The macro enetc_mdio_rd_reg() is just used in that particular case and
has a hardcoded parameter name "mdio_priv". Define a specific function
to use for readx_poll_timeout() instead. Also drop the TIMEOUT macro
since it is used just once.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before commit 6517798d ("enetc: Make MDIO accessors more generic and
export to include/linux/fsl") these macros actually had some benefits.
But after the commit it just makes the code hard to read. Drop the macro
indirections.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull ARC updates from Vineet Gupta:
 "Things are quieter on upstreaming front as we are mostly focusing on
  ARCv3/ARC64 port.

  This contains just build system updates from Masahiro Yamada"

* tag 'arc-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: build: use $(READELF) instead of hard-coded readelf
  ARC: build: remove unneeded extra-y
  ARC: build: move symlink creation to arch/arc/Makefile to avoid race
  ARC: build: add boot_targets to PHONY
  ARC: build: add uImage.lzma to the top-level target
  ARC: build: remove non-existing bootpImage from KBUILD_IMAGE

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from netfilter, wireless and bpf
  trees.

  Current release - regressions:

   - mt76: fix NULL pointer dereference in mt76u_status_worker and
     mt76s_process_tx_queue

   - net: ipa: fix interconnect enable bug

  Current release - always broken:

   - netfilter: fixes possible oops in mtype_resize in ipset

   - ath11k: fix number of coding issues found by static analysis tools
     and spurious error messages

  Previous releases - regressions:

   - e1000e: re-enable s0ix power saving flows for systems with the
     Intel i219-LM Ethernet controllers to fix power use regression

   - virtio_net: fix recursive call to cpus_read_lock() to avoid a
     deadlock

   - ipv4: ignore ECN bits for fib lookups in fib_compute_spec_dst()

   - sysfs: take the rtnl lock around XPS configuration

   - xsk: fix memory leak for failed bind and rollback reservation at
     NETDEV_TX_BUSY

   - r8169: work around power-saving bug on some chip versions

  Previous releases - always broken:

   - dcb: validate netlink message in DCB handler

   - tun: fix return value when the number of iovs exceeds MAX_SKB_FRAGS
     to prevent unnecessary retries

   - vhost_net: fix ubuf refcount when sendmsg fails

   - bpf: save correct stopping point in file seq iteration

   - ncsi: use real net-device for response handler

   - neighbor: fix div by zero caused by a data race (TOCTOU)

   - bareudp: fix use of incorrect min_headroom size and a false
     positive lockdep splat from the TX lock

   - mvpp2:
      - clear force link UP during port init procedure in case
        bootloader had set it
      - add TCAM entry to drop flow control pause frames
      - fix PPPoE with ipv6 packet parsing
      - fix GoP Networking Complex Control config of port 3
      - fix pkt coalescing IRQ-threshold configuration

   - xsk: fix race in SKB mode transmit with shared cq

   - ionic: account for vlan tag len in rx buffer len

   - stmmac: ignore the second clock input, current clock framework does
     not handle exclusive clock use well, other drivers may reconfigure
     the second clock

  Misc:

   - ppp: change PPPIOCUNBRIDGECHAN ioctl request number to follow
     existing scheme"

* tag 'net-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (99 commits)
  net: dsa: lantiq_gswip: Fix GSWIP_MII_CFG(p) register access
  net: dsa: lantiq_gswip: Enable GSWIP_MII_CFG_EN also for internal PHYs
  net: lapb: Decrease the refcount of "struct lapb_cb" in lapb_device_event
  r8169: work around power-saving bug on some chip versions
  net: usb: qmi_wwan: add Quectel EM160R-GL
  selftests: mlxsw: Set headroom size of correct port
  net: macb: Correct usage of MACB_CAPS_CLK_HW_CHG flag
  ibmvnic: fix: NULL pointer dereference.
  docs: networking: packet_mmap: fix old config reference
  docs: networking: packet_mmap: fix formatting for C macros
  vhost_net: fix ubuf refcount incorrectly when sendmsg fails
  bareudp: Fix use of incorrect min_headroom size
  bareudp: set NETIF_F_LLTX flag
  net: hdlc_ppp: Fix issues when mod_timer is called while timer is running
  atlantic: remove architecture depends
  erspan: fix version 1 check in gre_parse_header()
  net: hns: fix return value check in __lb_other_process()
  net: sched: prevent invalid Scell_log shift count
  net: neighbor: fix a crash caused by mod zero
  ipv4: Ignore ECN bits for fib lookups in fib_compute_spec_dst()
  ...

Pull AFS fixes from David Howells:
 "Two fixes.

  The first is the fix for the strnlen() array limit check and the
  second fixes the calculation of the number of dirent records used to
  represent any particular filename length"

* tag 'afs-fixes-04012021' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix directory entry size calculation
  afs: Work around strnlen() oops with CONFIG_FORTIFIED_SOURCE=y

Ever since commit 2a9127fc ("mm: rewrite wait_on_page_bit_common()
logic") we've had some very occasional reports of BUG_ON(PageWriteback)
in write_cache_pages(), which we thought we already fixed in commit
073861ed ("mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)").

But syzbot just reported another one, even with that commit in place.

And it turns out that there's a simpler way to trigger the BUG_ON() than
the one Hugh found with page re-use.  It all boils down to the fact that
the page writeback is ostensibly serialized by the page lock, but that
isn't actually really true.

Yes, the people _setting_ writeback all do so under the page lock, but
the actual clearing of the bit - and waking up any waiters - happens
without any page lock.

This gives us this fairly simple race condition:

  CPU1 = end previous writeback
  CPU2 = start new writeback under page lock
  CPU3 = write_cache_pages()

  CPU1          CPU2            CPU3
  ----          ----            ----

  end_page_writeback()
    test_clear_page_writeback(page)
    ... delayed...

                lock_page();
                set_page_writeback()
                unlock_page()

                                lock_page()
                                wait_on_page_writeback();

    wake_up_page(page, PG_writeback);
    .. wakes up CPU3 ..

                                BUG_ON(PageWriteback(page));

where the BUG_ON() happens because we woke up the PG_writeback bit
becasue of the _previous_ writeback, but a new one had already been
started because the clearing of the bit wasn't actually atomic wrt the
actual wakeup or serialized by the page lock.

The reason this didn't use to happen was that the old logic in waiting
on a page bit would just loop if it ever saw the bit set again.

The nice proper fix would probably be to get rid of the whole "wait for
writeback to clear, and then set it" logic in the writeback path, and
replace it with an atomic "wait-to-set" (ie the same as we have for page
locking: we set the page lock bit with a single "lock_page()", not with
"wait for lock bit to clear and then set it").

However, out current model for writeback is that the waiting for the
writeback bit is done by the generic VFS code (ie write_cache_pages()),
but the actual setting of the writeback bit is done much later by the
filesystem ".writepages()" function.

IOW, to make the writeback bit have that same kind of "wait-to-set"
behavior as we have for page locking, we'd have to change our roughly
~50 different writeback functions.  Painful.

Instead, just make "wait_on_page_writeback()" loop on the very unlikely
situation that the PG_writeback bit is still set, basically re-instating
the old behavior.  This is very non-optimal in case of contention, but
since we only ever set the bit under the page lock, that situation is
controlled.

Reported-by: syzbot+2fc0712f8f8b8b8fa0ef@syzkaller.appspotmail.com
Fixes: 2a9127fc ("mm: rewrite wait_on_page_bit_common() logic")
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Missing sanitization of rateest userspace string, bug has been
   triggered by syzbot, patch from Florian Westphal.

2) Report EOPNOTSUPP on missing set features in nft_dynset, otherwise
   error reporting to userspace via EINVAL is misleading since this is
   reserved for malformed netlink requests.

3) New binaries with old kernels might silently accept several set
   element expressions. New binaries set on the NFT_SET_EXPR and
   NFT_DYNSET_F_EXPR flags to request for several expressions per
   element, hence old kernels which do not support for this bail out
   with EOPNOTSUPP.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: nftables: add set expression flags
  netfilter: nft_dynset: report EOPNOTSUPP on missing set feature
  netfilter: xt_RATEEST: reject non-null terminated string from userspace
====================

Link: https://lore.kernel.org/r/20210103192920.18639-1-pablo@netfilter.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Martin Blumenstingl says:

====================
net: dsa: lantiq_gswip: two fixes for -net/-stable

While testing the lantiq_gswip driver in OpenWrt at least one board had
a non-working Ethernet port connected to an internal 100Mbit/s PHY22F
GPHY. The problem which could be observed:
- the PHY would detect the link just fine
- ethtool stats would see the TX counter rise
- the RX counter in ethtool was stuck at zero

It turns out that two independent patches are needed to fix this:
- first we need to enable the MII data lines also for internal PHYs
- second we need to program the GSWIP_MII_CFG registers for all ports
  except the CPU port

These two patches have also been tested by back-porting them on top of
Linux 5.4.86 in OpenWrt.

Special thanks to Hauke for debugging and brainstorming this on IRC
with me!
====================

Link: https://lore.kernel.org/r/20210103012544.3259029-1-martin.blumenstingl@googlemail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

There is one GSWIP_MII_CFG register for each switch-port except the CPU
port. The register offset for the first port is 0x0, 0x02 for the
second, 0x04 for the third and so on.

Update the driver to not only restrict the GSWIP_MII_CFG registers to
ports 0, 1 and 5. Handle ports 0..5 instead but skip the CPU port. This
means we are not overwriting the configuration for the third port (port
two since we start counting from zero) with the settings for the sixth
port (with number five) anymore.

The GSWIP_MII_PCDU(p) registers are not updated because there's really
only three (one for each of the following ports: 0, 1, 5).

Fixes: 14fceff4 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Enable GSWIP_MII_CFG_EN also for internal PHYs to make traffic flow.
Without this the PHY link is detected properly and ethtool statistics
for TX are increasing but there's no RX traffic coming in.

Fixes: 14fceff4 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Suggested-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In lapb_device_event, lapb_devtostruct is called to get a reference to
an object of "struct lapb_cb". lapb_devtostruct increases the refcount
of the object and returns a pointer to it. However, we didn't decrease
the refcount after we finished using the pointer. This patch fixes this
problem.

Fixes: a4989fa9 ("net/lapb: support netdev events")
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Link: https://lore.kernel.org/r/20201231174331.64539-1-xie.he.0141@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

A user reported failing network with RTL8168dp (a quite rare chip
version). Realtek confirmed that few chip versions suffer from a PLL
power-down hw bug.

Fixes: 07df5bd8 ("r8169: power down chip in probe")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/a1c39460-d533-7f9e-fa9d-2b8990b02426@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

New modem using ff/ff/30 for QCDM, ff/00/00 for  AT and NMEA,
and ff/ff/ff for RMNET/QMI.

T: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=5000 MxCh= 0
D: Ver= 3.20 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs= 1
P: Vendor=2c7c ProdID=0620 Rev= 4.09
S: Manufacturer=Quectel
S: Product=EM160R-GL
S: SerialNumber=e31cedc1
C:* #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=896mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=(none)
E: Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=01(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=83(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=82(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=85(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=84(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=03(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=87(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=86(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=04(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E: Ad=88(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
E: Ad=8e(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=0f(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Link: https://lore.kernel.org/r/20201230152451.245271-1-bjorn@mork.noSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The test was setting the headroom size of the wrong port. This was not
visible because of a firmware bug that canceled this bug.

Set the headroom size of the correct port, so that the test will pass
with both old and new firmware versions.

Fixes: bfa80478 ("selftests: mlxsw: Add a PFC test")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20201230114251.394009-1-idosch@idosch.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

A new flag MACB_CAPS_CLK_HW_CHG was added and all callers of
macb_set_tx_clk were gated on the presence of this flag.

-   if (!clk)
+ if (!bp->tx_clk || !(bp->caps & MACB_CAPS_CLK_HW_CHG))

However the flag was not added to anything other than the new
sama7g5_gem, turning that function call into a no op for all other
systems. This breaks the networking on Zynq.

The commit message adding this states: a new capability so that
macb_set_tx_clock() to not be called for IPs having this
capability

This strongly implies that present of the flag was intended to skip
the function not absence of the flag. Update the if statement to
this effect, which repairs the existing users.

Fixes: daafa1d3 ("net: macb: add capability to not set the clock rate")
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210104103802.13091-1-ckeepax@opensource.cirrus.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The error is due to dereference a null pointer in function
reset_one_sub_crq_queue():

if (!scrq) {
    netdev_dbg(adapter->netdev,
               "Invalid scrq reset. irq (%d) or msgs(%p).\n",
		scrq->irq, scrq->msgs);
		return -EINVAL;
}

If the expression is true, scrq must be a null pointer and cannot
dereference.

Fixes: 9281cf2d ("ibmvnic: avoid memset null scrq msgs")
Signed-off-by: YANG LI <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci <abaci@linux.alibaba.com>
Acked-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/1609312994-121032-1-git-send-email-abaci-bugfix@linux.alibaba.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Before commit 889b8f96 ("packet: Kill CONFIG_PACKET_MMAP.") there
used to be a CONFIG_PACKET_MMAP config symbol that depended on
CONFIG_PACKET. The text still implies that PACKET_MMAP can be disabled.
Remove that from the text, as well as reference to old kernel versions.

Also, drop reference to broken link to information for pre 2.6.5
kernels.

Make a slight working improvement (s/In/On/) while at it.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/80089f3783372c8fd7833f28ce774a171b2ef252.1609232919.git.baruch@tkos.co.ilSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The citation of macro definitions should appear in a code block.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/5cb47005e7a59b64299e038827e295822193384c.1609232919.git.baruch@tkos.co.ilSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Currently the vhost_zerocopy_callback() maybe be called to decrease
the refcount when sendmsg fails in tun. The error handling in vhost
handle_tx_zerocopy() will try to decrease the same refcount again.
This is wrong. To fix this issue, we only call vhost_net_ubuf_put()
when vq->heads[nvq->desc].len == VHOST_DMA_IN_PROGRESS.

Fixes: bab632d6 ("vhost: vhost TX zero-copy support")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/1609207308-20544-1-git-send-email-wangyunjian@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In the bareudp6_xmit_skb(), it calculates min_headroom.
At that point, it uses struct iphdr, but it's not correct.
So panic could occur.
The struct ipv6hdr should be used.

Test commands:
    ip netns add A
    ip netns add B
    ip link add veth0 netns A type veth peer name veth1 netns B
    ip netns exec A ip link set veth0 up
    ip netns exec A ip a a 2001:db8:0::1/64 dev veth0
    ip netns exec B ip link set veth1 up
    ip netns exec B ip a a 2001:db8:0::2/64 dev veth1

    for i in {10..1}
    do
            let A=$i-1
            ip netns exec A ip link add bareudp$i type bareudp dstport $i \
		    ethertype 0x86dd
            ip netns exec A ip link set bareudp$i up
            ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev bareudp$i
            ip netns exec A ip -6 r a 2001:db8:$i::2 encap ip6 src \
		    2001:db8:$A::1 dst 2001:db8:$A::2 via 2001:db8:$i::2 \
		    dev bareudp$i

            ip netns exec B ip link add bareudp$i type bareudp dstport $i \
		    ethertype 0x86dd
            ip netns exec B ip link set bareudp$i up
            ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev bareudp$i
            ip netns exec B ip -6 r a 2001:db8:$i::1 encap ip6 src \
		    2001:db8:$A::2 dst 2001:db8:$A::1 via 2001:db8:$i::1 \
		    dev bareudp$i
    done
    ip netns exec A ping 2001:db8:7::2

Splat looks like:
[   66.436679][    C2] skbuff: skb_under_panic: text:ffffffff928614c8 len:454 put:14 head:ffff88810abb4000 data:ffff88810abb3ffa tail:0x1c0 end:0x3ec0 dev:veth0
[   66.441626][    C2] ------------[ cut here ]------------
[   66.443458][    C2] kernel BUG at net/core/skbuff.c:109!
[   66.445313][    C2] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[   66.447606][    C2] CPU: 2 PID: 913 Comm: ping Not tainted 5.10.0+ #819
[   66.450251][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[   66.453713][    C2] RIP: 0010:skb_panic+0x15d/0x15f
[   66.455345][    C2] Code: 98 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 60 8b 78 93 41 57 41 56 41 55 48 8b 54 24 20 48 8b 74 24 28 e8 b5 40 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 08 c9 98 fe 8b 34 24 48 c7 c1 80
[   66.462314][    C2] RSP: 0018:ffff888119209648 EFLAGS: 00010286
[   66.464281][    C2] RAX: 0000000000000089 RBX: ffff888003159000 RCX: 0000000000000000
[   66.467216][    C2] RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed10232412c0
[   66.469768][    C2] RBP: ffff88810a53d440 R08: ffffed102328018d R09: ffffed102328018d
[   66.472297][    C2] R10: ffff888119400c67 R11: ffffed102328018c R12: 000000000000000e
[   66.474833][    C2] R13: ffff88810abb3ffa R14: 00000000000001c0 R15: 0000000000003ec0
[   66.477361][    C2] FS:  00007f37c0c72f00(0000) GS:ffff888119200000(0000) knlGS:0000000000000000
[   66.480214][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   66.482296][    C2] CR2: 000055a058808570 CR3: 000000011039e002 CR4: 00000000003706e0
[   66.484811][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   66.487793][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   66.490424][    C2] Call Trace:
[   66.491469][    C2]  <IRQ>
[   66.492374][    C2]  ? eth_header+0x28/0x190
[   66.494054][    C2]  ? eth_header+0x28/0x190
[   66.495401][    C2]  skb_push.cold.99+0x22/0x22
[   66.496700][    C2]  eth_header+0x28/0x190
[   66.497867][    C2]  neigh_resolve_output+0x3de/0x720
[   66.499615][    C2]  ? __neigh_update+0x7e8/0x20a0
[   66.501176][    C2]  __neigh_update+0x8bd/0x20a0
[   66.502749][    C2]  ndisc_update+0x34/0xc0
[   66.504010][    C2]  ndisc_recv_na+0x8da/0xb80
[   66.505041][    C2]  ? pndisc_redo+0x20/0x20
[   66.505888][    C2]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   66.506965][    C2]  ndisc_rcv+0x3a0/0x470
[   66.507797][    C2]  icmpv6_rcv+0xad9/0x1b00
[   66.508645][    C2]  ip6_protocol_deliver_rcu+0xcd6/0x1560
[   66.509719][    C2]  ip6_input_finish+0x5b/0xf0
[   66.510615][    C2]  ip6_input+0xcd/0x2d0
[   66.511406][    C2]  ? ip6_input_finish+0xf0/0xf0
[   66.512327][    C2]  ? rcu_read_lock_held+0x91/0xa0
[   66.513279][    C2]  ? ip6_protocol_deliver_rcu+0x1560/0x1560
[   66.514414][    C2]  ipv6_rcv+0xe8/0x300
[ ... ]
Acked-by: Guillaume Nault <gnault@redhat.com>
Fixes: 571912c6 ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152146.24270-1-ap420073@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Like other tunneling interfaces, the bareudp doesn't need TXLOCK.
So, It is good to set the NETIF_F_LLTX flag to improve performance and
to avoid lockdep's false-positive warning.

Test commands:
    ip netns add A
    ip netns add B
    ip link add veth0 netns A type veth peer name veth1 netns B
    ip netns exec A ip link set veth0 up
    ip netns exec A ip a a 10.0.0.1/24 dev veth0
    ip netns exec B ip link set veth1 up
    ip netns exec B ip a a 10.0.0.2/24 dev veth1

    for i in {2..1}
    do
            let A=$i-1
            ip netns exec A ip link add bareudp$i type bareudp \
		    dstport $i ethertype ip
            ip netns exec A ip link set bareudp$i up
            ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i
            ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \
		    dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i

            ip netns exec B ip link add bareudp$i type bareudp \
		    dstport $i ethertype ip
            ip netns exec B ip link set bareudp$i up
            ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i
            ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \
		    dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i
    done
    ip netns exec A ping 10.0.2.2

Splat looks like:
[   96.992803][  T822] ============================================
[   96.993954][  T822] WARNING: possible recursive locking detected
[   96.995102][  T822] 5.10.0+ #819 Not tainted
[   96.995927][  T822] --------------------------------------------
[   96.997091][  T822] ping/822 is trying to acquire lock:
[   96.998083][  T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   96.999813][  T822]
[   96.999813][  T822] but task is already holding lock:
[   97.001192][  T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   97.002908][  T822]
[   97.002908][  T822] other info that might help us debug this:
[   97.004401][  T822]  Possible unsafe locking scenario:
[   97.004401][  T822]
[   97.005784][  T822]        CPU0
[   97.006407][  T822]        ----
[   97.007010][  T822]   lock(_xmit_NONE#2);
[   97.007779][  T822]   lock(_xmit_NONE#2);
[   97.008550][  T822]
[   97.008550][  T822]  *** DEADLOCK ***
[   97.008550][  T822]
[   97.010057][  T822]  May be due to missing lock nesting notation
[   97.010057][  T822]
[   97.011594][  T822] 7 locks held by ping/822:
[   97.012426][  T822]  #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00
[   97.014191][  T822]  #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[   97.016045][  T822]  #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[   97.017897][  T822]  #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   97.019684][  T822]  #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp]
[   97.021573][  T822]  #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[   97.023424][  T822]  #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[   97.025259][  T822]
[   97.025259][  T822] stack backtrace:
[   97.026349][  T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819
[   97.027609][  T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[   97.029407][  T822] Call Trace:
[   97.030015][  T822]  dump_stack+0x99/0xcb
[   97.030783][  T822]  __lock_acquire.cold.77+0x149/0x3a9
[   97.031773][  T822]  ? stack_trace_save+0x81/0xa0
[   97.032661][  T822]  ? register_lock_class+0x1910/0x1910
[   97.033673][  T822]  ? register_lock_class+0x1910/0x1910
[   97.034679][  T822]  ? rcu_read_lock_sched_held+0x91/0xc0
[   97.035697][  T822]  ? rcu_read_lock_bh_held+0xa0/0xa0
[   97.036690][  T822]  lock_acquire+0x1b2/0x730
[   97.037515][  T822]  ? __dev_queue_xmit+0x1f52/0x2960
[   97.038466][  T822]  ? check_flags+0x50/0x50
[   97.039277][  T822]  ? netif_skb_features+0x296/0x9c0
[   97.040226][  T822]  ? validate_xmit_skb+0x29/0xb10
[   97.041151][  T822]  _raw_spin_lock+0x30/0x70
[   97.041977][  T822]  ? __dev_queue_xmit+0x1f52/0x2960
[   97.042927][  T822]  __dev_queue_xmit+0x1f52/0x2960
[   97.043852][  T822]  ? netdev_core_pick_tx+0x290/0x290
[   97.044824][  T822]  ? mark_held_locks+0xb7/0x120
[   97.045712][  T822]  ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
[   97.046824][  T822]  ? __local_bh_enable_ip+0xa5/0xf0
[   97.047771][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.048710][  T822]  ? trace_hardirqs_on+0x41/0x120
[   97.049626][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.050556][  T822]  ? __local_bh_enable_ip+0xa5/0xf0
[   97.051509][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.052443][  T822]  ? check_chain_key+0x244/0x5f0
[   97.053352][  T822]  ? rcu_read_lock_bh_held+0x56/0xa0
[   97.054317][  T822]  ? ip_finish_output2+0x6ea/0x2020
[   97.055263][  T822]  ? pneigh_lookup+0x410/0x410
[   97.056135][  T822]  ip_finish_output2+0x6ea/0x2020
[ ... ]
Acked-by: Guillaume Nault <gnault@redhat.com>
Fixes: 571912c6 ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull RCU fix from Paul McKenney:
 "This is a fix for a regression in the v5.10 merge window, but it was
  reported quite late in the v5.10 process, plus generating and testing
  the fix took some time.

  The regression is due to commit 36dadef2 ("kprobes: Init kprobes
  in early_initcall") which on powerpc can use RCU Tasks before
  initialization, resulting in boot failures.

  The fix is straightforward, simply moving initialization of RCU Tasks
  before the early_initcall()s. The fix has been exposed to -next and
  kbuild test robot testing, and has been tested by the PowerPC guys"

* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu-tasks: Move RCU-tasks initialization to before early_initcall()

Pull ENABLE_MUST_CHECK removal from Miguel Ojeda:
 "Remove CONFIG_ENABLE_MUST_CHECK (Masahiro Yamada)"

Note that this removes the config option by making the must-check
unconditional, not by removing must check itself.

* tag 'compiler-attributes-for-linus-v5.11' of git://github.com/ojeda/linux:
  Compiler Attributes: remove CONFIG_ENABLE_MUST_CHECK

The number of dirent records used by an AFS directory entry should be
calculated using the assumption that there is a 16-byte name field in the
first block, rather than a 20-byte name field (which is actually the case).
This miscalculation is historic and effectively standard, so we have to use
it.

The calculation we need to use is:

	1 + (((strlen(name) + 1) + 15) >> 5)

where we are adding one to the strlen() result to account for the NUL
termination.

Fix this by the following means:

 (1) Create an inline function to do the calculation for a given name
     length.

 (2) Use the function to calculate the number of records used for a dirent
     in afs_dir_iterate_block().

     Use this to move the over-end check out of the loop since it only
     needs to be done once.

     Further use this to only go through the loop for the 2nd+ records
     composing an entry.  The only test there now is for if the record is
     allocated - and we already checked the first block at the top of the
     outer loop.

 (3) Add a max name length check in afs_dir_iterate_block().

 (4) Make afs_edit_dir_add() and afs_edit_dir_remove() use the function
     from (1) to calculate the number of blocks rather than doing it
     incorrectly themselves.

Fixes: 63a4681f ("afs: Locally edit directory data for mkdir/create/unlink/...")
Fixes: ^1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>

AFS has a structured layout in its directory contents (AFS dirs are
downloaded as files and parsed locally by the client for lookup/readdir).
The slots in the directory are defined by union afs_xdr_dirent.  This,
however, only directly allows a name of a length that will fit into that
union.  To support a longer name, the next 1-8 contiguous entries are
annexed to the first one and the name flows across these.

afs_dir_iterate_block() uses strnlen(), limited to the space to the end of
the page, to find out how long the name is.  This worked fine until
6a39e62a.  With that commit, the compiler determines the size of the
array and asserts that the string fits inside that array.  This is a
problem for AFS because we *expect* it to overflow one or more arrays.

A similar problem also occurs in afs_dir_scan_block() when a directory file
is being locally edited to avoid the need to redownload it.  There strlen()
was being used safely because each page has the last byte set to 0 when the
file is downloaded and validated (in afs_dir_check_page()).

Fix this by changing the afs_xdr_dirent union name field to an
indeterminate-length array and dropping the overflow field.

(Note that whilst looking at this, I realised that the calculation of the
number of slots a dirent used is non-standard and not quite right, but I'll
address that in a separate patch.)

The issue can be triggered by something like:

        touch /afs/example.com/thisisaveryveryverylongname

and it generates a report that looks like:

        detected buffer overflow in strnlen
        ------------[ cut here ]------------
        kernel BUG at lib/string.c:1149!
        ...
        RIP: 0010:fortify_panic+0xf/0x11
        ...
        Call Trace:
         afs_dir_iterate_block+0x12b/0x35b
         afs_dir_iterate+0x14e/0x1ce
         afs_do_lookup+0x131/0x417
         afs_lookup+0x24f/0x344
         lookup_open.isra.0+0x1bb/0x27d
         open_last_lookups+0x166/0x237
         path_openat+0xe0/0x159
         do_filp_open+0x48/0xa4
         ? kmem_cache_alloc+0xf5/0x16e
         ? __clear_close_on_exec+0x13/0x22
         ? _raw_spin_unlock+0xa/0xb
         do_sys_openat2+0x72/0xde
         do_sys_open+0x3b/0x58
         do_syscall_64+0x2d/0x3a
         entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 6a39e62a ("lib: string.h: detect intra-object overflow in fortified string functions")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: Daniel Axtens <dja@axtens.net>

Pull s390 cleanups from Vasily Gorbik:
 "Update defconfigs and sort config select list"

* tag 's390-5.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/Kconfig: sort config S390 select list once again
  s390: update defconfigs

Pull power management fixes from Rafael Wysocki:
 "These fix a crash in intel_pstate during resume from suspend-to-RAM
  that may occur after recent changes and two resource leaks in error
  paths in the operating performance points (OPP) framework, add a new
  C-states table to intel_idle and update the cpuidle MAINTAINERS entry
  to cover the governors too.

  Specifics:

   - Fix recently introduced crash in the intel_pstate driver that
     occurs if scale-invariance is disabled during resume from
     suspend-to-RAM due to inconsistent changes of APERF or MPERF MSR
     values made by the platform firmware (Rafael Wysocki).

   - Fix a memory leak and add a missing clk_put() in error paths in the
     OPP framework (Quanyang Wang, Viresh Kumar).

   - Add new C-states table for SnowRidge processors to the intel_idle
     driver (Artem Bityutskiy).

   - Update the MAINTAINERS entry for cpuidle to make it clear that the
     governors are covered by it too (Lukas Bulwahn)"

* tag 'pm-5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_idle: add SnowRidge C-state table
  cpufreq: intel_pstate: Fix fast-switch fallback path
  opp: Call the missing clk_put() on error
  opp: fix memory leak in _allocate_opp_table
  MAINTAINERS: include governors into CPU IDLE TIME MANAGEMENT FRAMEWORK

* pm-cpufreq:
  cpufreq: intel_pstate: Fix fast-switch fallback path

* pm-cpuidle:
  intel_idle: add SnowRidge C-state table
  MAINTAINERS: include governors into CPU IDLE TIME MANAGEMENT FRAMEWORK

Pull SCSI fixes from James Bottomley:
 "This is a load of driver fixes (12 ufs, 1 mpt3sas, 1 cxgbi).

  The big core two fixes are for power management ("block: Do not accept
  any requests while suspended" and "block: Fix a race in the runtime
  power management code") which finally sorts out the resume problems
  we've occasionally been having.

  To make the resume fix, there are seven necessary precursors which
  effectively renames REQ_PREEMPT to REQ_PM, so every "special" request
  in block is automatically a power management exempt one.

  All of the non-PM preempt cases are removed except for the one in the
  SCSI Parallel Interface (spi) domain validation which is a genuine
  case where we have to run requests at high priority to validate the
  bus so this becomes an autopm get/put protected request"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (22 commits)
  scsi: cxgb4i: Fix TLS dependency
  scsi: ufs: Un-inline ufshcd_vops_device_reset function
  scsi: ufs: Re-enable WriteBooster after device reset
  scsi: ufs-mediatek: Use correct path to fix compile error
  scsi: mpt3sas: Signedness bug in _base_get_diag_triggers()
  scsi: block: Do not accept any requests while suspended
  scsi: block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT
  scsi: core: Only process PM requests if rpm_status != RPM_ACTIVE
  scsi: scsi_transport_spi: Set RQF_PM for domain validation commands
  scsi: ide: Mark power management requests with RQF_PM instead of RQF_PREEMPT
  scsi: ide: Do not set the RQF_PREEMPT flag for sense requests
  scsi: block: Introduce BLK_MQ_REQ_PM
  scsi: block: Fix a race in the runtime power management code
  scsi: ufs-pci: Enable UFSHCD_CAP_RPM_AUTOSUSPEND for Intel controllers
  scsi: ufs-pci: Fix recovery from hibernate exit errors for Intel controllers
  scsi: ufs-pci: Ensure UFS device is in PowerDown mode for suspend-to-disk ->poweroff()
  scsi: ufs-pci: Fix restore from S4 for Intel controllers
  scsi: ufs-mediatek: Keep VCC always-on for specific devices
  scsi: ufs: Allow regulators being always-on
  scsi: ufs: Clear UAC for RPMB after ufshcd resets
  ...

Pull block fixes from Jens Axboe:
 "Two minor block fixes from this last week that should go into 5.11:

   - Add missing NOWAIT debugfs definition (Andres)

   - Fix kerneldoc warning introduced this merge window (Randy)"

* tag 'block-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
  block: add debugfs stanza for QUEUE_FLAG_NOWAIT
  fs: block_dev.c: fix kernel-doc warnings from struct block_device changes

Pull io_uring fixes from Jens Axboe:
 "A few fixes that should go into 5.11, all marked for stable as well:

   - Fix issue around identity COW'ing and users that share a ring
     across processes

   - Fix a hang associated with unregistering fixed files (Pavel)

   - Move the 'process is exiting' cancelation a bit earlier, so
     task_works aren't affected by it (Pavel)"

* tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
  kernel/io_uring: cancel io_uring before task works
  io_uring: fix io_sqe_files_unregister() hangs
  io_uring: add a helper for setting a ref node
  io_uring: don't assume mm is constant across submits

Commit 436e980e ("kbuild: don't hardcode depmod path") stopped
hard-coding the path of depmod, but in the process caused trouble for
distributions that had that /sbin location, but didn't have it in the
PATH (generally because /sbin is limited to the super-user path).

Work around it for now by just adding /sbin to the end of PATH in the
depmod.sh script.
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For cancelling io_uring requests it needs either to be able to run
currently enqueued task_works or having it shut down by that moment.
Otherwise io_uring_cancel_files() may be waiting for requests that won't
ever complete.

Go with the first way and do cancellations before setting PF_EXITING and
so before putting the task_work infrastructure into a transition state
where task_work_run() would better not be called.

Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_sqe_files_unregister() uninterruptibly waits for enqueued ref nodes,
however requests keeping them may never complete, e.g. because of some
userspace dependency. Make sure it's interruptible otherwise it would
hang forever.

Cc: stable@vger.kernel.org # 5.6+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Setting a new reference node to a file data is not trivial, don't repeat
it, add and use a helper.

Cc: stable@vger.kernel.org # 5.6+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull ceph fixes from Ilya Dryomov:
 "A fix for an edge case in MClientRequest encoding and a couple of
  trivial fixups for the new msgr2 support"

* tag 'ceph-for-5.11-rc2' of git://github.com/ceph/ceph-client:
  libceph: add __maybe_unused to DEFINE_MSGR2_FEATURE
  libceph: align session_key and con_secret to 16 bytes
  libceph: fix auth_signature buffer allocation in secure mode
  ceph: reencode gid_list when reconnecting

Add C-state table for the SnowRidge SoC which is found on Intel Jacobsville
platforms.

The following has been changed.

 1. C1E latency changed from 10us to 15us. It was measured using the
    open source "wult" tool (the "nic" method, 15us is the 99.99th
    percentile).

 2. C1E power break even changed from 20us to 25us, which may result
    in less C1E residency in some workloads.

 3. C6 latency changed from 50us to 130us. Measured the same way as C1E.

The C6 C-state is supported only by some SnowRidge revisions, so add a C-state
table commentary about this.

On SnowRidge, C6 support is enumerated via the usual mechanism: "mwait" leaf of
the "cpuid" instruction. The 'intel_idle' driver does check this leaf, so even
though C6 is present in the table, the driver will only use it if the CPU does
support it.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When sugov_update_single_perf() falls back to the "frequency"
path due to the missing scale-invariance, it will call
cpufreq_driver_fast_switch() via sugov_fast_switch()
and the driver's ->fast_switch() callback will be invoked,
so it must not be NULL.

However, after commit a365ab6b ("cpufreq: intel_pstate: Implement
the ->adjust_perf() callback") intel_pstate sets ->fast_switch() to
NULL when it is going to use intel_cpufreq_adjust_perf(), which is a
mistake, because on x86 the scale-invariance may be turned off
dynamically, so modify it to retain the original ->adjust_perf()
callback pointer.

Fixes: a365ab6b ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback")
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull operating performance points (OPP) framework fixes for 5.11-rc2
from Viresh Kumar:

"This contains two patches to fix freeing of resources in error paths."

* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  opp: Call the missing clk_put() on error
  opp: fix memory leak in _allocate_opp_table