With below sequence, we can see wakeup default is enabled after re-load module,
if it was enabled before, so we need disable wakeup in flexcan_remove().

| # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup
| disabled
| # echo enabled > /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup
| # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup
| enabled
| # rmmod flexcan
| # modprobe flexcan
| # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup
| enabled

Fixes: de3578c1 ("can: flexcan: add self wakeup support")
Fixes: 915f9666 ("can: flexcan: add support for DT property 'wakeup-source'")
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201020184527.8190-1-qiangqing.zhang@nxp.com
[mkl: streamlined commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

For SoCs with ECC supported, even use FLEXCAN_QUIRK_DISABLE_MECR quirk to
disable non-correctable errors interrupt and freeze mode, had better use
FLEXCAN_QUIRK_SUPPORT_ECC quirk to initialize all memory.

Fixes: cdce8448 ("can: flexcan: add vf610 support for FlexCAN")
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201020155402.30318-6-qiangqing.zhang@nxp.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

After double check with Layerscape CAN owner (Pankaj Bansal), confirm
that LX2160A indeed supports ECC feature, so correct the feature table.

For SoCs with ECC supported, even use FLEXCAN_QUIRK_DISABLE_MECR quirk to
disable non-correctable errors interrupt and freeze mode, had better use
FLEXCAN_QUIRK_SUPPORT_ECC quirk to initialize all memory.

Fixes: 2c19bb43 ("can: flexcan: add lx2160ar1 support")
Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201020155402.30318-5-qiangqing.zhang@nxp.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

After double check with Layerscape CAN owner (Pankaj Bansal), confirm that
LS1021A doesn't support ECC feature, so remove FLEXCAN_QUIRK_DISABLE_MECR
quirk.

Fixes: 99b7668c ("can: flexcan: adding platform specific details for LS1021A")
Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201020155402.30318-4-qiangqing.zhang@nxp.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

A break is not needed if it is preceded by a return.
Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201019172412.31143-1-trix@redhat.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c:176:2-3: Unneeded semicolon

 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: 875347fe ("can: mcp25xxfd: add regmap infrastructure")
Signed-off-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20201019120805.GA63693@ae4257e0ab22Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During debugging it turned out that some people have setups where the SPI
communication is more prone to CRC errors.

Increase the severity of both the transfer retry and transfer failure message
to give users feedback without the need to recompile the driver with debug
enabled.

Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Thomas Kopp <thomas.kopp@microchip.com>
Link: http://lore.kernel.org/r/20201019190524.1285319-15-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Echo management is driven by PUCAN_MSG_LOOPED_BACK bit, while loopback
frames are identified with PUCAN_MSG_SELF_RECEIVE bit. Those bits are set
for each outgoing frame written to the IP core so that a copy of each one
will be placed into the rx path. Thus,

- when PUCAN_MSG_LOOPED_BACK is set then the rx frame is an echo of a
  previously sent frame,
- when PUCAN_MSG_LOOPED_BACK+PUCAN_MSG_SELF_RECEIVE are set, then the rx
  frame is an echo AND a loopback frame. Therefore, this frame must be
  put into the socket rx path too.

This patch fixes how CAN frames are handled when these are sent while the
can interface is configured in "loopback on" mode.
Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Link: https://lore.kernel.org/r/20201013153947.28012-1-s.grosjean@peak-system.com
Fixes: 8ac8321e ("can: peak: add support for PEAK PCAN-PCIe FD CAN-FD boards")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Fabian Inostroza <fabianinostrozap@gmail.com> has discovered a potential
problem in the hardware timestamp reporting from the PCAN-USB USB CAN interface
(only), related to the fact that a timestamp of an event may precede the
timestamp used for synchronization when both records are part of the same USB
packet. However, this case was used to detect the wrapping of the time counter.

This patch details and fixes the two identified cases where this problem can
occur.
Reported-by: Fabian Inostroza <fabianinostrozap@gmail.com>
Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Link: https://lore.kernel.org/r/20201014085631.15128-1-s.grosjean@peak-system.com
Fixes: bb478555 ("can: usb: PEAK-System Technik USB adapters driver core")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

These values come from skb->data so Smatch considers them untrusted.  I
believe Smatch is correct but I don't have a way to test this.

The usb_if->dev[] array has 2 elements but the index is in the 0-15
range without checks.  The cfd->len can be up to 255 but the maximum
valid size is CANFD_MAX_DLEN (64) so that could lead to memory
corruption.

Fixes: 0a25e1f4 ("can: peak_usb: add support for PEAK new CANFD USB adapters")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200813140604.GA456946@mwandaAcked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Calling pm_runtime_get_sync increments the counter even in case of
failure, causing incorrect ref count. Call pm_runtime_put if
pm_runtime_get_sync fails.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Link: https://lore.kernel.org/r/20200605033239.60664-1-navid.emamdoost@gmail.com
Fixes: 4716620d ("can: xilinx: Convert to runtime_pm")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The driver forgets to call clk_disable_unprepare() in error path after
a success calling for clk_prepare_enable().

Fix it by adding a clk_disable_unprepare() in error path.
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1594973079-27743-1-git-send-email-zhangchangzhong@huawei.com
Fixes: befa6011 ("can: ti_hecc: add missing prepare and unprepare of the clock")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Don't populate the const array plen on the stack but instead it static. Makes
the object code smaller by 926 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  26531	   1943	     64	  28538	   6f7a	net/can/isotp.o

After:
   text	   data	    bss	    dec	    hex	filename
  25509	   2039	     64	  27612	   6bdc	net/can/isotp.o

(gcc version 10.2.0)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201020154203.54711-1-colin.king@canonical.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

As reported by Thomas Wagner:

    https://github.com/hartkopp/can-isotp/issues/34

the timeout handling for data frames is not enabled when the isotp socket is
used in listen-only mode (sockopt CAN_ISOTP_LISTEN_MODE). This mode is enabled
by the isotpsniffer application which therefore became inconsistend with the
strict rx timeout rules when running the isotp protocol in the operational
mode.

This patch fixes this inconsistency by moving the return condition for the
listen-only mode behind the timeout handling code.
Reported-by: Thomas Wagner <thwa1@web.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: e057dd3f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://github.com/hartkopp/can-isotp/issues/34
Link: https://lore.kernel.org/r/20201019120229.89326-1-socketcan@hartkopp.netSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The help text for the CAN_ISOTP config symbol uses the acronym "PDU".  However,
this acronym is not explained here, nor in Documentation/networking/can.rst.

Expand the acronym to make it easier for users to decide if they need to enable
the CAN_ISOTP option or not.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201013141341.28487-1-geert+renesas@glider.beAcked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

When a netdev down event occurs after a successful call to
j1939_sk_bind(), j1939_netdev_notify() can handle it correctly.

But if the netdev already in down state before calling j1939_sk_bind(),
j1939_sk_release() will stay in wait_event_interruptible() blocked
forever. Because in this case, j1939_netdev_notify() won't be called and
j1939_tp_txtimer() won't call j1939_session_cancel() or other function
to clear session for ENETDOWN error, this lead to mismatch of
j1939_session_get/put() and jsk->skb_pending will never decrease to
zero.

To reproduce it use following commands:
1. ip link add dev vcan0 type vcan
2. j1939acd -r 100,80-120 1122334455667788 vcan0
3. presses ctrl-c and thread will be blocked forever

This patch adds check for ndev->flags in j1939_sk_bind() to avoid this
kind of situation and return with -ENETDOWN.

Fixes: 9d71dd0c ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1599460308-18770-1-git-send-email-zhangchangzhong@huawei.comAcked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch adds backquotes for code samples.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20201026094442.16587-1-yegorslists@googlemail.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The address was wrongly assigned to the PGN field and vice versa.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20201022083708.8755-1-yegorslists@googlemail.com
Fixes: 9d71dd0c ("can: add support of SAE J1939 protocol")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patches fixes the syntax an spelling of the j1939 documentation.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20201020101043.6369-1-yegorslists@googlemail.com
Fixes: 9d71dd0c ("can: add support of SAE J1939 protocol")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Due to naming conflicts, jacd was renamed to j1939acd in:

    https://github.com/linux-can/can-utils/pull/199Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20201020081134.3597-1-yegorslists@googlemail.com
Link: https://github.com/linux-can/can-utils/pull/199Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

All user space generated SKBs are owned by a socket (unless injected into the
key via AF_PACKET). If a socket is closed, all associated skbs will be cleaned
up.

This leads to a problem when a CAN driver calls can_put_echo_skb() on a
unshared SKB. If the socket is closed prior to the TX complete handler,
can_get_echo_skb() and the subsequent delivering of the echo SKB to all
registered callbacks, a SKB with a refcount of 0 is delivered.

To avoid the problem, in can_get_echo_skb() the original SKB is now always
cloned, regardless of shared SKB or not. If the process exists it can now
safely discard its SKBs, without disturbing the delivery of the echo SKB.

The problem shows up in the j1939 stack, when it clones the incoming skb, which
detects the already 0 refcount.

We can easily reproduce this with following example:

testj1939 -B -r can0: &
cansend can0 1823ff40#0123

WARNING: CPU: 0 PID: 293 at lib/refcount.c:25 refcount_warn_saturate+0x108/0x174
refcount_t: addition on 0; use-after-free.
Modules linked in: coda_vpu imx_vdoa videobuf2_vmalloc dw_hdmi_ahb_audio vcan
CPU: 0 PID: 293 Comm: cansend Not tainted 5.5.0-rc6-00376-g9e20dcb7040d #1
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
[<c010f570>] (dump_backtrace) from [<c010f90c>] (show_stack+0x20/0x24)
[<c010f8ec>] (show_stack) from [<c0c3e1a4>] (dump_stack+0x8c/0xa0)
[<c0c3e118>] (dump_stack) from [<c0127fec>] (__warn+0xe0/0x108)
[<c0127f0c>] (__warn) from [<c01283c8>] (warn_slowpath_fmt+0xa8/0xcc)
[<c0128324>] (warn_slowpath_fmt) from [<c0539c0c>] (refcount_warn_saturate+0x108/0x174)
[<c0539b04>] (refcount_warn_saturate) from [<c0ad2cac>] (j1939_can_recv+0x20c/0x210)
[<c0ad2aa0>] (j1939_can_recv) from [<c0ac9dc8>] (can_rcv_filter+0xb4/0x268)
[<c0ac9d14>] (can_rcv_filter) from [<c0aca2cc>] (can_receive+0xb0/0xe4)
[<c0aca21c>] (can_receive) from [<c0aca348>] (can_rcv+0x48/0x98)
[<c0aca300>] (can_rcv) from [<c09b1fdc>] (__netif_receive_skb_one_core+0x64/0x88)
[<c09b1f78>] (__netif_receive_skb_one_core) from [<c09b2070>] (__netif_receive_skb+0x38/0x94)
[<c09b2038>] (__netif_receive_skb) from [<c09b2130>] (netif_receive_skb_internal+0x64/0xf8)
[<c09b20cc>] (netif_receive_skb_internal) from [<c09b21f8>] (netif_receive_skb+0x34/0x19c)
[<c09b21c4>] (netif_receive_skb) from [<c0791278>] (can_rx_offload_napi_poll+0x58/0xb4)

Fixes: 0ae89beb ("can: add destructor for self generated skbs")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: http://lore.kernel.org/r/20200124132656.22156-1-o.rempel@pengutronix.deAcked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The can_get_echo_skb() function returns the number of received bytes to
be used for netdev statistics. In the case of RTR frames we get a valid
(potential non-zero) data length value which has to be passed for further
operations. But on the wire RTR frames have no payload length. Therefore
the value to be used in the statistics has to be zero for RTR frames.
Reported-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201020064443.80164-1-socketcan@hartkopp.net
Fixes: cf5046b3 ("can: dev: let can_get_echo_skb() return dlc of CAN frame")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

If a driver calls can_get_echo_skb() during a hardware IRQ (which is often, but
not always, the case), the 'WARN_ON(in_irq)' in
net/core/skbuff.c#skb_release_head_state() might be triggered, under network
congestion circumstances, together with the potential risk of a NULL pointer
dereference.

The root cause of this issue is the call to kfree_skb() instead of
dev_kfree_skb_irq() in net/core/dev.c#enqueue_to_backlog().

This patch prevents the skb to be freed within the call to netif_rx() by
incrementing its reference count with skb_get(). The skb is finally freed by
one of the in-irq-context safe functions: dev_consume_skb_any() or
dev_kfree_skb_any(). The "any" version is used because some drivers might call
can_get_echo_skb() in a normal context.

The reason for this issue to occur is that initially, in the core network
stack, loopback skb were not supposed to be received in hardware IRQ context.
The CAN stack is an exeption.

This bug was previously reported back in 2017 in [1] but the proposed patch
never got accepted.

While [1] directly modifies net/core/dev.c, we try to propose here a
smoother modification local to CAN network stack (the assumption
behind is that only CAN devices are affected by this issue).

[1] http://lore.kernel.org/r/57a3ffb6-3309-3ad5-5a34-e93c3fe3614d@cetitec.comSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20201002154219.4887-2-mailhol.vincent@wanadoo.fr
Fixes: 39549eef ("can: CAN Network device driver and Netlink interface")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

A CAN driver, using the rx-offload infrastructure, is reading CAN frames
(usually in IRQ context) from the hardware and placing it into the rx-offload
queue to be delivered to the networking stack via NAPI.

In case the rx-offload queue is full, trying to add more skbs results in the
skbs being dropped using kfree_skb(). If done from hard-IRQ context this
results in the following warning:

[  682.552693] ------------[ cut here ]------------
[  682.557360] WARNING: CPU: 0 PID: 3057 at net/core/skbuff.c:650 skb_release_head_state+0x74/0x84
[  682.566075] Modules linked in: can_raw can coda_vpu flexcan dw_hdmi_ahb_audio v4l2_jpeg imx_vdoa can_dev
[  682.575597] CPU: 0 PID: 3057 Comm: cansend Tainted: G        W         5.7.0+ #18
[  682.583098] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  682.589657] [<c0112628>] (unwind_backtrace) from [<c010c1c4>] (show_stack+0x10/0x14)
[  682.597423] [<c010c1c4>] (show_stack) from [<c06c481c>] (dump_stack+0xe0/0x114)
[  682.604759] [<c06c481c>] (dump_stack) from [<c0128f10>] (__warn+0xc0/0x10c)
[  682.611742] [<c0128f10>] (__warn) from [<c0129314>] (warn_slowpath_fmt+0x5c/0xc0)
[  682.619248] [<c0129314>] (warn_slowpath_fmt) from [<c0b95dec>] (skb_release_head_state+0x74/0x84)
[  682.628143] [<c0b95dec>] (skb_release_head_state) from [<c0b95e08>] (skb_release_all+0xc/0x24)
[  682.636774] [<c0b95e08>] (skb_release_all) from [<c0b95eac>] (kfree_skb+0x74/0x1c8)
[  682.644479] [<c0b95eac>] (kfree_skb) from [<bf001d1c>] (can_rx_offload_queue_sorted+0xe0/0xe8 [can_dev])
[  682.654051] [<bf001d1c>] (can_rx_offload_queue_sorted [can_dev]) from [<bf001d6c>] (can_rx_offload_get_echo_skb+0x48/0x94 [can_dev])
[  682.666007] [<bf001d6c>] (can_rx_offload_get_echo_skb [can_dev]) from [<bf01efe4>] (flexcan_irq+0x194/0x5dc [flexcan])
[  682.676734] [<bf01efe4>] (flexcan_irq [flexcan]) from [<c019c1ec>] (__handle_irq_event_percpu+0x4c/0x3ec)
[  682.686322] [<c019c1ec>] (__handle_irq_event_percpu) from [<c019c5b8>] (handle_irq_event_percpu+0x2c/0x88)
[  682.695993] [<c019c5b8>] (handle_irq_event_percpu) from [<c019c64c>] (handle_irq_event+0x38/0x5c)
[  682.704887] [<c019c64c>] (handle_irq_event) from [<c01a1058>] (handle_fasteoi_irq+0xc8/0x180)
[  682.713432] [<c01a1058>] (handle_fasteoi_irq) from [<c019b2c0>] (generic_handle_irq+0x30/0x44)
[  682.722063] [<c019b2c0>] (generic_handle_irq) from [<c019b8f8>] (__handle_domain_irq+0x64/0xdc)
[  682.730783] [<c019b8f8>] (__handle_domain_irq) from [<c06df4a4>] (gic_handle_irq+0x48/0x9c)
[  682.739158] [<c06df4a4>] (gic_handle_irq) from [<c0100b30>] (__irq_svc+0x70/0x98)
[  682.746656] Exception stack(0xe80e9dd8 to 0xe80e9e20)
[  682.751725] 9dc0:                                                       00000001 e80e8000
[  682.759922] 9de0: e820cf80 00000000 ffffe000 00000000 eaf08fe4 00000000 600d0013 00000000
[  682.768117] 9e00: c1732e3c c16093a8 e820d4c0 e80e9e28 c018a57c c018b870 600d0013 ffffffff
[  682.776315] [<c0100b30>] (__irq_svc) from [<c018b870>] (lock_acquire+0x108/0x4e8)
[  682.783821] [<c018b870>] (lock_acquire) from [<c0e938e4>] (down_write+0x48/0xa8)
[  682.791242] [<c0e938e4>] (down_write) from [<c02818dc>] (unlink_file_vma+0x24/0x40)
[  682.798922] [<c02818dc>] (unlink_file_vma) from [<c027a258>] (free_pgtables+0x34/0xb8)
[  682.806858] [<c027a258>] (free_pgtables) from [<c02835a4>] (exit_mmap+0xe4/0x170)
[  682.814361] [<c02835a4>] (exit_mmap) from [<c01248e0>] (mmput+0x5c/0x110)
[  682.821171] [<c01248e0>] (mmput) from [<c012e910>] (do_exit+0x374/0xbe4)
[  682.827892] [<c012e910>] (do_exit) from [<c0130888>] (do_group_exit+0x38/0xb4)
[  682.835132] [<c0130888>] (do_group_exit) from [<c0130914>] (__wake_up_parent+0x0/0x14)
[  682.843063] irq event stamp: 1936
[  682.846399] hardirqs last  enabled at (1935): [<c02938b0>] rmqueue+0xf4/0xc64
[  682.853553] hardirqs last disabled at (1936): [<c0100b20>] __irq_svc+0x60/0x98
[  682.860799] softirqs last  enabled at (1878): [<bf04cdcc>] raw_release+0x108/0x1f0 [can_raw]
[  682.869256] softirqs last disabled at (1876): [<c0b8f478>] release_sock+0x18/0x98
[  682.876753] ---[ end trace 7bca4751ce44c444 ]---

This patch fixes the problem by replacing the kfree_skb() by
dev_kfree_skb_any(), as rx-offload might be called from threaded IRQ handlers
as well.

Fixes: ca913f1a ("can: rx-offload: can_rx_offload_queue_sorted(): fix error handling, avoid skb mem leak")
Fixes: 6caf8a6d ("can: rx-offload: can_rx_offload_queue_tail(): fix error handling, avoid skb mem leak")
Link: http://lore.kernel.org/r/20201019190524.1285319-3-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

If can_init_proc() fail to create /proc/net/can directory, can_remove_proc()
will trigger a warning:

WARNING: CPU: 6 PID: 7133 at fs/proc/generic.c:672 remove_proc_entry+0x17b0
Kernel panic - not syncing: panic_on_warn set ...

Fix to return early from can_remove_proc() if can proc_dir does not exists.
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1594709090-3203-1-git-send-email-zhangchangzhong@huawei.com
Fixes: 8e8cda6d ("can: initial support for network namespaces")
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In order to automate the verification of DT nodes convert
fsl-flexcan.txt to fsl,flexcan.yaml
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201022075218.11880-3-o.rempel@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

For now we have only node name as common rule for all CAN controllers
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201022075218.11880-2-o.rempel@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

gpiod_to_irq() never return 0, but returns negative in
case of error, check it and set gpio_irq to 0.

Fixes: 73970055 ("sfp: add SFP module support")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201031031053.25264-1-yuehaibing@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Commit 5a18e1e0 introduced the 'failover_pending' state to track
the "failover pending window" - where we wait for the partner to become
ready (after a transport event) before actually attempting to failover.
i.e window is between following two events:

        a. we get a transport event due to a FAILOVER

        b. later, we get CRQ_INITIALIZED indicating the partner is
           ready  at which point we schedule a FAILOVER reset.

and ->failover_pending is true during this window.

If during this window, we attempt to open (or close) a device, we pretend
that the operation succeded and let the FAILOVER reset path complete the
operation.

This is fine, except if the transport event ("a" above) occurs during the
open and after open has already checked whether a failover is pending. If
that happens, we fail the open, which can cause the boot scripts to leave
the interface down requiring administrator to manually bring up the device.

This fix "extends" the failover pending window till we are _actually_
ready to perform the failover reset (i.e until after we get the RTNL
lock). Since open() holds the RTNL lock, we can be sure that we either
finish the open or if the open() fails due to the failover pending window,
we can again pretend that open is done and let the failover complete it.

We could try and block the open until failover is completed but a) that
could still timeout the application and b) Existing code "pretends" that
failover occurred "just after" open succeeded, so marks the open successful
and lets the failover complete the open. So, mark the open successful even
if the transport event occurs before we actually start the open.

Fixes: 5a18e1e0 ("ibmvnic: Fix failover case for non-redundant configuration")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Acked-by: Dany Madden <drt@linux.ibm.com>
Link: https://lore.kernel.org/r/20201030170711.1562994-1-sukadev@linux.ibm.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The qca8k only supports a switch-wide MTU setting, and the code to take
the max of all ports was only looking at the port currently being set.
Fix to examine all ports.
Reported-by: DENG Qingfang <dqfext@gmail.com>
Fixes: f58d2598 ("net: dsa: qca8k: implement the port MTU callbacks")
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201030183315.GA6736@earth.liSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Commit 978aa047 ("sctp: fix some type cast warnings introduced since
very beginning")' broke err reading from sctp_arg, because it reads the
value as 32-bit integer, although the value is stored as 16-bit integer.
Later this value is passed to the userspace in 16-bit variable, thus the
user always gets 0 on big-endian platforms. Fix it by reading the __u16
field of sctp_arg union, as reading err field would produce a sparse
warning.

Fixes: 978aa047 ("sctp: fix some type cast warnings introduced since very beginning")
Signed-off-by: Petr Malat <oss@malat.biz>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/20201030132633.7045-1-oss@malat.bizSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The TI CPTS does not natively support PTPv1, only PTPv2. But, as it
happens, the CPTS can provide HW timestamp for PTPv1 Sync messages, because
CPTS HW parser looks for PTP messageType id in PTP message octet 0 which
value is 0 for PTPv1. As result, CPTS HW can detect Sync messages for PTPv1
and PTPv2 (Sync messageType = 0 for both), but it fails for any other PTPv1
messages (Delay_req/resp) and will return PTP messageType id 0 for them.

The commit e9523a5a ("net: ethernet: ti: cpsw: enable
HWTSTAMP_FILTER_PTP_V1_L4_EVENT filter") added PTPv1 hw timestamping
advertisement by mistake, only to make Linux Kernel "timestamping" utility
work, and this causes issues with only PTPv1 compatible HW/SW - Sync HW
timestamped, but Delay_req/resp are not.

Hence, fix it disabling PTPv1 hw timestamping advertisement, so only PTPv1
compatible HW/SW can properly roll back to SW timestamping.

Fixes: e9523a5a ("net: ethernet: ti: cpsw: enable HWTSTAMP_FILTER_PTP_V1_L4_EVENT filter")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20201029190910.30789-1-grygorii.strashko@ti.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Camelia Groza says:

====================
dpaa_eth: buffer layout fixes

The patches are related to the software workaround for the A050385 erratum.
The first patch ensures optimal buffer usage for non-erratum scenarios. The
second patch fixes a currently inconsequential discrepancy between the
FMan and Ethernet drivers.

Changes in v3:
- refactor defines for clarity in 1/2
- add more details on the user impact in 1/2
- remove unnecessary inline identifier in 2/2

Changes in v2:
- make the returned value for TX ports explicit in 2/2
- simplify the buf_layout reference in 2/2
====================

Link: https://lore.kernel.org/r/cover.1604339942.git.camelia.groza@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The headroom reserved for received frames needs to be aligned to an
RX specific value. There is currently a discrepancy between the values
used in the Ethernet driver and the values passed to the FMan.
Coincidentally, the resulting aligned values are identical.

Fixes: 3c68b8ff ("dpaa_eth: FMan erratum A050385 workaround")
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Impose a larger RX private data area only when the A050385 erratum is
present on the hardware. A smaller buffer size is sufficient in all
other scenarios. This enables a wider range of linear Jumbo frame
sizes in non-erratum scenarios, instead of turning to multi
buffer Scatter/Gather frames. The maximum linear frame size is
increased by 128 bytes for non-erratum arm64 platforms.

Cleanup the hardware annotations header defines in the process.

Fixes: 3c68b8ff ("dpaa_eth: FMan erratum A050385 workaround")
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'mac80211-for-net-2020-10-30' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
A couple of fixes, for
 * HE on 2.4 GHz
 * a few issues syzbot found, but we have many more reports :-(
 * a regression in nl80211-transported EAPOL frames which had
   affected a number of users, from Mathy
 * kernel-doc markings in mac80211, from Mauro
 * a format argument in reg.c, from Ye Bin
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for net:

1) Incorrect netlink report logic in flowtable and genID.

2) Add a selftest to check that wireguard passes the right sk
   to ip_route_me_harder, from Jason A. Donenfeld.

3) Pass the actual sk to ip_route_me_harder(), also from Jason.

4) Missing expression validation of updates via nft --check.

5) Update byte and packet counters regardless of whether they
   match, from Stefano Brivio.
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The tunnel device such as vxlan, bareudp and geneve in the lwt mode set
the outer df only based TUNNEL_DONT_FRAGMENT.
And this was also the behavior for gre device before switching to use
ip_md_tunnel_xmit in commit 962924fa ("ip_gre: Refactor collect
metatdata mode tunnel xmit to ip_md_tunnel_xmit")

When the ip_gre in lwt mode xmit with ip_md_tunnel_xmi changed the rule and
make the discrepancy between handling of DF by different tunnels. So in the
ip_md_tunnel_xmit should follow the same rule like other tunnels.

Fixes: cfc7381b ("ip_tunnel: add collect_md mode to IPIP tunnel")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Link: https://lore.kernel.org/r/1604028728-31100-1-git-send-email-wenxu@ucloud.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In my test setup, I had a SAMA5D27 device configured with ip forwarding, and
second device with usb ethernet (r8152) sending ICMP packets.  If the packet
was larger than about 220 bytes, the SAMA5 device would "oops" with the
following trace:

kernel BUG at net/core/skbuff.c:1863!
Internal error: Oops - BUG: 0 [#1] ARM
Modules linked in: xt_MASQUERADE ppp_async ppp_generic slhc iptable_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 can_raw can bridge stp llc ipt_REJECT nf_reject_ipv4 sd_mod cdc_ether usbnet usb_storage r8152 scsi_mod mii o
ption usb_wwan usbserial micrel macb at91_sama5d2_adc phylink gpio_sama5d2_piobu m_can_platform m_can industrialio_triggered_buffer kfifo_buf of_mdio can_dev fixed_phy sdhci_of_at91 sdhci_pltfm libphy sdhci mmc_core ohci_at91 ehci_atmel o
hci_hcd iio_rescale industrialio sch_fq_codel spidev prox2_hal(O)
CPU: 0 PID: 0 Comm: swapper Tainted: G           O      5.9.1-prox2+ #1
Hardware name: Atmel SAMA5
PC is at skb_put+0x3c/0x50
LR is at macb_start_xmit+0x134/0xad0 [macb]
pc : [<c05258cc>]    lr : [<bf0ea5b8>]    psr: 20070113
sp : c0d01a60  ip : c07232c0  fp : c4250000
r10: c0d03cc8  r9 : 00000000  r8 : c0d038c0
r7 : 00000000  r6 : 00000008  r5 : c59b66c0  r4 : 0000002a
r3 : 8f659eff  r2 : c59e9eea  r1 : 00000001  r0 : c59b66c0
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c53c7d  Table: 2640c059  DAC: 00000051
Process swapper (pid: 0, stack limit = 0x75002d81)

<snipped stack>

[<c05258cc>] (skb_put) from [<bf0ea5b8>] (macb_start_xmit+0x134/0xad0 [macb])
[<bf0ea5b8>] (macb_start_xmit [macb]) from [<c053e504>] (dev_hard_start_xmit+0x90/0x11c)
[<c053e504>] (dev_hard_start_xmit) from [<c0571180>] (sch_direct_xmit+0x124/0x260)
[<c0571180>] (sch_direct_xmit) from [<c053eae4>] (__dev_queue_xmit+0x4b0/0x6d0)
[<c053eae4>] (__dev_queue_xmit) from [<c05a5650>] (ip_finish_output2+0x350/0x580)
[<c05a5650>] (ip_finish_output2) from [<c05a7e24>] (ip_output+0xb4/0x13c)
[<c05a7e24>] (ip_output) from [<c05a39d0>] (ip_forward+0x474/0x500)
[<c05a39d0>] (ip_forward) from [<c05a13d8>] (ip_sublist_rcv_finish+0x3c/0x50)
[<c05a13d8>] (ip_sublist_rcv_finish) from [<c05a19b8>] (ip_sublist_rcv+0x11c/0x188)
[<c05a19b8>] (ip_sublist_rcv) from [<c05a2494>] (ip_list_rcv+0xf8/0x124)
[<c05a2494>] (ip_list_rcv) from [<c05403c4>] (__netif_receive_skb_list_core+0x1a0/0x20c)
[<c05403c4>] (__netif_receive_skb_list_core) from [<c05405c4>] (netif_receive_skb_list_internal+0x194/0x230)
[<c05405c4>] (netif_receive_skb_list_internal) from [<c0540684>] (gro_normal_list.part.0+0x14/0x28)
[<c0540684>] (gro_normal_list.part.0) from [<c0541280>] (napi_complete_done+0x16c/0x210)
[<c0541280>] (napi_complete_done) from [<bf14c1c0>] (r8152_poll+0x684/0x708 [r8152])
[<bf14c1c0>] (r8152_poll [r8152]) from [<c0541424>] (net_rx_action+0x100/0x328)
[<c0541424>] (net_rx_action) from [<c01012ec>] (__do_softirq+0xec/0x274)
[<c01012ec>] (__do_softirq) from [<c012d6d4>] (irq_exit+0xcc/0xd0)
[<c012d6d4>] (irq_exit) from [<c0160960>] (__handle_domain_irq+0x58/0xa4)
[<c0160960>] (__handle_domain_irq) from [<c0100b0c>] (__irq_svc+0x6c/0x90)
Exception stack(0xc0d01ef0 to 0xc0d01f38)
1ee0:                                     00000000 0000003d 0c31f383 c0d0fa00
1f00: c0d2eb80 00000000 c0d2e630 4dad8c49 4da967b0 0000003d 0000003d 00000000
1f20: fffffff5 c0d01f40 c04e0f88 c04e0f8c 30070013 ffffffff
[<c0100b0c>] (__irq_svc) from [<c04e0f8c>] (cpuidle_enter_state+0x7c/0x378)
[<c04e0f8c>] (cpuidle_enter_state) from [<c04e12c4>] (cpuidle_enter+0x28/0x38)
[<c04e12c4>] (cpuidle_enter) from [<c014f710>] (do_idle+0x194/0x214)
[<c014f710>] (do_idle) from [<c014fa50>] (cpu_startup_entry+0xc/0x14)
[<c014fa50>] (cpu_startup_entry) from [<c0a00dc8>] (start_kernel+0x46c/0x4a0)
Code: e580c054 8a000002 e1a00002 e8bd8070 (e7f001f2)
---[ end trace 146c8a334115490c ]---

The solution was to force nonlinear buffers to be cloned.  This was previously
reported by Klaus Doth (https://www.spinics.net/lists/netdev/msg556937.html)
but never formally submitted as a patch.

This is the third revision, hopefully the formatting is correct this time!
Suggested-by: Klaus Doth <krnl@doth.eu>
Fixes: 653e92a9 ("net: macb: add support for padding and fcs computation")
Signed-off-by: Mark Deneen <mdeneen@saucontech.com>
Link: https://lore.kernel.org/r/20201030155814.622831-1-mdeneen@saucontech.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Hangbin Liu says:

====================
IPv6: reply ICMP error if fragment doesn't contain all headers

When our Engineer run latest IPv6 Core Conformance test, test v6LC.1.3.6:
First Fragment Doesn’t Contain All Headers[1] failed. The test purpose is to
verify that the node (Linux for example) should properly process IPv6 packets
that don’t include all the headers through the Upper-Layer header.

Based on RFC 8200, Section 4.5 Fragment Header

  -  If the first fragment does not include all headers through an
     Upper-Layer header, then that fragment should be discarded and
     an ICMP Parameter Problem, Code 3, message should be sent to
     the source of the fragment, with the Pointer field set to zero.

The first patch add a definition for ICMPv6 Parameter Problem, code 3.
The second patch add a check for the 1st fragment packet to make sure
Upper-Layer header exist.

[1] Page 68, v6LC.1.3.6: First Fragment Doesn’t Contain All Headers part A, B,
C and D at https://ipv6ready.org/docs/Core_Conformance_5_0_0.pdf
[2] My reproducer:

import sys, os
from scapy.all import *

def send_frag_dst_opt(src_ip6, dst_ip6):
    ip6 = IPv6(src = src_ip6, dst = dst_ip6, nh = 44)

    frag_1 = IPv6ExtHdrFragment(nh = 60, m = 1)
    dst_opt = IPv6ExtHdrDestOpt(nh = 58)

    frag_2 = IPv6ExtHdrFragment(nh = 58, offset = 4, m = 1)
    icmp_echo = ICMPv6EchoRequest(seq = 1)

    pkt_1 = ip6/frag_1/dst_opt
    pkt_2 = ip6/frag_2/icmp_echo

    send(pkt_1)
    send(pkt_2)

def send_frag_route_opt(src_ip6, dst_ip6):
    ip6 = IPv6(src = src_ip6, dst = dst_ip6, nh = 44)

    frag_1 = IPv6ExtHdrFragment(nh = 43, m = 1)
    route_opt = IPv6ExtHdrRouting(nh = 58)

    frag_2 = IPv6ExtHdrFragment(nh = 58, offset = 4, m = 1)
    icmp_echo = ICMPv6EchoRequest(seq = 2)

    pkt_1 = ip6/frag_1/route_opt
    pkt_2 = ip6/frag_2/icmp_echo

    send(pkt_1)
    send(pkt_2)

if __name__ == '__main__':
    src = sys.argv[1]
    dst = sys.argv[2]
    conf.iface = sys.argv[3]
    send_frag_dst_opt(src, dst)
    send_frag_route_opt(src, dst)
====================

Link: https://lore.kernel.org/r/20201027123313.3717941-1-liuhangbin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>