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Wei Fang authored
We encountered a kernel call trace issue which was related to ndo_xdp_xmit callback on our i.MX8MP platform. The reproduce steps show as follows. 1. The FEC port (eth0) connects to a PC port, and the PC uses pktgen_sample03_burst_single_flow.sh to generate packets and send these packets to the FEC port. Notice that the script must be executed before step 2. 2. Run the "./xdp_redirect eth0 eth1" command on i.MX8MP, the eth1 interface is the dwmac. Then there will be a call trace issue soon. Please see the log for more details. The root cause is that the NETDEV_XDP_ACT_NDO_XMIT feature is enabled by default, so when the step 2 command is exexcuted and packets have already been sent to eth0, the stmmac_xdp_xmit() starts running before the stmmac_xdp_set_prog() finishes. To resolve this issue, we disable the NETDEV_XDP_ACT_NDO_XMIT feature by default and turn on/off this feature when the bpf program is installed/uninstalled which just like the other ethernet drivers. Call Trace log: [ 306.311271] ------------[ cut here ]------------ [ 306.315910] WARNING: CPU: 0 PID: 15 at lib/timerqueue.c:55 timerqueue_del+0x68/0x70 [ 306.323590] Modules linked in: [ 306.326654] CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.4.0-rc1+ #37 [ 306.333277] Hardware name: NXP i.MX8MPlus EVK board (DT) [ 306.338591] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 306.345561] pc : timerqueue_del+0x68/0x70 [ 306.349577] lr : __remove_hrtimer+0x5c/0xa0 [ 306.353777] sp : ffff80000b7c3920 [ 306.357094] x29: ffff80000b7c3920 x28: 0000000000000000 x27: 0000000000000001 [ 306.364244] x26: ffff80000a763a40 x25: ffff0000d0285a00 x24: 0000000000000001 [ 306.371390] x23: 0000000000000001 x22: ffff000179389a40 x21: 0000000000000000 [ 306.378537] x20: ffff000179389aa0 x19: ffff0000d2951308 x18: 0000000000001000 [ 306.385686] x17: f1d3000000000000 x16: 00000000c39c1000 x15: 55e99bbe00001a00 [ 306.392835] x14: 09000900120aa8c0 x13: e49af1d300000000 x12: 000000000000c39c [ 306.399987] x11: 100055e99bbe0000 x10: ffff8000090b1048 x9 : ffff8000081603fc [ 306.407133] x8 : 000000000000003c x7 : 000000000000003c x6 : 0000000000000001 [ 306.414284] x5 : ffff0000d2950980 x4 : 0000000000000000 x3 : 0000000000000000 [ 306.421432] x2 : 0000000000000001 x1 : ffff0000d2951308 x0 : ffff0000d2951308 [ 306.428585] Call trace: [ 306.431035] timerqueue_del+0x68/0x70 [ 306.434706] __remove_hrtimer+0x5c/0xa0 [ 306.438549] hrtimer_start_range_ns+0x2bc/0x370 [ 306.443089] stmmac_xdp_xmit+0x174/0x1b0 [ 306.447021] bq_xmit_all+0x194/0x4b0 [ 306.450612] __dev_flush+0x4c/0x98 [ 306.454024] xdp_do_flush+0x18/0x38 [ 306.457522] fec_enet_rx_napi+0x6c8/0xc68 [ 306.461539] __napi_poll+0x40/0x220 [ 306.465038] net_rx_action+0xf8/0x240 [ 306.468707] __do_softirq+0x128/0x3a8 [ 306.472378] run_ksoftirqd+0x40/0x58 [ 306.475961] smpboot_thread_fn+0x1c4/0x288 [ 306.480068] kthread+0x124/0x138 [ 306.483305] ret_from_fork+0x10/0x20 [ 306.486889] ---[ end trace 0000000000000000 ]--- Fixes: 66c0e13a ("drivers: net: turn on XDP features") Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230524125714.357337-1-wei.fang@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>
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