An errseq_t is a way of recording errors in one place, and allowing any
number of "subscribers" to tell whether an error has been set again
since a previous time.

It's implemented as an unsigned 32-bit value that is managed with atomic
operations. The low order bits are designated to hold an error code
(max size of MAX_ERRNO). The upper bits are used as a counter.

The API works with consumers sampling an errseq_t value at a particular
point in time. Later, that value can be used to tell whether new errors
have been set since that time.

Note that there is a 1 in 512k risk of collisions here if new errors
are being recorded frequently, since we have so few bits to use as a
counter. To mitigate this, one bit is used as a flag to tell whether the
value has been sampled since a new value was recorded. That allows
us to avoid bumping the counter if no one has sampled it since it
was last bumped.

Later patches will build on this infrastructure to change how writeback
errors are tracked in the kernel.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>

The -EIO returned here can end up overriding whatever error is marked in
the address space, and be returned at fsync time, even when there is a
more appropriate error stored in the mapping.

Read errors are also sometimes tracked on a per-page level using
PG_error. Suppose we have a read error on a page, and then that page is
subsequently dirtied by overwriting the whole page. Writeback doesn't
clear PG_error, so we can then end up successfully writing back that
page and still return -EIO on fsync.

Worse yet, PG_error is cleared during a sync() syscall, but the -EIO
return from that is silently discarded. Any subsystem that is relying on
PG_error to report errors during fsync can easily lose writeback errors
due to this. All you need is a stray sync() call to wait for writeback
to complete and you've lost the error.

Since the handling of the PG_error flag is somewhat inconsistent across
subsystems, let's just rely on marking the address space when there are
writeback errors. Change the TestClearPageError call to ClearPageError,
and make __filemap_fdatawait_range a void return function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

filemap_write_and_wait{_range} will return an error if writeback
initiation fails, but won't clear errors in the address_space. This is
particularly problematic on DAX, as filemap_fdatawrite* is
effectively synchronous there. Ensure that we clear the AS_EIO/AS_ENOSPC
flags when filemap_fdatawrite* returns an error.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

Resetting this flag is almost certainly racy, and will be problematic
with some coming changes.

Make filemap_fdatawait_keep_errors return int, but not clear the flag(s).
Have jbd2 call it instead of filemap_fdatawait and don't attempt to
re-set the error flag if it fails.
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

I noticed on xfs that I could still sometimes get back an error on fsync
on a fd that was opened after the error condition had been cleared.

The problem is that the buffer code sets the write_io_error flag and
then later checks that flag to set the error in the mapping. That flag
perisists for quite a while however. If the file is later opened with
O_TRUNC, the buffers will then be invalidated and the mapping's error
set such that a subsequent fsync will return error. I think this is
incorrect, as there was no writeback between the open and fsync.

Add a new mark_buffer_write_io_error operation that sets the flag and
the error in the mapping at the same time. Replace all calls to
set_buffer_write_io_error with mark_buffer_write_io_error, and remove
the places that check this flag in order to set the error in the
mapping.

This sets the error in the mapping earlier, at the time that it's first
detected.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

ext2 currently does a test+clear of the AS_EIO flag, which is
is problematic for some coming changes.

What we really need to do instead is call filemap_check_errors
in __generic_file_fsync after syncing out the buffers. That
will be sufficient for this case, and help other callers detect
these errors properly as well.

With that, we don't need to twiddle it in ext2.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

The error code should be negative.  Since this ends up in the default case
anyway, this is harmless, but it's less confusing to negate it.  Also,
later patches will require a negative error code here.

Link: http://lkml.kernel.org/r/20170525103355.6760-1-jlayton@redhat.comSigned-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull input layer fixes from Dmitry Torokhov:
 "Just a few fixups to a couple of drivers"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elan_i2c - ignore signals when finishing updating firmware
  Input: elan_i2c - clear INT before resetting controller
  Input: atmel_mxt_ts - add T100 as a readable object
  Input: edt-ft5x06 - increase allowed data range for threshold parameter

Merge tag 'led_fixes_for_4-12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fix from Jacek Anaszewski:
 "A single LED fix for 4.12-rc3.

  leds-pca955x driver uses only i2c_smbus API and thus it should pass
  I2C_FUNC_SMBUS_BYTE_DATA flag to i2c_check_functionality"

* tag 'led_fixes_for_4-12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: pca955x: Correct I2C Functionality

Pull networking fixes from David Miller:

 1) Fix state pruning in bpf verifier wrt. alignment, from Daniel
    Borkmann.

 2) Handle non-linear SKBs properly in SCTP ICMP parsing, from Davide
    Caratti.

 3) Fix bit field definitions for rss_hash_type of descriptors in mlx5
    driver, from Jesper Brouer.

 4) Defer slave->link updates until bonding is ready to do a full commit
    to the new settings, from Nithin Sujir.

 5) Properly reference count ipv4 FIB metrics to avoid use after free
    situations, from Eric Dumazet and several others including Cong Wang
    and Julian Anastasov.

 6) Fix races in llc_ui_bind(), from Lin Zhang.

 7) Fix regression of ESP UDP encapsulation for TCP packets, from
    Steffen Klassert.

 8) Fix mdio-octeon driver Kconfig deps, from Randy Dunlap.

 9) Fix regression in setting DSCP on ipv6/GRE encapsulation, from Peter
    Dawson.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits)
  ipv4: add reference counting to metrics
  net: ethernet: ax88796: don't call free_irq without request_irq first
  ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets
  sctp: fix ICMP processing if skb is non-linear
  net: llc: add lock_sock in llc_ui_bind to avoid a race condition
  bonding: Don't update slave->link until ready to commit
  test_bpf: Add a couple of tests for BPF_JSGE.
  bpf: add various verifier test cases
  bpf: fix wrong exposure of map_flags into fdinfo for lpm
  bpf: add bpf_clone_redirect to bpf_helper_changes_pkt_data
  bpf: properly reset caller saved regs after helper call and ld_abs/ind
  bpf: fix incorrect pruning decision when alignment must be tracked
  arp: fixed -Wuninitialized compiler warning
  tcp: avoid fastopen API to be used on AF_UNSPEC
  net: move somaxconn init from sysctl code
  net: fix potential null pointer dereference
  geneve: fix fill_info when using collect_metadata
  virtio-net: enable TSO/checksum offloads for Q-in-Q vlans
  be2net: Fix offload features for Q-in-Q packets
  vlan: Fix tcp checksum offloads in Q-in-Q vlans
  ...

Pull XFS fixes from Darrick Wong:
 "A few miscellaneous bug fixes & cleanups:

   - Fix indlen block reservation accounting bug when splitting delalloc
     extent

   - Fix warnings about unused variables that appeared in -rc1.

   - Don't spew errors when bmapping a local format directory

   - Fix an off-by-one error in a delalloc eof assertion

   - Make fsmap only return inode information for CAP_SYS_ADMIN

   - Fix a potential mount time deadlock recovering cow extents

   - Fix unaligned memory access in _btree_visit_blocks

   - Fix various SEEK_HOLE/SEEK_DATA bugs"

* tag 'xfs-4.12-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: Move handling of missing page into one place in xfs_find_get_desired_pgoff()
  xfs: Fix off-by-in in loop termination in xfs_find_get_desired_pgoff()
  xfs: Fix missed holes in SEEK_HOLE implementation
  xfs: fix off-by-one on max nr_pages in xfs_find_get_desired_pgoff()
  xfs: fix unaligned access in xfs_btree_visit_blocks
  xfs: avoid mount-time deadlock in CoW extent recovery
  xfs: only return detailed fsmap info if the caller has CAP_SYS_ADMIN
  xfs: bad assertion for delalloc an extent that start at i_size
  xfs: fix warnings about unused stack variables
  xfs: BMAPX shouldn't barf on inline-format directories
  xfs: fix indlen accounting error on partial delalloc conversion

Andrey Konovalov reported crashes in ipv4_mtu()

I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :

1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &

2) At the same time run following loop :
while :
do
 ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done

Cong Wang attempted to add back rt->fi in commit
82486aa6 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.

Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)

I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.

Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.

Fixes: 2860583f ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function ax_init_dev (which is called only from the driver's .probe
function) calls free_irq in the error path without having requested the
irq in the first place. So drop the free_irq call in the error path.

Fixes: 825a2ff1 ("AX88796 network driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

This fix addresses two problems in the way the DSCP field is formulated
 on the encapsulating header of IPv6 tunnels.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195661

1) The IPv6 tunneling code was manipulating the DSCP field of the
 encapsulating packet using the 32b flowlabel. Since the flowlabel is
 only the lower 20b it was incorrect to assume that the upper 12b
 containing the DSCP and ECN fields would remain intact when formulating
 the encapsulating header. This fix handles the 'inherit' and
 'fixed-value' DSCP cases explicitly using the extant dsfield u8 variable.

2) The use of INET_ECN_encapsulate(0, dsfield) in ip6_tnl_xmit was
 incorrect and resulted in the DSCP value always being set to 0.

Commit 90427ef5 ("ipv6: fix flow labels when the traffic class
 is non-0") caused the regression by masking out the flowlabel
 which exposed the incorrect handling of the DSCP portion of the
 flowlabel in ip6_tunnel and ip6_gre.

Fixes: 90427ef5 ("ipv6: fix flow labels when the traffic class is non-0")
Signed-off-by: Peter Dawson <peter.a.dawson@boeing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sometimes ICMP replies to INIT chunks are ignored by the client, even if
the encapsulated SCTP headers match an open socket. This happens when the
ICMP packet is carried by a paged skb: use skb_header_pointer() to read
packet contents beyond the SCTP header, so that chunk header and initiate
tag are validated correctly.

v2:
- don't use skb_header_pointer() to read the transport header, since
  icmp_socket_deliver() already puts these 8 bytes in the linear area.
- change commit message to make specific reference to INIT chunks.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a race condition in llc_ui_bind if two or more processes/threads
try to bind a same socket.

If more processes/threads bind a same socket success that will lead to
two problems, one is this action is not what we expected, another is
will lead to kernel in unstable status or oops(in my simple test case,
cause llc2.ko can't unload).

The current code is test SOCK_ZAPPED bit to avoid a process to
bind a same socket twice but that is can't avoid more processes/threads
try to bind a same socket at the same time.

So, add lock_sock in llc_ui_bind like others, such as llc_ui_connect.
Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull block fixes from Jens Axboe:
 "A collection of fixes that should go into this series. This contains:

   - A set of NVMe fixes, pulled from Christoph. This includes a set of
     fixes for the fiber channel bits from James Smart, rdma queue depth
     fix from Marta, controller removal fixes from Ming, and some more
     APST quirk updates from Andy.

   - A blk-mq debugfs fix from Bart, fixing a problem with the
     untangling of the sysfs and debugfs blk-mq bits that was added in
     this series.

   - Error code fix in add_partition() from Dan.

   - A small series of fixes for the new blk-throttle code from Shaohua"

* 'for-linus' of git://git.kernel.dk/linux-block: (21 commits)
  blk-mq: Only register debugfs attributes for blk-mq queues
  nvme: Quirk APST on Intel 600P/P3100 devices
  nvme: only setup block integrity if supported by the driver
  nvme: replace is_flags field in nvme_ctrl_ops with a flags field
  nvme-pci: consistencly use ctrl->device for logging
  partitions/msdos: FreeBSD UFS2 file systems are not recognized
  block: fix an error code in add_partition()
  blk-throttle: force user to configure all settings for io.low
  blk-throttle: respect 0 bps/iops settings for io.low
  blk-throttle: output some debug info in trace
  blk-throttle: add hierarchy support for latency target and idle time
  nvme_fc: remove extra controller reference taken on reconnect
  nvme_fc: correct nvme status set on abort
  nvme_fc: set logging level on resets/deletes
  nvme_fc: revise comment on teardown
  nvme_fc: Support ctrl_loss_tmo
  nvme_fc: get rid of local reconnect_delay
  blk-mq: remove blk_mq_abort_requeue_list()
  nvme: avoid to use blk_mq_abort_requeue_list()
  nvme: use blk_mq_start_hw_queues() in nvme_kill_queues()
  ...

Pull PCI fixes from Bjorn Helgaas:

 - fix PCI_ENDPOINT build error (merged for v4.12)

 - fix Switchtec driver (merged for v4.12)

 - fix imx6 config read timeouts, fallout from changing to non-postable
   reads

 - add PM "needs_resume" flag for i915 suspend issue

* tag 'pci-v4.12-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/PM: Add needs_resume flag to avoid suspend complete optimization
  PCI: imx6: Fix config read timeout handling
  switchtec: Fix minor bug with partition ID register
  switchtec: Use new cdev_device_add() helper function
  PCI: endpoint: Make PCI_ENDPOINT depend on HAS_DMA

Pul ceph fixes from Ilya Dryomov:
 "A bunch of make W=1 and static checker fixups, a RECONNECT_SEQ
  messenger patch from Zheng and Luis' fallocate fix"

* tag 'ceph-for-4.12-rc3' of git://github.com/ceph/ceph-client:
  ceph: check that the new inode size is within limits in ceph_fallocate()
  libceph: cleanup old messages according to reconnect seq
  libceph: NULL deref on crush_decode() error path
  libceph: fix error handling in process_one_ticket()
  libceph: validate blob_struct_v in process_one_ticket()
  libceph: drop version variable from ceph_monmap_decode()
  libceph: make ceph_msg_data_advance() return void
  libceph: use kbasename() and kill ceph_file_part()

Pull MMC fixes from Ulf Hansson:
 "This contains fixes to make the WiFi work again for the ARM64 Hikey
  board.

  Together with a couple of DTS updates for the Hikey board we have also
  extended the mmc pwrseq_simple, to support a new power-off-delay-us DT
  property, as that was required to enable a graceful power off sequence
  for the WiFi chip"

* tag 'mmc-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  arm64: dts: hikey: Fix WiFi support
  arm64: dts: hi6220: Move board data from the dwmmc nodes to hikey dts
  arm64: dts: hikey: Add the SYS_5V and the VDD_3V3 regulators
  arm64: dts: hi6220: Move the fixed_5v_hub regulator to the hikey dts
  arm64: dts: hikey: Add clock for the pmic mfd
  mfd: dts: hi655x: Add clock binding for the pmic
  mmc: pwrseq_simple: Parse DTS for the power-off-delay-us property
  mmc: dt: pwrseq-simple: Invent power-off-delay-us

Pull sound fixes from Takashi Iwai:
 "This contains a few HD-audio device-specific quirks and an endianess
  fix for USB-audio, as well as the update of quirk model list document.
  All fixes are small and trivial.

  The document update could have been postponed, but it's a good thing
  for user and has absolutely zero risk of breakage, so included here"

* tag 'sound-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - apply STAC_9200_DELL_M22 quirk for Dell Latitude D430
  ALSA: hda - Update the list of quirk models
  ALSA: hda - Provide dual-codecs model option for a few Realtek codecs
  ALSA: hda - Apply dual-codec quirk for MSI Z270-Gaming mobo
  ALSA: hda - No loopback on ALC299 codec
  ALSA: usb-audio: fix Amanero Combo384 quirk on big-endian hosts

Pull drm fixes from Dave Airlie:
 "Not a whole lot happening here, a set of amdgpu fixes and one core
  deadlock fix, and some misc drivers fixes"

* tag 'drm-fixes-for-v4.12-rc3' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: fix null point error when rmmod amdgpu.
  drm/amd/powerplay: fix a signedness bugs
  drm/amdgpu: fix NULL pointer panic of emit_gds_switch
  drm/radeon: Unbreak HPD handling for r600+
  drm/amd/powerplay/smu7: disable mclk switching for high refresh rates
  drm/amd/powerplay/smu7: add vblank check for mclk switching (v2)
  drm/radeon/ci: disable mclk switching for high refresh rates (v2)
  drm/amdgpu/ci: disable mclk switching for high refresh rates (v2)
  drm/amdgpu: fix fundamental suspend/resume issue
  drm/gma500/psb: Actually use VBT mode when it is found
  drm: Fix deadlock retry loop in page_flip_ioctl
  drm: qxl: Delay entering atomic context during cursor update
  drm/radeon: Fix oops upon driver load on PowerXpress laptops

We need to return an error for any call that asks for MSI / MSI-X
vectors only, so that non-trivial fallback logic can work properly.

Also valid dev->irq and use the "correct" errno value based on feedback
from Linus.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Fixes: aff17164 ("PCI: Provide sensible IRQ vector alloc/free routines")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Christoph writes:

"A couple of fixes for the next rc on the nvme front. Various FC fixes
from James, controller removal fixes from Ming (including a block layer
patch), a APST related device quirk from Andy, a RDMA fix for small
queue depth device from Marta, as well as fixes for the lack of
metadata support in non-PCIe drivers and the printk logging format from
me."

The code in blk-mq-debugfs.c assumes that it is working on a blk-mq
queue and is not intended to work on a blk-sq queue. Hence only
register blk-mq debugfs attributes for blk-mq queues.

Fixes: commit 9c1051aa ("blk-mq: untangle debugfs and sysfs")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

They have known firmware bugs.  A fix is apparently in the works --
once fixed firmware is available, someone from Intel (Hi, Keith!)
can adjust the quirk accordingly.

Cc: stable@vger.kernel.org # v4.11
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Currently only the PCIe driver supports metadata, so we should not claim
integrity support for the other drivers.  This prevents nasty crashes
with targets that advertise metadata support on fabrics.

Also use the opportunity to factor out some code into a separate helper
that isn't even compiled if CONFIG_BLK_DEV_INTEGRITY is disabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>

So that we can have more flags for transport-specific behavior.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>

This is what most of the code already does and gives much more useful
prefixes than the device embedded in the pci_dev.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>

A bunch of bug fixes:
- Fix display flickering on some chips at high refresh rates
- suspend/resume fix
- hotplug fix
- a couple of segfault fixes for certain cases

* 'drm-fixes-4.12' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: fix null point error when rmmod amdgpu.
  drm/amd/powerplay: fix a signedness bugs
  drm/amdgpu: fix NULL pointer panic of emit_gds_switch
  drm/radeon: Unbreak HPD handling for r600+
  drm/amd/powerplay/smu7: disable mclk switching for high refresh rates
  drm/amd/powerplay/smu7: add vblank check for mclk switching (v2)
  drm/radeon/ci: disable mclk switching for high refresh rates (v2)
  drm/amdgpu/ci: disable mclk switching for high refresh rates (v2)
  drm/amdgpu: fix fundamental suspend/resume issue

Core Changes:
- Don't drop vblank reference more than once in cases of ww retry (Daniel)

Driver Changes:
- radeon: Fix oops during radeon probe trying to reference wrong device (Lukas)
- qxl: Avoid sleeping while in atomic context on cursor update (Gabriel)
- gma500: Use VBT mode instead of pre-programmed mode for LVDS (Patrik)

Cc: Lukas Wunner <lukas@wunner.de>
Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

* tag 'drm-misc-fixes-2017-05-25' of git://anongit.freedesktop.org/git/drm-misc:
  drm/gma500/psb: Actually use VBT mode when it is found
  drm: Fix deadlock retry loop in page_flip_ioctl
  drm: qxl: Delay entering atomic context during cursor update
  drm/radeon: Fix oops upon driver load on PowerXpress laptops

In the loadbalance arp monitoring scheme, when a slave link change is
detected, the slave->link is immediately updated and slave_state_changed
is set. Later down the function, the rtnl_lock is acquired and the
changes are committed, updating the bond link state.

However, the acquisition of the rtnl_lock can fail. The next time the
monitor runs, since slave->link is already updated, it determines that
link is unchanged. This results in the bond link state permanently out
of sync with the slave link.

This patch modifies bond_loadbalance_arp_mon() to handle link changes
identical to bond_ab_arp_{inspect/commit}(). The new link state is
maintained in slave->new_link until we're ready to commit at which point
it's copied into slave->link.

NOTE: miimon_{inspect/commit}() has a more complex state machine
requiring the use of the bond_{propose,commit}_link_state() functions
which maintains the intermediate state in slave->link_new_state. The arp
monitors don't require that.

Testing: This bug is very easy to reproduce with the following steps.
1. In a loop, toggle a slave link of a bond slave interface.
2. In a separate loop, do ifconfig up/down of an unrelated interface to
create contention for rtnl_lock.
Within a few iterations, the bond link goes out of sync with the slave
link.
Signed-off-by: Nithin Nayak Sujir <nsujir@tintri.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Jay Vosburgh <jay.vosburgh@canonical.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some JITs can optimize comparisons with zero.  Add a couple of
BPF_JSGE tests against immediate zero.
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
Various BPF fixes

Follow-up to fix incorrect pruning when alignment tracking is
in use and to properly clear regs after call to not leave stale
data behind, also a fix that adds bpf_clone_redirect to the
bpf_helper_changes_pkt_data helper and exposes correct map_flags
for lpm map into fdinfo. For details, please see individual
patches.

v1 -> v2:
  - Reworked first patch so that env->strict_alignment is the
    final indicator on whether we have to deal with strict
    alignment rather than having CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
    checks on various locations, so only checking env->strict_alignment
    is sufficient after that. Thanks for spotting, Dave!
  - Added patch 3 and 4.
  - Rest as is.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds various verifier test cases:

1) A test case for the pruning issue when tracking alignment
   is used.
2) Various PTR_TO_MAP_VALUE_OR_NULL tests to make sure pointer
   arithmetic turns such register into UNKNOWN_VALUE type.
3) Test cases for the special treatment of LD_ABS/LD_IND to
   make sure verifier doesn't break calling convention here.
   Latter is needed, since f.e. arm64 JIT uses r1 - r5 for
   storing temporary data, so they really must be marked as
   NOT_INIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via
attr->map_flags, since it does not support preallocation yet. We
check the flag, but we never copy the flag into trie->map.map_flags,
which is later on exposed into fdinfo and used by loaders such as
iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test
whether a pinned map has the same spec as the one from the BPF obj
file and if not, bails out, which is currently the case for lpm
since it exposes always 0 as flags.

Also copy over flags in array_map_alloc() and stack_map_alloc().
They always have to be 0 right now, but we should make sure to not
miss to copy them over at a later point in time when we add actual
flags for them to use.

Fixes: b95a5c4d ("bpf: add a longest prefix match trie map implementation")
Reported-by: Jarno Rajahalme <jarno@covalent.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The bpf_clone_redirect() still needs to be listed in
bpf_helper_changes_pkt_data() since we call into
bpf_try_make_head_writable() from there, thus we need
to invalidate prior pkt regs as well.

Fixes: 36bbef52 ("bpf: direct packet write and access for helpers for clsact progs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, after performing helper calls, we clear all caller saved
registers, that is r0 - r5 and fill r0 depending on struct bpf_func_proto
specification. The way we reset these regs can affect pruning decisions
in later paths, since we only reset register's imm to 0 and type to
NOT_INIT. However, we leave out clearing of other variables such as id,
min_value, max_value, etc, which can later on lead to pruning mismatches
due to stale data.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, when we enforce alignment tracking on direct packet access,
the verifier lets the following program pass despite doing a packet
write with unaligned access:

  0: (61) r2 = *(u32 *)(r1 +76)
  1: (61) r3 = *(u32 *)(r1 +80)
  2: (61) r7 = *(u32 *)(r1 +8)
  3: (bf) r0 = r2
  4: (07) r0 += 14
  5: (25) if r7 > 0x1 goto pc+4
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
  6: (2d) if r0 > r3 goto pc+1
   R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14)
   R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
  7: (63) *(u32 *)(r0 -4) = r0
  8: (b7) r0 = 0
  9: (95) exit

  from 6 to 8:
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
  8: (b7) r0 = 0
  9: (95) exit

  from 5 to 10:
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=2 R10=fp
  10: (07) r0 += 1
  11: (05) goto pc-6
  6: safe                           <----- here, wrongly found safe
  processed 15 insns

However, if we enforce a pruning mismatch by adding state into r8
which is then being mismatched in states_equal(), we find that for
the otherwise same program, the verifier detects a misaligned packet
access when actually walking that path:

  0: (61) r2 = *(u32 *)(r1 +76)
  1: (61) r3 = *(u32 *)(r1 +80)
  2: (61) r7 = *(u32 *)(r1 +8)
  3: (b7) r8 = 1
  4: (bf) r0 = r2
  5: (07) r0 += 14
  6: (25) if r7 > 0x1 goto pc+4
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=0,max_value=1
   R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
  7: (2d) if r0 > r3 goto pc+1
   R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14)
   R3=pkt_end R7=inv,min_value=0,max_value=1
   R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
  8: (63) *(u32 *)(r0 -4) = r0
  9: (b7) r0 = 0
  10: (95) exit

  from 7 to 9:
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=0,max_value=1
   R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
  9: (b7) r0 = 0
  10: (95) exit

  from 6 to 11:
   R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
   R3=pkt_end R7=inv,min_value=2
   R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
  11: (07) r0 += 1
  12: (b7) r8 = 0
  13: (05) goto pc-7                <----- mismatch due to r8
  7: (2d) if r0 > r3 goto pc+1
   R0=pkt(id=0,off=15,r=15) R1=ctx R2=pkt(id=0,off=0,r=15)
   R3=pkt_end R7=inv,min_value=2
   R8=imm0,min_value=0,max_value=0,min_align=2147483648 R10=fp
  8: (63) *(u32 *)(r0 -4) = r0
  misaligned packet access off 2+15+-4 size 4

The reason why we fail to see it in states_equal() is that the
third test in compare_ptrs_to_packet() ...

  if (old->off <= cur->off &&
      old->off >= old->range && cur->off >= cur->range)
          return true;

... will let the above pass. The situation we run into is that
old->off <= cur->off (14 <= 15), meaning that prior walked paths
went with smaller offset, which was later used in the packet
access after successful packet range check and found to be safe
already.

For example: Given is R0=pkt(id=0,off=0,r=0). Adding offset 14
as in above program to it, results in R0=pkt(id=0,off=14,r=0)
before the packet range test. Now, testing this against R3=pkt_end
with 'if r0 > r3 goto out' will transform R0 into R0=pkt(id=0,off=14,r=14)
for the case when we're within bounds. A write into the packet
at offset *(u32 *)(r0 -4), that is, 2 + 14 -4, is valid and
aligned (2 is for NET_IP_ALIGN). After processing this with
all fall-through paths, we later on check paths from branches.
When the above skb->mark test is true, then we jump near the
end of the program, perform r0 += 1, and jump back to the
'if r0 > r3 goto out' test we've visited earlier already. This
time, R0 is of type R0=pkt(id=0,off=15,r=0), and we'll prune
that part because this time we'll have a larger safe packet
range, and we already found that with off=14 all further insn
were already safe, so it's safe as well with a larger off.
However, the problem is that the subsequent write into the packet
with 2 + 15 -4 is then unaligned, and not caught by the alignment
tracking. Note that min_align, aux_off, and aux_off_align were
all 0 in this example.

Since we cannot tell at this time what kind of packet access was
performed in the prior walk and what minimal requirements it has
(we might do so in the future, but that requires more complexity),
fix it to disable this pruning case for strict alignment for now,
and let the verifier do check such paths instead. With that applied,
the test cases pass and reject the program due to misalignment.

Fixes: d1174416 ("bpf: Track alignment of register values in the verifier.")
Reference: http://patchwork.ozlabs.org/patch/761909/Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>