This patch fixes an issue seen on Power systems with ixgbe which results
in skb list corruption and an eventual kernel oops. The following is what
was observed:

CPU 1                                   CPU2
============================            ============================
1: ixgbe_xmit_frame_ring                ixgbe_clean_tx_irq
2:  first->skb = skb                     eop_desc = tx_buffer->next_to_watch
3:  ixgbe_tx_map                         read_barrier_depends()
4:   wmb                                 check adapter written status bit
5:   first->next_to_watch = tx_desc      napi_consume_skb(tx_buffer->skb ..);
6:   writel(i, tx_ring->tail);

The read_barrier_depends is insufficient to ensure that tx_buffer->skb does not
get loaded prior to tx_buffer->next_to_watch, which then results in loading
a stale skb pointer. This patch replaces the read_barrier_depends with
smp_rmb to ensure loads are ordered with respect to the load of
tx_buffer->next_to_watch.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

After a reset we rebuild the VSIs which is going to clobber any
promiscuous settings we had before reset.  This makes it so that we
restore the promiscuous settings we had before reset.
Signed-off-by: Alan Brady <alan.brady@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The current method for notifying clients of l2 parameters is broken
because we fail to copy the new parameters to the client instance
struct, we need to do the notification before the client 'open' function
pointer gets called, and lastly we should set the l2 parameters when
first adding a client instance.

This patch first introduces the i40evf_client_get_params function to
prevent code duplication in the i40evf_client_add_instance and the
i40evf_notify_client_l2_params functions.  We then fix the notify l2
params function to actually copy the parameters to client instance
struct and do the same in the *_add_instance' function.  Lastly this
patch reorganizes the priority in which client tasks fire so that if the
flag for notifying l2 params is set, it will trigger before the open
because the client needs these new parameters as part of a client open
task.
Signed-off-by: Alan Brady <alan.brady@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch allows detection of upcoming core reset in case NIC gets
stuck while performing FLR reset. The i40e_pf_reset() function returns
I40E_ERR_NOT_READY when global reset was detected.
Signed-off-by: Filip Sadowski <filip.sadowski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

It is safe to remove the upper limit of 64 queues on a channel
VSI. The upper bound is determined by the VSI's num_queue_pairs
and gets validated when the queue mapping info through mqprio
interface is subject to bound checking in the driver.
Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

num_mac should be increased only after the call to i40e_add_mac_filter().

Fixes: 5f527ba9 ("i40e: Limit the number of MAC and VLAN addresses that can be added for VFs")
Signed-off-by: Zijie Pan <zijie.pan@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Tushar Dave <tushar.n.dave@oracle.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Since commit 96a39aed ("i40e: Acquire NVM lock before
reads on all devices") we've used the NVM lock
to synchronize NVM reads even on devices which don't strictly
need the lock.

Doing so can cause a regression on older firmware prior to 1.5,
especially when downgrading the firmware.

Fix this by only grabbing the lock if we're running on an X722
device (which requires the lock as it uses the AdminQ to read
the NVM), or if we're currently running 1.5 or newer firmware.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Pull networking fixes from David Miller:

 1) Fix a reference to a module parameter which was lost during the
    GREv6 receive path rewrite, from Alexey Kodanev.

 2) Fix deref before NULL check in ipheth, from Gustavo A. R. Silva.

 3) RCU read lock imbalance in tun_build_skb(), from Xin Long.

 4) Some stragglers from the mac80211 folks:

      a) Timer conversions from Kees Cook

      b) Fix some sequencing issue when cfg80211 is built statically,
         from Johannes Berg

      c) Memory leak in mac80211_hwsim, from Ben Hutchings.

 5) Add new qmi_wwan device ID, from Sebastian Sjoholm.

 6) Fix use after free in tipc, from Jon Maloy.

 7) Missing kdoc in nfp driver, from Jakub Kicinski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  nfp: flower: add missing kdoc
  tipc: fix access of released memory
  net: qmi_wwan: add Quectel BG96 2c7c:0296
  mlxsw: spectrum: Do not try to create non-existing ports during unsplit
  mac80211: properly free requested-but-not-started TX agg sessions
  mac80211_hwsim: Fix memory leak in hwsim_new_radio_nl()
  cfg80211: initialize regulatory keys/database later
  mac80211: aggregation: Convert timers to use timer_setup()
  nl80211: don't expose wdev->ssid for most interfaces
  mac80211: Convert timers to use timer_setup()
  net: vxge: Fix some indentation issues
  net: ena: fix race condition between device reset and link up setup
  r8169: use same RTL8111EVL green settings as in vendor driver
  r8169: fix RTL8111EVL EEE and green settings
  tun: fix rcu_read_lock imbalance in tun_build_skb
  tcp: when scheduling TLP, time of RTO should account for current ACK
  usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set
  gre6: use log_ecn_error module parameter in ip6_tnl_rcv()

Pull orangefs updates from Mike Marshall:
 "Fix:

   - stop setting atime on inode dirty (Martin Brandenburg)

  Cleanups:

   - remove initialization of i_version (Jeff Layton)

   - use ARRAY_SIZE (Jérémy Lefaure)

   - call op_release sooner when creating inodes (Mike MarshallMartin
     Brandenburg)"

* tag 'for-linus-4.15-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: call op_release sooner when creating inodes
  orangefs: stop setting atime on inode dirty
  orangefs: use ARRAY_SIZE
  orangefs: remove initialization of i_version

Pull ceph updates from Ilya Dryomov:
 "We have a set of file locking improvements from Zheng, rbd rw/ro state
  handling code cleanup from myself and some assorted CephFS fixes from
  Jeff.

  rbd now defaults to single-major=Y, lifting the limit of ~240 rbd
  images per host for everyone"

* tag 'ceph-for-4.15-rc1' of git://github.com/ceph/ceph-client:
  rbd: default to single-major device number scheme
  libceph: don't WARN() if user tries to add invalid key
  rbd: set discard_alignment to zero
  ceph: silence sparse endianness warning in encode_caps_cb
  ceph: remove the bump of i_version
  ceph: present consistent fsid, regardless of arch endianness
  ceph: clean up spinlocking and list handling around cleanup_cap_releases()
  rbd: get rid of rbd_mapping::read_only
  rbd: fix and simplify rbd_ioctl_set_ro()
  ceph: remove unused and redundant variable dropping
  ceph: mark expected switch fall-throughs
  ceph: -EINVAL on decoding failure in ceph_mdsc_handle_fsmap()
  ceph: disable cached readdir after dropping positive dentry
  ceph: fix bool initialization/comparison
  ceph: handle 'session get evicted while there are file locks'
  ceph: optimize flock encoding during reconnect
  ceph: make lock_to_ceph_filelock() static
  ceph: keep auth cap when inode has flocks or posix locks

Pull printk updates from Petr Mladek:

 - print the warning about dropped messages on consoles on a separate
   line.   It makes it more legible.

 - one typo fix and small code clean up.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  added new line symbol after warning about dropped messages
  printk: fix typo in printk_safe.c
  printk: simplify no_printk()

Merge tag 'mac80211-for-davem-2017-11-20' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
A few things:
 * straggler timer conversions from Kees
 * memory leak fix in hwsim
 * fix some fallout from regdb changes if wireless is built-in
 * also free aggregation sessions in startup state when station
   goes away, to avoid crashing the timer
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 0115552e ("nfp: remove false positive offloads
in flower vxlan") missed adding kdoc for a new parameter
of nfp_flower_add_offload().
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the function tipc_group_filter_msg() finds that a member event
indicates that the member is leaving the group, it first deletes the
member instance, and then purges the message queue being handled
by the call. But the message queue is an aggregated field in the
just deleted item, leading the purge call to access freed memory.

We fix this by swapping the order of the two actions.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Quectel BG96 is an Qualcomm MDM9206 based IoT modem, supporting both
CAT-M and NB-IoT. Tested hardware is BG96 mounted on Quectel development
board (EVB). The USB id is added to qmi_wwan.c to allow QMI
communication with the BG96.
Signed-off-by: Sebastian Sjoholm <ssjoholm@mac.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

On some systems, when we unsplit a port we need to re-create two ports
instead. On other systems, only one needs to be re-created.

Do not try to create a port if during driver initialization it was
assigned a negative module number, which is invalid.

This avoids the following error during unsplit:
[  941.012478] mlxsw_spectrum 0000:01:00.0: Port 43: Failed to map module

The error is harmless and caused by the fact that a local port is
already mapped to module 0.

Fixes: be94535f ("mlxsw: spectrum: Make split flow match firmware requirements")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull fbdev updates from Bartlomiej Zolnierkiewicz:
 "There is nothing really major here (though removal of the dead igafb
  driver stands out in diffstat).

  Summary:

   - convert timers to use timer_setup() (Kees Cook, Thierry Reding)

   - fix panels support on iMX boards in mxsfb driver (Stefan Agner)

   - fix timeout on EDID read in udlfb driver (Ladislav Michl)

   - add missing modes to fix out of bounds access in controlfb driver
     (Geert Uytterhoeven)

   - update initialisation paths in sa1100fb driver to be more robust
     (Russell King)

   - fix error handling path of ->probe method in au1200fb driver
     (Christophe JAILLET)

   - fix handling of cases when either panel or crt is defined in
     sm501fb driver (Sudip Mukherjee, Colin Ian King)

   - add ability to the Goldfish FB driver to be recognized by OS via DT
     (Aleksandar Markovic)

   - structures constifications (Bhumika Goyal)

   - misc fixes (Allen Pais, Gustavo A. R. Silva, Dan Carpenter)

   - misc cleanups (Colin Ian King, Himanshu Jha, Markus Elfring)

   - remove dead igafb driver"

* tag 'fbdev-v4.15' of git://github.com/bzolnier/linux: (42 commits)
  OMAPFB: prevent buffer underflow in omapfb_parse_vram_param()
  video: fbdev: sm501fb: fix potential null pointer dereference on fbi
  fbcon: Initialize ops->info early
  video: fbdev: Convert timers to use timer_setup()
  video: fbdev: pxa3xx_gcu: Convert timers to use timer_setup()
  fbdev: controlfb: Add missing modes to fix out of bounds access
  video: fbdev: sis_main: mark expected switch fall-throughs
  video: fbdev: cirrusfb: mark expected switch fall-throughs
  video: fbdev: aty: radeon_pm: mark expected switch fall-throughs
  video: fbdev: sm501fb: mark expected switch fall-through in sm501fb_blank_crt
  video: fbdev: intelfb: remove redundant variables
  video/fbdev/dnfb: Use common error handling code in dnfb_probe()
  sm501fb: suspend and resume fb if it exists
  sm501fb: unregister framebuffer only if registered
  sm501fb: deallocate colormap only if allocated
  video: goldfishfb: Add support for device tree bindings
  Documentation: Add device tree binding for Goldfish FB driver
  video: udlfb: Fix read EDID timeout
  video: fbdev: remove dead igafb driver
  video: fbdev: mxsfb: fix pixelclock polarity
  ...

Pull DeviceTree fixes from Rob Herring:

 - Remove mc13892 as a trivial device

 - Improve of_find_node_by_name() documentation

 - Fix unit test dtc warnings

 - Clean-ups of USB binding documentation

 - Fix potential NULL deref in of_pci_map_rid

* tag 'devicetree-fixes-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: trivial-devices: Remove fsl,mc13892
  of: Document exactly what of_find_node_by_name() puts
  of: unittest: disable interrupts_property warning
  of: unittest: let dtc generate __local_fixups__
  dt-bindings: usb: document hub and host-controller properties
  dt-bindings: usb: clean up compatible property
  dt-bindings: usb: fix reg-property port-number range
  dt-bindings: usb: fix example hub node name
  of/pci: Fix theoretical NULL dereference

Pull jfs fixlet from Dave Kleikamp:
 "Update jfs git tree in MAINTAINERS"

* tag 'jfs-4.15-2' of git://github.com/kleikamp/linux-shaggy:
  MAINTAINERS: fix jfs tree location

This device's bindings are not trivial: Additional properties are
documented in in Documentation/devicetree/bindings/mfd/mc13xxx.txt.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>

It isn't clear if this function of_node_put()s the 'from'
argument, or the node it searches. Clearly indicate which
variable is touched. Fold in some more fixes from Randy too
because we're in the area.

Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rob Herring <robh@kernel.org>

JFS tree has been moved to github.
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

When deleting a station or otherwise tearing down all aggregation
sessions, make sure to delete requested but not yet started ones,
to avoid the following scenario:

 * session is requested, added to tid_start_tx[]
 * ieee80211_ba_session_work() runs, gets past BLOCK_BA check
 * ieee80211_sta_tear_down_BA_sessions() runs, locks &sta->ampdu_mlme.mtx,
   e.g. while deleting the station - deleting all active sessions
 * ieee80211_ba_session_work() continues since tear down flushes it, and
   calls ieee80211_tx_ba_session_handle_start() for the new session, arms
   the timer for it
 * station deletion continues to __cleanup_single_sta() and frees the
   session struct, while the timer is armed
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

hwsim_new_radio_nl() now copies the name attribute in order to add a
null-terminator.  mac80211_hwsim_new_radio() (indirectly) copies it
again into the net_device structure, so the first copy is not used or
freed later.  Free the first copy before returning.

Fixes: ff4dd73d ("mac80211_hwsim: check HWSIM_ATTR_RADIO_NAME length")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When cfg80211 is built as a module, everything is fine, and we
can keep the code as is; in fact, we have to, because there can
only be a single module_init().

When cfg80211 is built-in, however, it needs to initialize
before drivers (device_initcall/module_init), and thus used to
be at subsys_initcall(). I'd moved it to fs_initcall() earlier,
where it can remain. However, this is still too early because at
that point the key infrastructure hasn't been initialized yet,
so X.509 certificates can't be parsed yet.

To work around this problem, load the regdb keys only later in
a late_initcall(), at which point the necessary infrastructure
has been initialized.

Fixes: 90a53e44 ("cfg80211: implement regdb signature checking")
Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

This removes the tid mapping array and expands the tid structures to
add a pointer back to the station, along with the tid index itself.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
[switch tid variables to u8, the valid range is 0-15 at most,
 initialize tid_tx->sta/tid properly]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

For mesh, this is simply wrong - there's no SSID, only the
mesh ID, so don't expose it at all.
For (P2P) client, it's wrong, because it exposes an internal
value that's only used when certain APIs are used.
For AP, it's actually the only correct case, so leave that.
All other interface types shouldn't be setting this anyway,
so there it won't change anything.

Fixes: b84e7a05 ("nl80211: send the NL80211_ATTR_SSID in nl80211_send_iface()")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Pull ntb updates from Jon Mason:
 "Support for the switchtec ntb and related changes. Also, a couple of
  bug fixes"

[ The timing isn't great. I had asked people to send me pull requests
  before my family vacation, and this code has not even been in
  linux-next as far as I can tell. But Logan Gunthorpe pleaded for its
  inclusion because the Switchtec driver has apparently been around for
  a while, just never in linux-next - Linus ]

* tag 'ntb-4.15' of git://github.com/jonmason/ntb:
  ntb: intel: remove b2b memory window workaround for Skylake NTB
  NTB: make idt_89hpes_cfg const
  NTB: switchtec_ntb: Update switchtec documentation with notes for NTB
  NTB: switchtec_ntb: Add memory window support
  NTB: switchtec_ntb: Implement scratchpad registers
  NTB: switchtec_ntb: Implement doorbell registers
  NTB: switchtec_ntb: Add link management
  NTB: switchtec_ntb: Add skeleton NTB driver
  NTB: switchtec_ntb: Initialize hardware for doorbells and messages
  NTB: switchtec_ntb: Initialize hardware for memory windows
  NTB: switchtec_ntb: Introduce initial NTB driver
  NTB: Add check and comment for link up to mw_count() and mw_get_align()
  NTB: Ensure ntb_mw_get_align() is only called when the link is up
  NTB: switchtec: Add link event notifier callback
  NTB: switchtec: Add NTB hardware register definitions
  NTB: switchtec: Export class symbol for use in upper layer driver
  NTB: switchtec: Move structure definitions into a common header
  ntb: update maintainer list for Intel NTB driver

Some statements are not enough or too much indented.
Fix it to improve readalbility.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

In rare cases, ena driver would reset and re-start the device,
for example, in case of misbehaving application that causes
transmit timeout

The first step in the reset procedure is to stop the Tx traffic by
calling ena_carrier_off().

After the driver have just started the device reset procedure, device
happens to send an asynchronous notification (via AENQ) to the driver
than there was a link change (to link-up state).
This link change is mapped to a call to netif_carrier_on() which
re-activates the Tx queues, violating the assumption of no tx traffic
until device reset is completed, as the reset task might still be in
the process of queues initialization, leading to an access to
uninitialized memory.
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit b65a9cfc ("Untangling ima mess, part 2: deal with counters")
moved the call of ima_file_check() from may_open() to do_filp_open() at a
point where the file descriptor is already opened.

This breaks the assumption made by IMA that file descriptors being closed
belong to files whose access was granted by ima_file_check(). The
consequence is that security.ima and security.evm are updated with good
values, regardless of the current appraisal status.

For example, if a file does not have security.ima, IMA will create it after
opening the file for writing, even if access is denied. Access to the file
will be allowed afterwards.

Avoid this issue by checking the appraisal status before updating
security.ima.

Cc: stable@vger.kernel.org
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Pull small IDE cleanup from David Miller.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
  PNP: ide: constify pnp_device_id

Adjust the code to use the same green settings as in the latest
vendor driver.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Name of functions rtl_w0w1_eri and rtl_w0w1_phy is somewhat misleading
regarding order of arguments. One could assume that w0w1 means
argument with bits to be reset comes before argument with bits to set.
However this is not the case.
So fix the order of arguments in several statements.

In addition fix EEE advertisement. The current code resets the bits
for 100BaseT and 1000BaseT EEE advertisement what is not what we want.

I have a little of a hard time to find a proper "Fixes" line as the
issue seems to have been there forever (at least it existed already
when the driver was moved to the current place in 2011).

The patch was tested on a Zotac Mini-PC with a RTL8111E-VL chip.
Before the patch EEE was disabled, now it's properly advertised and
works fine.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rcu_read_lock in tun_build_skb is used to rcu_dereference tun->xdp_prog
safely, rcu_read_unlock should be done in every return path.

Now I could see one place missing it, where it returns NULL in switch-case
XDP_REDIRECT,  another palce using rcu_read_lock wrongly, where it returns
NULL in if (xdp_xmit) chunk.

So fix both in this patch.

Fixes: 761876c8 ("tap: XDP support")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the TLP scheduling logic so that when scheduling a TLP probe, we
ensure that the estimated time at which an RTO would fire accounts for
the fact that ACKs indicating forward progress should push back RTO
times.

After the following fix:

df92c839 ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")

we had an unintentional behavior change in the following kind of
scenario: suppose the RTT variance has been very low recently. Then
suppose we send out a flight of N packets and our RTT is 100ms:

t=0: send a flight of N packets
t=100ms: receive an ACK for N-1 packets

The response before df92c839 that was:
  -> schedule a TLP for now + RTO_interval

The response after df92c839 is:
  -> schedule a TLP for t=0 + RTO_interval

Since RTO_interval = srtt + RTT_variance, this means that we have
scheduled a TLP timer at a point in the future that only accounts for
RTT_variance. If the RTT_variance term is small, this means that the
timer fires soon.

Before df92c839 this would not happen, because in that code, when
we receive an ACK for a prefix of flight, we did:

    1) Near the top of tcp_ack(), switch from TLP timer to RTO
       at write_queue_head->paket_tx_time + RTO_interval:
            if (icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)
                   tcp_rearm_rto(sk);

    2) In tcp_clean_rtx_queue(), update the RTO to now + RTO_interval:
            if (flag & FLAG_ACKED) {
                   tcp_rearm_rto(sk);

    3) In tcp_ack() after tcp_fastretrans_alert() switch from RTO
       to TLP at now + RTO_interval:
            if (icsk->icsk_pending == ICSK_TIME_RETRANS)
                   tcp_schedule_loss_probe(sk);

In df92c839 we removed that 3-phase dance, and instead directly
set the TLP timer once: we set the TLP timer in cases like this to
write_queue_head->packet_tx_time + RTO_interval. So if the RTT
variance is small, then this means that this is setting the TLP timer
to fire quite soon. This means if the ACK for the tail of the flight
takes longer than an RTT to arrive (often due to delayed ACKs), then
the TLP timer fires too quickly.

Fixes: df92c839 ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

_dev_ is being dereferenced before it is null checked, hence there
is a potential null pointer dereference.

Fix this by moving the pointer dereference after _dev_ has been null
checked.

Addresses-Coverity-ID: 1462020
Fixes: bb1b40c7 ("usbnet: ipheth: prevent TX queue timeouts when device not ready")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After commit 308edfdf ("gre6: Cleanup GREv6 receive path, call
common GRE functions") it's not used anywhere in the module, but
previously was used in ip6gre_rcv().

Fixes: 308edfdf ("gre6: Cleanup GREv6 receive path, call common GRE functions")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The workaround code is never used because Skylake NTB does not need it.
Reported-by: Allen Hubbe <allen.hubbe@dell.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>