct encoding of set tunnel action attributes
  ...

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

The GLIBC folks would like to eliminate socketcall support
eventually, and this makes sense regardless so wire them
all up.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In sctp_close, sctp_make_abort_user may return NULL because of memory
allocation failure. If this happens, it will bypass any state change
and never free the assoc. The assoc has no chance to be freed and it
will be kept in memory with the state it had even after the socket is
closed by sctp_close().

So if sctp_make_abort_user fails to allocate memory, we should abort
the asoc via sctp_primitive_ABORT as well. Just like the annotation in
sctp_sf_cookie_wait_prm_abort and sctp_sf_do_9_1_prm_abort said,
"Even if we can't send the ABORT due to low memory delete the TCB.
This is a departure from our typical NOMEM handling".

But then the chunk is NULL (low memory) and the SCTP_CMD_REPLY cmd would
dereference the chunk pointer, and system crash. So we should add
SCTP_CMD_REPLY cmd only when the chunk is not NULL, just like other
places where it adds SCTP_CMD_REPLY cmd.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'wireless-drivers-for-davem-2015-12-28' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers

Kalle Valo says:

====================
iwlwifi

* don't load firmware that won't exist for 7260
* fix RCU splat
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit ceb5d58b ("net: fix sock_wake_async() rcu protection") from
the current 4.4 release cycle introduced a new flags member in
struct socket_wq and moved SOCKWQ_ASYNC_NOSPACE and SOCKWQ_ASYNC_WAITDATA
from struct socket's flags member into that new place.

Unfortunately, the new flags field is never initialized properly, at least
not for the struct socket_wq instance created in sock_alloc_inode().

One particular issue I encountered because of this is that my GNU Emacs
failed to draw anything on my desktop -- i.e. what I got is a transparent
window, including the title bar. Bisection lead to the commit mentioned
above and further investigation by means of strace told me that Emacs
is indeed speaking to my Xorg through an O_ASYNC AF_UNIX socket. This is
reproducible 100% of times and the fact that properly initializing the
struct socket_wq ->flags fixes the issue leads me to the conclusion that
somehow SOCKWQ_ASYNC_WAITDATA got set in the uninitialized ->flags,
preventing my Emacs from receiving any SIGIO's due to data becoming
available and it got stuck.

Make sock_alloc_inode() set the newly created struct socket_wq's ->flags
member to zero.

Fixes: ceb5d58b ("net: fix sock_wake_async() rcu protection")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull block fixes from Jens Axboe:
 "Make the block layer great again.

  Basically three amazing fixes in this pull request, split into 4
  patches.  Believe me, they should go into 4.4.  Two of them fix a
  regression, the third and last fixes an easy-to-trigger bug.

   - Fix a bad irq enable through null_blk, for queue_mode=1 and using
     timer completions.  Add a block helper to restart a queue
     asynchronously, and use that from null_blk.  From me.

   - Fix a performance issue in NVMe.  Some devices (Intel Pxxxx) expose
     a stripe boundary, and performance suffers if we cross it.  We took
     that into account for merging, but not for the newer splitting
     code.  Fix from Keith.

   - Fix a kernel oops in lightnvm with multiple channels.  From Matias"

* 'for-linus' of git://git.kernel.dk/linux-block:
  lightnvm: wrong offset in bad blk lun calculation
  null_blk: use async queue restart helper
  block: add blk_start_queue_async()
  block: Split bios on chunk boundaries

The total delay of HDMI hotplug detecting with 30ms is sometimes not
enoughtfor HDMI live status up with specific HDMI monitors in BSW platform.

After doing experiments for following monitors, it needs 80ms at least
for those worst cases.

Lenovo L246 1xwA (4 failed, necessary hot-plug delay: 58/40/60/40ms)
Philips HH2AP (9 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms)
BENQ ET-0035-N (6 failed, necessary hot-plug delay: 60/50/50/80/80/40ms)
DELL U2713HM (2 failed, necessary hot-plug delay: 58/59ms)
HP HP-LP2475w (5 failed, necessary hot-plug delay: 70/50/40/60/40ms)

It looks like 70-80 ms is BSW platform needs in some bad cases of the
monitors at this end (8 times delay at most). Keep less than 100ms for
HDCP pulse HPD low (with at least 100ms) to respond a plug out.
Reviewed-by: NCooper Chiou <cooper.chiou@intel.com>
Tested-by: NGary Wang <gary.c.wang@intel.com>
Cc: Gavin Hindman <gavin.hindman@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: NGary Wang <gary.c.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450858295-12804-1-git-send-email-gary.c.wang@intel.comTested-by: NShobhit Kumar <shobhit.kumar@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 237ed86c ("drm/i915: Check live status before reading edid")
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit f8d03ea0)
[Jani: undo the file mode change of the original commit]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Merge misc fixes from Andrew Morton:
 "9 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/vmstat: fix overflow in mod_zone_page_state()
  ocfs2/dlm: clear migration_pending when migration target goes down
  mm/memory_hotplug.c: check for missing sections in test_pages_in_a_zone()
  ocfs2: fix flock panic issue
  m32r: add io*_rep helpers
  m32r: fix build failure
  arch/x86/xen/suspend.c: include xen/xen.h
  mm: memcontrol: fix possible memcg leak due to interrupted reclaim
  ocfs2: fix BUG when calculate new backup super

Pull vfs fix from Al Viro:
 "Fix for 3.15 breakage of fcntl64() in arm OABI compat.  -stable
  fodder"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [PATCH] arm: fix handling of F_OFD_... in oabi_fcntl64()

mod_zone_page_state() takes a "delta" integer argument.  delta contains
the number of pages that should be added or subtracted from a struct
zone's vm_stat field.

If a zone is larger than 8TB this will cause overflows.  E.g.  for a
zone with a size slightly larger than 8TB the line

    mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);

in mm/page_alloc.c:free_area_init_core() will result in a negative
result for the NR_ALLOC_BATCH entry within the zone's vm_stat, since 8TB
contain 0x8xxxxxxx pages which will be sign extended to a negative
value.

Fix this by changing the delta argument to long type.

This could fix an early boot problem seen on s390, where we have a 9TB
system with only one node.  ZONE_DMA contains 2GB and ZONE_NORMAL the
rest.  The system is trying to allocate a GFP_DMA page but ZONE_DMA is
completely empty, so it tries to reclaim pages in an endless loop.

This was seen on a heavily patched 3.10 kernel.  One possible
explaination seem to be the overflows caused by mod_zone_page_state().
Unfortunately I did not have the chance to verify that this patch
actually fixes the problem, since I don't have access to the system
right now.  However the overflow problem does exist anyway.

Given the description that a system with slightly less than 8TB does
work, this seems to be a candidate for the observed problem.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have found a BUG on res->migration_pending when migrating lock
resources.  The situation is as follows.

dlm_mark_lockres_migration
  res->migration_pending = 1;
  __dlm_lockres_reserve_ast
  dlm_lockres_release_ast returns with res->migration_pending remains
      because other threads reserve asts
  wait dlm_migration_can_proceed returns 1
  >>>>>>> o2hb found that target goes down and remove target
          from domain_map
  dlm_migration_can_proceed returns 1
  dlm_mark_lockres_migrating returns -ESHOTDOWN with
      res->migration_pending still remains.

When reentering dlm_mark_lockres_migrating(), it will trigger the BUG_ON
with res->migration_pending.  So clear migration_pending when target is
down.
Signed-off-by: NJiufei Xue <xuejiufei@huawei.com>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

test_pages_in_a_zone() does not account for the possibility of missing
sections in the given pfn range.  pfn_valid_within always returns 1 when
CONFIG_HOLES_IN_ZONE is not set, allowing invalid pfns from missing
sections to pass the test, leading to a kernel oops.

Wrap an additional pfn loop with PAGES_PER_SECTION granularity to check
for missing sections before proceeding into the zone-check code.

This also prevents a crash from offlining memory devices with missing
sections.  Despite this, it may be a good idea to keep the related patch
'[PATCH 3/3] drivers: memory: prohibit offlining of memory blocks with
missing sections' because missing sections in a memory block may lead to
other problems not covered by the scope of this fix.
Signed-off-by: NAndrew Banman <abanman@sgi.com>
Acked-by: NAlex Thorlton <athorlton@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 4f656367 ("Move locks API users to locks_lock_inode_wait()")
move flock/posix lock indentify code to locks_lock_inode_wait(), but
missed to set fl_flags to FL_FLOCK which caused the following kernel
panic on 4.4.0_rc5.

  kernel BUG at fs/locks.c:1895!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: ocfs2(O) ocfs2_dlmfs(O) ocfs2_stack_o2cb(O) ocfs2_dlm(O) ocfs2_nodemanager(O) ocfs2_stackglue(O) iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi xen_kbdfront xen_netfront xen_fbfront xen_blkfront
  CPU: 0 PID: 20268 Comm: flock_unit_test Tainted: G           O    4.4.0-rc5-next-20151217 #1
  Hardware name: Xen HVM domU, BIOS 4.3.1OVM 05/14/2014
  task: ffff88007b3672c0 ti: ffff880028b58000 task.ti: ffff880028b58000
  RIP: locks_lock_inode_wait+0x2e/0x160
  Call Trace:
    ocfs2_do_flock+0x91/0x160 [ocfs2]
    ocfs2_flock+0x76/0xd0 [ocfs2]
    SyS_flock+0x10f/0x1a0
    entry_SYSCALL_64_fastpath+0x12/0x71
  Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 48 81 ec 88 00 00 00 8b 46 40 83 e0 03 83 f8 01 0f 84 ad 00 00 00 83 f8 02 74 04 <0f> 0b eb fe 4c 8d ad 60 ff ff ff 4c 8d 7b 58 e8 0e 8e 73 00 4d
  RIP  locks_lock_inode_wait+0x2e/0x160
   RSP <ffff880028b5bce8>
  ---[ end trace dfca74ec9b5b274c ]---

Fixes: 4f656367 ("Move locks API users to locks_lock_inode_wait()")
Signed-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

m32r allmodconfig was failing with the error:

  error: implicit declaration of function 'read'

On checking io.h it turned out that 'read' is not defined but 'readb' is
defined and 'ioread8' will then obviously mean 'readb'.

At the same time some of the helper functions ioreadN_rep() and
iowriteN_rep() were missing which also led to the build failure.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

m32r allmodconfig is failing with:

  In file included from ../include/linux/kvm_para.h:4:0,
                   from ../kernel/watchdog.c:26:
  ../include/uapi/linux/kvm_para.h:30:26: fatal error: asm/kvm_para.h: No such file or directory

kvm_para.h was not included in the build.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the build warning:

  arch/x86/xen/suspend.c: In function 'xen_arch_pre_suspend':
  arch/x86/xen/suspend.c:70:9: error: implicit declaration of function 'xen_pv_domain' [-Werror=implicit-function-declaration]
          if (xen_pv_domain())
              ^
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Memory cgroup reclaim can be interrupted with mem_cgroup_iter_break()
once enough pages have been reclaimed, in which case, in contrast to a
full round-trip over a cgroup sub-tree, the current position stored in
mem_cgroup_reclaim_iter of the target cgroup does not get invalidated
and so is left holding the reference to the last scanned cgroup.  If the
target cgroup does not get scanned again (we might have just reclaimed
the last page or all processes might exit and free their memory
voluntary), we will leak it, because there is nobody to put the
reference held by the iterator.

The problem is easy to reproduce by running the following command
sequence in a loop:

    mkdir /sys/fs/cgroup/memory/test
    echo 100M > /sys/fs/cgroup/memory/test/memory.limit_in_bytes
    echo $$ > /sys/fs/cgroup/memory/test/cgroup.procs
    memhog 150M
    echo $$ > /sys/fs/cgroup/memory/cgroup.procs
    rmdir test

The cgroups generated by it will never get freed.

This patch fixes this issue by making mem_cgroup_iter avoid taking
reference to the current position.  In order not to hit use-after-free
bug while running reclaim in parallel with cgroup deletion, we make use
of ->css_released cgroup callback to clear references to the dying
cgroup in all reclaim iterators that might refer to it.  This callback
is called right before scheduling rcu work which will free css, so if we
access iter->position from rcu read section, we might be sure it won't
go away under us.

[hannes@cmpxchg.org: clean up css ref handling]
Fixes: 5ac8fb31 ("mm: memcontrol: convert reclaim iterator to simple css refcounting")
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.19+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When resizing, it firstly extends the last gd.  Once it should backup
super in the gd, it calculates new backup super and update the
corresponding value.

But it currently doesn't consider the situation that the backup super is
already done.  And in this case, it still sets the bit in gd bitmap and
then decrease from bg_free_bits_count, which leads to a corrupted gd and
trigger the BUG in ocfs2_block_group_set_bits:

    BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);

So check whether the backup super is done and then do the updates.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Reviewed-by: NJiufei Xue <xuejiufei@huawei.com>
Reviewed-by: NYiwen Jiang <jiangyiwen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 2a037f31 ("MIPS: VDSO: Fix build error") tries to fix a build
error seen with binutils 2.24 and earlier. However, the fix does not work,
and again results in the already known build errors if the kernel is built
with an earlier version of binutils.

CC      arch/mips/vdso/gettimeofday.o
/tmp/ccnOVbHT.s: Assembler messages:
/tmp/ccnOVbHT.s:50: Error: can't resolve `_start' {*UND* section} - `L0 {.text section}
/tmp/ccnOVbHT.s:374: Error: can't resolve `_start' {*UND* section} - `L0 {.text section}
scripts/Makefile.build:258: recipe for target 'arch/mips/vdso/gettimeofday.o' failed
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1

Fixes: 2a037f31 ("MIPS: VDSO: Fix build error")
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11926/Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Propagate the return value of platform_get_irq on failure.

A simplified version of the semantic match that finds the two cases where
no error code is returned at all is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 5b48bb8506c5 ("openvswitch: Fix helper reference leak") fixed a
reference leak on helper objects, but inadvertently introduced a leak on
the ct template.

Previously, ct_info.ct->general.use was initialized to 0 by
nf_ct_tmpl_alloc() and only incremented when ovs_ct_copy_action()
returned successful. If an error occurred while adding the helper or
adding the action to the actions buffer, the __ovs_ct_free_action()
cleanup would use nf_ct_put() to free the entry; However, this relies on
atomic_dec_and_test(ct_info.ct->general.use). This reference must be
incremented first, or nf_ct_put() will never free it.

Fix the issue by acquiring a reference to the template immediately after
allocation.

Fixes: cae3a262 ("openvswitch: Allow attaching helpers to ct action")
Fixes: 5b48bb8506c5 ("openvswitch: Fix helper reference leak")
Signed-off-by: NJoe Stringer <joe@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>