Andrei Vagin pointed out that time to executue propagate_umount can go
non-linear (and take a ludicrious amount of time) when the mount
propogation trees of the mounts to be unmunted by a lazy unmount
overlap.

Make the walk of the mount propagation trees nearly linear by
remembering which mounts have already been visited, allowing
subsequent walks to detect when walking a mount propgation tree or a
subtree of a mount propgation tree would be duplicate work and to skip
them entirely.

Walk the list of mounts whose propgatation trees need to be traversed
from the mount highest in the mount tree to mounts lower in the mount
tree so that odds are higher that the code will walk the largest trees
first, allowing later tree walks to be skipped entirely.

Add cleanup_umount_visitation to remover the code's memory of which
mounts have been visited.

Add the functions last_slave and skip_propagation_subtree to allow
skipping appropriate parts of the mount propagation tree without
needing to change the logic of the rest of the code.

A script to generate overlapping mount propagation trees:

$ cat runs.h
set -e
mount -t tmpfs zdtm /mnt
mkdir -p /mnt/1 /mnt/2
mount -t tmpfs zdtm /mnt/1
mount --make-shared /mnt/1
mkdir /mnt/1/1

iteration=10
if [ -n "$1" ] ; then
	iteration=$1
fi

for i in $(seq $iteration); do
	mount --bind /mnt/1/1 /mnt/1/1
done

mount --rbind /mnt/1 /mnt/2

TIMEFORMAT='%Rs'
nr=$(( ( 2 ** ( $iteration + 1 ) ) + 1 ))
echo -n "umount -l /mnt/1 -> $nr        "
time umount -l /mnt/1

nr=$(cat /proc/self/mountinfo | grep zdtm | wc -l )
time umount -l /mnt/2

$ for i in $(seq 9 19); do echo $i; unshare -Urm bash ./run.sh $i; done

Here are the performance numbers with and without the patch:

     mhash |  8192   |  8192  | 1048576 | 1048576
    mounts | before  | after  |  before | after
    ------------------------------------------------
      1025 |  0.040s | 0.016s |  0.038s | 0.019s
      2049 |  0.094s | 0.017s |  0.080s | 0.018s
      4097 |  0.243s | 0.019s |  0.206s | 0.023s
      8193 |  1.202s | 0.028s |  1.562s | 0.032s
     16385 |  9.635s | 0.036s |  9.952s | 0.041s
     32769 | 60.928s | 0.063s | 44.321s | 0.064s
     65537 |         | 0.097s |         | 0.097s
    131073 |         | 0.233s |         | 0.176s
    262145 |         | 0.653s |         | 0.344s
    524289 |         | 2.305s |         | 0.735s
   1048577 |         | 7.107s |         | 2.603s

Andrei Vagin reports fixing the performance problem is part of the
work to fix CVE-2016-6213.

Cc: stable@vger.kernel.org
Fixes: a05964f3 ("[PATCH] shared mounts handling: umount")
Reported-by: Andrei Vagin <avagin@openvz.org>
Reviewed-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

While investigating some poor umount performance I realized that in
the case of overlapping mount trees where some of the mounts are locked
the code has been failing to unmount all of the mounts it should
have been unmounting.

This failure to unmount all of the necessary
mounts can be reproduced with:

$ cat locked_mounts_test.sh

mount -t tmpfs test-base /mnt
mount --make-shared /mnt
mkdir -p /mnt/b

mount -t tmpfs test1 /mnt/b
mount --make-shared /mnt/b
mkdir -p /mnt/b/10

mount -t tmpfs test2 /mnt/b/10
mount --make-shared /mnt/b/10
mkdir -p /mnt/b/10/20

mount --rbind /mnt/b /mnt/b/10/20

unshare -Urm --propagation unchaged /bin/sh -c 'sleep 5; if [ $(grep test /proc/self/mountinfo | wc -l) -eq 1 ] ; then echo SUCCESS ; else echo FAILURE ; fi'
sleep 1
umount -l /mnt/b
wait %%

$ unshare -Urm ./locked_mounts_test.sh

This failure is corrected by removing the prepass that marks mounts
that may be umounted.

A first pass is added that umounts mounts if possible and if not sets
mount mark if they could be unmounted if they weren't locked and adds
them to a list to umount possibilities.  This first pass reconsiders
the mounts parent if it is on the list of umount possibilities, ensuring
that information of umoutability will pass from child to mount parent.

A second pass then walks through all mounts that are umounted and processes
their children unmounting them or marking them for reparenting.

A last pass cleans up the state on the mounts that could not be umounted
and if applicable reparents them to their first parent that remained
mounted.

While a bit longer than the old code this code is much more robust
as it allows information to flow up from the leaves and down
from the trunk making the order in which mounts are encountered
in the umount propgation tree irrelevant.

Cc: stable@vger.kernel.org
Fixes: 0c56fe31 ("mnt: Don't propagate unmounts to locked mounts")
Reviewed-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

It was observed that in some pathlogical cases that the current code
does not unmount everything it should.  After investigation it
was determined that the issue is that mnt_change_mntpoint can
can change which mounts are available to be unmounted during mount
propagation which is wrong.

The trivial reproducer is:
$ cat ./pathological.sh

mount -t tmpfs test-base /mnt
cd /mnt
mkdir 1 2 1/1
mount --bind 1 1
mount --make-shared 1
mount --bind 1 2
mount --bind 1/1 1/1
mount --bind 1/1 1/1
echo
grep test-base /proc/self/mountinfo
umount 1/1
echo
grep test-base /proc/self/mountinfo

$ unshare -Urm ./pathological.sh

The expected output looks like:
46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000
47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000

46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000
47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000

The output without the fix looks like:
46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000
47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000

46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000
47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000
52 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000

That last mount in the output was in the propgation tree to be unmounted but
was missed because the mnt_change_mountpoint changed it's parent before the walk
through the mount propagation tree observed it.

Cc: stable@vger.kernel.org
Fixes: 1064f874 ("mnt: Tuck mounts under others instead of creating shadow/side mounts.")
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

When I introduced ptracer_cred I failed to consider the weirdness of
fork where the task_struct copies the old value by default.  This
winds up leaving ptracer_cred set even when a process forks and
the child process does not wind up being ptraced.

Because ptracer_cred is not set on non-ptraced processes whose
parents were ptraced this has broken the ability of the enlightenment
window manager to start setuid children.

Fix this by properly initializing ptracer_cred in ptrace_init_task

This must be done with a little bit of care to preserve the current value
of ptracer_cred when ptrace carries through fork.  Re-reading the
ptracer_cred from the ptracing process at this point is inconsistent
with how PT_PTRACE_CAP has been maintained all of these years.
Tested-by: Takashi Iwai <tiwai@suse.de>
Fixes: 64b875f7 ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Imagine we have a pid namespace and a task from its parent's pid_ns,
which made setns() to the pid namespace. The task is doing fork(),
while the pid namespace's child reaper is dying. We have the race
between them:

Task from parent pid_ns             Child reaper
copy_process()                      ..
  alloc_pid()                       ..
  ..                                zap_pid_ns_processes()
  ..                                  disable_pid_allocation()
  ..                                  read_lock(&tasklist_lock)
  ..                                  iterate over pids in pid_ns
  ..                                    kill tasks linked to pids
  ..                                  read_unlock(&tasklist_lock)
  write_lock_irq(&tasklist_lock);   ..
  attach_pid(p, PIDTYPE_PID);       ..
  ..                                ..

So, just created task p won't receive SIGKILL signal,
and the pid namespace will be in contradictory state.
Only manual kill will help there, but does the userspace
care about this? I suppose, the most users just inject
a task into a pid namespace and wait a SIGCHLD from it.

The patch fixes the problem. It simply checks for
(pid_ns->nr_hashed & PIDNS_HASH_ADDING) in copy_process().
We do it under the tasklist_lock, and can't skip
PIDNS_HASH_ADDING as noted by Oleg:

"zap_pid_ns_processes() does disable_pid_allocation()
and then takes tasklist_lock to kill the whole namespace.
Given that copy_process() checks PIDNS_HASH_ADDING
under write_lock(tasklist) they can't race;
if copy_process() takes this lock first, the new child will
be killed, otherwise copy_process() can't miss
the change in ->nr_hashed."

If allocation is disabled, we just return -ENOMEM
like it's made for such cases in alloc_pid().

v2: Do not move disable_pid_allocation(), do not
introduce a new variable in copy_process() and simplify
the patch as suggested by Oleg Nesterov.
Account the problem with double irq enabling
found by Eric W. Biederman.

Fixes: c876ad76 ("pidns: Stop pid allocation when init dies")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Mike Rapoport <rppt@linux.vnet.ibm.com>
CC: Michal Hocko <mhocko@suse.com>
CC: Andy Lutomirski <luto@kernel.org>
CC: "Eric W. Biederman" <ebiederm@xmission.com>
CC: Andrei Vagin <avagin@openvz.org>
CC: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Serge Hallyn <serge@hallyn.com>
Cc: stable@vger.kernel.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

The code can potentially sleep for an indefinite amount of time in
zap_pid_ns_processes triggering the hung task timeout, and increasing
the system average.  This is undesirable.  Sleep with a task state of
TASK_INTERRUPTIBLE instead of TASK_UNINTERRUPTIBLE to remove these
undesirable side effects.

Apparently under heavy load this has been allowing Chrome to trigger
the hung time task timeout error and cause ChromeOS to reboot.
Reported-by: Vovo Yang <vovoy@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 6347e900 ("pidns: guarantee that the pidns init will be the last pidns process reaped")
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Pull some more input subsystem updates from Dmitry Torokhov:
 "An updated xpad driver with a few more recognized device IDs, and a
  new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
  via SPI bus"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: cros_ec_keyb - remove extraneous 'const'
  Input: add support for PlayStation 1/2 joypads connected via SPI
  Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
  Input: xpad - sync supported devices with xboxdrv
  Input: xpad - sort supported devices by USB ID

Pull UBI/UBIFS updates from Richard Weinberger:

 - new config option CONFIG_UBIFS_FS_SECURITY

 - minor improvements

 - random fixes

* tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs:
  ubi: Add debugfs file for tracking PEB state
  ubifs: Fix a typo in comment of ioctl2ubifs & ubifs2ioctl
  ubifs: Remove unnecessary assignment
  ubifs: Fix cut and paste error on sb type comparisons
  ubi: fastmap: Fix slab corruption
  ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels
  ubi: Make mtd parameter readable
  ubi: Fix section mismatch

Pull UML fixes from Richard Weinberger:
 "No new stuff, just fixes"

* 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Add missing NR_CPUS include
  um: Fix to call read_initrd after init_bootmem
  um: Include kbuild.h instead of duplicating its macros
  um: Fix PTRACE_POKEUSER on x86_64
  um: Set number of CPUs
  um: Fix _print_addr()

Merge misc fixes from Andrew Morton:
 "15 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, docs: update memory.stat description with workingset* entries
  mm: vmscan: scan until it finds eligible pages
  mm, thp: copying user pages must schedule on collapse
  dax: fix PMD data corruption when fault races with write
  dax: fix data corruption when fault races with write
  ext4: return to starting transaction in ext4_dax_huge_fault()
  mm: fix data corruption due to stale mmap reads
  dax: prevent invalidation of mapped DAX entries
  Tigran has moved
  mm, vmalloc: fix vmalloc users tracking properly
  mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
  gcov: support GCC 7.1
  mm, vmstat: Remove spurious WARN() during zoneinfo print
  time: delete current_fs_time()
  hwpoison, memcg: forcibly uncharge LRU pages

Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache
workingset transition") introduced three new entries in memory stat
file:

 - workingset_refault
 - workingset_activate
 - workingset_nodereclaim

This commit adds a corresponding description to the cgroup v2 docs.

Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.comSigned-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Although there are a ton of free swap and anonymous LRU page in elgible
zones, OOM happened.

  balloon invoked oom-killer: gfp_mask=0x17080c0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOTRACK), nodemask=(null),  order=0, oom_score_adj=0
  CPU: 7 PID: 1138 Comm: balloon Not tainted 4.11.0-rc6-mm1-zram-00289-ge228d67e9677-dirty #17
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
  Call Trace:
   oom_kill_process+0x21d/0x3f0
   out_of_memory+0xd8/0x390
   __alloc_pages_slowpath+0xbc1/0xc50
   __alloc_pages_nodemask+0x1a5/0x1c0
   pte_alloc_one+0x20/0x50
   __pte_alloc+0x1e/0x110
   __handle_mm_fault+0x919/0x960
   handle_mm_fault+0x77/0x120
   __do_page_fault+0x27a/0x550
   trace_do_page_fault+0x43/0x150
   do_async_page_fault+0x2c/0x90
   async_page_fault+0x28/0x30
  Mem-Info:
  active_anon:424716 inactive_anon:65314 isolated_anon:0
   active_file:52 inactive_file:46 isolated_file:0
   unevictable:0 dirty:27 writeback:0 unstable:0
   slab_reclaimable:3967 slab_unreclaimable:4125
   mapped:133 shmem:43 pagetables:1674 bounce:0
   free:4637 free_pcp:225 free_cma:0
  Node 0 active_anon:1698864kB inactive_anon:261256kB active_file:208kB inactive_file:184kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:532kB dirty:108kB writeback:0kB shmem:172kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no
  DMA free:7316kB min:32kB low:44kB high:56kB active_anon:8064kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:464kB slab_unreclaimable:40kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
  lowmem_reserve[]: 0 992 992 1952
  DMA32 free:9088kB min:2048kB low:3064kB high:4080kB active_anon:952176kB inactive_anon:0kB active_file:36kB inactive_file:0kB unevictable:0kB writepending:88kB present:1032192kB managed:1019388kB mlocked:0kB slab_reclaimable:13532kB slab_unreclaimable:16460kB kernel_stack:3552kB pagetables:6672kB bounce:0kB free_pcp:56kB local_pcp:24kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 959
  Movable free:3644kB min:1980kB low:2960kB high:3940kB active_anon:738560kB inactive_anon:261340kB active_file:188kB inactive_file:640kB unevictable:0kB writepending:20kB present:1048444kB managed:1010816kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:832kB local_pcp:60kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 0
  DMA: 1*4kB (E) 0*8kB 18*16kB (E) 10*32kB (E) 10*64kB (E) 9*128kB (ME) 8*256kB (E) 2*512kB (E) 2*1024kB (E) 0*2048kB 0*4096kB = 7524kB
  DMA32: 417*4kB (UMEH) 181*8kB (UMEH) 68*16kB (UMEH) 48*32kB (UMEH) 14*64kB (MH) 3*128kB (M) 1*256kB (H) 1*512kB (M) 2*1024kB (M) 0*2048kB 0*4096kB = 9836kB
  Movable: 1*4kB (M) 1*8kB (M) 1*16kB (M) 1*32kB (M) 0*64kB 1*128kB (M) 2*256kB (M) 4*512kB (M) 1*1024kB (M) 0*2048kB 0*4096kB = 3772kB
  378 total pagecache pages
  17 pages in swap cache
  Swap cache stats: add 17325, delete 17302, find 0/27
  Free swap  = 978940kB
  Total swap = 1048572kB
  524157 pages RAM
  0 pages HighMem/MovableOnly
  12629 pages reserved
  0 pages cma reserved
  0 pages hwpoisoned
  [ pid ]   uid  tgid total_vm      rss nr_ptes nr_pmds swapents oom_score_adj name
  [  433]     0   433     4904        5      14       3       82             0 upstart-udev-br
  [  438]     0   438    12371        5      27       3      191         -1000 systemd-udevd

With investigation, skipping page of isolate_lru_pages makes reclaim
void because it returns zero nr_taken easily so LRU shrinking is
effectively nothing and just increases priority aggressively.  Finally,
OOM happens.

The problem is that get_scan_count determines nr_to_scan with eligible
zones so although priority drops to zero, it couldn't reclaim any pages
if the LRU contains mostly ineligible pages.

get_scan_count:

        size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
	size = size >> sc->priority;

Assumes sc->priority is 0 and LRU list is as follows.

	N-N-N-N-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H

(Ie, small eligible pages are in the head of LRU but others are
 almost ineligible pages)

In that case, size becomes 4 so VM want to scan 4 pages but 4 pages from
tail of the LRU are not eligible pages.  If get_scan_count counts
skipped pages, it doesn't reclaim any pages remained after scanning 4
pages so it ends up OOM happening.

This patch makes isolate_lru_pages try to scan pages until it encounters
eligible zones's pages.

[akpm@linux-foundation.org: clean up mind-bending `for' statement.  Tweak comment text]
Fixes: 3db65812 ("Revert "mm, vmscan: account for skipped pages as a partial scan"")
Link: http://lkml.kernel.org/r/1494457232-27401-1-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We have encountered need_resched warnings in __collapse_huge_page_copy()
while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.

mm->mmap_sem is held for write, but the iteration is well bounded.

Reschedule as needed.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.comSigned-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is based on a patch from Jan Kara that fixed the equivalent race in
the DAX PTE fault path.

Currently DAX PMD read fault can race with write(2) in the following
way:

CPU1 - write(2)                 CPU2 - read fault
                                dax_iomap_pmd_fault()
                                  ->iomap_begin() - sees hole

dax_iomap_rw()
  iomap_apply()
    ->iomap_begin - allocates blocks
    dax_iomap_actor()
      invalidate_inode_pages2_range()
        - there's nothing to invalidate

                                  grab_mapping_entry()
				  - we add huge zero page to the radix tree
				    and map it to page tables

The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.

Fix the problem by locking exception entry before mapping blocks for the
fault.  That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).

Fixes: 9f141d6e ("dax: Call ->iomap_begin without entry lock during dax fault")
Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.comSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently DAX read fault can race with write(2) in the following way:

CPU1 - write(2)			CPU2 - read fault
				dax_iomap_pte_fault()
				  ->iomap_begin() - sees hole
dax_iomap_rw()
  iomap_apply()
    ->iomap_begin - allocates blocks
    dax_iomap_actor()
      invalidate_inode_pages2_range()
        - there's nothing to invalidate
				  grab_mapping_entry()
				  - we add zero page in the radix tree
				    and map it to page tables

The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.

Fix the problem by locking exception entry before mapping blocks for the
fault.  That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).

Fixes: 9f141d6e
Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

DAX will return to locking exceptional entry before mapping blocks for a
page fault to fix possible races with concurrent writes.  To avoid lock
inversion between exceptional entry lock and transaction start, start
the transaction already in ext4_dax_huge_fault().

Fixes: 9f141d6e
Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently, we didn't invalidate page tables during invalidate_inode_pages2()
for DAX.  That could result in e.g. 2MiB zero page being mapped into
page tables while there were already underlying blocks allocated and
thus data seen through mmap were different from data seen by read(2).
The following sequence reproduces the problem:

 - open an mmap over a 2MiB hole

 - read from a 2MiB hole, faulting in a 2MiB zero page

 - write to the hole with write(3p). The write succeeds but we
   incorrectly leave the 2MiB zero page mapping intact.

 - via the mmap, read the data that was just written. Since the zero
   page mapping is still intact we read back zeroes instead of the new
   data.

Fix the problem by unconditionally calling invalidate_inode_pages2_range()
in dax_iomap_actor() for new block allocations and by properly
invalidating page tables in invalidate_inode_pages2_range() for DAX
mappings.

Fixes: c6dcf52c
Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
v4.

This series fixes data corruption that can happen for DAX mounts when
page faults race with write(2) and as a result page tables get out of
sync with block mappings in the filesystem and thus data seen through
mmap is different from data seen through read(2).

The series passes testing with t_mmap_stale test program from Ross and
also other mmap related tests on DAX filesystem.

This patch (of 4):

dax_invalidate_mapping_entry() currently removes DAX exceptional entries
only if they are clean and unlocked.  This is done via:

  invalidate_mapping_pages()
    invalidate_exceptional_entry()
      dax_invalidate_mapping_entry()

However, for page cache pages removed in invalidate_mapping_pages()
there is an additional criteria which is that the page must not be
mapped.  This is noted in the comments above invalidate_mapping_pages()
and is checked in invalidate_inode_page().

For DAX entries this means that we can can end up in a situation where a
DAX exceptional entry, either a huge zero page or a regular DAX entry,
could end up mapped but without an associated radix tree entry.  This is
inconsistent with the rest of the DAX code and with what happens in the
page cache case.

We aren't able to unmap the DAX exceptional entry because according to
its comments invalidate_mapping_pages() isn't allowed to block, and
unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.

Since we essentially never have unmapped DAX entries to evict from the
radix tree, just remove dax_invalidate_mapping_entry().

Fixes: c6dcf52c ("mm: Invalidate DAX radix tree entries only if appropriate")
Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.czSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>    [4.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Cc: Tigran Aivazian <aivazian.tigran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 1f5307b1 ("mm, vmalloc: properly track vmalloc users") has
pulled asm/pgtable.h include dependency to linux/vmalloc.h and that
turned out to be a bad idea for some architectures.  E.g.  m68k fails
with

   In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
                    from arch/m68k/include/asm/pgtable.h:4,
                    from include/linux/vmalloc.h:9,
                    from arch/m68k/kernel/module.c:9:
   arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
>> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
    #define pgd_offset_k(address) pgd_offset(&init_mm, address)

as spotted by kernel build bot. nios2 fails for other reason

  In file included from include/asm-generic/io.h:767:0,
                   from arch/nios2/include/asm/io.h:61,
                   from include/linux/io.h:25,
                   from arch/nios2/include/asm/pgtable.h:18,
                   from include/linux/mm.h:70,
                   from include/linux/pid_namespace.h:6,
                   from include/linux/ptrace.h:9,
                   from arch/nios2/include/uapi/asm/elf.h:23,
                   from arch/nios2/include/asm/elf.h:22,
                   from include/linux/elf.h:4,
                   from include/linux/module.h:15,
                   from init/main.c:16:
  include/linux/vmalloc.h: In function '__vmalloc_node_flags':
  include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?

which is due to the newly added #include <asm/pgtable.h>, which on nios2
includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
again includes <linux/vmalloc.h>.

Tweaking that around just turns out a bigger headache than necessary.
This patch reverts 1f5307b1 and reimplements the original fix in a
different way.  __vmalloc_node_flags can stay static inline which will
cover vmalloc* functions.  We only have one external user
(kvmalloc_node) and we can export __vmalloc_node_flags_caller and
provide the caller directly.  This is much simpler and it doesn't really
need any games with header files.

[akpm@linux-foundation.org: coding-style fixes]
[mhocko@kernel.org: revert old comment]
  Link: http://lkml.kernel.org/r/20170509211054.GB16325@dhcp22.suse.cz
Fixes: 1f5307b1 ("mm, vmalloc: properly track vmalloc users")
Link: http://lkml.kernel.org/r/20170509153702.GR6481@dhcp22.suse.czSigned-off-by: Michal Hocko <mhocko@suse.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

One return case of `__collapse_huge_page_swapin()` does not invoke
tracepoint while every other return case does.  This commit adds a
tracepoint invocation for the case.

Link: http://lkml.kernel.org/r/20170507101813.30187-1-sj38.park@gmail.comSigned-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Starting from GCC 7.1, __gcov_exit is a new symbol expected to be
implemented in a profiling runtime.

[akpm@linux-foundation.org: coding-style fixes]
[mliska@suse.cz: v2]
  Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz
Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.czSigned-off-by: Martin Liska <mliska@suse.cz>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After commit e2ecc8a7 ("mm, vmstat: print non-populated zones in
zoneinfo"), /proc/zoneinfo will show unpopulated zones.

A memoryless node, having no populated zones at all, was previously
ignored, but will now trigger the WARN() in is_zone_first_populated().

Remove this warning, as its only purpose was to warn of a situation that
has since been enabled.

Aside: The "per-node stats" are still printed under the first populated
zone, but that's not necessarily the first stanza any more.  I'm not
sure which criteria is more important with regard to not breaking
parsers, but it looks a little weird to the eye.

Fixes:  e2ecc8a7 ("mm, vmstat: print node-based stats in zoneinfo file")
Link: http://lkml.kernel.org/r/1493854905-10918-1-git-send-email-arbab@linux.vnet.ibm.comSigned-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

All uses of the current_fs_time() function have been replaced by other
time interfaces.

And, its use cases can be fulfilled by current_time() or ktime_get_*
variants.

Link: http://lkml.kernel.org/r/1491613030-11599-13-git-send-email-deepa.kernel@gmail.comSigned-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Laurent Dufour has noticed that hwpoinsoned pages are kept charged.  In
his particular case he has hit a bad_page("page still charged to
cgroup") when onlining a hwpoison page.  While this looks like something
that shouldn't happen in the first place because onlining hwpages and
returning them to the page allocator makes only little sense it shows a
real problem.

hwpoison pages do not get freed usually so we do not uncharge them (at
least not since commit 0a31bc97 ("mm: memcontrol: rewrite uncharge
API")).  Each charge pins memcg (since e8ea14cc ("mm: memcontrol:
take a css reference for each charged page")) as well and so the
mem_cgroup and the associated state will never go away.  Fix this leak
by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache().
We also have to tweak uncharge_list because it cannot rely on zero ref
count for these pages.

[akpm@linux-foundation.org: coding-style fixes]
Fixes: 0a31bc97 ("mm: memcontrol: rewrite uncharge API")
Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.czSigned-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-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>

Pull libnvdimm fixes from Dan Williams:
 "Incremental fixes and a small feature addition on top of the main
  libnvdimm 4.12 pull request:

   - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX.
     The size regression is fixed by moving all dax helpers into the
     dax-core and only specifying "select DAX" for FS_DAX and
     dax-capable drivers. He also asked for clarification of the
     NR_DEV_DAX config option which, on closer look, does not need to be
     a config option at all. Mike also throws in a DEV_DAX_PMEM fixup
     for good measure.

   - Ben's attention to detail on -stable patch submissions caught a
     case where the recent fixes to arch_copy_from_iter_pmem() missed a
     condition where we strand dirty data in the cache. This is tagged
     for -stable and will also be included in the rework of the pmem api
     to a proposed {memcpy,copy_user}_flushcache() interface for 4.13.

   - Vishal adds a feature that missed the initial pull due to pending
     review feedback. It allows the kernel to clear media errors when
     initializing a BTT (atomic sector update driver) instance on a pmem
     namespace.

   - Ross noticed that the dax_device + dax_operations conversion broke
     __dax_zero_page_range(). The nvdimm unit tests fail to check this
     path, but xfstests immediately trips over it. No excuse for missing
     this before submitting the 4.12 pull request.

  These all pass the nvdimm unit tests and an xfstests spot check. The
  set has received a build success notification from the kbuild robot"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  filesystem-dax: fix broken __dax_zero_page_range() conversion
  libnvdimm, btt: ensure that initializing metadata clears poison
  libnvdimm: add an atomic vs process context flag to rw_bytes
  x86, pmem: Fix cache flushing for iovec write < 8 bytes
  device-dax: kill NR_DEV_DAX
  block, dax: move "select DAX" from BLOCK to FS_DAX
  device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX

Pull sound fixes from Takashi Iwai:
 "This contains a one-liner change that has a significant impact:
  disabling the build of OSS. It's been unmaintained for long time, and
  we'd like to drop the stuff. Finally, as the first step, stop the
  build. Let's see whether it works without much complaints.

  Other than that, there are two small fixes for HD-audio"

* tag 'sound-fix-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  sound: Disable the build of OSS drivers
  ALSA: hda: Fix cpu lockup when stopping the cmd dmas
  ALSA: hda - Add mute led support for HP EliteBook 840 G3

Pull more power-supply updates from Sebastian Reichel:
 "The power-supply subsystem has a few more changes for the v4.12 merge
  window:

   - New battery driver for AXP20X and AXP22X PMICs

   - Improve max17042_battery for usage on x86

   - Misc small cleanups & fixes"

* tag 'for-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply: (34 commits)
  power: supply: cpcap-charger: Keep trickle charger bits disabled
  power: supply: cpcap-charger: Fix enable for 3.8V charge setting
  power: supply: cpcap-charger: Fix charge voltage configuration
  power: supply: cpcap-charger: Fix charger name
  power: supply: twl4030-charger: make twl4030_bci_property_is_writeable static
  power: supply: sbs-battery: Add alert callback
  mailmap: add Sebastian Reichel
  power: supply: avoid unused twl4030-madc.h
  power: supply: sbs-battery: Correct supply status with current draw
  power: supply: sbs-battery: Don't ignore the first external power change
  power: supply: pda_power: move from timer to delayed_work
  power: supply: max17042_battery: Add support for the SCOPE property
  power: supply: max17042_battery: Add support for the CHARGE_NOW property
  power: supply: max17042_battery: Add support for the CHARGE_FULL_DESIGN property
  power: supply: max17042_battery: mAh readings depend on r_sns value
  power: supply: max17042_battery: Add support for the VOLT_MIN property
  power: supply: max17042_battery: Add support for the TECHNOLOGY attribute
  power: supply: max17042_battery: Add external_power_changed callback
  power: supply: max17042_battery: Add support for the STATUS property
  power: supply: max17042_battery: Add default platform_data fallback data
  ...

Pull thermal management updates from Zhang Rui:

 - Fix a problem where orderly_shutdown() is called for multiple times
   due to multiple critical overheating events raised in a short period
   by platform thermal driver. (Keerthy)

 - Introduce a backup thermal shutdown mechanism, which invokes
   kernel_power_off()/emergency_restart() directly, after
   orderly_shutdown() being issued for certain amount of time(specified
   via Kconfig). This is useful in certain conditions that userspace may
   be unable to power off the system in a clean manner and leaves the
   system in a critical state, like in the middle of driver probing
   phase. (Keerthy)

 - Introduce a new interface in thermal devfreq_cooling code so that the
   driver can provide more precise data regarding actual power to the
   thermal governor every time the power budget is calculated. (Lukasz
   Luba)

 - Introduce BCM 2835 soc thermal driver and northstar thermal driver,
   within a new sub-folder. (Rafał Miłecki)

 - Introduce DA9062/61 thermal driver. (Steve Twiss)

 - Remove non-DT booting on TI-SoC driver. Also add support to fetching
   coefficients from DT. (Keerthy)

 - Refactorf RCAR Gen3 thermal driver. (Niklas Söderlund)

 - Small fix on MTK and intel-soc-dts thermal driver. (Dawei Chien,
   Brian Bian)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (25 commits)
  thermal: core: Add a back up thermal shutdown mechanism
  thermal: core: Allow orderly_poweroff to be called only once
  Thermal: Intel SoC DTS: Change interrupt request behavior
  trace: thermal: add another parameter 'power' to the tracing function
  thermal: devfreq_cooling: add new interface for direct power read
  thermal: devfreq_cooling: refactor code and add get_voltage function
  thermal: mt8173: minor mtk_thermal.c cleanups
  thermal: bcm2835: move to the broadcom subdirectory
  thermal: broadcom: ns: specify myself as MODULE_AUTHOR
  thermal: da9062/61: Thermal junction temperature monitoring driver
  Documentation: devicetree: thermal: da9062/61 TJUNC temperature binding
  thermal: broadcom: add Northstar thermal driver
  dt-bindings: thermal: add support for Broadcom's Northstar thermal
  thermal: bcm2835: add thermal driver for bcm2835 SoC
  dt-bindings: Add thermal zone to bcm2835-thermal example
  thermal: rcar_gen3_thermal: add suspend and resume support
  thermal: rcar_gen3_thermal: store device match data in private structure
  thermal: rcar_gen3_thermal: enable hardware interrupts for trip points
  thermal: rcar_gen3_thermal: record and check number of TSCs found
  thermal: rcar_gen3_thermal: check that TSC exists before memory allocation
  ...

Pull drm fixes from Dave Airlie:
 "AMD, nouveau, one i915, and one EDID fix for v4.12-rc1

  Some fixes that it would be good to have in rc1. It contains the i915
  quiet fix that you reported.

  It also has an amdgpu fixes pull, with lots of ongoing work on Vega10
  which is new in this kernel and is preliminary support so may have a
  fair bit of movement.

  Otherwise a few non-Vega10 AMD fixes, one EDID fix and some nouveau
  regression fixers"

* tag 'drm-fixes-for-v4.12-rc1' of git://people.freedesktop.org/~airlied/linux: (144 commits)
  drm/i915: Make vblank evade warnings optional
  drm/nouveau/therm: remove ineffective workarounds for alarm bugs
  drm/nouveau/tmr: avoid processing completed alarms when adding a new one
  drm/nouveau/tmr: fix corruption of the pending list when rescheduling an alarm
  drm/nouveau/tmr: handle races with hw when updating the next alarm time
  drm/nouveau/tmr: ack interrupt before processing alarms
  drm/nouveau/core: fix static checker warning
  drm/nouveau/fb/ram/gf100-: remove 0x10f200 read
  drm/nouveau/kms/nv50: skip core channel cursor update on position-only changes
  drm/nouveau/kms/nv50: fix source-rect-only plane updates
  drm/nouveau/kms/nv50: remove pointless argument to window atomic_check_acquire()
  drm/amd/powerplay: refine pwm1_enable callback functions for CI.
  drm/amd/powerplay: refine pwm1_enable callback functions for vi.
  drm/amd/powerplay: refine pwm1_enable callback functions for Vega10.
  drm/amdgpu: refine amdgpu pwm1_enable sysfs interface.
  drm/amdgpu: add amd fan ctrl mode enums.
  drm/amd/powerplay: add more smu message on Vega10.
  drm/amdgpu: fix dependency issue
  drm/amd: fix init order of sched job
  drm/amdgpu: add some additional vega10 pci ids
  ...

Pull SCSI target updates from Nicholas Bellinger:
 "Things were a lot more calm than previously expected. It's primarily
  fixes in various areas, with most of the new functionality centering
  around TCMU backend driver work that Xiubo Li has been driving.

  Here's the summary on the feature side:

   - Make T10-PI verify configurable for emulated (FILEIO + RD) backends
    (Dmitry Monakhov)
   - Allow target-core/TCMU pass-through to use in-kernel SPC-PR logic
    (Bryant Ly + MNC)
   - Add TCMU support for growing ring buffer size (Xiubo Li + MNC)
   - Add TCMU support for global block data pool (Xiubo Li + MNC)

  and on the bug-fix side:

   - Fix COMPARE_AND_WRITE non GOOD status handling for READ phase
    failures (Gary Guo + nab)
   - Fix iscsi-target hang with explicitly changing per NodeACL
    CmdSN number depth with concurrent login driven session
    reinstatement.  (Gary Guo + nab)
   - Fix ibmvscsis fabric driver ABORT task handling (Bryant Ly)
   - Fix target-core/FILEIO zero length handling (Bart Van Assche)

  Also, there was an OOPs introduced with the WRITE_VERIFY changes that
  I ended up reverting at the last minute, because as not unusual Bart
  and I could not agree on the fix in time for -rc1. Since it's specific
  to a conformance test, it's been reverted for now.

  There is a separate patch in the queue to address the underlying
  control CDB write overflow regression in >= v4.3 separate from the
  WRITE_VERIFY revert here, that will be pushed post -rc1"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (30 commits)
  Revert "target: Fix VERIFY and WRITE VERIFY command parsing"
  IB/srpt: Avoid that aborting a command triggers a kernel warning
  IB/srpt: Fix abort handling
  target/fileio: Fix zero-length READ and WRITE handling
  ibmvscsis: Do not send aborted task response
  tcmu: fix module removal due to stuck thread
  target: Don't force session reset if queue_depth does not change
  iscsi-target: Set session_fall_back_to_erl0 when forcing reinstatement
  target: Fix compare_and_write_callback handling for non GOOD status
  tcmu: Recalculate the tcmu_cmd size to save cmd area memories
  tcmu: Add global data block pool support
  tcmu: Add dynamic growing data area feature support
  target: fixup error message in target_tg_pt_gp_tg_pt_gp_id_store()
  target: fixup error message in target_tg_pt_gp_alua_access_type_store()
  target/user: PGR Support
  target: Add WRITE_VERIFY_16
  Documentation/target: add an example script to configure an iSCSI target
  target: Use kmalloc_array() in transport_kmap_data_sg()
  target: Use kmalloc_array() in compare_and_write_callback()
  target: Improve size determinations in two functions
  ...

Pull misc vfs updates from Al Viro:
 "Making sure that something like a referral point won't end up as pwd
  or root.

  The main part is the last commit (fixing mntns_install()); that one
  fixes a hard-to-hit race. The fchdir() commit is making fchdir(2) a
  bit more robust - it should be impossible to get opened files (even
  O_PATH ones) for referral points in the first place, so the existing
  checks are OK, but checking the same thing as in chdir(2) is just as
  cheap.

  The path_init() commit removes a redundant check that shouldn't have
  been there in the first place"

* 'work.sane_pwd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make sure that mntns_install() doesn't end up with referral for root
  path_init(): don't bother with checking MAY_EXEC for LOOKUP_ROOT
  make sure that fchdir() won't accept referral points, etc.

Pull perf updates/fixes from Ingo Molnar:
 "Mostly tooling updates, but also two kernel fixes: a call chain
  handling robustness fix and an x86 PMU driver event definition fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/callchain: Force USER_DS when invoking perf_callchain_user()
  tools build: Fixup sched_getcpu feature test
  perf tests kmod-path: Don't fail if compressed modules aren't supported
  perf annotate: Fix AArch64 comment char
  perf tools: Fix spelling mistakes
  perf/x86: Fix Broadwell-EP DRAM RAPL events
  perf config: Refactor a duplicated code for obtaining config file name
  perf symbols: Allow user probes on versioned symbols
  perf symbols: Accept symbols starting at address 0
  tools lib string: Adopt prefixcmp() from perf and subcmd
  perf units: Move parse_tag_value() to units.[ch]
  perf ui gtk: Move gtk .so name to the only place where it is used
  perf tools: Move HAS_BOOL define to where perl headers are used
  perf memswap: Split the byteswap memory range wrappers from util.[ch]
  perf tools: Move event prototypes from util.h to event.h
  perf buildid: Move prototypes from util.h to build-id.h

Pull timer fix from Ingo Molnar:
 "A single ARM Juno clocksource driver fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/arm_arch_timer: Fix arch_timer_mem_find_best_frame()

Pull stackprotector fixlet from Ingo Molnar:
 "A single fix/enhancement to increase stackprotector canary randomness
  on 64-bit kernels with very little cost"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - two boot crash fixes
   - unwinder fixes
   - kexec related kernel direct mappings enhancements/fixes
   - more Clang support quirks
   - minor cleanups
   - Documentation fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel_rdt: Fix a typo in Documentation
  x86/build: Don't add -maccumulate-outgoing-args w/o compiler support
  x86/boot/32: Fix UP boot on Quark and possibly other platforms
  x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()
  x86/kexec/64: Use gbpages for identity mappings if available
  x86/mm: Add support for gbpages to kernel_ident_mapping_init()
  x86/boot: Declare error() as noreturn
  x86/mm/kaslr: Use the _ASM_MUL macro for multiplication to work around Clang incompatibility
  x86/mm: Fix boot crash caused by incorrect loop count calculation in sync_global_pgds()
  x86/asm: Don't use RBP as a temporary register in csum_partial_copy_generic()
  x86/microcode/AMD: Remove redundant NULL check on mc

Pull xen fixes from Juergen Gross:
 "This contains two fixes for booting under Xen introduced during this
  merge window and two fixes for older problems, where one is just much
  more probable due to another merge window change"

* tag 'for-linus-4.12b-rc0c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: adjust early dom0 p2m handling to xen hypervisor behavior
  x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
  xen/x86: Do not call xen_init_time_ops() until shared_info is initialized
  x86/xen: fix xsave capability setting

Pull more powerpc updates from Michael Ellerman:
 "The change to the Linux page table geometry was delayed for more
  testing with 16G pages, and there's the new CPU features stuff which
  just needed one more polish before going in. Plus a few changes from
  Scott which came in a bit late. And then various fixes, mostly minor.

  Summary highlights:

   - rework the Linux page table geometry to lower memory usage on
     64-bit Book3S (IBM chips) using the Hash MMU.

   - support for a new device tree binding for discovering CPU features
     on future firmwares.

   - Freescale updates from Scott:
      "Includes a fix for a powerpc/next mm regression on 64e, a fix for
       a kernel hang on 64e when using a debugger inside a relocated
       kernel, a qman fix, and misc qe improvements."

  Thanks to: Christophe Leroy, Gavin Shan, Horia Geantă, LiuHailong,
  Nicholas Piggin, Roy Pledge, Scott Wood, Valentin Longchamp"

* tag 'powerpc-4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Support new device tree binding for discovering CPU features
  powerpc: Don't print cpu_spec->cpu_name if it's NULL
  of/fdt: introduce of_scan_flat_dt_subnodes and of_get_flat_dt_phandle
  powerpc/64s: Fix unnecessary machine check handler relocation branch
  powerpc/mm/book3s/64: Rework page table geometry for lower memory usage
  powerpc: Fix distclean with Makefile.postlink
  powerpc/64e: Don't place the stack beyond TASK_SIZE
  powerpc/powernv: Block PCI config access on BCM5718 during EEH recovery
  powerpc/8xx: Adding support of IRQ in MPC8xx GPIO
  soc/fsl/qbman: Disable IRQs for deferred QBMan work
  soc/fsl/qe: add EXPORT_SYMBOL for the 2 qe_tdm functions
  soc/fsl/qe: only apply QE_General4 workaround on affected SoCs
  soc/fsl/qe: round brg_freq to 1kHz granularity
  soc/fsl/qe: get rid of immrbar_virt_to_phys()
  net: ethernet: ucc_geth: fix MEM_PART_MURAM mode
  powerpc/64e: Fix hang when debugging programs with relocated kernel

Pull MIPS updates from James Hogan:
 "math-emu:
   - Add missing clearing of BLTZALL and BGEZALL emulation counters
   - Fix BC1EQZ and BC1NEZ condition handling
   - Fix BLEZL and BGTZL identification

  BPF:
   - Add JIT support for SKF_AD_HATYPE
   - Use unsigned access for unsigned SKB fields
   - Quit clobbering callee saved registers in JIT code
   - Fix multiple problems in JIT skb access helpers

  Loongson 3:
   - Select MIPS_L1_CACHE_SHIFT_6

  Octeon:
   - Remove vestiges of CONFIG_CAVIUM_OCTEON_2ND_KERNEL
   - Remove unused L2C types and macros.
   - Remove unused SLI types and macros.
   - Fix compile error when USB is not enabled.
   - Octeon: Remove unused PCIERCX types and macros.
   - Octeon: Clean up platform code.

  SNI:
   - Remove recursive include of cpu-feature-overrides.h

  Sibyte:
   - Export symbol periph_rev to sb1250-mac network driver.
   - Fix Kconfig warning.

  Generic platform:
   - Enable Root FS on NFS in generic_defconfig

  SMP-MT:
   - Use CPU interrupt controller IPI IRQ domain support

  UASM:
   - Add support for LHU for uasm.
   - Remove needless ISA abstraction

  mm:
   - Add 48-bit VA space and 4-level page tables for 4K pages.

  PCI:
   - Add controllers before the specified head

  irqchip driver for MIPS CPU:
   - Replace magic 0x100 with IE_SW0
   - Prepare for non-legacy IRQ domains
   - Introduce IPI IRQ domain support

  MAINTAINERS:
   - Update email-id of Rahul Bedarkar

  NET:
   - sb1250-mac: Add missing MODULE_LICENSE()

  CPUFREQ:
   - Loongson2: drop set_cpus_allowed_ptr()

  Misc:
   - Disable Werror when W= is set
   - Opt into HAVE_COPY_THREAD_TLS
   - Enable GENERIC_CPU_AUTOPROBE
   - Use common outgoing-CPU-notification code
   - Remove dead define of ST_OFF
   - Remove CONFIG_ARCH_HAS_ILOG2_U{32,64}
   - Stengthen IPI IRQ domain sanity check
   - Remove confusing else statement in __do_page_fault()
   - Don't unnecessarily include kmalloc.h into <asm/cache.h>.
   - Delete unused definition of SMP_CACHE_SHIFT.
   - Delete redundant definition of SMP_CACHE_BYTES"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (39 commits)
  MIPS: Sibyte: Fix Kconfig warning.
  MIPS: Sibyte: Export symbol periph_rev to sb1250-mac network driver.
  NET: sb1250-mac: Add missing MODULE_LICENSE()
  MAINTAINERS: Update email-id of Rahul Bedarkar
  MIPS: Remove confusing else statement in __do_page_fault()
  MIPS: Stengthen IPI IRQ domain sanity check
  MIPS: smp-mt: Use CPU interrupt controller IPI IRQ domain support
  irqchip: mips-cpu: Introduce IPI IRQ domain support
  irqchip: mips-cpu: Prepare for non-legacy IRQ domains
  irqchip: mips-cpu: Replace magic 0x100 with IE_SW0
  MIPS: Remove CONFIG_ARCH_HAS_ILOG2_U{32,64}
  MIPS: generic: Enable Root FS on NFS in generic_defconfig
  MIPS: mach-rm: Remove recursive include of cpu-feature-overrides.h
  MIPS: Opt into HAVE_COPY_THREAD_TLS
  CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()
  MIPS: uasm: Remove needless ISA abstraction
  MIPS: Remove dead define of ST_OFF
  MIPS: Use common outgoing-CPU-notification code
  MIPS: math-emu: Fix BC1EQZ and BC1NEZ condition handling
  MIPS: r2-on-r6-emu: Clear BLTZALL and BGEZALL debugfs counters
  ...