Pull networking fixes from David Miller:

 1) Disable RISCV BPF JIT builds when !MMU, from Björn Töpel.

 2) nf_tables leaves dangling pointer after free, fix from Eric Dumazet.

 3) Out of boundary write in __xsk_rcv_memcpy(), fix from Li RongQing.

 4) Adjust icmp6 message source address selection when routes have a
    preferred source address set, from Tim Stallard.

 5) Be sure to validate HSR protocol version when creating new links,
    from Taehee Yoo.

 6) CAP_NET_ADMIN should be sufficient to manage l2tp tunnels even in
    non-initial namespaces, from Michael Weiß.

 7) Missing release firmware call in mlx5, from Eran Ben Elisha.

 8) Fix variable type in macsec_changelink(), caught by KASAN. Fix from
    Taehee Yoo.

 9) Fix pause frame negotiation in marvell phy driver, from Clemens
    Gruber.

10) Record RX queue early enough in tun packet paths such that XDP
    programs will see the correct RX queue index, from Gilberto Bertin.

11) Fix double unlock in mptcp, from Florian Westphal.

12) Fix offset overflow in ARM bpf JIT, from Luke Nelson.

13) marvell10g needs to soft reset PHY when coming out of low power
    mode, from Russell King.

14) Fix MTU setting regression in stmmac for some chip types, from
    Florian Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (101 commits)
  amd-xgbe: Use __napi_schedule() in BH context
  mISDN: make dmril and dmrim static
  net: stmmac: dwmac-sunxi: Provide TX and RX fifo sizes
  net: dsa: mt7530: fix tagged frames pass-through in VLAN-unaware mode
  tipc: fix incorrect increasing of link window
  Documentation: Fix tcp_challenge_ack_limit default value
  net: tulip: make early_486_chipsets static
  dt-bindings: net: ethernet-phy: add desciption for ethernet-phy-id1234.d400
  ipv6: remove redundant assignment to variable err
  net/rds: Use ERR_PTR for rds_message_alloc_sgs()
  net: mscc: ocelot: fix untagged packet drops when enslaving to vlan aware bridge
  selftests/bpf: Check for correct program attach/detach in xdp_attach test
  libbpf: Fix type of old_fd in bpf_xdp_set_link_opts
  libbpf: Always specify expected_attach_type on program load if supported
  xsk: Add missing check on user supplied headroom size
  mac80211: fix channel switch trigger from unknown mesh peer
  mac80211: fix race in ieee80211_register_hw()
  net: marvell10g: soft-reset the PHY when coming out of low power
  net: marvell10g: report firmware version
  net/cxgb4: Check the return from t4_query_params properly
  ...

The driver uses __napi_schedule_irqoff() which is fine as long as it is
invoked with disabled interrupts by everybody. Since the commit
mentioned below the driver may invoke xgbe_isr_task() in tasklet/softirq
context. This may lead to list corruption if another driver uses
__napi_schedule_irqoff() in IRQ context.

Use __napi_schedule() which safe to use from IRQ and softirq context.

Fixes: 85b85c85 ("amd-xgbe: Re-issue interrupt if interrupt status not cleared")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the following sparse warning:

drivers/isdn/hardware/mISDN/mISDNisar.c:746:12: warning: symbol 'dmril'
was not declared. Should it be static?
drivers/isdn/hardware/mISDN/mISDNisar.c:749:12: warning: symbol 'dmrim'
was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After commit bfcb8132 ("net: dsa:
configure the MTU for switch ports") my Lamobo R1 platform which uses
an allwinner,sun7i-a20-gmac compatible Ethernet MAC started to fail
by rejecting a MTU of 1536. The reason for that is that the DMA
capabilities are not readable on this version of the IP, and there
is also no 'tx-fifo-depth' property being provided in Device Tree. The
property is documented as optional, and is not provided.

Chen-Yu indicated that the FIFO sizes are 4KB for TX and 16KB for RX, so
provide these values through platform data as an immediate fix until
various Device Tree sources get updated accordingly.

Fixes: eaf4fac4 ("net: stmmac: Do not accept invalid MTU values")
Suggested-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In VLAN-unaware mode, the Egress Tag (EG_TAG) field in Port VLAN
Control register must be set to Consistent to let tagged frames pass
through as is, otherwise their tags will be stripped.

Fixes: 83163f7d ("net: dsa: mediatek: add VLAN support for MT7530")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: René van Dorst <opensource@vdorst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull SELinux fix from Paul Moore:
 "One small SELinux fix to ensure we cleanup properly on an error
  condition"

* tag 'selinux-pr-20200416' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: free str on error in str_read()

Pull ceph fixes from Ilya Dryomov:

 - a set of patches for a deadlock on "rbd map" error path

 - a fix for invalid pointer dereference and uninitialized variable use
   on asynchronous create and unlink error paths.

* tag 'ceph-for-5.7-rc2' of git://github.com/ceph/ceph-client:
  ceph: fix potential bad pointer deref in async dirops cb's
  rbd: don't mess with a page vector in rbd_notify_op_lock()
  rbd: don't test rbd_dev->opts in rbd_dev_image_release()
  rbd: call rbd_dev_unprobe() after unwatching and flushing notifies
  rbd: avoid a deadlock on header_rwsem when flushing notifies

Pull tracing fix from Steven Rostedt:
 "This fixes a small race between allocating a snapshot buffer and
  setting the snapshot trigger.

  On a slow machine, the trigger can occur before the snapshot is
  allocated causing a warning to be displayed in the ring buffer, and no
  snapshot triggering. Reversing the allocation and the enabling of the
  trigger fixes the problem"

* tag 'trace-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation

If seq_file .next function does not change position index,
read after some lseek can generate unexpected output:

    $ dd if=/proc/keys bs=1  # full usual output
    0f6bfdf5 I--Q---     2 perm 3f010000  1000  1000 user      4af2f79ab8848d0a: 740
    1fb91b32 I--Q---     3 perm 1f3f0000  1000 65534 keyring   _uid.1000: 2
    27589480 I--Q---     1 perm 0b0b0000     0     0 user      invocation_id: 16
    2f33ab67 I--Q---   152 perm 3f030000     0     0 keyring   _ses: 2
    33f1d8fa I--Q---     4 perm 3f030000  1000  1000 keyring   _ses: 1
    3d427fda I--Q---     2 perm 3f010000  1000  1000 user      69ec44aec7678e5a: 740
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    521+0 records in
    521+0 records out
    521 bytes copied, 0,00123769 s, 421 kB/s

But a read after lseek in middle of last line results in the partial
last line and then a repeat of the final line:

    $ dd if=/proc/keys bs=500 skip=1
    dd: /proc/keys: cannot skip to specified offset
    g   _uid_ses.1000: 1
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    97 bytes copied, 0,000135035 s, 718 kB/s

and a read after lseek beyond end of file results in the last line being
shown:

    $ dd if=/proc/keys bs=1000 skip=1   # read after lseek beyond end of file
    dd: /proc/keys: cannot skip to specified offset
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    76 bytes copied, 0,000119981 s, 633 kB/s

See https://bugzilla.kernel.org/show_bug.cgi?id=206283

Fixes: 1f4aace6 ("fs/seq_file.c: simplify seq_file iteration code ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull EFI fixes from Ingo Molnar:
 "Misc EFI fixes, including the boot failure regression caused by the
  BSS section not being cleared by the loaders"

* tag 'efi-urgent-2020-04-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Revert struct layout change to fix kexec boot regression
  efi/x86: Don't remap text<->rodata gap read-only for mixed mode
  efi/x86: Fix the deletion of variables in mixed mode
  efi/libstub/file: Merge file name buffers to reduce stack usage
  Documentation/x86, efi/x86: Clarify EFI handover protocol and its requirements
  efi/arm: Deal with ADR going out of range in efi_enter_kernel()
  efi/x86: Always relocate the kernel for EFI handover entry
  efi/x86: Move efi stub globals from .bss to .data
  efi/libstub/x86: Remove redundant assignment to pointer hdr
  efi/cper: Use scnprintf() for avoiding potential buffer overflow

In commit 16ad3f40 ("tipc: introduce variable window congestion
control"), we allow link window to change with the congestion avoidance
algorithm. However, there is a bug that during the slow-start if packet
retransmission occurs, the link will enter the fast-recovery phase, set
its window to the 'ssthresh' which is never less than 300, so the link
window suddenly increases to that limit instead of decreasing.

Consequently, two issues have been observed:

- For broadcast-link: it can leave a gap between the link queues that a
new packet will be inserted and sent before the previous ones, i.e. not
in-order.

- For unicast: the algorithm does not work as expected, the link window
jumps to the slow-start threshold whereas packet retransmission occurs.

This commit fixes the issues by avoiding such the link window increase,
but still decreasing if the 'ssthresh' is lowered.

Fixes: 16ad3f40 ("tipc: introduce variable window congestion control")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

The default value of tcp_challenge_ack_limit has been changed from
100 to 1000 and this patch fixes its documentation.
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the following sparse warning:

drivers/net/ethernet/dec/tulip/tulip_core.c:1280:28: warning: symbol
'early_486_chipsets' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The description below is already in use in
'rk3228-evb.dts', 'rk3229-xms6.dts' and 'rk3328.dtsi'
but somehow never added to a document, so add
"ethernet-phy-id1234.d400", "ethernet-phy-ieee802.3-c22"
for ethernet-phy nodes on Rockchip platforms to
'ethernet-phy.yaml'.
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The variable err is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In [see "Fixes:"] I missed the fact that str_read() may give back an
allocated pointer even if it returns an error, causing a potential
memory leak in filename_trans_read_one(). Fix this by making the
function free the allocated string whenever it returns a non-zero value,
which also makes its behavior more obvious and prevents repeating the
same mistake in the future.
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1461665 ("Resource leaks")
Fixes: c3a27611 ("selinux: optimize storage of filename transitions")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Returning the error code via a 'int *ret' when the function returns a
pointer is very un-kernely and causes gcc 10's static analysis to choke:

net/rds/message.c: In function ‘rds_message_map_pages’:
net/rds/message.c:358:10: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  358 |   return ERR_PTR(ret);

Use a typical ERR_PTR return instead.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To rehash a previous explanation given in commit 1c44ce56 ("net:
mscc: ocelot: fix vlan_filtering when enslaving to bridge before link is
up"), the switch driver operates the in a mode where a single VLAN can
be transmitted as untagged on a particular egress port. That is the
"native VLAN on trunk port" use case.

The configuration for this native VLAN is driven in 2 ways:
 - Set the egress port rewriter to strip the VLAN tag for the native
   VID (as it is egress-untagged, after all).
 - Configure the ingress port to drop untagged and priority-tagged
   traffic, if there is no native VLAN. The intention of this setting is
   that a trunk port with no native VLAN should not accept untagged
   traffic.

Since both of the above configurations for the native VLAN should only
be done if VLAN awareness is requested, they are actually done from the
ocelot_port_vlan_filtering function, after the basic procedure of
toggling the VLAN awareness flag of the port.

But there's a problem with that simplistic approach: we are trying to
juggle with 2 independent variables from a single function:
 - Native VLAN of the port - its value is held in port->vid.
 - VLAN awareness state of the port - currently there are some issues
   here, more on that later*.
The actual problem can be seen when enslaving the switch ports to a VLAN
filtering bridge:
 0. The driver configures a pvid of zero for each port, when in
    standalone mode. While the bridge configures a default_pvid of 1 for
    each port that gets added as a slave to it.
 1. The bridge calls ocelot_port_vlan_filtering with vlan_aware=true.
    The VLAN-filtering-dependent portion of the native VLAN
    configuration is done, considering that the native VLAN is 0.
 2. The bridge calls ocelot_vlan_add with vid=1, pvid=true,
    untagged=true. The native VLAN changes to 1 (change which gets
    propagated to hardware).
 3. ??? - nobody calls ocelot_port_vlan_filtering again, to reapply the
    VLAN-filtering-dependent portion of the native VLAN configuration,
    for the new native VLAN of 1. One can notice that after toggling "ip
    link set dev br0 type bridge vlan_filtering 0 && ip link set dev br0
    type bridge vlan_filtering 1", the new native VLAN finally makes it
    through and untagged traffic finally starts flowing again. But
    obviously that shouldn't be needed.

So it is clear that 2 independent variables need to both re-trigger the
native VLAN configuration. So we introduce the second variable as
ocelot_port->vlan_aware.

*Actually both the DSA Felix driver and the Ocelot driver already had
each its own variable:
 - Ocelot: ocelot_port_private->vlan_aware
 - Felix: dsa_port->vlan_filtering
but the common Ocelot library needs to work with a single, common,
variable, so there is some refactoring done to move the vlan_aware
property from the private structure into the common ocelot_port
structure.

Fixes: 97bb69e1 ("net: mscc: ocelot: break apart ocelot_vlan_port_apply")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2020-04-15

The following pull-request contains BPF updates for your *net* tree.

We've added 10 non-merge commits during the last 3 day(s) which contain
a total of 11 files changed, 238 insertions(+), 95 deletions(-).

The main changes are:

1) Fix offset overflow for BPF_MEM BPF_DW insn mapping on arm32 JIT,
   from Luke Nelson and Xi Wang.

2) Prevent mprotect() to make frozen & mmap()'ed BPF map writeable
   again, from Andrii Nakryiko and Jann Horn.

3) Fix type of old_fd in bpf_xdp_set_link_opts to int in libbpf and add
   selftests, from Toke Høiland-Jørgensen.

4) Fix AF_XDP to check that headroom cannot be larger than the available
   space in the chunk, from Magnus Karlsson.

5) Fix reset of XDP prog when expected_fd is set, from David Ahern.

6) Fix a segfault in bpftool's struct_ops command when BTF is not
   available, from Daniel T. Lee.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-net-2020-04-15' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
A couple of fixes:
 * FTM responder policy netlink validation fix
   (but the only user validates again later)
 * kernel-doc fixes
 * a fix for a race in mac80211 radio registration vs. userspace
 * a mesh channel switch fix
 * a fix for a syzbot reported kasprintf() issue
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

David Ahern noticed that there was a bug in the EXPECTED_FD code so
programs did not get detached properly when that parameter was supplied.
This case was not included in the xdp_attach tests; so let's add it to be
sure that such a bug does not sneak back in down.

Fixes: 87854a0b ("selftests/bpf: Add tests for attaching XDP programs")
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200414145025.182163-2-toke@redhat.com

The 'old_fd' parameter used for atomic replacement of XDP programs is
supposed to be an FD, but was left as a u32 from an earlier iteration of
the patch that added it. It was converted to an int when read, so things
worked correctly even with negative values, but better change the
definition to correctly reflect the intention.

Fixes: bd5ca3ef ("libbpf: Add function to set link XDP fd while specifying old program")
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200414145025.182163-1-toke@redhat.com

For some types of BPF programs that utilize expected_attach_type, libbpf won't
set load_attr.expected_attach_type, even if expected_attach_type is known from
section definition. This was done to preserve backwards compatibility with old
kernels that didn't recognize expected_attach_type attribute yet (which was
added in 5e43f899 ("bpf: Check attach type at prog load time"). But this
is problematic for some BPF programs that utilize newer features that require
kernel to know specific expected_attach_type (e.g., extended set of return
codes for cgroup_skb/egress programs).

This patch makes libbpf specify expected_attach_type by default, but also
detect support for this field in kernel and not set it during program load.
This allows to have a good metadata for bpf_program
(e.g., bpf_program__get_extected_attach_type()), but still work with old
kernels (for cases where it can work at all).

Additionally, due to expected_attach_type being always set for recognized
program types, bpf_program__attach_cgroup doesn't have to do extra checks to
determine correct attach type, so remove that additional logic.

Also adjust section_names selftest to account for this change.

More detailed discussion can be found in [0].

  [0] https://lore.kernel.org/bpf/20200412003604.GA15986@rdna-mbp.dhcp.thefacebook.com/

Fixes: 5cf1e914 ("bpf: cgroup inet skb programs can return 0 to 3")
Fixes: 5e43f899 ("bpf: Check attach type at prog load time")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20200414182645.1368174-1-andriin@fb.com

Add a check that the headroom cannot be larger than the available
space in the chunk. In the current code, a malicious user can set the
headroom to a value larger than the chunk size minus the fixed XDP
headroom. That way packets with a length larger than the supported
size in the umem could get accepted and result in an out-of-bounds
write.

Fixes: c0c77d8f ("xsk: add user memory registration support sockopt")
Reported-by: Bui Quang Minh <minhquangbui99@gmail.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207225
Link: https://lore.kernel.org/bpf/1586849715-23490-1-git-send-email-magnus.karlsson@intel.com

Previously mesh channel switch happens if beacon contains
CSA IE without checking the mesh peer info. Due to that
channel switch happens even if the beacon is not from
its own mesh peer. Fixing that by checking if the CSA
originated from the same mesh network before proceeding
for channel switch.
Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Link: https://lore.kernel.org/r/1585403604-29274-1-git-send-email-tamizhr@codeaurora.orgSigned-off-by: Johannes Berg <johannes.berg@intel.com>

A race condition leading to a kernel crash is observed during invocation
of ieee80211_register_hw() on a dragonboard410c device having wcn36xx
driver built as a loadable module along with a wifi manager in user-space
waiting for a wifi device (wlanX) to be active.

Sequence diagram for a particular kernel crash scenario:

    user-space  ieee80211_register_hw()  ieee80211_tasklet_handler()
    ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       |                    |                 |
       |<---phy0----wiphy_register()          |
       |-----iwd if_add---->|                 |
       |                    |<---IRQ----(RX packet)
       |              Kernel crash            |
       |              due to unallocated      |
       |              workqueue.              |
       |                    |                 |
       |       alloc_ordered_workqueue()      |
       |                    |                 |
       |              Misc wiphy init.        |
       |                    |                 |
       |            ieee80211_if_add()        |
       |                    |                 |

As evident from above sequence diagram, this race condition isn't specific
to a particular wifi driver but rather the initialization sequence in
ieee80211_register_hw() needs to be fixed. So re-order the initialization
sequence and the updated sequence diagram would look like:

    user-space  ieee80211_register_hw()  ieee80211_tasklet_handler()
    ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       |                    |                 |
       |       alloc_ordered_workqueue()      |
       |                    |                 |
       |              Misc wiphy init.        |
       |                    |                 |
       |<---phy0----wiphy_register()          |
       |-----iwd if_add---->|                 |
       |                    |<---IRQ----(RX packet)
       |                    |                 |
       |            ieee80211_if_add()        |
       |                    |                 |

Cc: stable@vger.kernel.org
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/1586254255-28713-1-git-send-email-sumit.garg@linaro.org
[Johannes: fix rtnl imbalances]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation

Traced event can trigger 'snapshot' operation(i.e. calls snapshot_trigger()
or snapshot_count_trigger()) when register_snapshot_trigger() has completed
registration but doesn't allocate buffer for 'snapshot' event trigger.  In
the rare case, 'snapshot' operation always detects the lack of allocated
buffer so make register_snapshot_trigger() allocate buffer first.

trigger-snapshot.tc in kselftest reproduces the issue on slow vm:
-----------------------------------------------------------
cat trace
...
ftracetest-3028  [002] ....   236.784290: sched_process_fork: comm=ftracetest pid=3028 child_comm=ftracetest child_pid=3036
     <...>-2875  [003] ....   240.460335: tracing_snapshot_instance_cond: *** SNAPSHOT NOT ALLOCATED ***
     <...>-2875  [003] ....   240.460338: tracing_snapshot_instance_cond: *** stopping trace here!   ***
-----------------------------------------------------------

Link: http://lkml.kernel.org/r/20200414015145.66236-1-yangx.jy@cn.fujitsu.com

Cc: stable@vger.kernel.org
Fixes: 93e31ffb ("tracing: Add 'snapshot' event trigger command")
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Russell King says:

====================
Fix 88x3310 leaving power save mode

This series fixes a problem with the 88x3310 PHY on Macchiatobin
coming out of powersave mode noticed by Matteo Croce.  It seems
that certain PHY firmwares do not properly exit powersave mode,
resulting in a fibre link not coming up.

The solution appears to be to soft-reset the PHY after clearing
the powersave bit.

We add support for reporting the PHY firmware version to the kernel
log, and use it to trigger this new behaviour if we have v0.3.x.x
or more recent firmware on the PHY.  This, however, is a guess as
the firmware revision documentation does not mention this issue,
and we know that v0.2.1.0 works without this fix but v0.3.3.0 and
later does not.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Soft-reset the PHY when coming out of low power mode, which seems to
be necessary with firmware versions 0.3.3.0 and 0.3.10.0.

This depends on ("net: marvell10g: report firmware version")

Fixes: c9cc1c81 ("net: phy: marvell10g: place in powersave mode at probe")
Reported-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Report the firmware version when probing the PHY to allow issues
attributable to firmware to be diagnosed.
Tested-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Positive return values are also failures that don't set val,
although this probably can't happen. Fixes gcc 10 warning:

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c: In function ‘t4_phy_fw_ver’:
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:3747:14: warning: ‘val’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 3747 |  *phy_fw_ver = val;

Fixes: 01b69614 ("cxgb4: Add PHY firmware support for T420-BT cards")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow all the RGMII modes to be used.  (Not only "rgmii", "rgmii-id"
but "rgmii-txid", "rgmii-rxid")
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
mv88e6xxx fixed link fixes

Recent changes for how the MAC is configured broke fixed links, as
used by CPU/DSA ports, and for SFPs when phylink cannot be used. The
first fix is unchanged from v1. The second fix takes a different
solution than v1. If a CPU or DSA port is known to have a PHYLINK
instance, configure the port down before instantiating the PHYLINK, so
it is in the down state as expected by PHYLINK.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

DSA and CPU ports can be configured in two ways. By default, the
driver should configure such ports to there maximum bandwidth. For
most use cases, this is sufficient. When this default is insufficient,
a phylink instance can be bound to such ports, and phylink will
configure the port, e.g. based on fixed-link properties. phylink
assumes the port is initially down. Given that the driver should have
already configured it to its maximum speed, ask the driver to down
the port before instantiating the phylink instance.

Fixes: 30c4a5b0 ("net: mv88e6xxx: use resolved link config in mac_link_up()")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 88e6185 is reporting it has detected a PHY, when a port is
connected to an SFP. As a result, the fixed-phy configuration is not
being applied. That then breaks packet transfer, since the port is
reported as being down.

Add additional conditions to check the interface mode, and if it is
fixed always configure the port on link up/down, independent of the
PPU status.

Fixes: 30c4a5b0 ("net: mv88e6xxx: use resolved link config in mac_link_up()")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Shannon Nelson says:

====================
ionic: address automated build complaints

Kernel build checks found a couple of things to improve.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove an unused initialized value.

Fixes: 7e4d4759 ("ionic: replay filters after fw upgrade")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the appropriate header for using dynamic_hex_dump(), which
seems to be incidentally included in some configurations but
not all.

Fixes: 7e4d4759 ("ionic: replay filters after fw upgrade")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the DATA packet transmission to disable nofrag for UDPv4 on an AF_INET6
socket as well as UDPv6 when trying to transmit fragmentably.

Without this, packets filled to the normal size used by the kernel AFS
client of 1412 bytes be rejected by udp_sendmsg() with EMSGSIZE
immediately.  The ->sk_error_report() notification hook is called, but
rxrpc doesn't generate a trace for it.

This is a temporary fix; a more permanent solution needs to involve
changing the size of the packets being filled in accordance with the MTU,
which isn't currently done in AF_RXRPC.  The reason for not doing so was
that, barring the last packet in an rx jumbo packet, jumbos can only be
assembled out of 1412-byte packets - and the plan was to construct jumbos
on the fly at transmission time.

Also, there's no point turning on IPV6_MTU_DISCOVER, since IPv6 has to
engage in this anyway since fragmentation is only done by the sender.  We
can then condense the switch-statement in rxrpc_send_data_packet().

Fixes: 75b54cb5 ("rxrpc: Add IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

KSZ9131 will not work with some switches due to workaround for KSZ9031
introduced in commit d2fd719b
("net/phy: micrel: Add workaround for bad autoneg").
Use genphy_read_status instead of dedicated ksz9031_read_status.

Fixes: bff5b4b3 ("net: phy: micrel: add Microchip KSZ9131 initial driver")
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>