BACKPORT: zram: handle multiple pages attached bio's bvec

Patch series "zram clean up", v2.

This patchset aims to clean up zram .

[1] clean up multiple pages's bvec handling.
[2] clean up partial IO handling
[3-6] clean up zram via using accessor and removing pointless structure.

With [2-6] applied, we can get a few hundred bytes as well as huge
readibility enhance.

x86: 708 byte save

    add/remove: 1/1 grow/shrink: 0/11 up/down: 478/-1186 (-708)
    function                                     old     new   delta
    zram_special_page_read                         -     478    +478
    zram_reset_device                            317     314      -3
    mem_used_max_store                           131     128      -3
    compact_store                                 96      93      -3
    mm_stat_show                                 203     197      -6
    zram_add                                     719     712      -7
    zram_slot_free_notify                        229     214     -15
    zram_make_request                            819     803     -16
    zram_meta_free                               128     111     -17
    zram_free_page                               180     151     -29
    disksize_store                               432     361     -71
    zram_decompress_page.isra                    504       -    -504
    zram_bvec_rw                                2592    2080    -512
    Total: Before=25350773, After=25350065, chg -0.00%

ppc64: 231 byte save

    add/remove: 2/0 grow/shrink: 1/9 up/down: 681/-912 (-231)
    function                                     old     new   delta
    zram_special_page_read                         -     480    +480
    zram_slot_lock                                 -     200    +200
    vermagic                                      39      40      +1
    mm_stat_show                                 256     248      -8
    zram_meta_free                               200     184     -16
    zram_add                                     944     912     -32
    zram_free_page                               348     308     -40
    disksize_store                               572     492     -80
    zram_decompress_page                         664     564    -100
    zram_slot_free_notify                        292     160    -132
    zram_make_request                           1132    1000    -132
    zram_bvec_rw                                2768    2396    -372
    Total: Before=17565825, After=17565594, chg -0.00%

This patch (of 6):

Johannes Thumshirn reported system goes the panic when using NVMe over
Fabrics loopback target with zram.

The reason is zram expects each bvec in bio contains a single page
but nvme can attach a huge bulk of pages attached to the bio's bvec
so that zram's index arithmetic could be wrong so that out-of-bound
access makes system panic.

[1] in mainline solved solved the problem by limiting max_sectors with
SECTORS_PER_PAGE but it makes zram slow because bio should split with
each pages so this patch makes zram aware of multiple pages in a bvec
so it could solve without any regression(ie, bio split).

[1] 0bc315381fe9, zram: set physical queue limits to avoid array out of
    bounds accesses

Link: http://lkml.kernel.org/r/20170413134057.GA27499@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e86942c7b6c1e1dd5e539f3bf3cfb63799163048)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ibedc9e8163fc16a0c2569e8c3e33dd81bb325ee5

UPSTREAM: zram: fix operator precedence to get offset

In zram_rw_page, the logic to get offset is wrong by operator precedence
(i.e., "<<" is higher than "&").  With wrong offset, zram can corrupt
the user's data.  This patch fixes it.

Fixes: 8c7f01025 ("zram: implement rw_page operation of zram")
Link: http://lkml.kernel.org/r/1492042622-12074-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I6abb2aef381463976aea1fa8e7f5ca07367190e9

BACKPORT: zram: extend zero pages to same element pages

The idea is that without doing more calculations we extend zero pages to
same element pages for zram.  zero page is special case of same element
page with zero element.

1. the test is done under android 7.0
2. startup too many applications circularly
3. sample the zero pages, same pages (none-zero element)
   and total pages in function page_zero_filled

the result is listed as below:

ZERO SAME TOTAL
36214 17842 598196

ZERO/TOTAL  SAME/TOTAL   (ZERO+SAME)/TOTAL ZERO/SAME
AVERAGE 0.060631909  0.024990816  0.085622726 2.663825038
STDEV 0.00674612  0.005887625  0.009707034 2.115881328
MAX 0.069698422  0.030046087  0.094975336 7.56043956
MIN 0.03959586  0.007332205  0.056055193 1.928985507

from the above data, the benefit is about 2.5% and up to 3% of total
swapout pages.

The defect of the patch is that when we recovery a page from non-zero
element the operations are low efficient for partial read.

This patch extends zero_page to same_page so if there is any user to
have monitored zero_pages, he will be surprised if the number is
increased but it's not harmful, I believe.

[minchan@kernel.org: do not free same element pages in zram_meta_free]
Link: http://lkml.kernel.org/r/20170207065741.GA2567@bbox
Link: http://lkml.kernel.org/r/1483692145-75357-1-git-send-email-zhouxianrong@huawei.com
Link: http://lkml.kernel.org/r/1486307804-27903-1-git-send-email-minchan@kernel.org
Signed-off-by: zhouxianrong <zhouxianrong@huawei.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 8e19d540d107ee897eb9a874844060c94e2376c0)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I92ebb07a6ad96be82443d6e0c0d4f25cbe936915

BACKPORT: zram: remove waitqueue for IO done

zram_reset_device() waits for ongoing writepage pages to be completed by
zram->refcount logic.  However, it's pointless because before the reset,
we prevent further opening of zram by zram->claim and flush all of
pending IO by fsync_bdev so there should be no pending IO at the
zram_reset_device().

So let's remove that code which is even broken due to the lack of
wake_up elsewhere.

Link: http://lkml.kernel.org/r/1485145031-11661-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit a09759acaacf6cf738e1bc6c66d41485c87fd371)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I97170fb576be7baae63f82334af0dd5e91b16763

UPSTREAM: zram: remove obsolete sysfs attrs

We had a deprecated_attr_warn() warning for 2 years and now the time has
come and we finally can do the cleanup.

The plan was as follows:

: per-stat sysfs attributes are considered to be deprecated.
: The basic strategy is:
: -- the existing RW nodes will be downgraded to WO nodes (in linux 4.11)
: -- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
:
: The list of deprecated attributes can be found here:
: Documentation/ABI/obsolete/sysfs-block-zram
:
: Basically, every attribute that has its own read accessible sysfs
: node (e.g. num_reads) *AND* is accessible via one of the stat files
: (zram<id>/stat or zram<id>/io_stat or zram<id>/mm_stat) is considered
: to be deprecated.

The patch also removes `obsolete/sysfs-block-zram', clean ups
`testing/sysfs-block-zram' and tweaks zram.txt files.

Link: http://lkml.kernel.org/r/20170118035838.11090-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit c87d1655c29500b459fb135258a93f8309ada9c7)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Idd86259230d6a4bf0feeee53b5b69f3f3df774d4

UPSTREAM: zram: support BDI_CAP_STABLE_WRITES

zram has used per-cpu stream feature from v4.7.  It aims for increasing
cache hit ratio of scratch buffer for compressing.  Downside of that
approach is that zram should ask memory space for compressed page in
per-cpu context which requires stricted gfp flag which could be failed.
If so, it retries to allocate memory space out of per-cpu context so it
could get memory this time and compress the data again, copies it to the
memory space.

In this scenario, zram assumes the data should never be changed but it is
not true without stable page support.  So, If the data is changed under
us, zram can make buffer overrun so that zsmalloc free object chain is
broken so system goes crash like below

   https://bugzilla.suse.com/show_bug.cgi?id=997574

This patch adds BDI_CAP_STABLE_WRITES to zram for declaring "I am block
device needing *stable write*".

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-4-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit b09ab054b69b07077bd3292f67e777861ac796e5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I3134a5882c1939792ffa71b8f31f7ab642a0e9a3

UPSTREAM: zram: revalidate disk under init_lock

Commit b4c5c60920e3 ("zram: avoid lockdep splat by revalidate_disk")
moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat.  However, commit 08eee69fcf6b ("zram: remove
init_lock in zram_make_request") removed init_lock in IO path so there
is no worry about lockdep splat.  So, let's restore it.

This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next
patch.

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e7ccfc4ccb703e0f033bd4617580039898e912dd)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Iebb6f694e46a797f8ce34029857c01c0c71086c7

BACKPORT: mm: support anonymous stable page

During developemnt for zram-swap asynchronous writeback, I found strange
corruption of compressed page, resulting in:

  Modules linked in: zram(E)
  CPU: 3 PID: 1520 Comm: zramd-1 Tainted: G            E   4.8.0-mm1-00320-ge0d4894c9c38-dirty #3274
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
  task: ffff88007620b840 task.stack: ffff880078090000
  RIP: set_freeobj.part.43+0x1c/0x1f
  RSP: 0018:ffff880078093ca8  EFLAGS: 00010246
  RAX: 0000000000000018 RBX: ffff880076798d88 RCX: ffffffff81c408c8
  RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000246
  RBP: ffff880078093cb0 R08: 0000000000000000 R09: 0000000000000000
  R10: ffff88005bc43030 R11: 0000000000001df3 R12: ffff880076798d88
  R13: 000000000005bc43 R14: ffff88007819d1b8 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff88007e380000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fc934048f20 CR3: 0000000077b01000 CR4: 00000000000406e0
  Call Trace:
    obj_malloc+0x22b/0x260
    zs_malloc+0x1e4/0x580
    zram_bvec_rw+0x4cd/0x830 [zram]
    page_requests_rw+0x9c/0x130 [zram]
    zram_thread+0xe6/0x173 [zram]
    kthread+0xca/0xe0
    ret_from_fork+0x25/0x30

With investigation, it reveals currently stable page doesn't support
anonymous page.  IOW, reuse_swap_page can reuse the page without waiting
writeback completion so it can overwrite page zram is compressing.

Unfortunately, zram has used per-cpu stream feature from v4.7.
It aims for increasing cache hit ratio of scratch buffer for
compressing. Downside of that approach is that zram should ask
memory space for compressed page in per-cpu context which requires
stricted gfp flag which could be failed. If so, it retries to
allocate memory space out of per-cpu context so it could get memory
this time and compress the data again, copies it to the memory space.

In this scenario, zram assumes the data should never be changed
but it is not true unless stable page supports. So, If the data is
changed under us, zram can make buffer overrun because second
compression size could be bigger than one we got in previous trial
and blindly, copy bigger size object to smaller buffer which is
buffer overrun. The overrun breaks zsmalloc free object chaining
so system goes crash like above.

I think below is same problem.
https://bugzilla.suse.com/show_bug.cgi?id=997574

Unfortunately, reuse_swap_page should be atomic so that we cannot wait on
writeback in there so the approach in this patch is simply return false if
we found it needs stable page.  Although it increases memory footprint
temporarily, it happens rarely and it should be reclaimed easily althoug
it happened.  Also, It would be better than waiting of IO completion,
which is critial path for application latency.

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox
Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit f05714293a591038304ddae7cb0dd747bb3786cc)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I0fa5012aff9daf614b2d1d04f35b86ff7043ff21

UPSTREAM: zram: use __GFP_MOVABLE for memory allocation

Zsmalloc is ready for page migration so zram can use __GFP_MOVABLE from
now on.

I did test to see how it helps to make higher order pages.  Test
scenario is as follows.

KVM guest, 1G memory, ext4 formated zram block device,

  for i in `seq 1 8`;
  do
          dd if=/dev/vda1 of=mnt/test$i.txt bs=128M count=1 &
  done

  wait `pidof dd`

  for i in `seq 1 2 8`;
  do
          rm -rf mnt/test$i.txt
  done
  fstrim -v mnt

  echo "init"
  cat /proc/buddyinfo

  echo "compaction"
  echo 1 > /proc/sys/vm/compact_memory
  cat /proc/buddyinfo

old:

  init
  Node 0, zone      DMA    208    120     51     41     11      0      0      0      0      0      0
  Node 0, zone    DMA32  16380  13777   9184   3805    789     54      3      0      0      0      0
  compaction
  Node 0, zone      DMA    132     82     40     39     16      2      1      0      0      0      0
  Node 0, zone    DMA32   5219   5526   4969   3455   1831    677    139     15      0      0      0

new:

  init
  Node 0, zone      DMA    379    115     97     19      2      0      0      0      0      0      0
  Node 0, zone    DMA32  18891  16774  10862   3947    637     21      0      0      0      0      0
  compaction
  Node 0, zone      DMA    214     66     87     29     10      3      0      0      0      0      0
  Node 0, zone    DMA32   1612   3139   3154   2469   1745    990    384     94      7      0      0

As you can see, compaction made so many high-order pages. Yay!

Link: http://lkml.kernel.org/r/1464736881-24886-13-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 9bc482d3460501ac809457af26b46b72cd7dc212)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I5d7f6eaa4c2d8d3f4da30fc2bd21f4db1be95e50

UPSTREAM: zram: drop gfp_t from zcomp_strm_alloc()

We now allocate streams from CPU_UP hot-plug path, there are no
context-dependent stream allocations anymore and we can schedule from
zcomp_strm_alloc().  Use GFP_KERNEL directly and drop a gfp_t parameter.

Link: http://lkml.kernel.org/r/20160531122017.2878-9-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 16d37725a042cc66f9ee95889dd40e734264508e)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: If09c4a97f3d3e45ad578d2b1d64b26f65617774d

UPSTREAM: zram: add more compression algorithms

Add "deflate", "lz4hc", "842" algorithms to the list of known
compression backends.  The real availability of those algorithms,
however, depends on the corresponding CONFIG_CRYPTO_FOO config options.

[sergey.senozhatsky@gmail.com: zram-add-more-compression-algorithms-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-7-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-8-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit eb9f56d82547db407779967a2251ea28969245b0)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie46c7676363ef13c559b45dab4968e2cc48a6cbe

UPSTREAM: zram: delete custom lzo/lz4

Remove lzo/lz4 backends, we use crypto API now.

[sergey.senozhatsky@gmail.com: zram-delete-custom-lzo-lz4-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-6-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-7-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ce1ed9f98e888aa220fb09da2e2bcfcfba218a27)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ic2aa300a1a66b61740da73833dab252dc0d4b74a

UPSTREAM: zram: cosmetic: cleanup documentation

zram documentation is a mix of different styles: spaces, tabs, tabs +
spaces, etc.  Clean it up.

Link: http://lkml.kernel.org/r/20160531122017.2878-6-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 69a30a8d2ac17c8080cf6ebfc91149fd6c2648b3)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ib71a1933e3da12b3a9f29b805a458cdc9815c36b

UPSTREAM: zram: use crypto api to check alg availability

There is no way to get a string with all the crypto comp algorithms
supported by the crypto comp engine, so we need to maintain our own
backends list.  At the same time we additionally need to use
crypto_has_comp() to make sure that the user has requested a compression
algorithm that is recognized by the crypto comp engine.  Relying on
/proc/crypto is not an options here, because it does not show
not-yet-inserted compression modules.

Example:

 modprobe zram
 cat /proc/crypto | grep -i lz4
 modprobe lz4
 cat /proc/crypto | grep -i lz4
name         : lz4
driver       : lz4-generic
module       : lz4

So the user can't tell exactly if the lz4 is really supported from
/proc/crypto output, unless someone or something has loaded it.

This patch also adds crypto_has_comp() to zcomp_available_show().  We
store all the compression algorithms names in zcomp's `backends' array,
regardless the CONFIG_CRYPTO_FOO configuration, but show only those that
are also supported by crypto engine.  This helps user to know the exact
list of compression algorithms that can be used.

Example:
  module lz4 is not loaded yet, but is supported by the crypto
  engine. /proc/crypto has no information on this module, while
  zram's `comp_algorithm' lists it:

 cat /proc/crypto | grep -i lz4

 cat /sys/block/zram0/comp_algorithm
[lzo] lz4 deflate lz4hc 842

We still use the `backends' array to determine if the requested
compression backend is known to crypto api.  This array, however, may not
contain some entries, therefore as the last step we call crypto_has_comp()
function which attempts to insmod the requested compression algorithm to
determine if crypto api supports it.  The advantage of this method is that
now we permit the usage of out-of-tree crypto compression modules
(implementing S/W or H/W compression).

[sergey.senozhatsky@gmail.com: zram-use-crypto-api-to-check-alg-availability-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-4-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-5-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 415403be37e204632b17bdb6857890fe5a220cea)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I7c823238329bd6e5180386507d16123228804cc5

BACKPORT: zram: switch to crypto compress API

We don't have an idle zstreams list anymore and our write path now works
absolutely differently, preventing preemption during compression.  This
removes possibilities of read paths preempting writes at wrong places
(which could badly affect the performance of both paths) and at the same
time opens the door for a move from custom LZO/LZ4 compression backends
implementation to a more generic one, using crypto compress API.

Joonsoo Kim [1] attempted to do this a while ago, but faced with the
need of introducing a new crypto API interface.  The root cause was the
fact that crypto API compression algorithms require a compression stream
structure (in zram terminology) for both compression and decompression
ops, while in reality only several of compression algorithms really need
it.  This resulted in a concept of context-less crypto API compression
backends [2].  Both write and read paths, though, would have been
executed with the preemption enabled, which in the worst case could have
resulted in a decreased worst-case performance, e.g.  consider the
following case:

CPU0

zram_write()
  spin_lock()
    take the last idle stream
  spin_unlock()

<< preempted >>

zram_read()
  spin_lock()
   no idle streams
  spin_unlock()
  schedule()

resuming zram_write compression()

but it took me some time to realize that, and it took even longer to
evolve zram and to make it ready for crypto API.  The key turned out to be
-- drop the idle streams list entirely.  Without the idle streams list we
are free to use compression algorithms that require compression stream for
decompression (read), because streams are now placed in per-cpu data and
each write path has to disable preemption for compression op, almost
completely eliminating the aforementioned case (technically, we still have
a small chance, because write path has a fast and a slow paths and the
slow path is executed with the preemption enabled; but the frequency of
failed fast path is too low).

TEST
====

- 4 CPUs, x86_64 system
- 3G zram, lzo
- fio tests: read, randread, write, randwrite, rw, randrw

test script [3] command:
 ZRAM_SIZE=3G LOG_SUFFIX=XXXX FIO_LOOPS=5 ./zram-fio-test.sh

                   BASE           PATCHED
jobs1
READ:           2527.2MB/s  2482.7MB/s
READ:           2102.7MB/s  2045.0MB/s
WRITE:          1284.3MB/s  1324.3MB/s
WRITE:          1080.7MB/s  1101.9MB/s
READ:           430125KB/s  437498KB/s
WRITE:          430538KB/s  437919KB/s
READ:           399593KB/s  403987KB/s
WRITE:          399910KB/s  404308KB/s
jobs2
READ:           8133.5MB/s  7854.8MB/s
READ:           7086.6MB/s  6912.8MB/s
WRITE:          3177.2MB/s  3298.3MB/s
WRITE:          2810.2MB/s  2871.4MB/s
READ:           1017.6MB/s  1023.4MB/s
WRITE:          1018.2MB/s  1023.1MB/s
READ:           977836KB/s  984205KB/s
WRITE:          979435KB/s  985814KB/s
jobs3
READ:           13557MB/s  13391MB/s
READ:           11876MB/s  11752MB/s
WRITE:          4641.5MB/s  4682.1MB/s
WRITE:          4164.9MB/s  4179.3MB/s
READ:           1453.8MB/s  1455.1MB/s
WRITE:          1455.1MB/s  1458.2MB/s
READ:           1387.7MB/s  1395.7MB/s
WRITE:          1386.1MB/s  1394.9MB/s
jobs4
READ:           20271MB/s  20078MB/s
READ:           18033MB/s  17928MB/s
WRITE:          6176.8MB/s  6180.5MB/s
WRITE:          5686.3MB/s  5705.3MB/s
READ:           2009.4MB/s  2006.7MB/s
WRITE:          2007.5MB/s  2004.9MB/s
READ:           1929.7MB/s  1935.6MB/s
WRITE:          1926.8MB/s  1932.6MB/s
jobs5
READ:           18823MB/s  19024MB/s
READ:           18968MB/s  19071MB/s
WRITE:          6191.6MB/s  6372.1MB/s
WRITE:          5818.7MB/s  5787.1MB/s
READ:           2011.7MB/s  1981.3MB/s
WRITE:          2011.4MB/s  1980.1MB/s
READ:           1949.3MB/s  1935.7MB/s
WRITE:          1940.4MB/s  1926.1MB/s
jobs6
READ:           21870MB/s  21715MB/s
READ:           19957MB/s  19879MB/s
WRITE:          6528.4MB/s  6537.6MB/s
WRITE:          6098.9MB/s  6073.6MB/s
READ:           2048.6MB/s  2049.9MB/s
WRITE:          2041.7MB/s  2042.9MB/s
READ:           2013.4MB/s  1990.4MB/s
WRITE:          2009.4MB/s  1986.5MB/s
jobs7
READ:           21359MB/s  21124MB/s
READ:           19746MB/s  19293MB/s
WRITE:          6660.4MB/s  6518.8MB/s
WRITE:          6211.6MB/s  6193.1MB/s
READ:           2089.7MB/s  2080.6MB/s
WRITE:          2085.8MB/s  2076.5MB/s
READ:           2041.2MB/s  2052.5MB/s
WRITE:          2037.5MB/s  2048.8MB/s
jobs8
READ:           20477MB/s  19974MB/s
READ:           18922MB/s  18576MB/s
WRITE:          6851.9MB/s  6788.3MB/s
WRITE:          6407.7MB/s  6347.5MB/s
READ:           2134.8MB/s  2136.1MB/s
WRITE:          2132.8MB/s  2134.4MB/s
READ:           2074.2MB/s  2069.6MB/s
WRITE:          2087.3MB/s  2082.4MB/s
jobs9
READ:           19797MB/s  19994MB/s
READ:           18806MB/s  18581MB/s
WRITE:          6878.7MB/s  6822.7MB/s
WRITE:          6456.8MB/s  6447.2MB/s
READ:           2141.1MB/s  2154.7MB/s
WRITE:          2144.4MB/s  2157.3MB/s
READ:           2084.1MB/s  2085.1MB/s
WRITE:          2091.5MB/s  2092.5MB/s
jobs10
READ:           19794MB/s  19784MB/s
READ:           18794MB/s  18745MB/s
WRITE:          6984.4MB/s  6676.3MB/s
WRITE:          6532.3MB/s  6342.7MB/s
READ:           2150.6MB/s  2155.4MB/s
WRITE:          2156.8MB/s  2161.5MB/s
READ:           2106.4MB/s  2095.6MB/s
WRITE:          2109.7MB/s  2098.4MB/s

                                    BASE                       PATCHED
jobs1                              perfstat
stalled-cycles-frontend     102,480,595,419 (  41.53%)   114,508,864,804 (  46.92%)
stalled-cycles-backend       51,941,417,832 (  21.05%)    46,836,112,388 (  19.19%)
instructions                283,612,054,215 (    1.15)   283,918,134,959 (    1.16)
branches                     56,372,560,385 ( 724.923)    56,449,814,753 ( 733.766)
branch-misses                   374,826,000 (   0.66%)       326,935,859 (   0.58%)
jobs2                              perfstat
stalled-cycles-frontend     155,142,745,777 (  40.99%)   164,170,979,198 (  43.82%)
stalled-cycles-backend       70,813,866,387 (  18.71%)    66,456,858,165 (  17.74%)
instructions                463,436,648,173 (    1.22)   464,221,890,191 (    1.24)
branches                     91,088,733,902 ( 760.088)    91,278,144,546 ( 769.133)
branch-misses                   504,460,363 (   0.55%)       394,033,842 (   0.43%)
jobs3                              perfstat
stalled-cycles-frontend     201,300,397,212 (  39.84%)   223,969,902,257 (  44.44%)
stalled-cycles-backend       87,712,593,974 (  17.36%)    81,618,888,712 (  16.19%)
instructions                642,869,545,023 (    1.27)   644,677,354,132 (    1.28)
branches                    125,724,560,594 ( 690.682)   126,133,159,521 ( 694.542)
branch-misses                   527,941,798 (   0.42%)       444,782,220 (   0.35%)
jobs4                              perfstat
stalled-cycles-frontend     246,701,197,429 (  38.12%)   280,076,030,886 (  43.29%)
stalled-cycles-backend      119,050,341,112 (  18.40%)   110,955,641,671 (  17.15%)
instructions                822,716,962,127 (    1.27)   825,536,969,320 (    1.28)
branches                    160,590,028,545 ( 688.614)   161,152,996,915 ( 691.068)
branch-misses                   650,295,287 (   0.40%)       550,229,113 (   0.34%)
jobs5                              perfstat
stalled-cycles-frontend     298,958,462,516 (  38.30%)   344,852,200,358 (  44.16%)
stalled-cycles-backend      137,558,742,122 (  17.62%)   129,465,067,102 (  16.58%)
instructions              1,005,714,688,752 (    1.29) 1,007,657,999,432 (    1.29)
branches                    195,988,773,962 ( 697.730)   196,446,873,984 ( 700.319)
branch-misses                   695,818,940 (   0.36%)       624,823,263 (   0.32%)
jobs6                              perfstat
stalled-cycles-frontend     334,497,602,856 (  36.71%)   387,590,419,779 (  42.38%)
stalled-cycles-backend      163,539,365,335 (  17.95%)   152,640,193,639 (  16.69%)
instructions              1,184,738,177,851 (    1.30) 1,187,396,281,677 (    1.30)
branches                    230,592,915,640 ( 702.902)   231,253,802,882 ( 702.356)
branch-misses                   747,934,786 (   0.32%)       643,902,424 (   0.28%)
jobs7                              perfstat
stalled-cycles-frontend     396,724,684,187 (  37.71%)   460,705,858,952 (  43.84%)
stalled-cycles-backend      188,096,616,496 (  17.88%)   175,785,787,036 (  16.73%)
instructions              1,364,041,136,608 (    1.30) 1,366,689,075,112 (    1.30)
branches                    265,253,096,936 ( 700.078)   265,890,524,883 ( 702.839)
branch-misses                   784,991,589 (   0.30%)       729,196,689 (   0.27%)
jobs8                              perfstat
stalled-cycles-frontend     440,248,299,870 (  36.92%)   509,554,793,816 (  42.46%)
stalled-cycles-backend      222,575,930,616 (  18.67%)   213,401,248,432 (  17.78%)
instructions              1,542,262,045,114 (    1.29) 1,545,233,932,257 (    1.29)
branches                    299,775,178,439 ( 697.666)   300,528,458,505 ( 694.769)
branch-misses                   847,496,084 (   0.28%)       748,794,308 (   0.25%)
jobs9                              perfstat
stalled-cycles-frontend     506,269,882,480 (  37.86%)   592,798,032,820 (  44.43%)
stalled-cycles-backend      253,192,498,861 (  18.93%)   233,727,666,185 (  17.52%)
instructions              1,721,985,080,913 (    1.29) 1,724,666,236,005 (    1.29)
branches                    334,517,360,255 ( 694.134)   335,199,758,164 ( 697.131)
branch-misses                   873,496,730 (   0.26%)       815,379,236 (   0.24%)
jobs10                             perfstat
stalled-cycles-frontend     549,063,363,749 (  37.18%)   651,302,376,662 (  43.61%)
stalled-cycles-backend      281,680,986,810 (  19.07%)   277,005,235,582 (  18.55%)
instructions              1,901,859,271,180 (    1.29) 1,906,311,064,230 (    1.28)
branches                    369,398,536,153 ( 694.004)   370,527,696,358 ( 688.409)
branch-misses                   967,929,335 (   0.26%)       890,125,056 (   0.24%)

                            BASE           PATCHED
seconds elapsed        79.421641008 78.735285546
seconds elapsed        61.471246133 60.869085949
seconds elapsed        62.317058173 62.224188495
seconds elapsed        60.030739363 60.081102518
seconds elapsed        74.070398362 74.317582865
seconds elapsed        84.985953007 85.414364176
seconds elapsed        97.724553255 98.173311344
seconds elapsed        109.488066758 110.268399318
seconds elapsed        122.768189405 122.967164498
seconds elapsed        135.130035105 136.934770801

On my other system (8 x86_64 CPUs, short version of test results):

                            BASE           PATCHED
seconds elapsed        19.518065994 19.806320662
seconds elapsed        15.172772749 15.594718291
seconds elapsed        13.820925970 13.821708564
seconds elapsed        13.293097816 14.585206405
seconds elapsed        16.207284118 16.064431606
seconds elapsed        17.958376158 17.771825767
seconds elapsed        19.478009164 19.602961508
seconds elapsed        21.347152811 21.352318709
seconds elapsed        24.478121126 24.171088735
seconds elapsed        26.865057442 26.767327618

So performance-wise the numbers are quite similar.

Also update zcomp interface to be more aligned with the crypto API.

[1] http://marc.info/?l=linux-kernel&m=144480832108927&w=2
[2] http://marc.info/?l=linux-kernel&m=145379613507518&w=2
[3] https://github.com/sergey-senozhatsky/zram-perf-test

Link: http://lkml.kernel.org/r/20160531122017.2878-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ebaf9ab56d9d5f350969bd1ea8f47234623c9684)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ia0c362b7419de59e6c6ea81c37f99ef1d22c2b4b

UPSTREAM: zram: rename zstrm find-release functions

This has started as a 'add zlib support' work, but after some thinking I
saw no blockers for a bigger change -- a switch to crypto API.

We don't have an idle zstreams list anymore and our write path now works
absolutely differently, preventing preemption during compression.  This
removes possibilities of read paths preempting writes at wrong places
and opens the door for a move from custom LZO/LZ4 compression backends
implementation to a more generic one, using crypto compress API.

This patch set also eliminates the need of a new context-less crypto API
interface, which was quite hard to sell, so we can move along faster.

benchmarks:

(x86_64, 4GB, zram-perf script)

perf reported run-time fio (max jobs=3).  I performed fio test with the
increasing number of parallel jobs (max to 3) on a 3G zram device, using
`static' data and the following crypto comp algorithms:

842, deflate, lz4, lz4hc, lzo

the output was:

 - test running time (which can tell us what algorithms performs faster)

and

 - zram mm_stat (which tells the compressed memory size, max used memory, etc).

It's just for information.  for example, LZ4HC has twice the running
time of LZO, but the compressed memory size is: 23592960 vs 34603008
bytes.

  test-fio-zram-842
     197.907655282 seconds time elapsed
     201.623142884 seconds time elapsed
     226.854291345 seconds time elapsed
  test-fio-zram-DEFLATE
     253.259516155 seconds time elapsed
     258.148563401 seconds time elapsed
     290.251909365 seconds time elapsed
  test-fio-zram-LZ4
      27.022598717 seconds time elapsed
      29.580522717 seconds time elapsed
      33.293463430 seconds time elapsed
  test-fio-zram-LZ4HC
      56.393954615 seconds time elapsed
      74.904659747 seconds time elapsed
     101.940998564 seconds time elapsed
  test-fio-zram-LZO
      28.155948075 seconds time elapsed
      30.390036330 seconds time elapsed
      34.455773159 seconds time elapsed

zram mm_stat-s (max fio jobs=3)

  test-fio-zram-842
  mm_stat (jobs1): 3221225472 673185792 690266112        0 690266112        0        0
  mm_stat (jobs2): 3221225472 673185792 690266112        0 690266112        0        0
  mm_stat (jobs3): 3221225472 673185792 690266112        0 690266112        0        0
  test-fio-zram-DEFLATE
  mm_stat (jobs1): 3221225472  24379392  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  24379392  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  24379392  37761024        0  37761024        0        0
  test-fio-zram-LZ4
  mm_stat (jobs1): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  23592960  37761024        0  37761024        0        0
  test-fio-zram-LZ4HC
  mm_stat (jobs1): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  23592960  37761024        0  37761024        0        0
  test-fio-zram-LZO
  mm_stat (jobs1): 3221225472  34603008  50335744        0  50335744        0        0
  mm_stat (jobs2): 3221225472  34603008  50335744        0  50335744        0        0
  mm_stat (jobs3): 3221225472  34603008  50335744        0  50339840        0        0

This patch (of 8):

We don't perform any zstream idle list lookup anymore, so
zcomp_strm_find()/zcomp_strm_release() names are not representative.

Rename to zcomp_stream_get()/zcomp_stream_put().

Link: http://lkml.kernel.org/r/20160531122017.2878-2-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 2aea8493d326bdf15446768333e1d2c91b040b5c)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I2f4c9e215bca73ba5adb1354aaec6e32e420920d

UPSTREAM: zram: introduce per-device debug_stat sysfs node

debug_stat sysfs is read-only and represents various debugging data that
zram developers may need.  This file is not meant to be used by anyone
else: its content is not documented and will change any time w/o any
notice.  Therefore, the output of debug_stat file contains a version
string.  To avoid any confusion, we will increase the version number
every time we modify the output.

At the moment this file exports only one value -- the number of
re-compressions, IOW, the number of times compression fast path has
failed.  This stat is temporary any will be useful in case if any
per-cpu compression streams regressions will be reported.

Link: http://lkml.kernel.org/r/20160513230834.GB26763@bbox
Link: http://lkml.kernel.org/r/20160511134553.12655-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 623e47fc64f8de480b322b7ed68855f97137e2a5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie0ef61db7aa0b2c713de1d8bf48e8a545b4276e9

UPSTREAM: zram: remove max_comp_streams internals

Remove the internal part of max_comp_streams interface, since we
switched to per-cpu streams.  We will keep RW max_comp_streams attr
around, because:

a) we may (silently) switch back to idle compression streams list and
   don't want to disturb user space

b) max_comp_streams attr must wait for the next 'lay off cycle'; we
   give user space 2 years to adjust before we remove/downgrade the attr,
   and there are already several attrs scheduled for removal in 4.11, so
   it's too late for max_comp_streams.

This slightly change a user visible behaviour:

- First, reading from max_comp_stream file now will always return the
  number of online CPUs.

- Second, writing to max_comp_stream will not take any effect.

Link: http://lkml.kernel.org/r/20160503165546.25201-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 43209ea2d17aae1540d4e28274e36404f72702f2)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I1902e741b4d3b83c5bd0d66bf1bae021dbfe2056

UPSTREAM: zram: user per-cpu compression streams

Remove idle streams list and keep compression streams in per-cpu data.
This removes two contented spin_lock()/spin_unlock() calls from write
path and also prevent write OP from being preempted while holding the
compression stream, which can cause slow downs.

For instance, let's assume that we have N cpus and N-2
max_comp_streams.TASK1 owns the last idle stream, TASK2-TASK3 come in
with the write requests:

  TASK1            TASK2              TASK3
 zram_bvec_write()
  spin_lock
  find stream
  spin_unlock

  compress

  <<preempted>>   zram_bvec_write()
                   spin_lock
                   find stream
                   spin_unlock
                     no_stream
                       schedule
                                     zram_bvec_write()
                                      spin_lock
                                      find_stream
                                      spin_unlock
                                        no_stream
                                          schedule
   spin_lock
   release stream
   spin_unlock
     wake up TASK2

not only TASK2 and TASK3 will not get the stream, TASK1 will be
preempted in the middle of its operation; while we would prefer it to
finish compression and release the stream.

Test environment: x86_64, 4 CPU box, 3G zram, lzo

The following fio tests were executed:
      read, randread, write, randwrite, rw, randrw
with the increasing number of jobs from 1 to 10.

                  4 streams        8 streams       per-cpu
  ===========================================================
  jobs1
  READ:           2520.1MB/s       2566.5MB/s      2491.5MB/s
  READ:           2102.7MB/s       2104.2MB/s      2091.3MB/s
  WRITE:          1355.1MB/s       1320.2MB/s      1378.9MB/s
  WRITE:          1103.5MB/s       1097.2MB/s      1122.5MB/s
  READ:           434013KB/s       435153KB/s      439961KB/s
  WRITE:          433969KB/s       435109KB/s      439917KB/s
  READ:           403166KB/s       405139KB/s      403373KB/s
  WRITE:          403223KB/s       405197KB/s      403430KB/s
  jobs2
  READ:           7958.6MB/s       8105.6MB/s      8073.7MB/s
  READ:           6864.9MB/s       6989.8MB/s      7021.8MB/s
  WRITE:          2438.1MB/s       2346.9MB/s      3400.2MB/s
  WRITE:          1994.2MB/s       1990.3MB/s      2941.2MB/s
  READ:           981504KB/s       973906KB/s      1018.8MB/s
  WRITE:          981659KB/s       974060KB/s      1018.1MB/s
  READ:           937021KB/s       938976KB/s      987250KB/s
  WRITE:          934878KB/s       936830KB/s      984993KB/s
  jobs3
  READ:           13280MB/s        13553MB/s       13553MB/s
  READ:           11534MB/s        11785MB/s       11755MB/s
  WRITE:          3456.9MB/s       3469.9MB/s      4810.3MB/s
  WRITE:          3029.6MB/s       3031.6MB/s      4264.8MB/s
  READ:           1363.8MB/s       1362.6MB/s      1448.9MB/s
  WRITE:          1361.9MB/s       1360.7MB/s      1446.9MB/s
  READ:           1309.4MB/s       1310.6MB/s      1397.5MB/s
  WRITE:          1307.4MB/s       1308.5MB/s      1395.3MB/s
  jobs4
  READ:           20244MB/s        20177MB/s       20344MB/s
  READ:           17886MB/s        17913MB/s       17835MB/s
  WRITE:          4071.6MB/s       4046.1MB/s      6370.2MB/s
  WRITE:          3608.9MB/s       3576.3MB/s      5785.4MB/s
  READ:           1824.3MB/s       1821.6MB/s      1997.5MB/s
  WRITE:          1819.8MB/s       1817.4MB/s      1992.5MB/s
  READ:           1765.7MB/s       1768.3MB/s      1937.3MB/s
  WRITE:          1767.5MB/s       1769.1MB/s      1939.2MB/s
  jobs5
  READ:           18663MB/s        18986MB/s       18823MB/s
  READ:           16659MB/s        16605MB/s       16954MB/s
  WRITE:          3912.4MB/s       3888.7MB/s      6126.9MB/s
  WRITE:          3506.4MB/s       3442.5MB/s      5519.3MB/s
  READ:           1798.2MB/s       1746.5MB/s      1935.8MB/s
  WRITE:          1792.7MB/s       1740.7MB/s      1929.1MB/s
  READ:           1727.6MB/s       1658.2MB/s      1917.3MB/s
  WRITE:          1726.5MB/s       1657.2MB/s      1916.6MB/s
  jobs6
  READ:           21017MB/s        20922MB/s       21162MB/s
  READ:           19022MB/s        19140MB/s       18770MB/s
  WRITE:          3968.2MB/s       4037.7MB/s      6620.8MB/s
  WRITE:          3643.5MB/s       3590.2MB/s      6027.5MB/s
  READ:           1871.8MB/s       1880.5MB/s      2049.9MB/s
  WRITE:          1867.8MB/s       1877.2MB/s      2046.2MB/s
  READ:           1755.8MB/s       1710.3MB/s      1964.7MB/s
  WRITE:          1750.5MB/s       1705.9MB/s      1958.8MB/s
  jobs7
  READ:           21103MB/s        20677MB/s       21482MB/s
  READ:           18522MB/s        18379MB/s       19443MB/s
  WRITE:          4022.5MB/s       4067.4MB/s      6755.9MB/s
  WRITE:          3691.7MB/s       3695.5MB/s      5925.6MB/s
  READ:           1841.5MB/s       1933.9MB/s      2090.5MB/s
  WRITE:          1842.7MB/s       1935.3MB/s      2091.9MB/s
  READ:           1832.4MB/s       1856.4MB/s      1971.5MB/s
  WRITE:          1822.3MB/s       1846.2MB/s      1960.6MB/s
  jobs8
  READ:           20463MB/s        20194MB/s       20862MB/s
  READ:           18178MB/s        17978MB/s       18299MB/s
  WRITE:          4085.9MB/s       4060.2MB/s      7023.8MB/s
  WRITE:          3776.3MB/s       3737.9MB/s      6278.2MB/s
  READ:           1957.6MB/s       1944.4MB/s      2109.5MB/s
  WRITE:          1959.2MB/s       1946.2MB/s      2111.4MB/s
  READ:           1900.6MB/s       1885.7MB/s      2082.1MB/s
  WRITE:          1896.2MB/s       1881.4MB/s      2078.3MB/s
  jobs9
  READ:           19692MB/s        19734MB/s       19334MB/s
  READ:           17678MB/s        18249MB/s       17666MB/s
  WRITE:          4004.7MB/s       4064.8MB/s      6990.7MB/s
  WRITE:          3724.7MB/s       3772.1MB/s      6193.6MB/s
  READ:           1953.7MB/s       1967.3MB/s      2105.6MB/s
  WRITE:          1953.4MB/s       1966.7MB/s      2104.1MB/s
  READ:           1860.4MB/s       1897.4MB/s      2068.5MB/s
  WRITE:          1858.9MB/s       1895.9MB/s      2066.8MB/s
  jobs10
  READ:           19730MB/s        19579MB/s       19492MB/s
  READ:           18028MB/s        18018MB/s       18221MB/s
  WRITE:          4027.3MB/s       4090.6MB/s      7020.1MB/s
  WRITE:          3810.5MB/s       3846.8MB/s      6426.8MB/s
  READ:           1956.1MB/s       1994.6MB/s      2145.2MB/s
  WRITE:          1955.9MB/s       1993.5MB/s      2144.8MB/s
  READ:           1852.8MB/s       1911.6MB/s      2075.8MB/s
  WRITE:          1855.7MB/s       1914.6MB/s      2078.1MB/s

perf stat

                                  4 streams                       8 streams                       per-cpu
  ====================================================================================================================
  jobs1
  stalled-cycles-frontend      23,174,811,209 (  38.21%)     23,220,254,188 (  38.25%)       23,061,406,918 (  38.34%)
  stalled-cycles-backend       11,514,174,638 (  18.98%)     11,696,722,657 (  19.27%)       11,370,852,810 (  18.90%)
  instructions                 73,925,005,782 (    1.22)     73,903,177,632 (    1.22)       73,507,201,037 (    1.22)
  branches                     14,455,124,835 ( 756.063)     14,455,184,779 ( 755.281)       14,378,599,509 ( 758.546)
  branch-misses                    69,801,336 (   0.48%)         80,225,529 (   0.55%)           72,044,726 (   0.50%)
  jobs2
  stalled-cycles-frontend      49,912,741,782 (  46.11%)     50,101,189,290 (  45.95%)       32,874,195,633 (  35.11%)
  stalled-cycles-backend       27,080,366,230 (  25.02%)     27,949,970,232 (  25.63%)       16,461,222,706 (  17.58%)
  instructions                122,831,629,690 (    1.13)    122,919,846,419 (    1.13)      121,924,786,775 (    1.30)
  branches                     23,725,889,239 ( 692.663)     23,733,547,140 ( 688.062)       23,553,950,311 ( 794.794)
  branch-misses                    90,733,041 (   0.38%)         96,320,895 (   0.41%)           84,561,092 (   0.36%)
  jobs3
  stalled-cycles-frontend      66,437,834,608 (  45.58%)     63,534,923,344 (  43.69%)       42,101,478,505 (  33.19%)
  stalled-cycles-backend       34,940,799,661 (  23.97%)     34,774,043,148 (  23.91%)       21,163,324,388 (  16.68%)
  instructions                171,692,121,862 (    1.18)    171,775,373,044 (    1.18)      170,353,542,261 (    1.34)
  branches                     32,968,962,622 ( 628.723)     32,987,739,894 ( 630.512)       32,729,463,918 ( 717.027)
  branch-misses                   111,522,732 (   0.34%)        110,472,894 (   0.33%)           99,791,291 (   0.30%)
  jobs4
  stalled-cycles-frontend      98,741,701,675 (  49.72%)     94,797,349,965 (  47.59%)       54,535,655,381 (  33.53%)
  stalled-cycles-backend       54,642,609,615 (  27.51%)     55,233,554,408 (  27.73%)       27,882,323,541 (  17.14%)
  instructions                220,884,807,851 (    1.11)    220,930,887,273 (    1.11)      218,926,845,851 (    1.35)
  branches                     42,354,518,180 ( 592.105)     42,362,770,587 ( 590.452)       41,955,552,870 ( 716.154)
  branch-misses                   138,093,449 (   0.33%)        131,295,286 (   0.31%)          121,794,771 (   0.29%)
  jobs5
  stalled-cycles-frontend     116,219,747,212 (  48.14%)    110,310,397,012 (  46.29%)       66,373,082,723 (  33.70%)
  stalled-cycles-backend       66,325,434,776 (  27.48%)     64,157,087,914 (  26.92%)       32,999,097,299 (  16.76%)
  instructions                270,615,008,466 (    1.12)    270,546,409,525 (    1.14)      268,439,910,948 (    1.36)
  branches                     51,834,046,557 ( 599.108)     51,811,867,722 ( 608.883)       51,412,576,077 ( 729.213)
  branch-misses                   158,197,086 (   0.31%)        142,639,805 (   0.28%)          133,425,455 (   0.26%)
  jobs6
  stalled-cycles-frontend     138,009,414,492 (  48.23%)    139,063,571,254 (  48.80%)       75,278,568,278 (  32.80%)
  stalled-cycles-backend       79,211,949,650 (  27.68%)     79,077,241,028 (  27.75%)       37,735,797,899 (  16.44%)
  instructions                319,763,993,731 (    1.12)    319,937,782,834 (    1.12)      316,663,600,784 (    1.38)
  branches                     61,219,433,294 ( 595.056)     61,250,355,540 ( 598.215)       60,523,446,617 ( 733.706)
  branch-misses                   169,257,123 (   0.28%)        154,898,028 (   0.25%)          141,180,587 (   0.23%)
  jobs7
  stalled-cycles-frontend     162,974,812,119 (  49.20%)    159,290,061,987 (  48.43%)       88,046,641,169 (  33.21%)
  stalled-cycles-backend       92,223,151,661 (  27.84%)     91,667,904,406 (  27.87%)       44,068,454,971 (  16.62%)
  instructions                369,516,432,430 (    1.12)    369,361,799,063 (    1.12)      365,290,380,661 (    1.38)
  branches                     70,795,673,950 ( 594.220)     70,743,136,124 ( 597.876)       69,803,996,038 ( 732.822)
  branch-misses                   181,708,327 (   0.26%)        165,767,821 (   0.23%)          150,109,797 (   0.22%)
  jobs8
  stalled-cycles-frontend     185,000,017,027 (  49.30%)    182,334,345,473 (  48.37%)       99,980,147,041 (  33.26%)
  stalled-cycles-backend      105,753,516,186 (  28.18%)    107,937,830,322 (  28.63%)       51,404,177,181 (  17.10%)
  instructions                418,153,161,055 (    1.11)    418,308,565,828 (    1.11)      413,653,475,581 (    1.38)
  branches                     80,035,882,398 ( 592.296)     80,063,204,510 ( 589.843)       79,024,105,589 ( 730.530)
  branch-misses                   199,764,528 (   0.25%)        177,936,926 (   0.22%)          160,525,449 (   0.20%)
  jobs9
  stalled-cycles-frontend     210,941,799,094 (  49.63%)    204,714,679,254 (  48.55%)      114,251,113,756 (  33.96%)
  stalled-cycles-backend      122,640,849,067 (  28.85%)    122,188,553,256 (  28.98%)       58,360,041,127 (  17.35%)
  instructions                468,151,025,415 (    1.10)    467,354,869,323 (    1.11)      462,665,165,216 (    1.38)
  branches                     89,657,067,510 ( 585.628)     89,411,550,407 ( 588.990)       88,360,523,943 ( 730.151)
  branch-misses                   218,292,301 (   0.24%)        191,701,247 (   0.21%)          178,535,678 (   0.20%)
  jobs10
  stalled-cycles-frontend     233,595,958,008 (  49.81%)    227,540,615,689 (  49.11%)      160,341,979,938 (  43.07%)
  stalled-cycles-backend      136,153,676,021 (  29.03%)    133,635,240,742 (  28.84%)       65,909,135,465 (  17.70%)
  instructions                517,001,168,497 (    1.10)    516,210,976,158 (    1.11)      511,374,038,613 (    1.37)
  branches                     98,911,641,329 ( 585.796)     98,700,069,712 ( 591.583)       97,646,761,028 ( 728.712)
  branch-misses                   232,341,823 (   0.23%)        199,256,308 (   0.20%)          183,135,268 (   0.19%)

per-cpu streams tend to cause significantly less stalled cycles; execute
less branches and hit less branch-misses.

perf stat reported execution time

                          4 streams        8 streams       per-cpu
  ====================================================================
  jobs1
  seconds elapsed        20.909073870     20.875670495    20.817838540
  jobs2
  seconds elapsed        18.529488399     18.720566469    16.356103108
  jobs3
  seconds elapsed        18.991159531     18.991340812    16.766216066
  jobs4
  seconds elapsed        19.560643828     19.551323547    16.246621715
  jobs5
  seconds elapsed        24.746498464     25.221646740    20.696112444
  jobs6
  seconds elapsed        28.258181828     28.289765505    22.885688857
  jobs7
  seconds elapsed        32.632490241     31.909125381    26.272753738
  jobs8
  seconds elapsed        35.651403851     36.027596308    29.108024711
  jobs9
  seconds elapsed        40.569362365     40.024227989    32.898204012
  jobs10
  seconds elapsed        44.673112304     43.874898137    35.632952191

Please see
Link: http://marc.info/?l=linux-kernel&m=146166970727530
Link: http://marc.info/?l=linux-kernel&m=146174716719650
for more test results (under low memory conditions).

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit da9556a2367cf2261ab4d3e100693c82fb1ddb26)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I1af1a466f0ac3f74f9c36f06685111ccef0f4ec4

BACKPORT: zsmalloc: require GFP in zs_malloc()

Pass GFP flags to zs_malloc() instead of using a fixed mask supplied to
zs_create_pool(), so we can be more flexible, but, more importantly, we
need this to switch zram to per-cpu compression streams -- zram will try
to allocate handle with preemption disabled in a fast path and switch to
a slow path (using different gfp mask) if the fast one has failed.

Apart from that, this also align zs_malloc() interface with zspool/zbud.

[sergey.senozhatsky@gmail.com: pass GFP flags to zs_malloc() instead of using a fixed mask]
Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish
Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit d0d8da2dc49dfdfe1d788eaf4d55eb5d4964d926)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I31276c9351be21a4ed588681b332e98142b76526

UPSTREAM: zram/zcomp: do not zero out zcomp private pages

Do not __GFP_ZERO allocated zcomp ->private pages.  We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream.  For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e02d238c9852a91b30da9ea32ce36d1416cdc683)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I911832da703f596998a4139d6033ef1564848c9e

UPSTREAM: zram: pass gfp from zcomp frontend to backend

Each zcomp backend uses own gfp flag but it's pointless because the
context they could be called is driven by upper layer(ie, zcomp
frontend).  As well, zcomp frondend could call them in different
context.  One context(ie, zram init part) is it should be better to make
sure successful allocation other context(ie, further stream allocation
part for accelarating I/O speed) is just optional so let's pass gfp down
from driver (ie, zcomp frontend) like normal MM convention.

[sergey.senozhatsky@gmail.com: add missing __vmalloc zero and highmem gfps]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 75d8947a36d0c9aedd69118d1f14bf424005c7c2)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I572d0565de5aff94ebe0782eba9d34f9c9862060

gud: fix mobicore initialization

* backported from s9

Change-Id: I48476e899495490ded64a9e173e3daa3c4cdafa0

video: mdnie: fix lux node permissions

video: mdnie: Lift RGB tuning restrictions

Change-Id: Ibbf1efd2aa19a2790773bd84da3364cfeffffe4b

BACKPORT: ARM64: dts: msm: Mount the system partition during early init

Add support to early mount system partition so that system
modules can be loaded during early init for msm8226 and msm8974.

Change-Id: I9d75bec6ff9bada5ab2db6de2a58e40323aa6ca2

fs: ifdef samsung zswap lmkd integration

Signed-off-by: Michael Benedict <michaelbt@live.com>

defconfig: enable zram

Signed-off-by: Michael Benedict <michaelbt@live.com>

defconfig: sync

Signed-off-by: Michael Benedict <michaelbt@live.com>

crypto: fix section mismatch

Signed-off-by: Michael Benedict <michaelbt@live.com>

defconfig: disable crypto_fips

Signed-off-by: Michael Benedict <michaelbt@live.com>

Enable CONFIG_NETFILTER_XT_TARGET_CT
resolves issues with tethering after november security update

ARM64: configs: Enable support for sdFAT filesystem
 * Update default charset for FAT to UTF-8, matching sdFAT's default.

fs: sdfat: Add MODULE_ALIAS_FS for supported filesystems

* This is the proper thing to do for filesystem drivers

Change-Id: I109b201d85e324cc0a72c3fcd09df4a3e1703042
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

fs: sdfat: Add config option to register sdFAT for VFAT

Change-Id: I72ba7a14b56175535884390e8601960b5d8ed1cf
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

fs: sdfat: Add config option to register sdFAT for exFAT

Change-Id: Id57abf0a4bd0b433fecc622eecb383cd4ea29d17
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

dos2unix bbdpl Kconfig

Signed-off-by: Michael Benedict <michaelbt@live.com>

selinux: remove sec_selinux

Signed-off-by: Michael Benedict <michaelbt@live.com>

MTP: force generic mtp driver instead of Samsung one

Selinux: force permissive

sigcontext ifdifed 64bit

battery: sec_battery: export {CURRENT/VOLTAGE}_MAX to sysfs

Change-Id: I54c775bb80c2151bdc69ea9fb53a48a34327bbef

usb: remove tizen if function

Signed-off-by: Michael Benedict <michaelbt@live.com>

firmware: convert binary to ihex

Signed-off-by: Michael Benedict <michaelbt@live.com>

dts: import specific dts to each defconfig

Signed-off-by: Michael Benedict <michaelbt@live.com>

net: ipv4: only use when knox_ncm is enabled

Signed-off-by: Michael Benedict <michaelbt@live.com>

defconfig: disable samsung unnecessary security feature

Signed-off-by: Michael Benedict <michaelbt@live.com>

source: N950F DSE2

source: G955F DSE4

Signed-off-by: Michael Benedict <michaelbt@live.com>

source: G950F DSE4

Signed-off-by: Michael Benedict <michaelbt@live.com>

Merge 4.4.111 into android-4.4

Changes in 4.4.111
x86/kasan: Write protect kasan zero shadow
kernel/acct.c: fix the acct->needcheck check in check_free_space()
crypto: n2 - cure use after free
crypto: chacha20poly1305 - validate the digest size
crypto: pcrypt - fix freeing pcrypt instances
sunxi-rsb: Include OF based modalias in device uevent
fscache: Fix the default for fscache_maybe_release_page()
kernel: make groups_sort calling a responsibility group_info allocators
kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
ARC: uaccess: dont use "l" gcc inline asm constraint modifier
Input: elantech - add new icbody type 15
x86/microcode/AMD: Add support for fam17h microcode loading
parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
x86/tlb: Drop the _GPL from the cpu_tlbstate export
genksyms: Handle string literals with spaces in reference files
module: keep percpu symbols in module's symtab
module: Issue warnings when tainting kernel
proc: much faster /proc/vmstat
Map the vsyscall page with _PAGE_USER
Fix build error in vma.c
Linux 4.4.111

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Linux 4.4.111

Fix build error in vma.c

This fixes the following much-reported build issue:

arch/x86/entry/vdso/vma.c: In function ‘map_vdso’:
arch/x86/entry/vdso/vma.c:175:9: error:
        implicit declaration of function ‘pvclock_pvti_cpu0_va’

on some arches and configurations.

Thanks to Guenter for being persistent enough to get it fixed :)

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Map the vsyscall page with _PAGE_USER

This needs to happen early in kaiser_pagetable_walk(), before the
hierarchy is established so that _PAGE_USER permission can be really
set.

A proper fix would be to teach kaiser_pagetable_walk() to update those
permissions but the vsyscall page is the only exception here so ...

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

proc: much faster /proc/vmstat

commit 68ba0326b4e14988f9e0c24a6e12a85cf2acd1ca upstream.

Every current KDE system has process named ksysguardd polling files
below once in several seconds:

$ strace -e trace=open -p $(pidof ksysguardd)
Process 1812 attached
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/proc/net/dev", O_RDONLY)         = 8
open("/proc/net/wireless", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/proc/stat", O_RDONLY)            = 8
open("/proc/vmstat", O_RDONLY)          = 8

Hell knows what it is doing but speed up reading /proc/vmstat by 33%!

Benchmark is open+read+close 1.000.000 times.

BEFORE
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

      13146.768464      task-clock (msec)         #    0.960 CPUs utilized            ( +-  0.60% )
                15      context-switches          #    0.001 K/sec                    ( +-  1.41% )
                 1      cpu-migrations            #    0.000 K/sec                    ( +- 11.11% )
               104      page-faults               #    0.008 K/sec                    ( +-  0.57% )
    45,489,799,349      cycles                    #    3.460 GHz                      ( +-  0.03% )
     9,970,175,743      stalled-cycles-frontend   #   21.92% frontend cycles idle     ( +-  0.10% )
     2,800,298,015      stalled-cycles-backend    #   6.16% backend cycles idle       ( +-  0.32% )
    79,241,190,850      instructions              #    1.74  insn per cycle
                                                  #    0.13  stalled cycles per insn  ( +-  0.00% )
    17,616,096,146      branches                  # 1339.956 M/sec                    ( +-  0.00% )
       176,106,232      branch-misses             #    1.00% of all branches          ( +-  0.18% )

      13.691078109 seconds time elapsed                                          ( +-  0.03% )
      ^^^^^^^^^^^^

AFTER
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

       8688.353749      task-clock (msec)         #    0.950 CPUs utilized            ( +-  1.25% )
                10      context-switches          #    0.001 K/sec                    ( +-  2.13% )
                 1      cpu-migrations            #    0.000 K/sec
               104      page-faults               #    0.012 K/sec                    ( +-  0.56% )
    30,384,010,730      cycles                    #    3.497 GHz                      ( +-  0.07% )
    12,296,259,407      stalled-cycles-frontend   #   40.47% frontend cycles idle     ( +-  0.13% )
     3,370,668,651      stalled-cycles-backend    #  11.09% backend cycles idle       ( +-  0.69% )
    28,969,052,879      instructions              #    0.95  insn per cycle
                                                  #    0.42  stalled cycles per insn  ( +-  0.01% )
     6,308,245,891      branches                  #  726.058 M/sec                    ( +-  0.00% )
       214,685,502      branch-misses             #    3.40% of all branches          ( +-  0.26% )

       9.146081052 seconds time elapsed                                          ( +-  0.07% )
       ^^^^^^^^^^^

vsnprintf() is slow because:

1. format_decode() is busy looking for format specifier: 2 branches
   per character (not in this case, but in others)

2. approximately million branches while parsing format mini language
   and everywhere

3.  just look at what string() does /proc/vmstat is good case because
   most of its content are strings

Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

module: Issue warnings when tainting kernel

commit 3205c36cf7d96024626f92d65f560035df1abcb2 upstream.

While most of the locations where a kernel taint bit is set are accompanied
with a warning message, there are two which set their bits silently.  If
the tainting module gets unloaded later on, it is almost impossible to tell
what was the reason for setting the flag.

Signed-off-by: Libor Pechacek <lpechacek@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

module: keep percpu symbols in module's symtab

commit e0224418516b4d8a6c2160574bac18447c354ef0 upstream.

Currently, percpu symbols from .data..percpu ELF section of a module are
not copied over and stored in final symtab array of struct module.
Consequently such symbol cannot be returned via kallsyms API (for
example kallsyms_lookup_name). This can be especially confusing when the
percpu symbol is exported. Only its __ksymtab et al. are present in its
symtab.

The culprit is in layout_and_allocate() function where SHF_ALLOC flag is
dropped for .data..percpu section. There is in fact no need to copy the
section to final struct module, because kernel module loader allocates
extra percpu section by itself. Unfortunately only symbols from
SHF_ALLOC sections are copied due to a check in is_core_symbol().

The patch changes is_core_symbol() function to copy over also percpu
symbols (their st_shndx points to .data..percpu ELF section). We do it
only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the
function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally
elf_type() returns type 'a' for a percpu symbol because its address is
absolute.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

genksyms: Handle string literals with spaces in reference files

commit a78f70e8d65e88b9f631d073f68cb26dcd746298 upstream.

The reference files use spaces to separate tokens, however, we must
preserve spaces inside string literals. Currently the only case in the
tree is struct edac_raw_error_desc in <linux/edac.h>:

$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
$ mv drivers/edac/amd64_edac.{symtypes,symref}
$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
drivers/edac/amd64_edac.c:527: warning: amd64_get_dram_hole_info: modversion changed because of changes in struct edac_raw_error_desc

Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/tlb: Drop the _GPL from the cpu_tlbstate export

commit 1e5476815fd7f98b888e01a0f9522b63085f96c9 upstream.

The recent changes for PTI touch cpu_tlbstate from various tlb_flush
inlines. cpu_tlbstate is exported as GPL symbol, so this causes a
regression when building out of tree drivers for certain graphics cards.

Aside of that the export was wrong since it was introduced as it should
have been EXPORT_PER_CPU_SYMBOL_GPL().

Use the correct PER_CPU export and drop the _GPL to restore the previous
state which allows users to utilize the cards they payed for.

As always I'm really thrilled to make this kind of change to support the
#friends (or however the hot hashtag of today is spelled) from that closet
sauce graphics corp.

Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
Fixes: 6fd166aae78c ("x86/mm: Use/Fix PCID to optimize user/kernel switches")
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel

commit 88776c0e70be0290f8357019d844aae15edaa967 upstream.

Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."

Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.

As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.

This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/microcode/AMD: Add support for fam17h microcode loading

commit f4e9b7af0cd58dd039a0fb2cd67d57cea4889abf upstream.

The size for the Microcode Patch Block (MPB) for an AMD family 17h
processor is 3200 bytes.  Add a #define for fam17h so that it does
not default to 2048 bytes and fail a microcode load/update.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171130224640.15391.40247.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alice Ferrazzi <alicef@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Input: elantech - add new icbody type 15

commit 10d900303f1c3a821eb0bef4e7b7ece16768fba4 upstream.

The touchpad of Lenovo Thinkpad L480 reports it's version as 15.

Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARC: uaccess: dont use "l" gcc inline asm constraint modifier

commit 79435ac78d160e4c245544d457850a56f805ac0d upstream.

This used to setup the LP_COUNT register automatically, but now has been
removed.

There was an earlier fix 3c7c7a2fc8811 which fixed instance in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains and was not pedantic as it is now !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()

commit 426915796ccaf9c2bd9bb06dc5702225957bc2e5 upstream.

complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy
the thread group, today this is wrong in many ways.

If nothing else, fatal_signal_pending() should always imply that the
whole thread group (except ->group_exit_task if it is not NULL) is
killed, this check breaks the rule.

After the previous changes we can rely on sig_task_ignored();
sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want
to kill this task and sig == SIGKILL OR it is traced and debugger can
intercept the signal.

This should hopefully fix the problem reported by Dmitry.  This
test-case

static int init(void *arg)
{
for (;;)
pause();
}

int main(void)
{
char stack[16 * 1024];

for (;;) {
int pid = clone(init, stack + sizeof(stack)/2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid > 0);

assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);
assert(waitpid(-1, NULL, WSTOPPED) == pid);

assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0);
assert(syscall(__NR_tkill, pid, SIGKILL) == 0);
assert(pid == wait(NULL));
}
}

triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in
task_participate_group_stop().  do_signal_stop()->signal_group_exit()
checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending()
checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING.

And his should fix the minor security problem reported by Kyle,
SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the
task is the root of a pid namespace.

Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Kyle Huey <me@kylehuey.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals

commit ac25385089f673560867eb5179228a44ade0cfc1 upstream.

Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only()
signals even if force == T.  This simplifies the next change and this
matches the same check in get_signal() which will drop these signals
anyway.

Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL

commit 628c1bcba204052d19b686b5bac149a644cdb72e upstream.

The comment in sig_ignored() says "Tracers may want to know about even
ignored signals" but SIGKILL can not be reported to debugger and it is
just wrong to return 0 in this case: SIGKILL should only kill the
SIGNAL_UNKILLABLE task if it comes from the parent ns.

Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on
sig_task_ignored().

SISGTOP coming from within the namespace is not really right too but at
least debugger can intercept it, and we can't drop it here because this
will break "gdb -p 1": ptrace_attach() won't work.  Perhaps we will add
another ->ptrace check later, we will see.

Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel: make groups_sort calling a responsibility group_info allocators

commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fscache: Fix the default for fscache_maybe_release_page()

commit 98801506552593c9b8ac11021b0cdad12cab4f6b upstream.

Fix the default for fscache_maybe_release_page() for when the cookie isn't
valid or the page isn't cached.  It mustn't return false as that indicates
the page cannot yet be freed.

The problem with the default is that if, say, there's no cache, but a
network filesystem's pages are using up almost all the available memory, a
system can OOM because the filesystem ->releasepage() op will not allow
them to be released as fscache_maybe_release_page() incorrectly prevents
it.

This can be tested by writing a sequence of 512MiB files to an AFS mount.
It does not affect NFS or CIFS because both of those wrap the call in a
check of PG_fscache and it shouldn't bother Ceph as that only has
PG_private set whilst writeback is in progress.  This might be an issue for
9P, however.

Note that the pages aren't entirely stuck.  Removing a file or unmounting
will clear things because that uses ->invalidatepage() instead.

Fixes: 201a15428bd5 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sunxi-rsb: Include OF based modalias in device uevent

commit e2bf801ecd4e62222a46d1ba9e57e710171d29c1 upstream.

Include the OF-based modalias in the uevent sent when registering devices
on the sunxi RSB bus, so that user space has a chance to autoload the
kernel module for the device.

Fixes a regression caused by commit 3f241bfa60bd ("arm64: allwinner: a64:
pine64: Use dcdc1 regulator for mmc0"). When the axp20x-rsb module for
the AXP803 PMIC is built as a module, it is not loaded and the system
ends up with an disfunctional MMC controller.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: pcrypt - fix freeing pcrypt instances

commit d76c68109f37cb85b243a1cf0f40313afd2bae68 upstream.

pcrypt is using the old way of freeing instances, where the ->free()
method specified in the 'struct crypto_template' is passed a pointer to
the 'struct crypto_instance'.  But the crypto_instance is being
kfree()'d directly, which is incorrect because the memory was actually
allocated as an aead_instance, which contains the crypto_instance at a
nonzero offset.  Thus, the wrong pointer was being kfree()'d.

Fix it by switching to the new way to free aead_instance's where the
->free() method is specified in the aead_instance itself.

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 0496f56065e0 ("crypto: pcrypt - Add support for new AEAD interface")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: chacha20poly1305 - validate the digest size

commit e57121d08c38dabec15cf3e1e2ad46721af30cae upstream.

If the rfc7539 template was instantiated with a hash algorithm with
digest size larger than 16 bytes (POLY1305_DIGEST_SIZE), then the digest
overran the 'tag' buffer in 'struct chachapoly_req_ctx', corrupting the
subsequent memory, including 'cryptlen'.  This caused a crash during
crypto_skcipher_decrypt().

Fix it by, when instantiating the template, requiring that the
underlying hash algorithm has the digest size expected for Poly1305.

Reproducer:

    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>

    int main()
    {
            int algfd, reqfd;
            struct sockaddr_alg addr = {
                    .salg_type = "aead",
                    .salg_name = "rfc7539(chacha20,sha256)",
            };
            unsigned char buf[32] = { 0 };

            algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(algfd, (void *)&addr, sizeof(addr));
            setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, sizeof(buf));
            reqfd = accept(algfd, 0, 0);
            write(reqfd, buf, 16);
            read(reqfd, buf, 16);
    }

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 71ebc4d1b27d ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: n2 - cure use after free

commit 203f45003a3d03eea8fa28d74cfc74c354416fdb upstream.

queue_cache_init is first called for the Control Word Queue
(n2_crypto_probe). At that time, queue_cache[0] is NULL and a new
kmem_cache will be allocated. If the subsequent n2_register_algs call
fails, the kmem_cache will be released in queue_cache_destroy, but
queue_cache_init[0] is not set back to NULL.

So when the Module Arithmetic Unit gets probed next (n2_mau_probe),
queue_cache_init will not allocate a kmem_cache again, but leave it
as its bogus value, causing a BUG() to trigger when queue_cache[0] is
eventually passed to kmem_cache_zalloc:

n2_crypto: Found N2CP at /virtual-devices@100/n2cp@7
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
n2_crypto: md5 alg registration failed
n2cp f028687c: /virtual-devices@100/n2cp@7: Unable to register algorithms.
called queue_cache_destroy
n2cp: probe of f028687c failed with error -22
n2_crypto: Found NCP at /virtual-devices@100/ncp@6
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
kernel BUG at mm/slab.c:2993!
Call Trace:
 [0000000000604488] kmem_cache_alloc+0x1a8/0x1e0
                  (inlined) kmem_cache_zalloc
                  (inlined) new_queue
                  (inlined) spu_queue_setup
                  (inlined) handle_exec_unit
 [0000000010c61eb4] spu_mdesc_scan+0x1f4/0x460 [n2_crypto]
 [0000000010c62b80] n2_mau_probe+0x100/0x220 [n2_crypto]
 [000000000084b174] platform_drv_probe+0x34/0xc0

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/acct.c: fix the acct->needcheck check in check_free_space()

commit 4d9570158b6260f449e317a5f9ed030c2504a615 upstream.

As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check
is very wrong, we need time_is_after_jiffies() to make sys_acct() work.

Ignoring the overflows, the code should "goto out" if needcheck >
jiffies, while currently it checks "needcheck < jiffies" and thus in the
likely case check_free_space() does nothing until jiffies overflow.

In particular this means that sys_acct() is simply broken, acct_on()
sets acct->needcheck = jiffies and expects that check_free_space()
should set acct->active = 1 after the free-space check, but this won't
happen if jiffies increments in between.

This was broken by commit 32dc73086015 ("get rid of timer in
kern/acct.c") in 2011, then another (correct) commit 795a2f22a8ea
("acct() should honour the limits from the very beginning") made the
problem more visible.

Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com
Fixes: 32dc73086015 ("get rid of timer in kern/acct.c")
Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/kasan: Write protect kasan zero shadow

commit 063fb3e56f6dd29b2633b678b837e1d904200e6f upstream.

After kasan_init() executed, no one is allowed to write to kasan_zero_page,
so write protect it.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clocksource: arch_timer: make virtual counter access configurable

Change-Id: Ibdb1fd768b748002b90bfc165612c12c8311f8a2
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

arm64: issue isb when trapping CNTVCT_EL0 access

Change-Id: I6005a6e944494257bfc2243fde2f7a09c3fd76c6
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

BACKPORT: arm64: Add CNTFRQ_EL0 trap handler

We now trap accesses to CNTVCT_EL0 when the counter is broken
enough to require the kernel to mediate the access. But it
turns out that some existing userspace (such as OpenMPI) do
probe for the counter frequency, leading to an UNDEF exception
as CNTVCT_EL0 and CNTFRQ_EL0 share the same control bit.

The fix is to handle the exception the same way we do for CNTVCT_EL0.

Fixes: a86bd139f2ae ("arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabled")
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 9842119a238bfb92cbab63258dabb54f0e7b111b)

Change-Id: I2f163e2511bab6225f319c0a9e732735cbd108a0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

BACKPORT: arm64: Add CNTVCT_EL0 trap handler

Since people seem to make a point in breaking the userspace visible
counter, we have no choice but to trap the access. Add the required
handler.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6126ce0588eb5a0752d5c8b5796a7fca324fd887)

Change-Id: I0705f47c85a78040df38df18f51a4a22500b904d
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

ANDROID: sdcardfs: Fix missing break on default_normal

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 64672411
Change-Id: I98796df95dc9846adb77a11f49a1a254fb1618b1

ANDROID: usb: f_fs: Prevent gadget unbind if it is already unbound

Upon usb composition switch there is possibility of ep0 file
release happening after gadget driver bind. In case of composition
switch from adb to a non-adb composition gadget will never gets
bound again resulting into failure of usb device enumeration. Fix
this issue by checking FFS_FL_BOUND flag and avoid extra
gadget driver unbind if it is already done as part of composition
switch.

Change-Id: I1638001ff4a94f08224b188aa42425f3d732fa2b
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>

arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry

Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's
actually more useful as a mitigation against speculation attacks that
can leak arbitrary kernel data to userspace through speculation.

Reword the Kconfig help message to reflect this, and make the option
depend on EXPERT so that it is on by default for the majority of users.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

arm64: use RET instruction for exiting the trampoline

Speculation attacks against the entry trampoline can potentially resteer
the speculative instruction stream through the indirect branch and into
arbitrary gadgets within the kernel.

This patch defends against these attacks by forcing a misprediction
through the return stack: a dummy BL instruction loads an entry into
the stack, so that the predicted program flow of the subsequent RET
instruction is to a branch-to-self instruction which is finally resolved
as a branch to the kernel vectors with speculation suppressed.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: kaslr: Put kernel vectors address in separate data page

The literal pool entry for identifying the vectors base is the only piece
of information in the trampoline page that identifies the true location
of the kernel.

This patch moves it into a page-aligned region of the .rodata section
and maps this adjacent to the trampoline text via an additional fixmap
entry, which protects against any accidental leakage of the trampoline
contents.

Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 6c27c4082f4f70b9f41df4d0adf51128b40351df)

Change-Id: Iffe72dc5e7ee171d83a7b916a16146e35ddf904e
[ghackmann@google.com:
 - adjust context
 - replace ARM64_WORKAROUND_QCOM_FALKOR_E1003 alternative with
   compile-time CONFIG_ARCH_MSM8996 check]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Introduce TTBR_ASID_MASK for getting at the ASID in the TTBR

There are now a handful of open-coded masks to extract the ASID from a
TTBR value, so introduce a TTBR_ASID_MASK and use that instead.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit b519538dfefc2f8478a1bcb458459c861d431784)

Change-Id: I538071c8ec96dca587205c78839c07b6c772fa91
[ghackmann@google.com: adjust context, applying asm-uaccess.h changes
 to uaccess.h instead]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0

Add a Kconfig entry to control use of the entry trampoline, which allows
us to unmap the kernel whilst running in userspace and improve the
robustness of KASLR.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 084eb77cd3a81134d02500977dc0ecc9277dc97d)

Change-Id: Iac41787b660dde902f32325afd2f454da600b60d
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: entry: Add fake CPU feature for unmapping the kernel at EL0

Allow explicit disabling of the entry trampoline on the kernel command
line (kpti=off) by adding a fake CPU feature (ARM64_UNMAP_KERNEL_AT_EL0)
that can be used to toggle the alternative sequences in our entry code and
avoid use of the trampoline altogether if desired. This also allows us to
make use of a static key in arm64_kernel_unmapped_at_el0().

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit ea1e3de85e94d711f63437c04624aa0e8de5c8b3)

Change-Id: I11cb874d12a7d0921f452c62b0752e0028a8e0a7
[ghackmann@google.com:
 - adjust context
 - apply cpucaps.h changes to cpufeature.h
 - replace cpus_have_const_cap() with cpus_have_cap()
 - tweak unmap_kernel_at_el0() declaration to match 4.4 APIs]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasks

When unmapping the kernel at EL0, we use tpidrro_el0 as a scratch register
during exception entry from native tasks and subsequently zero it in
the kernel_ventry macro. We can therefore avoid zeroing tpidrro_el0
in the context-switch path for native tasks using the entry trampoline.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 18011eac28c7cb31c87b86b7d0e5b01894405c7f)

Change-Id: Ief7b4099f055420a7a23c8dcf497269192f5fb58
[ghackmann@google.com: adjust context]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: erratum: Work around Falkor erratum #E1003 in trampoline code

We rely on an atomic swizzling of TTBR1 when transitioning from the entry
trampoline to the kernel proper on an exception. We can't rely on this
atomicity in the face of Falkor erratum #E1003, so on affected cores we
can issue a TLB invalidation to invalidate the walk cache prior to
jumping into the kernel. There is still the possibility of a TLB conflict
here due to conflicting walk cache entries prior to the invalidation, but
this doesn't appear to be the case on these CPUs in practice.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit d1777e686ad10ba7c594304429c6045fb79255a1)

Change-Id: Ia6c7ffd47745c179738250afa01cb8bf8594b235
[ghackmann@google.com: replace runtime alternative_if with a
 compile-time check for Code Aurora's out-of-tree CONFIG_ARCH_MSM8996.
 Kryo needs this workaround too, and 4.4 doesn't have any of the
 upstream Falkor errata infrastructure needed to detect this at boot time.]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: entry: Hook up entry trampoline to exception vectors

Hook up the entry trampoline to our exception vectors so that all
exceptions from and returns to EL0 go via the trampoline, which swizzles
the vector base register accordingly. Transitioning to and from the
kernel clobbers x30, so we use tpidrro_el0 and far_el1 as scratch
registers for native tasks.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 4bf3286d29f3a88425d8d8cd53428cbb8f865f04)

Change-Id: Id1e175bdaa0ec2bf8e59f941502183907902a710
[ghackmann@google.com: adjust context, replacing
 alternative_if_not ARM64_WORKAROUND_845719 block with upstream version]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: entry: Explicitly pass exception level to kernel_ventry macro

We will need to treat exceptions from EL0 differently in kernel_ventry,
so rework the macro to take the exception level as an argument and
construct the branch target using that.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 5b1f7fe41909cde40decad9f0e8ee585777a0538)

Change-Id: Iab10d2237e24c008d05856a4bd953504de6e10a8
[ghackmann@google.com: adjust context and kernel entry point names]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Map entry trampoline into trampoline and kernel page tables

The exception entry trampoline needs to be mapped at the same virtual
address in both the trampoline page table (which maps nothing else)
and also the kernel page table, so that we can swizzle TTBR1_EL1 on
exceptions from and return to EL0.

This patch maps the trampoline at a fixed virtual address in the fixmap
area of the kernel virtual address space, which allows the kernel proper
to be randomized with respect to the trampoline when KASLR is enabled.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 51a0048beb449682d632d0af52a515adb9f9882e)

Change-Id: I31b2dcdf4db36c3e31181fe43ccb984f9efb6ac6
[ghackmann@google.com:
 - adjust context
 - tweak __create_pgd_mapping() call to match 4.4 APIs]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: entry: Add exception trampoline page for exceptions from EL0

To allow unmapping of the kernel whilst running at EL0, we need to
point the exception vectors at an entry trampoline that can map/unmap
the kernel on entry/exit respectively.

This patch adds the trampoline page, although it is not yet plugged
into the vector table and is therefore unused.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit c7b9adaf85f818d747eeff5145eb4095ccd587fb)

Change-Id: Idd27ab26f1ec1db2ff756fc33ebb782201806f7c
[ghackmann@google.com: adjust context]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Invalidate both kernel and user ASIDs when performing TLBI

Since an mm has both a kernel and a user ASID, we need to ensure that
broadcast TLB maintenance targets both address spaces so that things
like CoW continue to work with the uaccess primitives in the kernel.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 9b0de864b5bc298ea53005ad812f3386f81aee9c)

Change-Id: I2369f242a6461795349568cc68ae6324244e6709
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Add arm64_kernel_unmapped_at_el0 helper

In order for code such as TLB invalidation to operate efficiently when
the decision to map the kernel at EL0 is determined at runtime, this
patch introduces a helper function, arm64_kernel_unmapped_at_el0, to
determine whether or not the kernel is mapped whilst running in userspace.

Currently, this just reports the value of CONFIG_UNMAP_KERNEL_AT_EL0,
but will later be hooked up to a fake CPU capability using a static key.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit fc0e1299da548b32440051f58f08e0c1eb7edd0b)

Change-Id: I0f48eadf55ee97f09553380a62d9fffe54d9dc83
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Allocate ASIDs in pairs

In preparation for separate kernel/user ASIDs, allocate them in pairs
for each mm_struct. The bottom bit distinguishes the two: if it is set,
then the ASID will map only userspace.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 0c8ea531b7740754cf374ca8b7510655f569c5e3)

Change-Id: I283c99292b165e04ff1b6b9cb5806805974ae915
[ghackmann@google.com: adjust context]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN

With the ASID now installed in TTBR1, we can re-enable ARM64_SW_TTBR0_PAN
by ensuring that we switch to a reserved ASID of zero when disabling
user access and restore the active user ASID on the uaccess enable path.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 27a921e75711d924617269e0ba4adb8bae9fd0d1)

Change-Id: I3b06e02766753c59fac975363a2ead5c5e45b8f3
[ghackmann@google.com: adjust context, applying asm-uaccess.h changes to
 uaccess.h]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Move ASID from TTBR0 to TTBR1

In preparation for mapping kernelspace and userspace with different
ASIDs, move the ASID to TTBR1 and update switch_mm to context-switch
TTBR0 via an invalid mapping (the zero page).

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 7655abb953860485940d4de74fb45a8192149bb6)

Change-Id: Id8a18e16dfab5c8b7bc31174b14100142a6af3b0
[ghackmann@google.com: adjust context]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN

We're about to rework the way ASIDs are allocated, switch_mm is
implemented and low-level kernel entry/exit is handled, so keep the
ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting.

It will be re-enabled in a subsequent patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit 376133b7edc20f237a42e4c72415cc9e8c0a9704)

Change-Id: I38d3f7a66b1d52abcea3e23b1e80277b03c6dbe0
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

FROMLIST: arm64: mm: Use non-global mappings for kernel space

In preparation for unmapping the kernel whilst running in userspace,
make the kernel mappings non-global so we can avoid expensive TLB
invalidation on kernel exit to userspace.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
 commit e046eb0c9bf26d94be9e4592c00c7a78b0fa9bfd)

Change-Id: If53d6db042f8fefff3ecf8a7658291e1f1ac659f
[ghackmann@google.com: apply pgtable-prot.h changes to pgtable.h instead]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

UPSTREAM: arm64: factor out entry stack manipulation

In subsequent patches, we will detect stack overflow in our exception
entry code, by verifying the SP after it has been decremented to make
space for the exception regs.

This verification code is small, and we can minimize its impact by
placing it directly in the vectors. To avoid redundant modification of
the SP, we also need to move the initial decrement of the SP into the
vectors.

As a preparatory step, this patch introduces kernel_ventry, which
performs this decrement, and updates the entry code accordingly.
Subsequent patches will fold SP verification into kernel_ventry.

There should be no functional change as a result of this patch.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[Mark: turn into prep patch, expand commit msg]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
(cherry picked from commit b11e5759bfac0c474d95ec4780b1566350e64cad)

Change-Id: I5883da81b374498f2f9e16ccb596b22c5568f2fe
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>