By default we set DCACHE_REFERENCED and I_REFERENCED on any dentry or
inode we create.  This is problematic as this means that it takes two
trips through the LRU for any of these objects to be reclaimed,
regardless of their actual lifetime.  With enough pressure from these
caches we can easily evict our working set from page cache with single
use objects.  So instead only set *REFERENCED if we've already been
added to the LRU list.  This means that we've been touched since the
first time we were accessed, and so more likely to need to hang out in
cache.

To illustrate this issue I wrote the following scripts

https://github.com/josefbacik/debug-scripts/tree/master/cache-pressure

on my test box.  It is a single socket 4 core CPU with 16gib of RAM and
I tested on an Intel 2tib NVME drive.  The cache-pressure.sh script
creates a new file system and creates 2 6.5gib files in order to take up
13gib of the 16gib of ram with pagecache.  Then it runs a test program
that reads these 2 files in a loop, and keeps track of how often it has
to read bytes for each loop.  On an ideal system with no pressure we
should have to read 0 bytes indefinitely.  The second thing this script
does is start a fs_mark job that creates a ton of 0 length files,
putting pressure on the system with slab only allocations.  On exit the
script prints out how many bytes were read by the read-file program.
The results are as follows

Without patch:
/mnt/btrfs-test/reads/file1: total read during loops 27262988288
/mnt/btrfs-test/reads/file2: total read during loops 27262976000

With patch:
/mnt/btrfs-test/reads/file2: total read during loops 18640457728
/mnt/btrfs-test/reads/file1: total read during loops 9565376512

This patch results in a 50% reduction of the amount of pages evicted
from our working set.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

cmd in COMPATIBLE_IOCTL is always a u32, so cast it so there isn't a
warning about an overflow in XFORM.

From: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: NMark Charlebois <charlebm@gmail.com>
Signed-off-by: NBehan Webster <behanw@converseincode.com>
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Currently we just stash anything we got into file->f_flags, and the
report it in fcntl(F_GETFD).  This patch just clears out all unknown
flags so that we don't pass them to the fs or report them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a central define for all valid open flags, and use it in the uniqueness
check.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

_submit_bh() allowed submitting a buffer_head for I/O using custom
bio_flags.  It used to be used by jbd to set BIO_SNAP_STABLE, introduced
by commit 71368511 ("mm: make snapshotting pages for stable writes a
per-bio operation").  However, the code and flag has since been removed
and no _submit_bh() users remain.

These days, bio_flags are mostly used internally by the block layer to
track the state of bio's.  As such, it doesn't really make sense for
filesystems to use them instead of op_flags when wanting special
behavior for block requests.

Therefore, remove _submit_bh() and trim the bio_flags argument from
submit_bh_wbc().

Cc: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory.  Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Drop duplicate header percpu-rwsem.h from linux/fs.h.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Previous AFFS patch fixed OFS write operations but unveiled
another bug: files greater than 4KB are being created with a wrong
size resulting in errors like the following:

dd if=/dev/zero of=file bs=4097 count=1
cp file /mnt/affs/
cp: error writing '/mnt/affs/file': Bad address
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We called unconditionally affs_bread_ino() with create 0 resulting in
"error (device ...): get_block(): strange block request 0"
when trying to write on AFFS OFS format.

This patch adds create parameter to that function.
0 for affs_readpage_ofs()
1 for affs_write_begin_ofs()

Bug was found here:
https://bugzilla.kernel.org/show_bug.cgi?id=114961Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

node generation has to be stored on disk.
AFAICS we won't be able to manage it on AFFS.
This patch removes relevant check in affs_nfs_get_inode()
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Have that file in global include/linux is not needed.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

AFFS symbolic links were broken since kernel 2.6.29

Problem was bisected to the following

commit ebd09abb ("vfs: ensure page symlinks are NUL-terminated")
commit 03514685 ("vfs: introduce helper function to safely
NUL-terminate symlinks")

AFFS wasn't setting inode size when reading symbolic link from disk or
creating a new one. Result was zero allocation in pagecache.

ln -s file symlink

ls -lrt

file
symlink ->

This patch adds inode isize information on inode get and symbolic link
addition.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull ARM SoC fixes from Olof Johansson:
 "Again, a batch that's been sitting a couple of weeks, mostly because
  I anticipated a bit more material but it didn't show up -- which is
  good.

  These are all your garden variety fixes for ARM platforms.

  The most visible issue fixed here is probably the SMP reset issue on
  OMAP, the rest are minor stuff"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: allwinner: a64: add pmu0 regs for USB PHY
  ARM: OMAP2+: omap_device: Sync omap_device and pm_runtime after probe defer
  reset: add exported __reset_control_get, return NULL if optional
  ARM: orion5x: only call into phylib when available
  ARM: omap2+: Revert omap-smp.c changes resetting CPU1 during boot
  ARM: dts: am335x-evmsk: adjust mmc2 param to allow suspend
  ARM: dts: ti: fix PCI bus dtc warnings
  ARM: dts: am335x-baltos: disable EEE for Atheros 8035 PHY
  ARM: dts: OMAP3: Fix MFG ID EEPROM
  ARM: sun8i: a33: add operating-points-v2 property to all nodes
  ARM: sun8i: a33: remove highest OPP to fix CPU crashes

Pull block fixes from Jens Axboe:
 "Four small fixes.

  Three of them fix the same error in NVMe, in loop, fc, and rdma
  respectively.  The last fix from Ming fixes a regression in this
  series, where our bvec gap logic was wrong and causes an oops on
  NVMe for certain conditions"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix bio_will_gap() for first bvec with offset
  nvme-fc: Fix sqsize wrong assignment based on ctrl MQES capability
  nvme-rdma: Fix sqsize wrong assignment based on ctrl MQES capability
  nvme-loop: Fix sqsize wrong assignment based on ctrl MQES capability

Merge tag 'omap-for-v4.11/fixes-rc6-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Regression fix for omap interconnect code for deferred probe.
Without this fix we can get PM related warnings for devices that
use deferred probe. If necessary, this fix can wait for the
v4.12 merge window no problem.

* tag 'omap-for-v4.11/fixes-rc6-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP2+: omap_device: Sync omap_device and pm_runtime after probe defer
  ARM: omap2+: Revert omap-smp.c changes resetting CPU1 during boot
  ARM: dts: am335x-evmsk: adjust mmc2 param to allow suspend
  ARM: dts: ti: fix PCI bus dtc warnings
  ARM: dts: am335x-baltos: disable EEE for Atheros 8035 PHY
  ARM: dts: OMAP3: Fix MFG ID EEPROM
Signed-off-by: NOlof Johansson <olof@lixom.net>

Pull cgroup fix from Tejun Heo:
 "Unfortunately, the commit to fix the cgroup mount race in the previous
  pull request can lead to hangs.

  The original bug has been around for a while and isn't too likely to
  be triggered in usual use cases. Revert the commit for now"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup: avoid attaching a cgroup root to two different superblocks"

Pull tty fix from Greg KH:
 "Here is a single tty core revert for a patch that was reported to
  cause problems.

  The original issue is one that we have lived with for decades, so
  trying to scramble to fix the fix in time for 4.11-final does not make
  sense due to the fragility of the tty ldisc layer. Just reverting it
  makes sense for now"

* tag 'tty-4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "tty: don't panic on OOM in tty_set_ldisc()"

Pull ftrace fix from Steven Rostedt:
 "While rewriting the function probe code, I stumbled over a long
  standing bug. This bug has been there sinc function tracing was added
  way back when. But my new development depends on this bug being fixed,
  and it should be fixed regardless as it causes ftrace to disable
  itself when triggered, and a reboot is required to enable it again.

  The bug is that the function probe does not disable itself properly if
  there's another probe of its type still enabled. For example:

     # cd /sys/kernel/debug/tracing
     # echo schedule:traceoff > set_ftrace_filter
     # echo do_IRQ:traceoff > set_ftrace_filter
     # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
     # echo do_IRQ:traceoff > set_ftrace_filter

  The above registers two traceoff probes (one for schedule and one for
  do_IRQ, and then removes do_IRQ.

  But since there still exists one for schedule, it is not done
  properly. When adding do_IRQ back, the breakage in the accounting is
  noticed by the ftrace self tests, and it causes a warning and disables
  ftrace"

* tag 'trace-v4.11-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix removing of second function probe

This reverts commit bfb0b80d.

Andrei reports CRIU test hangs with the patch applied.  The bug fixed
by the patch isn't too likely to trigger in actual uses.  Revert the
patch for now.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAndrei Vagin <avagin@virtuozzo.com>
Link: http://lkml.kernel.org/r/20170414232737.GC20350@outlook.office365.com

Pull nvdimm fixes from Dan Williams:
 "A small crop of lockdep, sleeping while atomic, and other fixes /
  band-aids in advance of the full-blown reworks targeting the next
  merge window. The largest change here is "libnvdimm: fix blk free
  space accounting" which deletes a pile of buggy code that better
  testing would have caught before merging. The next change that is
  borderline too big for a late rc is switching the device-dax locking
  from rcu to srcu, I couldn't think of a smaller way to make that fix.

  The __copy_user_nocache fix will have a full replacement in 4.12 to
  move those pmem special case considerations into the pmem driver. The
  "libnvdimm: band aid btt vs clear poison locking" commit admits that
  our error clearing support for btt went in broken, so we just disable
  it in 4.11 and -stable. A replacement / full fix is in the pipeline
  for 4.12

  Some of these would have been caught earlier had DEBUG_ATOMIC_SLEEP
  been enabled on my development station. I wonder if we should have:

      config DEBUG_ATOMIC_SLEEP
        default PROVE_LOCKING

  ...since I mistakenly thought I got both with PROVE_LOCKING=y.

  These have received a build success notification from the 0day robot,
  and some have appeared in a -next release with no reported issues"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  x86, pmem: fix broken __copy_user_nocache cache-bypass assumptions
  device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation
  libnvdimm: band aid btt vs clear poison locking
  libnvdimm: fix reconfig_mutex, mmap_sem, and jbd2_handle lockdep splat
  libnvdimm: fix blk free space accounting
  acpi, nfit, libnvdimm: fix interleave set cookie calculation (64-bit comparison)

Pull SCSI fixes from James Bottomley:
 "This is seven small fixes which are all for user visible issues that
  fortunately only occur in rare circumstances.

  The most serious is the sr one in which QEMU can cause us to read
  beyond the end of a buffer (I don't think it's exploitable, but just
  in case).

  The next is the sd capacity fix which means all non 512 byte sector
  drives greater than 2TB fail to be correctly sized.

  The rest are either in new drivers (qedf) or on error legs"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ipr: do not set DID_PASSTHROUGH on CHECK CONDITION
  scsi: aacraid: fix PCI error recovery path
  scsi: sd: Fix capacity calculation with 32-bit sector_t
  scsi: qla2xxx: Add fix to read correct register value for ISP82xx.
  scsi: qedf: Fix crash due to unsolicited FIP VLAN response.
  scsi: sr: Sanity check returned mode data
  scsi: sd: Consider max_xfer_blocks if opt_xfer_blocks is unusable

Pull parisc fix from Helge Deller:
 "Mikulas Patocka fixed a few bugs in our new pa_memcpy() assembler
  function, e.g. one bug made the kernel unbootable if source and
  destination address are the same"

* 'parisc-4.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix bugs in pa_memcpy

Otherwise lockdep says:

[ 1337.483798] ================================================
[ 1337.483999] [ BUG: lock held when returning to user space! ]
[ 1337.484252] 4.11.0-rc6 #19 Not tainted
[ 1337.484423] ------------------------------------------------
[ 1337.484626] mount/14766 is leaving the kernel with locks still held!
[ 1337.484841] 1 lock held by mount/14766:
[ 1337.485017]  #0:  (&type->s_umount_key#33/1){+.+.+.}, at: [<ffffffff8124171f>] sget_userns+0x2af/0x520

Caught by xfstests generic/413 which tried to mount with the unsupported
mount option dax.  Then xfstests generic/422 ran sync which deadlocks.
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>
Acked-by: NMike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Normal pathname lookup doesn't allow empty pathnames, but using
AT_EMPTY_PATH (with name_to_handle_at() or fstatat(), for example) you
can trigger an empty pathname lookup.

And not only is the RCU lookup in that case entirely unnecessary
(because we'll obviously immediately finalize the end result), it is
actively wrong.

Why? An empth path is a special case that will return the original
'dirfd' dentry - and that dentry may not actually be RCU-free'd,
resulting in a potential use-after-free if we were to initialize the
path lazily under the RCU read lock and depend on complete_walk()
finalizing the dentry.

Found by syzkaller and KASAN.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reported-by: NVegard Nossum <vegard.nossum@gmail.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The patch 554bfece ("parisc: Fix access
fault handling in pa_memcpy()") reimplements the pa_memcpy function.
Unfortunatelly, it makes the kernel unbootable. The crash happens in the
function ide_complete_cmd where memcpy is called with the same source
and destination address.

This patch fixes a few bugs in pa_memcpy:

* When jumping to .Lcopy_loop_16 for the first time, don't skip the
  instruction "ldi 31,t0" (this bug made the kernel unbootable)
* Use the COND macro when comparing length, so that the comparison is
  64-bit (a theoretical issue, in case the length is greater than
  0xffffffff)
* Don't use the COND macro after the "extru" instruction (the PA-RISC
  specification says that the upper 32-bits of extru result are undefined,
  although they are set to zero in practice)
* Fix exception addresses in .Lcopy16_fault and .Lcopy8_fault
* Rename .Lcopy_loop_4 to .Lcopy_loop_8 (so that it is consistent with
  .Lcopy8_fault)

Cc: <stable@vger.kernel.org> # v4.9+
Fixes: 554bfece ("parisc: Fix access fault handling in pa_memcpy()")
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NHelge Deller <deller@gmx.de>

Pull input fixes from Dmitry Torokhov:
 "Just a small update to xpad driver to recognize yet another gamepad,
  and another change making sure userio.h is exported"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: xpad - add support for Razer Wildcat gamepad
  uapi: add missing install of userio.h

Pull networking fixes from David Miller:
 "Things seem to be settling down as far as networking is concerned,
  let's hope this trend continues...

   1) Add iov_iter_revert() and use it to fix the behavior of
      skb_copy_datagram_msg() et al., from Al Viro.

   2) Fix the protocol used in the synthetic SKB we cons up for the
      purposes of doing a simulated route lookup for RTM_GETROUTE
      requests. From Florian Larysch.

   3) Don't add noop_qdisc to the per-device qdisc hashes, from Cong
      Wang.

   4) Don't call netdev_change_features with the team lock held, from
      Xin Long.

   5) Revert TCP F-RTO extension to catch more spurious timeouts because
      it interacts very badly with some middle-boxes. From Yuchung
      Cheng.

   6) Fix the loss of error values in l2tp {s,g}etsockopt calls, from
      Guillaume Nault.

   7) ctnetlink uses bit positions where it should be using bit masks,
      fix from Liping Zhang.

   8) Missing RCU locking in netfilter helper code, from Gao Feng.

   9) Avoid double frees and use-after-frees in tcp_disconnect(), from
      Eric Dumazet.

  10) Don't do a changelink before we register the netdevice in
      bridging, from Ido Schimmel.

  11) Lock the ipv6 device address list properly, from Rabin Vincent"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (29 commits)
  netfilter: ipt_CLUSTERIP: Fix wrong conntrack netns refcnt usage
  netfilter: nft_hash: do not dump the auto generated seed
  drivers: net: usb: qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201
  ipv6: Fix idev->addr_list corruption
  net: xdp: don't export dev_change_xdp_fd()
  bridge: netlink: register netdevice before executing changelink
  bridge: implement missing ndo_uninit()
  bpf: reference may_access_skb() from __bpf_prog_run()
  tcp: clear saved_syn in tcp_disconnect()
  netfilter: nf_ct_expect: use proper RCU list traversal/update APIs
  netfilter: ctnetlink: skip dumping expect when nfct_help(ct) is NULL
  netfilter: make it safer during the inet6_dev->addr_list traversal
  netfilter: ctnetlink: make it safer when checking the ct helper name
  netfilter: helper: Add the rcu lock when call __nf_conntrack_helper_find
  netfilter: ctnetlink: using bit to represent the ct event
  netfilter: xt_TCPMSS: add more sanity tests on tcph->doff
  net: tcp: Increase TCP_MIB_OUTRSTS even though fail to alloc skb
  l2tp: don't mask errors in pppol2tp_getsockopt()
  l2tp: don't mask errors in pppol2tp_setsockopt()
  tcp: restrict F-RTO to work-around broken middle-boxes
  ...

Pull x86 fixes from Thomas Gleixner:
 "A set of small fixes for x86:

   - fix locking in RDT to prevent memory leaks and freeing in use
     memory

   - prevent setting invalid values for vdso32_enabled which cause
     inconsistencies for user space resulting in application crashes.

   - plug a race in the vdso32 code between fork and sysctl which causes
     inconsistencies for user space resulting in application crashes.

   - make MPX signal delivery work in compat mode

   - make the dmesg output of traps and faults readable again"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel_rdt: Fix locking in rdtgroup_schemata_write()
  x86/debug: Fix the printk() debug output of signal_fault(), do_trap() and do_general_protection()
  x86/vdso: Plug race between mapping and ELF header setup
  x86/vdso: Ensure vdso32_enabled gets set to valid values only
  x86/signals: Fix lower/upper bound reporting in compat siginfo

Pull perf fixes from Thomas Gleixner:
 "Two small fixes for perf:

   - the move to support cross arch annotation introduced per arch
     initialization requirements, fullfill them for s/390 (Christian
     Borntraeger)

   - add the missing initialization to the LBR entries to avoid exposing
     random or stale data"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Avoid exposing wrong/stale data in intel_pmu_lbr_read_32()
  perf annotate s390: Fix perf annotate error -95 (4.10 regression)

Pull irq fixes from Thomas Gleixner:
 "The irq department provides:

   - two fixes for the CPU affinity spread infrastructure to prevent
     unbalanced spreading in corner cases which leads to horrible
     performance, because interrupts are rather aggregated than spread

   - add a missing spinlock initializer in the imx-gpcv2 init code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-imx-gpcv2: Fix spinlock initialization
  irq/affinity: Fix extra vecs calculation
  irq/affinity: Fix CPU spread for unbalanced nodes

Pull EFI fixes from Thomas Gleixner:
 "Three fixes from EFI land:

   - prevent accessing a Graphic Output Device (GOP) which the kernel
     does not know to handle

   - prevent PCI reconfiguration to modify a BAR which covers the
     framebuffer because that's already in use through the EFI GOP
     interface

   - avoid reserving EFI runtime regions as this results in bogus memory
     mappings"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Don't try to reserve runtime regions
  efi/fb: Avoid reconfiguration of BAR that covers the framebuffer
  efi/libstub: Skip GOP with PIXEL_BLT_ONLY format

Pull btrfs fixes from Chris Mason:
 "Dave Sterba collected a few more fixes for the last rc.

  These aren't marked for stable, but I'm putting them in with a batch
  were testing/sending by hand for this release"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix potential use-after-free for cloned bio
  Btrfs: fix segmentation fault when doing dio read
  Btrfs: fix invalid dereference in btrfs_retry_endio
  btrfs: drop the nossd flag when remounting with -o ssd

Pull more CIFS fixes from Steve French:
 "As promised, here is the remaining set of cifs/smb3 fixes for stable
  (and a fix for one regression) now that they have had additional
  review and testing"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix SMB3 mount without specifying a security mechanism
  CIFS: store results of cifs_reopen_file to avoid infinite wait
  CIFS: remove bad_network_name flag
  CIFS: reconnect thread reschedule itself
  CIFS: handle guest access errors to Windows shares
  CIFS: Fix null pointer deref during read resp processing

When two function probes are added to set_ftrace_filter, and then one of
them is removed, the update to the function locations is not performed, and
the record keeping of the function states are corrupted, and causes an
ftrace_bug() to occur.

This is easily reproducable by adding two probes, removing one, and then
adding it back again.

 # cd /sys/kernel/debug/tracing
 # echo schedule:traceoff > set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter
 # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter

Causes:
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220
 Modules linked in: [...]
 CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
 Call Trace:
  dump_stack+0x68/0x9f
  __warn+0x111/0x130
  ? trace_irq_work_interrupt+0xa0/0xa0
  warn_slowpath_null+0x1d/0x20
  ftrace_get_addr_curr+0x143/0x220
  ? __fentry__+0x10/0x10
  ftrace_replace_code+0xe3/0x4f0
  ? ftrace_int3_handler+0x90/0x90
  ? printk+0x99/0xb5
  ? 0xffffffff81000000
  ftrace_modify_all_code+0x97/0x110
  arch_ftrace_update_code+0x10/0x20
  ftrace_run_update_code+0x1c/0x60
  ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0
  register_ftrace_function_probe+0x4b6/0x590
  ? ftrace_startup+0x310/0x310
  ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30
  ? update_stack_state+0x88/0x110
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? preempt_count_sub+0x18/0xd0
  ? mutex_lock_nested+0x104/0x800
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? __unwind_start+0x1c0/0x1c0
  ? _mutex_lock_nest_lock+0x800/0x800
  ftrace_trace_probe_callback.isra.3+0xc0/0x130
  ? func_set_flag+0xe0/0xe0
  ? __lock_acquire+0x642/0x1790
  ? __might_fault+0x1e/0x20
  ? trace_get_user+0x398/0x470
  ? strcmp+0x35/0x60
  ftrace_trace_onoff_callback+0x48/0x70
  ftrace_regex_write.isra.43.part.44+0x251/0x320
  ? match_records+0x420/0x420
  ftrace_filter_write+0x2b/0x30
  __vfs_write+0xd7/0x330
  ? do_loop_readv_writev+0x120/0x120
  ? locks_remove_posix+0x90/0x2f0
  ? do_lock_file_wait+0x160/0x160
  ? __lock_is_held+0x93/0x100
  ? rcu_read_lock_sched_held+0x5c/0xb0
  ? preempt_count_sub+0x18/0xd0
  ? __sb_start_write+0x10a/0x230
  ? vfs_write+0x222/0x240
  vfs_write+0xef/0x240
  SyS_write+0xab/0x130
  ? SyS_read+0x130/0x130
  ? trace_hardirqs_on_caller+0x182/0x280
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL_64_fastpath+0x18/0xad
 RIP: 0033:0x7fe61c157c30
 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30
 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001
 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400
 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c
  ? trace_hardirqs_off_caller+0xc0/0x110
 ---[ end trace 99fa09b3d9869c2c ]---
 Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150)

Cc: stable@vger.kernel.org
Fixes: 59df055f ("ftrace: trace different functions with a different tracer")
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Commit 729204ef("block: relax check on sg gap") allows us to merge
bios, if both are physically contiguous.  This change can merge a huge
number of small bios, through mkfs for example, mkfs.ntfs running time
can be decreased to ~1/10.

But if one rq starts with a non-aligned buffer (the 1st bvec's bv_offset
is non-zero) and if we allow the merge, it is quite difficult to respect
sg gap limit, especially the max segment size, or we risk having an
unaligned virtual boundary.  This patch tries to avoid the issue by
disallowing a merge, if the req starts with an unaligned buffer.

Also add comments to explain why the merged segment can't end in
unaligned virt boundary.

Fixes: 729204ef ("block: relax check on sg gap")
Tested-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMing Lei <ming.lei@redhat.com>

Rewrote parts of the commit message and comments.
Signed-off-by: NJens Axboe <axboe@fb.com>

Pull fbdev fixes from Bartlomiej Zolnierkiewicz:

 - fix probing time checks in omapfb driver (regression fix)

 - fix optional VBAT support in ssd1307fb driver (regression fix)

 - fix connecting to backend in xen-fbfront driver

* tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux:
  fbdev: omapfb: delete check_required_callbacks()
  xen, fbfront: fix connecting to backend
  fbdev/ssd1307fb: fix optional VBAT support

Pull power management fixes from Rafael Wysocki:
 "These fix a cpufreq core regression related to CPU online/offline and
  several issues in the turbostat and cpupower utilities.

  Specifics:

   - Allow CPUs to be put back online even if the cpufreq driver is
     unable to work with them (eg. due to missing information from
     platform firmware), which was the previous behavior expected by
     users, but changed in the 4.9 time frame (Chen Yu).

   - Fix a few minor issues in the turbostat utility, introduced mostly
     during the recent update of it (Len Brown, Doug Smythies).

   - Fix a cpupower utility bug causing it to report incorrect values
     for turbo frequencies in some cases (Ben Hutchings)"

* tag 'pm-4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpupower: Fix turbo frequency reporting for pre-Sandy Bridge cores
  cpufreq: Bring CPUs up even if cpufreq_online() failed
  tools/power turbostat: update version number
  tools/power turbostat: fix impossibly large CPU%c1 value
  tools/power turbostat: turbostat.8 add missing column definitions
  tools/power turbostat: update HWP dump to decimal from hex
  tools/power turbostat: enable package THERM_INTERRUPT dump
  tools/power turbostat: show missing Core and GFX power on SKL and KBL
  tools/power turbostat: bugfix: GFXMHz column not changing

Pull ACPI fixes from Rafael Wysocki:

 "These revert a recent ACPICA commit that turned out to be problematic
  and fix a device enumeration breakage from the 4.8 cycle.

  Specifics:

   - Revert a recent ACPICA commit targeted at catching firmware bugs
     which promptly did that and caused functional problems to appear
     (Rafael Wysocki).

   - Fix a device enumeration problem introduced in the 4.8 time frame
     which caused the ACPI docking station driver to report incorrect
     status via sysfs among other things (Rafael Wysocki)"

* tag 'acpi-4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPICA: Resources: Not a valid resource if buffer length too long"
  ACPI / scan: Set the visited flag for all enumerated devices