Since commit 2f1e8ea7 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the Microchip sub-driver for KSZ8863 was introduced after the bad
commit, it has never worked with DSA masters which decide to unregister
their net_device on shutdown, effectively hanging the reboot process.
To fix that, we need to call dsa_switch_shutdown.

Since this driver expects the MDIO bus to be backed by mdio_bitbang, I
don't think there is currently any MDIO bus driver which implements its
->shutdown by redirecting it to ->remove, but in any case, to be
compatible with that pattern, it is necessary to implement an "if this
then not that" scheme, to avoid ->remove and ->shutdown from being
called both for the same struct device.

Fixes: 60a36476 ("net: dsa: microchip: Add Microchip KSZ8863 SMI based driver support")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 2f1e8ea7 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the hellcreek driver was introduced after the bad commit, it has
never worked with DSA masters which decide to unregister their
net_device on shutdown, effectively hanging the reboot process.

Hellcreek is a platform device driver, so we probably cannot have the
oddities of ->shutdown and ->remove getting both called for the exact
same struct device. But to be in line with the pattern from the other
device drivers which are on slow buses, implement the same "if this then
not that" pattern of either running the ->shutdown or the ->remove hook.
The driver's current ->remove implementation makes that very easy
because it already zeroes out its device_drvdata on ->remove.

Fixes: e4b27ebc ("net: dsa: Add DSA driver for Hirschmann Hellcreek switches")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Lino reports that on his system with bcmgenet as DSA master and KSZ9897
as a switch, rebooting or shutting down never works properly.

What does the bcmgenet driver have special to trigger this, that other
DSA masters do not? It has an implementation of ->shutdown which simply
calls its ->remove implementation. Otherwise said, it unregisters its
network interface on shutdown.

This message can be seen in a loop, and it hangs the reboot process there:

unregister_netdevice: waiting for eth0 to become free. Usage count = 3

So why 3?

A usage count of 1 is normal for a registered network interface, and any
virtual interface which links itself as an upper of that will increment
it via dev_hold. In the case of DSA, this is the call path:

dsa_slave_create
-> netdev_upper_dev_link
   -> __netdev_upper_dev_link
      -> __netdev_adjacent_dev_insert
         -> dev_hold

So a DSA switch with 3 interfaces will result in a usage count elevated
by two, and netdev_wait_allrefs will wait until they have gone away.

Other stacked interfaces, like VLAN, watch NETDEV_UNREGISTER events and
delete themselves, but DSA cannot just vanish and go poof, at most it
can unbind itself from the switch devices, but that must happen strictly
earlier compared to when the DSA master unregisters its net_device, so
reacting on the NETDEV_UNREGISTER event is way too late.

It seems that it is a pretty established pattern to have a driver's
->shutdown hook redirect to its ->remove hook, so the same code is
executed regardless of whether the driver is unbound from the device, or
the system is just shutting down. As Florian puts it, it is quite a big
hammer for bcmgenet to unregister its net_device during shutdown, but
having a common code path with the driver unbind helps ensure it is well
tested.

So DSA, for better or for worse, has to live with that and engage in an
arms race of implementing the ->shutdown hook too, from all individual
drivers, and do something sane when paired with masters that unregister
their net_device there. The only sane thing to do, of course, is to
unlink from the master.

However, complications arise really quickly.

The pattern of redirecting ->shutdown to ->remove is not unique to
bcmgenet or even to net_device drivers. In fact, SPI controllers do it
too (see dspi_shutdown -> dspi_remove), and presumably, I2C controllers
and MDIO controllers do it too (this is something I have not researched
too deeply, but even if this is not the case today, it is certainly
plausible to happen in the future, and must be taken into consideration).

Since DSA switches might be SPI devices, I2C devices, MDIO devices, the
insane implication is that for the exact same DSA switch device, we
might have both ->shutdown and ->remove getting called.

So we need to do something with that insane environment. The pattern
I've come up with is "if this, then not that", so if either ->shutdown
or ->remove gets called, we set the device's drvdata to NULL, and in the
other hook, we check whether the drvdata is NULL and just do nothing.
This is probably not necessary for platform devices, just for devices on
buses, but I would really insist for consistency among drivers, because
when code is copy-pasted, it is not always copy-pasted from the best
sources.

So depending on whether the DSA switch's ->remove or ->shutdown will get
called first, we cannot really guarantee even for the same driver if
rebooting will result in the same code path on all platforms. But
nonetheless, we need to do something minimally reasonable on ->shutdown
too to fix the bug. Of course, the ->remove will do more (a full
teardown of the tree, with all data structures freed, and this is why
the bug was not caught for so long). The new ->shutdown method is kept
separate from dsa_unregister_switch not because we couldn't have
unregistered the switch, but simply in the interest of doing something
quick and to the point.

The big question is: does the DSA switch's ->shutdown get called earlier
than the DSA master's ->shutdown? If not, there is still a risk that we
might still trigger the WARN_ON in unregister_netdevice that says we are
attempting to unregister a net_device which has uppers. That's no good.
Although the reference to the master net_device won't physically go away
even if DSA's ->shutdown comes afterwards, remember we have a dev_hold
on it.

The answer to that question lies in this comment above device_link_add:

 * A side effect of the link creation is re-ordering of dpm_list and the
 * devices_kset list by moving the consumer device and all devices depending
 * on it to the ends of these lists (that does not happen to devices that have
 * not been registered when this function is called).

so the fact that DSA uses device_link_add towards its master is not
exactly for nothing. device_shutdown() walks devices_kset from the back,
so this is our guarantee that DSA's shutdown happens before the master's
shutdown.

Fixes: 2f1e8ea7 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

MDIO-attached devices might have interrupts and other things that might
need quiesced when we kexec into a new kernel. Things are even more
creepy when those interrupt lines are shared, and in that case it is
absolutely mandatory to disable all interrupt sources.

Moreover, MDIO devices might be DSA switches, and DSA needs its own
shutdown method to unlink from the DSA master, which is a new
requirement that appeared after commit 2f1e8ea7 ("net: dsa: link
interfaces with the DSA master to get rid of lockdep warnings").

So introduce a ->shutdown method in the MDIO device driver structure.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After d12e1c46 ("net: dsa: b53: Set correct number of ports in the
DSA struct") we stopped setting dsa_switch::num_ports to DSA_MAX_PORTS,
which created an off by one error between the statically allocated
bcm_sf2_priv::port_sts array (of size DSA_MAX_PORTS). When
dsa_is_cpu_port() is used, we end-up accessing an out of bounds member
and causing a NPD.

Fix this by iterating with the appropriate port count using
ds->num_ports.

Fixes: d12e1c46 ("net: dsa: b53: Set correct number of ports in the DSA struct")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

NXP Legal insists that the following are not fine:

- Saying "NXP Semiconductors" instead of "NXP", since the company's
  registered name is "NXP"

- Putting a "(c)" sign in the copyright string

- Putting a comma in the copyright string

The only accepted copyright string format is "Copyright <year-range> NXP".

This patch changes the copyright headers in the networking files that
were sent by me, or derived from code sent by me.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If resource allocation and registration fail for a muxed tty device
(e.g. if there are no more minor numbers) the driver should not try to
deregister the never-registered (or already-deregistered) tty.

Fix up the error handling to avoid dereferencing a NULL pointer when
attempting to remove the character device.

Fixes: 72dc1c09 ("HSO: add option hso driver")
Cc: stable@vger.kernel.org	# 2.6.27
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  Current release - regressions:

   - vhost_net: fix OoB on sendmsg() failure

   - mlx5: bridge, fix uninitialized variable usage

   - bnxt_en: fix error recovery regression

  Current release - new code bugs:

   - bpf, mm: fix lockdep warning triggered by stack_map_get_build_id_offset()

  Previous releases - regressions:

   - r6040: restore MDIO clock frequency after MAC reset

   - tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()

   - dsa: flush switchdev workqueue before tearing down CPU/DSA ports

  Previous releases - always broken:

   - ptp: dp83640: don't define PAGE0, avoid compiler warning

   - igc: fix tunnel segmentation offloads

   - phylink: update SFP selected interface on advertising changes

   - stmmac: fix system hang caused by eee_ctrl_timer during suspend/resume

   - mlx5e: fix mutual exclusion between CQE compression and HW TS

  Misc:

   - bpf, cgroups: fix cgroup v2 fallback on v1/v2 mixed mode

   - sfc: fallback for lack of xdp tx queues

   - hns3: add option to turn off page pool feature"

* tag 'net-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (67 commits)
  mlxbf_gige: clear valid_polarity upon open
  igc: fix tunnel offloading
  net/{mlx5|nfp|bnxt}: Remove unnecessary RTNL lock assert
  net: wan: wanxl: define CROSS_COMPILE_M68K
  selftests: nci: replace unsigned int with int
  net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports
  Revert "net: phy: Uniform PHY driver access"
  net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup
  ptp: dp83640: don't define PAGE0
  bnx2x: Fix enabling network interfaces without VFs
  Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers""
  tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
  net-caif: avoid user-triggerable WARN_ON(1)
  bpf, selftests: Add test case for mixed cgroup v1/v2
  bpf, selftests: Add cgroup v1 net_cls classid helpers
  bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
  bpf: Add oversize check before call kvcalloc()
  net: hns3: fix the timing issue of VF clearing interrupt sources
  net: hns3: fix the exception when query imp info
  net: hns3: disable mac in flr process
  ...

tx timeout and slot time are currently specified in units of HZ.  On
Alpha, HZ is defined as 1024.  When building alpha:allmodconfig, this
results in the following error message.

  drivers/net/hamradio/6pack.c: In function 'sixpack_open':
  drivers/net/hamradio/6pack.c:71:41: error:
  	unsigned conversion from 'int' to 'unsigned char'
  	changes value from '256' to '0'

In the 6PACK protocol, tx timeout is specified in units of 10 ms and
transmitted over the wire:

    https://www.linux-ax25.org/wiki/6PACK

Defining a value dependent on HZ doesn't really make sense, and
presumably comes from the (very historical) situation where HZ was
originally 100.

Note that the SIXP_SLOTTIME use explicitly is about 10ms granularity:

        mod_timer(&sp->tx_t, jiffies + ((when + 1) * HZ) / 100);

and the SIXP_TXDELAY walue is sent as a byte over the wire.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With the new static annotation, the compiler warns when the functions
are actually unused:

   drivers/gpu/drm/rockchip/cdn-dp-core.c:1123:12: error: 'cdn_dp_resume' defined but not used [-Werror=unused-function]
    1123 | static int cdn_dp_resume(struct device *dev)
         |            ^~~~~~~~~~~~~

Mark them __maybe_unused to suppress that warning as well.

[ Not so 'new' static annotations any more, and I removed the part of
  the patch that added __maybe_unused to cdn_dp_suspend(), because it's
  used by the shutdown/remove code.

  So only the resume function ends up possibly unused if CONFIG_PM isn't
  set     - Linus ]

Fixes: 7c49abb4 ("drm/rockchip: cdn-dp-core: Make cdn_dp_core_suspend/resume static")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm:allmodconfig fails to build with the following error.

  drivers/cpufreq/vexpress-spc-cpufreq.c:454:13: error:
					unused variable 'cur_cluster'

Remove the unused variable.

Fixes: bb8c26d9 ("cpufreq: vexpress: Set CPUFREQ_IS_COOLING_DEV flag")
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some drivers pass a pointer to volatile data to virt_to_bus() and
virt_to_phys(), and that works fine.  One exception is alpha.  This
results in a number of compile errors such as

  drivers/net/wan/lmc/lmc_main.c: In function 'lmc_softreset':
  drivers/net/wan/lmc/lmc_main.c:1782:50: error:
	passing argument 1 of 'virt_to_bus' discards 'volatile'
	qualifier from pointer target type

  drivers/atm/ambassador.c: In function 'do_loader_command':
  drivers/atm/ambassador.c:1747:58: error:
	passing argument 1 of 'virt_to_bus' discards 'volatile'
	qualifier from pointer target type

Declare the parameter of virt_to_phys and virt_to_bus as pointer to
volatile to fix the problem.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This driver isn't enabled most places because of the ISA config
dependency, but alpha still has it.  And I think the 'Jensen' actually
did have an ISA slot.

However, it doesn't build cleanly, because the "Vortex bus master" code
just casts the skb->data pointer to 'int':

        outl((int) (skb->data), ioaddr + Wn7_MasterAddr);

which is all kinds of broken.  Even on a good old traditional PC/AT it
would be broken because the high bits will be random kernel address
bits, but presumably the hardware ignores those bits.  I mean, it's ISA.
We're talking 16MB dma limits. The "good old days".

Make the build happy with this kind of craziness by using the proper
isa_virt_to_bus() handling that the full bus master code uses anyway
(the Vortex bus mastering is a limited special case).

Who knows, this might even work.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull parisc fix from Helge Deller:
 "Fix a build warning when using the PAGE0 pointer"

* tag 'for-5.15/parisc-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Use absolute_pointer() to define PAGE0

Pull m68k fixes from Geert Uytterhoeven:

 - Warning fixes to mitigate CONFIG_WERROR=y

* tag 'm68k-for-v5.15-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: mvme: Remove overdue #warnings in RTC handling
  m68k: Double cast io functions to unsigned long

The network interface managed by the mlxbf_gige driver can
get into a problem state where traffic does not flow.
In this state, the interface will be up and enabled, but
will stop processing received packets.  This problem state
will happen if three specific conditions occur:
    1) driver has received more than (N * RxRingSize) packets but
       less than (N+1 * RxRingSize) packets, where N is an odd number
       Note: the command "ethtool -g <interface>" will display the
       current receive ring size, which currently defaults to 128
    2) the driver's interface was disabled via "ifconfig oob_net0 down"
       during the window described in #1.
    3) the driver's interface is re-enabled via "ifconfig oob_net0 up"

This patch ensures that the driver's "valid_polarity" field is
cleared during the open() method so that it always matches the
receive polarity used by hardware.  Without this fix, the driver
needs to be unloaded and reloaded to correct this problem state.

Fixes: f92e1869 ("Add Mellanox BlueField Gigabit Ethernet driver")
Reviewed-by: Asmaa Mnebhi <asmaa@nvidia.com>
Signed-off-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Checking tunnel offloading, it turns out that offloading doesn't work
as expected.  The following script allows to reproduce the issue.
Call it as `testscript DEVICE LOCALIP REMOTEIP NETMASK'

=== SNIP ===
if [ $# -ne 4 ]
then
  echo "Usage $0 DEVICE LOCALIP REMOTEIP NETMASK"
  exit 1
fi
DEVICE="$1"
LOCAL_ADDRESS="$2"
REMOTE_ADDRESS="$3"
NWMASK="$4"
echo "Driver: $(ethtool -i ${DEVICE} | awk '/^driver:/{print $2}') "
ethtool -k "${DEVICE}" | grep tx-udp
echo
echo "Set up NIC and tunnel..."
ip addr add "${LOCAL_ADDRESS}/${NWMASK}" dev "${DEVICE}"
ip link set "${DEVICE}" up
sleep 2
ip link add vxlan1 type vxlan id 42 \
		   remote "${REMOTE_ADDRESS}" \
		   local "${LOCAL_ADDRESS}" \
		   dstport 0 \
		   dev "${DEVICE}"
ip addr add fc00::1/64 dev vxlan1
ip link set vxlan1 up
sleep 2
rm -f vxlan.pcap
echo "Running tcpdump and iperf3..."
( nohup tcpdump -i any -w vxlan.pcap >/dev/null 2>&1 ) &
sleep 2
iperf3 -c fc00::2 >/dev/null
pkill tcpdump
echo
echo -n "Max. Paket Size: "
tcpdump -r vxlan.pcap -nnle 2>/dev/null \
| grep "${LOCAL_ADDRESS}.*> ${REMOTE_ADDRESS}.*OTV" \
| awk '{print $8}' | awk -F ':' '{print $1}' \
| sort -n | tail -1
echo
ip link del vxlan1
ip addr del ${LOCAL_ADDRESS}/${NWMASK} dev "${DEVICE}"
=== SNAP ===

The expected outcome is

  Max. Paket Size: 64904

This is what you see on igb, the code igc has been taken from.
However, on igc the output is

  Max. Paket Size: 1516

so the GSO aggregate packets are segmented by the kernel before calling
igc_xmit_frame.  Inside the subsequent call to igc_tso, the check for
skb_is_gso(skb) fails and the function returns prematurely.

It turns out that this occurs because the feature flags aren't set
entirely correctly in igc_probe.  In contrast to the original code
from igb_probe, igc_probe neglects to set the flags required to allow
tunnel offloading.

Setting the same flags as igb fixes the issue on igc.

Fixes: 34428dff ("igc: Add GSO partial support")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Corinna Vinschen <vinschen@redhat.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the assert from the callback priv lookup function since it does
not require RTNL lock and is already protected by flow_indr_block_lock.

This will avoid warnings from being emitted to dmesg if the driver
registers its callback after an ingress qdisc was created for a
netdevice.

The warnings started after the following patch was merged:
commit 74fc4f82 ("net: Fix offloading indirect devices dependency on qdisc order creation")
Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It was used but never set.  The hardcoded value from before the dawn of
time was non-standard; the usual name for cross-tools is $TRIPLET-$TOOL
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

Should not use comparison of unsigned expressions < 0.
Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use absolute_pointer() wrapper for PAGE0 to avoid this compiler warning:

  arch/parisc/kernel/setup.c: In function 'start_parisc':
  error: '__builtin_memcmp_eq' specified bound 8 exceeds source size 0
Signed-off-by: Helge Deller <deller@gmx.de>
Co-Developed-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'hyperv-fixes-signed-20210915' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Fix kernel crash caused by uio driver (Vitaly Kuznetsov)

 - Remove on-stack cpumask from HV APIC code (Wei Liu)

* tag 'hyperv-fixes-signed-20210915' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutself
  asm-generic/hyperv: provide cpumask_to_vpset_noself
  Drivers: hv: vmbus: Fix kernel crash upon unbinding a device from uio_hv_generic driver

Pull RTC fix from Alexandre Belloni:
 "Fix a locking issue in the cmos rtc driver"

* tag 'rtc-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: cmos: Disable irq around direct invocation of cmos_interrupt()

Sometimes when unbinding the mv88e6xxx driver on Turris MOX, these error
messages appear:

mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 1 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 0 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 100 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 1 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 0 from fdb: -2

(and similarly for other ports)

What happens is that DSA has a policy "even if there are bugs, let's at
least not leak memory" and dsa_port_teardown() clears the dp->fdbs and
dp->mdbs lists, which are supposed to be empty.

But deleting that cleanup code, the warnings go away.

=> the FDB and MDB lists (used for refcounting on shared ports, aka CPU
and DSA ports) will eventually be empty, but are not empty by the time
we tear down those ports. Aka we are deleting them too soon.

The addresses that DSA complains about are host-trapped addresses: the
local addresses of the ports, and the MAC address of the bridge device.

The problem is that offloading those entries happens from a deferred
work item scheduled by the SWITCHDEV_FDB_DEL_TO_DEVICE handler, and this
races with the teardown of the CPU and DSA ports where the refcounting
is kept.

In fact, not only it races, but fundamentally speaking, if we iterate
through the port list linearly, we might end up tearing down the shared
ports even before we delete a DSA user port which has a bridge upper.

So as it turns out, we need to first tear down the user ports (and the
unused ones, for no better place of doing that), then the shared ports
(the CPU and DSA ports). In between, we need to ensure that all work
items scheduled by our switchdev handlers (which only run for user
ports, hence the reason why we tear them down first) have finished.

Fixes: 161ca59d ("net: dsa: reference count the MDB entries at the cross-chip notifier level")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210914134726.2305133-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit 3ac8eed6, which did
more than it said on the box, and not only it replaced to_phy_driver
with phydev->drv, but it also removed the "!drv" check, without actually
explaining why that is fine.

That patch in fact breaks suspend/resume on any system which has PHY
devices with no drivers bound.

The stack trace is:

Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8
pc : mdio_bus_phy_suspend+0xd8/0xec
lr : dpm_run_callback+0x38/0x90
Call trace:
 mdio_bus_phy_suspend+0xd8/0xec
 dpm_run_callback+0x38/0x90
 __device_suspend+0x108/0x3cc
 dpm_suspend+0x140/0x210
 dpm_suspend_start+0x7c/0xa0
 suspend_devices_and_enter+0x13c/0x540
 pm_suspend+0x2a4/0x330

Examples why that assumption is not fine:

- There is an MDIO bus with a PHY device that doesn't have a specific
  PHY driver loaded, because mdiobus_register() automatically creates a
  PHY device for it but there is no specific PHY driver in the system.
  Normally under those circumstances, the generic PHY driver will be
  bound lazily to it (at phy_attach_direct time). But some Ethernet
  drivers attach to their PHY at .ndo_open time. Until then it, the
  to-be-driven-by-genphy PHY device will not have a driver. The blamed
  patch amounts to saying "you need to open all net devices before the
  system can suspend, to avoid the NULL pointer dereference".

- There is any raw MDIO device which has 'plausible' values in the PHY
  ID registers 2 and 3, which is located on an MDIO bus whose driver
  does not set bus->phy_mask = ~0 (which prevents auto-scanning of PHY
  devices). An example could be a MAC's internal MDIO bus with PCS
  devices on it, for serial links such as SGMII. PHY devices will get
  created for those PCSes too, due to that MDIO bus auto-scanning, and
  although those PHY devices are not used, they do not bother anybody
  either. PCS devices are usually managed in Linux as raw MDIO devices.
  Nonetheless, they do not have a PHY driver, nor does anybody attempt
  to connect to them (because they are not a PHY), and therefore this
  patch breaks that.

The goal itself of the patch is questionable, so I am going for a
straight revert. to_phy_driver does not seem to have a need to be
replaced by phydev->drv, in fact that might even trigger code paths
which were not given too deep of a thought.

For instance:

phy_probe populates phydev->drv at the beginning, but does not clean it
up on any error (including EPROBE_DEFER). So if the phydev driver
requests probe deferral, phydev->drv will remain populated despite there
being no driver bound.

If a system suspend starts in between the initial probe deferral request
and the subsequent probe retry, we will be calling the phydev->drv->suspend
method, but _before_ any phydev->drv->probe call has succeeded.

That is to say, if the phydev->drv is allocating any driver-private data
structure in ->probe, it pretty much expects that data structure to be
available in ->suspend. But it may not. That is a pretty insane
environment to present to PHY drivers.

In the code structure before the blamed patch, mdio_bus_phy_may_suspend
would just say "no, don't suspend" to any PHY device which does not have
a driver pointer _in_the_device_structure_ (not the phydev->drv). That
would essentially ensure that ->suspend will never get called for a
device that has not yet successfully completed probe. This is the code
structure the patch is returning to, via the revert.

Fixes: 3ac8eed6 ("net: phy: Uniform PHY driver access")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210914140515.2311548-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

DSA supports connecting to a phy-handle, and has a fallback to a non-OF
based method of connecting to an internal PHY on the switch's own MDIO
bus, if no phy-handle and no fixed-link nodes were present.

The -ENODEV error code from the first attempt (phylink_of_phy_connect)
is what triggers the second attempt (phylink_connect_phy).

However, when the first attempt returns a different error code than
-ENODEV, this results in an unbalance of calls to phylink_create and
phylink_destroy by the time we exit the function. The phylink instance
has leaked.

There are many other error codes that can be returned by
phylink_of_phy_connect. For example, phylink_validate returns -EINVAL.
So this is a practical issue too.

Fixes: aab9c406 ("net: dsa: Plug in PHYLINK support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20210914134331.2303380-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The qnx4 directory entries are 64-byte blocks that have different
contents depending on the a status byte that is in the last byte of the
block.

In particular, a directory entry can be either a "link info" entry with
a 48-byte name and pointers to the real inode information, or an "inode
entry" with a smaller 16-byte name and the full inode information.

But the code was written to always just treat the directory name as if
it was part of that "inode entry", and just extend the name to the
longer case if the status byte said it was a link entry.

That work just fine and gives the right results, but now that gcc is
tracking data structure accesses much more, the code can trigger a
compiler error about using up to 48 bytes (the long name) in a structure
that only has that shorter name in it:

   fs/qnx4/dir.c: In function ‘qnx4_readdir’:
   fs/qnx4/dir.c:51:32: error: ‘strnlen’ specified bound 48 exceeds source size 16 [-Werror=stringop-overread]
      51 |                         size = strnlen(de->di_fname, size);
         |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from fs/qnx4/qnx4.h:3,
                    from fs/qnx4/dir.c:16:
   include/uapi/linux/qnx4_fs.h:45:25: note: source object declared here
      45 |         char            di_fname[QNX4_SHORT_NAME_MAX];
         |                         ^~~~~~~~

which is because the source code doesn't really make this whole "one of
two different types" explicit.

Fix this by introducing a very explicit union of the two types, and
basically explaining to the compiler what is really going on.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The sparc mdesc code does pointer games with 'struct mdesc_hdr', but
didn't describe to the compiler how that header is then followed by the
data that the header describes.

As a result, gcc is now unhappy since it does stricter pointer range
tracking, and doesn't understand about how these things work.  This
results in various errors like:

    arch/sparc/kernel/mdesc.c: In function ‘mdesc_node_by_name’:
    arch/sparc/kernel/mdesc.c:647:22: error: ‘strcmp’ reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread]
      647 |                 if (!strcmp(names + ep[ret].name_offset, name))
          |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

which are easily avoided by just describing 'struct mdesc_hdr' better,
and making the node_block() helper function look into that unsized
data[] that follows the header.

This makes the sparc64 build happy again at least for my cross-compiler
version (gcc version 11.2.1).

Link: https://lore.kernel.org/lkml/CAHk-=wi4NW3NC0xWykkw=6LnjQD6D_rtRtxY9g8gQAJXtQMi8A@mail.gmail.com/
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge absolute_pointer macro series from Guenter Roeck:
 "Kernel test builds currently fail for several architectures with error
  messages such as the following.

  drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
  arch/m68k/include/asm/string.h:72:25: error:
        '__builtin_memcpy' reading 6 bytes from a region of size 0
                [-Werror=stringop-overread]

  Such warnings may be reported by gcc 11.x for string and memory
  operations on fixed addresses if gcc's builtin functions are used for
  those operations.

  This series introduces absolute_pointer() to fix the problem.
  absolute_pointer() disassociates a pointer from its originating symbol
  type and context, and thus prevents gcc from making assumptions about
  pointers passed to memory operations"

* emailed patches from Guenter Roeck <linux@roeck-us.net>:
  alpha: Use absolute_pointer to define COMMAND_LINE
  alpha: Move setup.h out of uapi
  net: i825xx: Use absolute_pointer for memcpy from fixed memory location
  compiler.h: Introduce absolute_pointer macro

alpha:allmodconfig fails to build with the following error
when using gcc 11.x.

  arch/alpha/kernel/setup.c: In function 'setup_arch':
  arch/alpha/kernel/setup.c:493:13: error:
	'strcmp' reading 1 or more bytes from a region of size 0

Avoid the problem by declaring COMMAND_LINE as absolute_pointer().
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Most of the contents of setup.h have no value for userspace
applications.  The file was probably moved to uapi accidentally.

Keep the file in uapi to define the alpha-specific COMMAND_LINE_SIZE.
Move all other defines to arch/alpha/include/asm/setup.h.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcc 11.x reports the following compiler warning/error.

  drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
  arch/m68k/include/asm/string.h:72:25: error:
	'__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]

Use absolute_pointer() to work around the problem.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

absolute_pointer() disassociates a pointer from its originating symbol
type and context. Use it to prevent compiler warnings/errors such as

  drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
  arch/m68k/include/asm/string.h:72:25: error:
	'__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]

Such warnings may be reported by gcc 11.x for string and memory
operations on fixed addresses.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The lib/bootconfig.c file is shared with the 'bootconfig' tooling, and
as a result, the changes incommit 77e02cf5 ("memblock: introduce
saner 'memblock_free_ptr()' interface") need to also be reflected in the
tooling header file.

So define the new memblock_free_ptr() wrapper, and remove unused __pa()
and memblock_free().

Fixes: 77e02cf5 ("memblock: introduce saner 'memblock_free_ptr()' interface")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Building dp83640.c on arch/parisc/ produces a build warning for
PAGE0 being redefined. Since the macro is not used in the dp83640
driver, just make it a comment for documentation purposes.

In file included from ../drivers/net/phy/dp83640.c:23:
../drivers/net/phy/dp83640_reg.h:8: warning: "PAGE0" redefined
    8 | #define PAGE0                     0x0000
                 from ../drivers/net/phy/dp83640.c:11:
../arch/parisc/include/asm/page.h:187: note: this is the location of the previous definition
  187 | #define PAGE0   ((struct zeropage *)__PAGE_OFFSET)

Fixes: cb646e2b ("ptp: Added a clock driver for the National Semiconductor PHYTER.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Cochran <richard.cochran@omicron.at>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210913220605.19682-1-rdunlap@infradead.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This function is called to enable SR-IOV when available,
not enabling interfaces without VFs was a regression.

Fixes: 65161c35 ("bnx2x: Fix missing error code in bnx2x_iov_init_one()")
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Reported-by: YunQiang Su <wzssyqa@gmail.com>
Tested-by: YunQiang Su <wzssyqa@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Shai Malin <smalin@marvell.com>
Link: https://lore.kernel.org/r/20210912190523.27991-1-bunk@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

On sparc64, __fls() returns an "int", but the drm TTM code expected it
to be "unsigned long" as on x86.  As a result, on sparc (and arc, and
m68k) you get build errors because 'min()' checks that the types match.

As suggested by Linus, it can use min_t instead of min to force the type
to be "unsigned int".
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.

Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:

   https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/

or just random memory corruption if the debug checks don't catch it:

   https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.

I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.

So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer.  And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 40caa127 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linus proposes to revert an accounting for sops objects in
do_semtimedop() because it's really just a temporary buffer
for a single semtimedop() system call.

This object can consume up to 2 pages, syscall is sleeping
one, size and duration can be controlled by user, and this
allocation can be repeated by many thread at the same time.

However Shakeel Butt pointed that there are much more popular
objects with the same life time and similar memory
consumption, the accounting of which was decided to be
rejected for performance reasons.

Considering at least 2 pages for task_struct and 2 pages for
the kernel stack, a back of the envelope calculation gives a
footprint amplification of <1.5 so this temporal buffer can be
safely ignored.

The factor would IMO be interesting if it was >> 2 (from the
PoV of excessive (ab)use, fine-grained accounting seems to be
currently unfeasible due to performance impact).

Link: https://lore.kernel.org/lkml/90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com/
Fixes: 18319498 ("memcg: enable accounting of ipc resources")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Stephen reported that the build was broken since commit
6d2ef226 ("compiler_attributes.h: drop __has_attribute() support for
gcc4"), with errors such as:

  include/linux/compiler_attributes.h:296:5: warning: "__has_attribute" is not defined, evaluates to 0 [-Wundef]
    296 | #if __has_attribute(__warning__)
        |     ^~~~~~~~~~~~~~~
  make[2]: *** [arch/powerpc/boot/Makefile:225: arch/powerpc/boot/crt0.o] Error 1

But we expect __has_attribute() to always be defined now that we've
stopped using GCC 4.

Linus debugged it to the point of reading the GCC sources, and noticing
that the problem is that __has_attribute() is not defined when
preprocessing assembly files, which is what we're doing here.

Our assembly files don't include, or need, compiler_attributes.h, but
they are getting it unconditionally from the -include in BOOT_CFLAGS,
which is then added in its entirety to BOOT_AFLAGS.

That -include was added in commit 77433830 ("powerpc: boot: include
compiler_attributes.h") so that we'd have "fallthrough" and other
attributes defined for the C files in arch/powerpc/boot. But it's not
needed for assembly files.

The minimal fix is to move the addition to BOOT_CFLAGS of -include
compiler_attributes.h until after we've copied BOOT_CFLAGS into
BOOT_AFLAGS. That avoids including compiler_attributes.h for asm files,
but makes no other change to BOOT_CFLAGS or BOOT_AFLAGS.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Debugged-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>