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2022-02-24can: bittiming: mark function arguments and local variables as constMarc Kleine-Budde1-3/+3
This patch marks the arguments of some functions as well as some local variables as constant. Link: https://lore.kernel.org/all/20220124215642.3474154-7-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: dev: reorder struct can_priv members for better packingVincent Mailhol1-3/+3
Save eight bytes of holes on x86-64 architectures by reordering the members of struct can_priv. Before: | $ pahole -C can_priv drivers/net/can/dev/dev.o | struct can_priv { | struct net_device * dev; /* 0 8 */ | struct can_device_stats can_stats; /* 8 24 */ | const struct can_bittiming_const * bittiming_const; /* 32 8 */ | const struct can_bittiming_const * data_bittiming_const; /* 40 8 */ | struct can_bittiming bittiming; /* 48 32 */ | /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ | struct can_bittiming data_bittiming; /* 80 32 */ | const struct can_tdc_const * tdc_const; /* 112 8 */ | struct can_tdc tdc; /* 120 12 */ | /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ | unsigned int bitrate_const_cnt; /* 132 4 */ | const u32 * bitrate_const; /* 136 8 */ | const u32 * data_bitrate_const; /* 144 8 */ | unsigned int data_bitrate_const_cnt; /* 152 4 */ | u32 bitrate_max; /* 156 4 */ | struct can_clock clock; /* 160 4 */ | unsigned int termination_const_cnt; /* 164 4 */ | const u16 * termination_const; /* 168 8 */ | u16 termination; /* 176 2 */ | | /* XXX 6 bytes hole, try to pack */ | | struct gpio_desc * termination_gpio; /* 184 8 */ | /* --- cacheline 3 boundary (192 bytes) --- */ | u16 termination_gpio_ohms[2]; /* 192 4 */ | enum can_state state; /* 196 4 */ | u32 ctrlmode; /* 200 4 */ | u32 ctrlmode_supported; /* 204 4 */ | int restart_ms; /* 208 4 */ | | /* XXX 4 bytes hole, try to pack */ | | struct delayed_work restart_work; /* 216 88 */ | | /* XXX last struct has 4 bytes of padding */ | | /* --- cacheline 4 boundary (256 bytes) was 48 bytes ago --- */ | int (*do_set_bittiming)(struct net_device *); /* 304 8 */ | int (*do_set_data_bittiming)(struct net_device *); /* 312 8 */ | /* --- cacheline 5 boundary (320 bytes) --- */ | int (*do_set_mode)(struct net_device *, enum can_mode); /* 320 8 */ | int (*do_set_termination)(struct net_device *, u16); /* 328 8 */ | int (*do_get_state)(const struct net_device *, enum can_state *); /* 336 8 */ | int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 344 8 */ | unsigned int echo_skb_max; /* 352 4 */ | | /* XXX 4 bytes hole, try to pack */ | | struct sk_buff * * echo_skb; /* 360 8 */ | | /* size: 368, cachelines: 6, members: 32 */ | /* sum members: 354, holes: 3, sum holes: 14 */ | /* paddings: 1, sum paddings: 4 */ | /* last cacheline: 48 bytes */ | }; After: | $ pahole -C can_priv drivers/net/can/dev/dev.o | struct can_priv { | struct net_device * dev; /* 0 8 */ | struct can_device_stats can_stats; /* 8 24 */ | const struct can_bittiming_const * bittiming_const; /* 32 8 */ | const struct can_bittiming_const * data_bittiming_const; /* 40 8 */ | struct can_bittiming bittiming; /* 48 32 */ | /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ | struct can_bittiming data_bittiming; /* 80 32 */ | const struct can_tdc_const * tdc_const; /* 112 8 */ | struct can_tdc tdc; /* 120 12 */ | /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ | unsigned int bitrate_const_cnt; /* 132 4 */ | const u32 * bitrate_const; /* 136 8 */ | const u32 * data_bitrate_const; /* 144 8 */ | unsigned int data_bitrate_const_cnt; /* 152 4 */ | u32 bitrate_max; /* 156 4 */ | struct can_clock clock; /* 160 4 */ | unsigned int termination_const_cnt; /* 164 4 */ | const u16 * termination_const; /* 168 8 */ | u16 termination; /* 176 2 */ | | /* XXX 6 bytes hole, try to pack */ | | struct gpio_desc * termination_gpio; /* 184 8 */ | /* --- cacheline 3 boundary (192 bytes) --- */ | u16 termination_gpio_ohms[2]; /* 192 4 */ | unsigned int echo_skb_max; /* 196 4 */ | struct sk_buff * * echo_skb; /* 200 8 */ | enum can_state state; /* 208 4 */ | u32 ctrlmode; /* 212 4 */ | u32 ctrlmode_supported; /* 216 4 */ | int restart_ms; /* 220 4 */ | struct delayed_work restart_work; /* 224 88 */ | | /* XXX last struct has 4 bytes of padding */ | | /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ | int (*do_set_bittiming)(struct net_device *); /* 312 8 */ | /* --- cacheline 5 boundary (320 bytes) --- */ | int (*do_set_data_bittiming)(struct net_device *); /* 320 8 */ | int (*do_set_mode)(struct net_device *, enum can_mode); /* 328 8 */ | int (*do_set_termination)(struct net_device *, u16); /* 336 8 */ | int (*do_get_state)(const struct net_device *, enum can_state *); /* 344 8 */ | int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 352 8 */ | | /* size: 360, cachelines: 6, members: 32 */ | /* sum members: 354, holes: 1, sum holes: 6 */ | /* paddings: 1, sum paddings: 4 */ | /* last cacheline: 40 bytes */ | }; Link: https://lore.kernel.org/all/20211213160226.56219-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: dev: add sanity check in can_set_static_ctrlmode()Vincent Mailhol1-2/+9
Previous patch removed can_priv::ctrlmode_static to replace it with can_get_static_ctrlmode(). A condition sine qua non for this to work is that the controller static modes should never be set in can_priv::ctrlmode_supported (c.f. the comment on can_priv::ctrlmode_supported which states that it is for "options that can be *modified* by netlink"). Also, this condition is already correctly fulfilled by all existing drivers which rely on the ctrlmode_static feature. Nonetheless, we added an extra safeguard in can_set_static_ctrlmode() to return an error value and to warn the developer who would be adventurous enough to set to static a given feature that is already set to supported. The drivers which rely on the static controller mode are then updated to check the return value of can_set_static_ctrlmode(). Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode()Vincent Mailhol1-2/+5
The statically enabled features of a CAN controller can be retrieved using below formula: | u32 ctrlmode_static = priv->ctrlmode & ~priv->ctrlmode_supported; As such, there is no need to store this information. This patch remove the field ctrlmode_static of struct can_priv and provides, in replacement, the inline function can_get_static_ctrlmode() which returns the same value. Link: https://lore.kernel.org/all/20211213160226.56219-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: do not increase tx_bytes statistics for RTR framesVincent Mailhol1-2/+3
The actual payload length of the CAN Remote Transmission Request (RTR) frames is always 0, i.e. no payload is transmitted on the wire. However, those RTR frames still use the DLC to indicate the length of the requested frame. As such, net_device_stats::tx_bytes should not be increased when sending RTR frames. The function can_get_echo_skb() already returns the correct length, even for RTR frames (c.f. [1]). However, for historical reasons, the drivers do not use can_get_echo_skb()'s return value and instead, most of them store a temporary length (or dlc) in some local structure or array. Using the return value of can_get_echo_skb() solves the issue. After doing this, such length/dlc fields become unused and so this patch does the adequate cleaning when needed. This patch fixes all the CAN drivers. Finally, can_get_echo_skb() is decorated with the __must_check attribute in order to force future drivers to correctly use its return value (else the compiler would emit a warning). [1] commit ed3320cec279 ("can: dev: __can_get_echo_skb(): fix real payload length return value for RTR frames") Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Jernej Skrabec <jernej.skrabec@gmail.com> Cc: Yasushi SHOJI <yashi@spacecubics.com> Cc: Oliver Hartkopp <socketcan@hartkopp.net> Cc: Stephane Grosjean <s.grosjean@peak-system.com> Cc: Andreas Larsson <andreas@gaisler.com> Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 [mkl: add conversion for grcan] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-12-08can: bittiming: replace CAN units with the generic ones from linux/units.hVincent Mailhol1-7/+0
In [1], we introduced a set of units in linux/can/bittiming.h. Since then, generic SI prefixes were added to linux/units.h in [2]. Those new prefixes can perfectly replace CAN specific ones. This patch replaces all occurrences of the CAN units with their corresponding prefix (from linux/units) and the unit (as a comment) according to below table. CAN units SI metric prefix (from linux/units) + unit (as a comment) ------------------------------------------------------------------------ CAN_KBPS KILO /* BPS */ CAN_MBPS MEGA /* BPS */ CAM_MHZ MEGA /* Hz */ The definition are then removed from linux/can/bittiming.h [1] commit 1d7750760b70 ("can: bittiming: add CAN_KBPS, CAN_MBPS and CAN_MHZ macros") [2] commit 26471d4a6cf8 ("units: Add SI metric prefix definitions") Link: https://lore.kernel.org/all/20211124014536.782550-1-mailhol.vincent@wanadoo.fr Suggested-by: Jimmy Assarsson <extja@kvaser.com> Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: dev: add can_tdc_get_relative_tdco() helper functionVincent Mailhol1-0/+29
struct can_tdc::tdco represents the absolute offset from TDCV. Some controllers use instead an offset relative to the Sample Point (SP) such that: | SSP = TDCV + absolute TDCO | = TDCV + SP + relative TDCO Consequently: | relative TDCO = absolute TDCO - SP The function can_tdc_get_relative_tdco() allow to retrieve this relative TDCO value. Link: https://lore.kernel.org/all/20210918095637.20108-7-mailhol.vincent@wanadoo.fr CC: Stefan Mätje <Stefan.Maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: netlink: add can_priv::do_get_auto_tdcv() to retrieve tdcv from deviceVincent Mailhol1-0/+1
Some CAN device can measure the TDCV (Transmission Delay Compensation Value) automatically for each transmitted CAN frames. A callback function do_get_auto_tdcv() is added to retrieve that value. This function is used only if CAN_CTRLMODE_TDC_AUTO is enabled (if CAN_CTRLMODE_TDC_MANUAL is selected, the TDCV value is provided by the user). If the device does not support reporting of TDCV, do_get_auto_tdcv() should be set to NULL and TDCV will not be reported by the netlink interface. On success, do_get_auto_tdcv() shall return 0. If the value can not be measured by the device, for example because network is down or because no frames were transmitted yet, can_priv::do_get_auto_tdcv() shall return a negative error code (e.g. -EINVAL) to signify that the value is not yet available. In such cases, TDCV is not reported by the netlink interface. Link: https://lore.kernel.org/all/20210918095637.20108-6-mailhol.vincent@wanadoo.fr CC: Stefan Mätje <stefan.maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: change can_calc_tdco()'s prototype to not directly modify privVincent Mailhol1-2/+7
The function can_calc_tdco() directly retrieves can_priv from the net_device and directly modifies it. This is annoying for the upcoming patch. In drivers/net/can/dev/netlink.c:can_changelink(), the data bittiming are written to a temporary structure and memcpyed to can_priv only after everything succeeded. In the next patch, where we will introduce the netlink interface for TDC parameters, we will add a new TDC block which can potentially fail. For this reason, the data bittiming temporary structure has to be copied after that to-be-introduced TDC block. However, TDC also needs to access data bittiming information. We change the prototype so that the data bittiming structure is passed to can_calc_tdco() as an argument instead of retrieving it from priv. This way can_calc_tdco() can access the data bittiming before it gets memcpyed to priv. Link: https://lore.kernel.org/all/20210918095637.20108-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: change unit of TDC parameters to clock periodsVincent Mailhol1-11/+17
In the current implementation, all Transmission Delay Compensation (TDC) parameters are expressed in time quantum. However, ISO 11898-1 actually specifies that these should be expressed in *minimum* time quantum. Furthermore, the minimum time quantum is specified to be "one node clock period long" (c.f. paragraph 11.3.1.1 "Bit time"). For sake of simplicity, we prefer to use the "clock period" term instead of "minimum time quantum" because we believe that it is more broadly understood. This patch fixes that discrepancy by updating the documentation and the formula for TDCO calculation. N.B. In can_calc_tdco(), the sample point (in time quantum) was calculated using a division, thus introducing a risk of rounding and truncation errors. On top of changing the unit to clock period, we also modified the formula to use only additions. Link: https://lore.kernel.org/all/20210918095637.20108-3-mailhol.vincent@wanadoo.fr Suggested-by: Stefan Mätje <Stefan.Maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: allow TDC{V,O} to be zero and add can_tdc_const::tdc{v,o,f}_minVincent Mailhol2-17/+51
ISO 11898-1 specifies in section 11.3.3 "Transmitter delay compensation" that "the configuration range for [the] SSP position shall be at least 0 to 63 minimum time quanta." Because SSP = TDCV + TDCO, it means that we should allow both TDCV and TDCO to hold zero value in order to honor SSP's minimum possible value. However, current implementation assigned special meaning to TDCV and TDCO's zero values: * TDCV = 0 -> TDCV is automatically measured by the transceiver. * TDCO = 0 -> TDC is off. In order to allow for those values to really be zero and to maintain current features, we introduce two new flags: * CAN_CTRLMODE_TDC_AUTO indicates that the controller support automatic measurement of TDCV. * CAN_CTRLMODE_TDC_MANUAL indicates that the controller support manual configuration of TDCV. N.B.: current implementation failed to provide an option for the driver to indicate that only manual mode was supported. TDC is disabled if both CAN_CTRLMODE_TDC_AUTO and CAN_CTRLMODE_TDC_MANUAL flags are off, c.f. the helper function can_tdc_is_enabled() which is also introduced in this patch. Also, this patch adds three fields: tdcv_min, tdco_min and tdcf_min to struct can_tdc_const. While we are not convinced that those three fields could be anything else than zero, we can imagine that some controllers might specify a lower bound on these. Thus, those minimums are really added "just in case". Comments of struct can_tdc and can_tdc_const are updated accordingly. Finally, the changes are applied to the etas_es58x driver. Link: https://lore.kernel.org/all/20210918095637.20108-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-08-19can: dev: provide optional GPIO based termination supportOleksij Rempel1-0/+8
For CAN buses to work, a termination resistor has to be present at both ends of the bus. This resistor is usually 120 Ohms, other values may be required for special bus topologies. This patch adds support for a generic GPIO based CAN termination. The resistor value has to be specified via device tree, and it can only be attached to or detached from the bus. By default the termination is not active. Link: https://lore.kernel.org/r/20210818071232.20585-4-o.rempel@pengutronix.de Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: flexcan: add platform data headerAngelo Dureghello1-0/+23
Add platform data header for flexcan. Link: https://lore.kernel.org/r/20210702094841.327679-1-angelo@kernel-space.org Signed-off-by: Angelo Dureghello <angelo@kernel-space.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: bittiming: fix documentation for struct can_tdcMarc Kleine-Budde1-2/+2
This patch fixes a typo in the documentation for struct can_tdc::tdcv. The number "0" refers to automatic mode not the letter "O". Further two grammar errors in the documentation for struct can_tdc are fixed. First grammar error: add a missing third person 's'. Second grammar error: replace "such as" by "such that". The intent is to give a condition, not an example. Fixes: 289ea9e4ae59 ("can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)") Link: https://lore.kernel.org/r/20210616095922.2430415-1-mkl@pengutronix.de Link: https://lore.kernel.org/r/20210616124057.60723-1-mailhol.vincent@wanadoo.fr Co-developed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to ↵Marc Kleine-Budde1-0/+1
be called from threaded interrupt After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de Suggested-by: Daniel Glöckner <dg@emlix.com> Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: can_rx_offload_irq_finish(): directly call napi_schedule()Marc Kleine-Budde1-5/+0
Instead of calling can_rx_offload_schedule() call napi_schedule() directly. As this was the last use of can_rx_offload_schedule() remove this helper function. Link: https://lore.kernel.org/r/20210724204745.736053-3-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: add skb queue for use during ISRMarc Kleine-Budde1-0/+2
Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Co-developed-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: bittiming: add CAN_KBPS, CAN_MBPS and CAN_MHZ macrosVincent Mailhol1-0/+8
Add three macro to simplify the readability of big bit timing numbers: - CAN_KBPS: kilobits per second (one thousand) - CAN_MBPS: megabits per second (one million) - CAN_MHZ: megahertz per second (one million) Example: u32 bitrate_max = 8 * CAN_MBPS; struct can_clock clock = {.freq = 80 * CAN_MHZ}; instead of: u32 bitrate_max = 8000000; struct can_clock clock = {.freq = 80000000}; Apply the new macro to driver/net/can/dev/bittiming.c. Link: https://lore.kernel.org/r/20210306054040.76483-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: bittiming: add calculation for CAN FD Transmitter Delay Compensation (TDC)Vincent Mailhol1-0/+6
The logic for the tdco calculation is to just reuse the normal sample point: tdco = sp. Because the sample point is expressed in tenth of percent and the tdco is expressed in time quanta, a conversion is needed. At the end, ssp = tdcv + tdco = tdcv + sp. Another popular method is to set tdco to the middle of the bit: tdc->tdco = can_bit_time(dbt) / 2 During benchmark tests, we could not find a clear advantages for one of the two methods. The tdco calculation is triggered each time the data_bittiming is changed so that users relying on automated calculation can use the netlink interface the exact same way without need of new parameters. For example, a command such as: ip link set canX type can bitrate 500000 dbitrate 4000000 fd on would trigger the calculation. The user using CONFIG_CAN_CALC_BITTIMING who does not want automated calculation needs to manually set tdco to zero. For example with: ip link set canX type can tdco 0 bitrate 500000 dbitrate 4000000 fd on (if the tdco parameter is provided in a previous command, it will be overwritten). If tdcv is set to zero (default), it is automatically calculated by the transiver for each frame. As such, there is no code in the kernel to calculate it. tdcf has no automated calculation functions because we could not figure out a formula for this parameter. Link: https://lore.kernel.org/r/20210224002008.4158-6-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: dev: reorder struct can_priv members for better packingVincent Mailhol1-6/+7
Save eight bytes of holes on x86-64 architectures by reordering struct can_priv members. Before: $ pahole -C can_priv drivers/net/can/dev/dev.o struct can_priv { struct net_device * dev; /* 0 8 */ struct can_device_stats can_stats; /* 8 24 */ struct can_bittiming bittiming; /* 32 32 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct can_bittiming data_bittiming; /* 64 32 */ const struct can_bittiming_const * bittiming_const; /* 96 8 */ const struct can_bittiming_const * data_bittiming_const; /* 104 8 */ struct can_tdc tdc; /* 112 12 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 2 boundary (128 bytes) --- */ const struct can_tdc_const * tdc_const; /* 128 8 */ const u16 * termination_const; /* 136 8 */ unsigned int termination_const_cnt; /* 144 4 */ u16 termination; /* 148 2 */ /* XXX 2 bytes hole, try to pack */ const u32 * bitrate_const; /* 152 8 */ unsigned int bitrate_const_cnt; /* 160 4 */ /* XXX 4 bytes hole, try to pack */ const u32 * data_bitrate_const; /* 168 8 */ unsigned int data_bitrate_const_cnt; /* 176 4 */ u32 bitrate_max; /* 180 4 */ struct can_clock clock; /* 184 4 */ enum can_state state; /* 188 4 */ /* --- cacheline 3 boundary (192 bytes) --- */ u32 ctrlmode; /* 192 4 */ u32 ctrlmode_supported; /* 196 4 */ u32 ctrlmode_static; /* 200 4 */ int restart_ms; /* 204 4 */ struct delayed_work restart_work; /* 208 168 */ /* XXX last struct has 4 bytes of padding */ /* --- cacheline 5 boundary (320 bytes) was 56 bytes ago --- */ int (*do_set_bittiming)(struct net_device *); /* 376 8 */ /* --- cacheline 6 boundary (384 bytes) --- */ int (*do_set_data_bittiming)(struct net_device *); /* 384 8 */ int (*do_set_mode)(struct net_device *, enum can_mode); /* 392 8 */ int (*do_set_termination)(struct net_device *, u16); /* 400 8 */ int (*do_get_state)(const struct net_device *, enum can_state *); /* 408 8 */ int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 416 8 */ unsigned int echo_skb_max; /* 424 4 */ /* XXX 4 bytes hole, try to pack */ struct sk_buff * * echo_skb; /* 432 8 */ /* size: 440, cachelines: 7, members: 31 */ /* sum members: 426, holes: 4, sum holes: 14 */ /* paddings: 1, sum paddings: 4 */ /* last cacheline: 56 bytes */ }; After: $ pahole -C can_priv drivers/net/can/dev/dev.o struct can_priv { struct net_device * dev; /* 0 8 */ struct can_device_stats can_stats; /* 8 24 */ const struct can_bittiming_const * bittiming_const; /* 32 8 */ const struct can_bittiming_const * data_bittiming_const; /* 40 8 */ struct can_bittiming bittiming; /* 48 32 */ /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ struct can_bittiming data_bittiming; /* 80 32 */ const struct can_tdc_const * tdc_const; /* 112 8 */ struct can_tdc tdc; /* 120 12 */ /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ unsigned int bitrate_const_cnt; /* 132 4 */ const u32 * bitrate_const; /* 136 8 */ const u32 * data_bitrate_const; /* 144 8 */ unsigned int data_bitrate_const_cnt; /* 152 4 */ u32 bitrate_max; /* 156 4 */ struct can_clock clock; /* 160 4 */ unsigned int termination_const_cnt; /* 164 4 */ const u16 * termination_const; /* 168 8 */ u16 termination; /* 176 2 */ /* XXX 2 bytes hole, try to pack */ enum can_state state; /* 180 4 */ u32 ctrlmode; /* 184 4 */ u32 ctrlmode_supported; /* 188 4 */ /* --- cacheline 3 boundary (192 bytes) --- */ u32 ctrlmode_static; /* 192 4 */ int restart_ms; /* 196 4 */ struct delayed_work restart_work; /* 200 168 */ /* XXX last struct has 4 bytes of padding */ /* --- cacheline 5 boundary (320 bytes) was 48 bytes ago --- */ int (*do_set_bittiming)(struct net_device *); /* 368 8 */ int (*do_set_data_bittiming)(struct net_device *); /* 376 8 */ /* --- cacheline 6 boundary (384 bytes) --- */ int (*do_set_mode)(struct net_device *, enum can_mode); /* 384 8 */ int (*do_set_termination)(struct net_device *, u16); /* 392 8 */ int (*do_get_state)(const struct net_device *, enum can_state *); /* 400 8 */ int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 408 8 */ unsigned int echo_skb_max; /* 416 4 */ /* XXX 4 bytes hole, try to pack */ struct sk_buff * * echo_skb; /* 424 8 */ /* size: 432, cachelines: 7, members: 31 */ /* sum members: 426, holes: 2, sum holes: 6 */ /* paddings: 1, sum paddings: 4 */ /* last cacheline: 48 bytes */ }; Link: https://lore.kernel.org/r/20210224002008.4158-3-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)Vincent Mailhol2-0/+68
At high bit rates, the propagation delay from the TX pin to the RX pin of the transceiver causes measurement errors: the sample point on the RX pin might occur on the previous bit. This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter delay compensation" (TDC). This patch adds two new structures: can_tdc and can_tdc_const in order to implement this TDC. The structures are then added to can_priv. A controller supports TDC if an only if can_priv::tdc_const is not NULL. TDC is active if and only if: - fd flag is on - can_priv::tdc.tdco is not zero. It is the driver responsibility to check those two conditions are met. No new controller modes are introduced (i.e. no CAN_CTRL_MODE_TDC) in order not to be redundant with above logic. The names of the parameters are chosen to match existing CAN controllers specification. References: - Bosch C_CAN FD8: https://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf - Microchip CAN FD Controller Module: http://ww1.microchip.com/downloads/en/DeviceDoc/MCP251XXFD-CAN-FD-Controller-Module-Family-Reference-Manual-20005678B.pdf - SAM E701/S70/V70/V71 Family: https://www.mouser.com/datasheet/2/268/60001527A-1284321.pdf Link: https://lore.kernel.org/r/20210224002008.4158-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: dev: can_free_echo_skb(): extend to return can frame lengthMarc Kleine-Budde1-1/+2
In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack even if the transmission failed for some reason. To avoid to calculate this length twice, extend can_free_echo_skb() to return that value. Convert all users of this function, too. This patch is the natural extension of commit: | 9420e1d495e2 ("can: dev: can_get_echo_skb(): extend to return can | frame length") Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-01can: skb: can_skb_set_owner(): fix ref counting if socket was closed before ↵Oleksij Rempel1-2/+6
setting skb ownership There are two ref count variables controlling the free()ing of a socket: - struct sock::sk_refcnt - which is changed by sock_hold()/sock_put() - struct sock::sk_wmem_alloc - which accounts the memory allocated by the skbs in the send path. In case there are still TX skbs on the fly and the socket() is closed, the struct sock::sk_refcnt reaches 0. In the TX-path the CAN stack clones an "echo" skb, calls sock_hold() on the original socket and references it. This produces the following back trace: | WARNING: CPU: 0 PID: 280 at lib/refcount.c:25 refcount_warn_saturate+0x114/0x134 | refcount_t: addition on 0; use-after-free. | Modules linked in: coda_vpu(E) v4l2_jpeg(E) videobuf2_vmalloc(E) imx_vdoa(E) | CPU: 0 PID: 280 Comm: test_can.sh Tainted: G E 5.11.0-04577-gf8ff6603c617 #203 | Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) | Backtrace: | [<80bafea4>] (dump_backtrace) from [<80bb0280>] (show_stack+0x20/0x24) r7:00000000 r6:600f0113 r5:00000000 r4:81441220 | [<80bb0260>] (show_stack) from [<80bb593c>] (dump_stack+0xa0/0xc8) | [<80bb589c>] (dump_stack) from [<8012b268>] (__warn+0xd4/0x114) r9:00000019 r8:80f4a8c2 r7:83e4150c r6:00000000 r5:00000009 r4:80528f90 | [<8012b194>] (__warn) from [<80bb09c4>] (warn_slowpath_fmt+0x88/0xc8) r9:83f26400 r8:80f4a8d1 r7:00000009 r6:80528f90 r5:00000019 r4:80f4a8c2 | [<80bb0940>] (warn_slowpath_fmt) from [<80528f90>] (refcount_warn_saturate+0x114/0x134) r8:00000000 r7:00000000 r6:82b44000 r5:834e5600 r4:83f4d540 | [<80528e7c>] (refcount_warn_saturate) from [<8079a4c8>] (__refcount_add.constprop.0+0x4c/0x50) | [<8079a47c>] (__refcount_add.constprop.0) from [<8079a57c>] (can_put_echo_skb+0xb0/0x13c) | [<8079a4cc>] (can_put_echo_skb) from [<8079ba98>] (flexcan_start_xmit+0x1c4/0x230) r9:00000010 r8:83f48610 r7:0fdc0000 r6:0c080000 r5:82b44000 r4:834e5600 | [<8079b8d4>] (flexcan_start_xmit) from [<80969078>] (netdev_start_xmit+0x44/0x70) r9:814c0ba0 r8:80c8790c r7:00000000 r6:834e5600 r5:82b44000 r4:82ab1f00 | [<80969034>] (netdev_start_xmit) from [<809725a4>] (dev_hard_start_xmit+0x19c/0x318) r9:814c0ba0 r8:00000000 r7:82ab1f00 r6:82b44000 r5:00000000 r4:834e5600 | [<80972408>] (dev_hard_start_xmit) from [<809c6584>] (sch_direct_xmit+0xcc/0x264) r10:834e5600 r9:00000000 r8:00000000 r7:82b44000 r6:82ab1f00 r5:834e5600 r4:83f27400 | [<809c64b8>] (sch_direct_xmit) from [<809c6c0c>] (__qdisc_run+0x4f0/0x534) To fix this problem, only set skb ownership to sockets which have still a ref count > 0. Fixes: 0ae89beb283a ("can: add destructor for self generated skbs") Cc: Oliver Hartkopp <socketcan@hartkopp.net> Cc: Andre Naujoks <nautsch2@gmail.com> Link: https://lore.kernel.org/r/20210226092456.27126-1-o.rempel@pengutronix.de Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-02-25net: introduce CAN specific pointer in the struct net_deviceOleksij Rempel1-0/+12
Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv") the CAN framework uses per device specific data in the AF_CAN protocol. For this purpose the struct net_device->ml_priv is used. Later the ml_priv usage in CAN was extended for other users, one of them being CAN_J1939. Later in the kernel ml_priv was converted to an union, used by other drivers. E.g. the tun driver started storing it's stats pointer. Since tun devices can claim to be a CAN device, CAN specific protocols will wrongly interpret this pointer, which will cause system crashes. Mostly this issue is visible in the CAN_J1939 stack. To fix this issue, we request a dedicated CAN pointer within the net_device struct. Reported-by: syzbot+5138c4dd15a0401bec7b@syzkaller.appspotmail.com Fixes: 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv") Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically") Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20210223070127.4538-1-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-27can: dev: export can_get_state_str() functionVincent Mailhol1-0/+1
The can_get_state_str() function is also relevant to the drivers. Export the symbol and make it visible in the can/dev.h header. Link: https://lore.kernel.org/r/20210119170355.12040-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14can: dev: can_rx_offload_get_echo_skb(): extend to return can frame lengthMarc Kleine-Budde1-1/+2
In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack after queueing and after transmission completion. To avoid to calculate this length twice, extend can_rx_offload_get_echo_skb() to return that value. Convert all users of this function, too. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-15-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14can: dev: can_get_echo_skb(): extend to return can frame lengthMarc Kleine-Budde1-1/+2
In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack after queueing and after transmission completion. To avoid to calculate this length twice, extend can_get_echo_skb() to return that value. Convert all users of this function, too. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14can: dev: can_put_echo_skb(): extend to handle frame_lenVincent Mailhol1-1/+1
Add a frame_len argument to can_put_echo_skb() which is used to save length of the CAN frame into field frame_len of struct can_skb_priv so that it can be later used after transmission completion. Convert all users of this function, too. Drivers which implement BQL call can_put_echo_skb() with the output of can_skb_get_frame_len(skb) and drivers which do not simply pass zero as an input (in the same way that NULL would be given to can_get_echo_skb()). This way, we have a nice symmetry between the two echo functions. Link: https://lore.kernel.org/r/20210111061335.39983-1-mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-13-mkl@pengutronix.de Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
2021-01-14can: dev: extend struct can_skb_priv to hold CAN frame lengthMarc Kleine-Budde1-1/+3
In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack after queueing and after transmission completion. To avoid to calculate this length twice, extend the struct can_skb_priv to hold the length of the CAN frame and extend __can_get_echo_skb() to return that value. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-12-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14can: length: can_skb_get_frame_len(): introduce function to get data length ↵Vincent Mailhol1-0/+120
of frame in data link layer This patch adds the function can_skb_get_frame_len() which returns the length of a CAN frame on the data link layer, including Start-of-frame, Identifier, various other bits, the actual data, the CRC, the End-of-frame, the Inter frame spacing. Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com> Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com> Co-developed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Co-developed-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/20210111141930.693847-11-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14can: length: canfd_sanitize_len(): add function to sanitize CAN-FD data lengthMarc Kleine-Budde1-0/+6
The data field in CAN-FD frames have specifig frame length (0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64). This function "rounds" up a given length to the next valid CAN-FD frame length. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-10-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-13can: dev: move netlink related code into seperate fileMarc Kleine-Budde1-0/+6
This patch moves the netlink related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-7-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-13can: dev: move skb related into seperate fileMarc Kleine-Budde2-76/+77
This patch moves the skb related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-6-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-13can: dev: move length related code into seperate fileMarc Kleine-Budde2-40/+49
This patch moves all CAN frame length related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-5-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-13can: dev: move bittiming related code into seperate fileMarc Kleine-Budde2-15/+45
This patch moves the bittiming related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20210111141930.693847-4-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20can: drivers: introduce helpers to access Classical CAN DLC valuesOliver Hartkopp1-0/+25
This patch adds the following helper to functions to access Classical CAN DLC values. can_get_cc_dlc(): get the data length code for Classical CAN raw DLC access can_frame_set_cc_len(): set len and len8_dlc value for Classical CAN raw DLC access Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201110154913.1404582-2-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20can: rename CAN FD related can_len2dlc and can_dlc2len helpersOliver Hartkopp1-2/+2
The helper functions can_len2dlc and can_dlc2len are only relevant for CAN FD data length code (DLC) conversion. To fit the introduced can_cc_dlc2len for Classical CAN we rename: can_dlc2len -> can_fd_dlc2len to get the payload length from the DLC can_len2dlc -> can_fd_len2dlc to get the DLC from the payload length Suggested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201110101852.1973-6-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20can: replace can_dlc as variable/element for payload lengthOliver Hartkopp1-2/+2
The naming of can_dlc as element of struct can_frame and also as variable name is misleading as it claims to be a 'data length CODE' but in reality it always was a plain data length. With the indroduction of a new 'len' element in struct can_frame we can now remove can_dlc as name and make clear which of the former uses was a plain length (-> 'len') or a data length code (-> 'dlc') value. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201120100444.3199-1-socketcan@hartkopp.net [mkl: gs_usb: keep struct gs_host_frame::can_dlc as is] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20can: remove obsolete get_canfd_dlc() macroOliver Hartkopp2-2/+1
The macro was always used together with can_dlc2len() which sanitizes the given dlc value on its own. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201110101852.1973-4-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20can: rename get_can_dlc() macro with can_cc_dlc2len()Oliver Hartkopp1-4/+4
The get_can_dlc() macro is used to ensure the payload length information of the Classical CAN frame to be max 8 bytes (the CAN_MAX_DLEN). Rename the macro and use the correct constant in preparation of the len/dlc cleanup for Classical CAN frames. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201110101852.1973-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-04can: can_create_echo_skb(): fix echo skb generation: always use skb_clone()Oleksij Rempel1-12/+8
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: 0ae89beb283a ("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.de Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-10-12can: remove obsolete version stringsOliver Hartkopp1-7/+0
As pointed out by Jakub Kicinski here: http://lore.kernel.org/r/20201009175751.5c54097f@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com this patch removes the obsolete version information of the different CAN protocols and the AF_CAN core module. Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20201012074354.25839-2-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-10-08can: dev: add a helper function to calculate the duration of one bitVincent Mailhol1-0/+15
Rename macro CAN_CALC_SYNC_SEG to CAN_SYNC_SEG and make it available through include/linux/can/dev.h Add an helper function can_bit_time() which returns the duration (in time quanta) of one CAN bit. Rationale for this patch: the sync segment and the bit time are two concepts which are defined in the CAN ISO standard. Device drivers for CAN might need those. Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for additional information. Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20201002154219.4887-6-mailhol.vincent@wanadoo.fr [mkl: Let can_bit_time() return an unsinged int, make argument const] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-10-06can: dev: fix type of get_can_dlc() and get_canfd_dlc() macrosVincent Mailhol1-3/+3
The macros get_can_dlc() and get_canfd_dlc() are not visible in userland. As such, type u8 should be preferred over type __u8. Reference: https://lkml.org/lkml/2020/10/1/708 Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/r/20201002154219.4887-3-mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-09-21can: rx-offload: can_rx_offload_add_manual(): add new initialization functionMarc Kleine-Budde1-0/+3
This patch adds a new initialization function: can_rx_offload_add_manual() It should be used to add support rx-offload to a driver, if the callback mechanism should not be used. Use e.g. can_rx_offload_queue_sorted() to queue skbs into rx-offload. Link: https://lore.kernel.org/r/20200915223527.1417033-33-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-09-21can: dev: can_put_echo_skb(): propagate error in case of errorsMarc Kleine-Budde1-2/+2
The function can_put_echo_skb() can fail for several reasons. It may fail due to OOM, but when it fails it's usually due to locking problems in the driver. In order to help developing and debugging of new drivers propagate error value in case of errors. Link: https://lore.kernel.org/r/20200915223527.1417033-12-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-09-21can: include: fix spelling mistakesMarc Kleine-Budde2-2/+2
This patch fixes spelling erros found by "codespell" in the include/linux/can subtree. Link: https://lore.kernel.org/r/20200915223527.1417033-4-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-06-16can: Replace zero-length array with flexible-arrayGustavo A. R. Silva1-1/+1
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-04-18can: dev: peak_canfd.h: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-2/+2
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2020-01-02can: can_dropped_invalid_skb(): ensure an initialized headroom in outgoing ↵Oliver Hartkopp1-0/+34
CAN sk_buffs KMSAN sysbot detected a read access to an untinitialized value in the headroom of an outgoing CAN related sk_buff. When using CAN sockets this area is filled appropriately - but when using a packet socket this initialization is missing. The problematic read access occurs in the CAN receive path which can only be triggered when the sk_buff is sent through a (virtual) CAN interface. So we check in the sending path whether we need to perform the missing initializations. Fixes: d3b58c47d330d ("can: replace timestamp as unique skb attribute") Reported-by: syzbot+b02ff0707a97e4e79ebb@syzkaller.appspotmail.com Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Cc: linux-stable <stable@vger.kernel.org> # >= v4.1 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>