kernel/linux.git/include/linux/can/skb.h, branch v6.19.11

can: canxl: update CAN infrastructure for CAN XL frames

2022-09-15T07:08:09+00:00

- add new ETH_P_CANXL ethernet protocol type - update skb checks for CAN XL - add alloc_canxl_skb() which now needs a data length parameter - introduce init_can_skb_reserve() to reduce code duplication Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-6-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: skb: add skb CAN frame data length helpers

2022-09-15T07:08:08+00:00

Add two helpers to retrieve the data length from CAN sk_buffs and prepare the length information to be a uint16 value for the CAN XL support. Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: skb: unify skb CAN frame identification helpers

2022-09-15T07:08:08+00:00

Replace open coded checks for sk_buffs containing Classical CAN and CAN FD frame structures as a preparation for CAN XL support. With the added length check the unintended processing of CAN XL frames having the CANXL_XLF bit set can be suppressed even when the skb->len fits to non CAN XL frames. The CAN_RAW socket needs a rework to use these helpers. Therefore the use of these helpers is postponed to the CAN_RAW CAN XL integration. The J1939 protocol gets a check for Classical CAN frames too. Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-2-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: skb: move can_dropped_invalid_skb() and can_skb_headroom_valid() to skb.c

2022-06-11T15:11:02+00:00

The functions can_dropped_invalid_skb() and can_skb_headroom_valid() grew a lot over the years to a point which it does not make much sense to have them defined as static inline in header files. Move those two functions to the .c counterpart of skb.h. can_skb_headroom_valid()'s only caller being can_dropped_invalid_skb(), the declaration is removed from the header. Only can_dropped_invalid_skb() gets its symbol exported. While doing so, do a small cleanup: add brackets around the else block in can_dropped_invalid_skb(). Link: https://lore.kernel.org/all/20220610143009.323579-7-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Reported-by: kernel test robot Acked-by: Max Staudt Tested-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

can: do not increase tx_bytes statistics for RTR frames

2022-01-05T11:09:05+00:00

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 Cc: Alexandre Belloni Cc: Ludovic Desroches Cc: Maxime Ripard Cc: Chen-Yu Tsai Cc: Jernej Skrabec Cc: Yasushi SHOJI Cc: Oliver Hartkopp Cc: Stephane Grosjean Cc: Andreas Larsson Tested-by: Jimmy Assarsson # kvaser Signed-off-by: Vincent Mailhol Acked-by: Stefan Mätje # esd_usb2 Tested-by: Stefan Mätje # esd_usb2 [mkl: add conversion for grcan] Signed-off-by: Marc Kleine-Budde

can: dev: can_free_echo_skb(): extend to return can frame length

2021-03-30T09:14:28+00:00

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

can: skb: can_skb_set_owner(): fix ref counting if socket was closed before setting skb ownership

2021-03-01T10:45:04+00:00

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 Cc: Andre Naujoks Link: https://lore.kernel.org/r/20210226092456.27126-1-o.rempel@pengutronix.de Suggested-by: Eric Dumazet Signed-off-by: Oleksij Rempel Reviewed-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

can: dev: can_get_echo_skb(): extend to return can frame length

2021-01-14T07:43:43+00:00

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 Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: can_put_echo_skb(): extend to handle frame_len

2021-01-14T07:43:43+00:00

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 Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-13-mkl@pengutronix.de Signed-off-by: Vincent Mailhol

can: dev: extend struct can_skb_priv to hold CAN frame length

2021-01-14T07:43:42+00:00

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 Link: https://lore.kernel.org/r/20210111141930.693847-12-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde