Hi BL, On Thu Dec 09 2021, Ong Boon Leong wrote: > To replicate the issue:- > > 1) Add 2 flower filters for VLAN Priority based frame steering:- > $ IFDEVNAME=eth0 > $ tc qdisc add dev $IFDEVNAME ingress > $ tc qdisc add dev $IFDEVNAME root mqprio num_tc 8 \ > map 0 1 2 3 4 5 6 7 0 0 0 0 0 0 0 0 \ > queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0 > $ tc filter add dev $IFDEVNAME parent ffff: protocol 802.1Q \ > flower vlan_prio 0 hw_tc 0 > $ tc filter add dev $IFDEVNAME parent ffff: protocol 802.1Q \ > flower vlan_prio 1 hw_tc 1 > > 2) Get the 'pref' id > $ tc filter show dev $IFDEVNAME ingress > > 3) Delete a specific tc flower record > $ tc filter del dev $IFDEVNAME parent ffff: pref 49151 > > From dmesg, we will observe kernel NULL pointer ooops > > [ 197.170464] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [ 197.171367] #PF: supervisor read access in kernel mode > [ 197.171367] #PF: error_code(0x0000) - not-present page > [ 197.171367] PGD 0 P4D 0 > [ 197.171367] Oops: 0000 [#1] PREEMPT SMP NOPTI > [ 197.171367] CPU: 0 PID: 3216 Comm: tc Tainted: G U E 5.16.0-rc2+ #12 > [ 197.171367] Hardware name: Intel Corporation Elkhart Lake Embedded Platform/ElkhartLake LPDDR4x T3 CRB, BIOS EHLSFWI1.R00.3273.A04.2107240322 07/24/2021 > [ 197.171367] RIP: 0010:tc_setup_cls+0x20b/0x4a0 [stmmac] > [ 197.171367] Code: fe ff ff c7 43 14 00 00 00 00 48 c7 03 00 00 00 00 c7 43 1c 00 00 00 00 49 8b 44 24 28 48 8b bd b0 00 00 00 41 0f b7 54 24 58 <48> 8b 00 0f bf 8f 38 08 00 00 81 ea e0 ff 00 00 8b 00 25 00 04 00 > [ 197.171367] RSP: 0018:ffff940940a037c0 EFLAGS: 00010246 > [ 197.171367] RAX: 0000000000000000 RBX: ffff92e826cae2c8 RCX: ffff92e825f39000 > [ 197.171367] RDX: 0000000000000000 RSI: ffff92e826cae2a8 RDI: ffff92e82f0c0000 > [ 197.171367] RBP: ffff92e82f0c0940 R08: 0000000000000000 R09: ffff92e825f39434 > [ 197.171367] R10: ffff92e826c5af00 R11: ffff940940a038a8 R12: ffff940940a038a8 > [ 197.171367] R13: 0000000000000000 R14: 0000000000000000 R15: ffff92e830a5b600 > [ 197.171367] FS: 00007fa7b0c47740(0000) GS:ffff92e964200000(0000) knlGS:0000000000000000 > [ 197.171367] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 197.171367] CR2: 0000000000000000 CR3: 0000000124c50000 CR4: 0000000000350ef0 > [ 197.171367] Call Trace: > [ 197.171367] > [ 197.171367] ? __stmmac_disable_all_queues+0xa8/0xe0 [stmmac] > [ 197.171367] stmmac_setup_tc_block_cb+0x70/0x110 [stmmac] > [ 197.171367] tc_setup_cb_destroy+0xb3/0x180 > [ 197.171367] fl_hw_destroy_filter+0x94/0xc0 [cls_flower] > [ 197.171367] __fl_delete+0x16a/0x180 [cls_flower] > [ 197.171367] fl_destroy+0xb9/0x140 [cls_flower] > [ 197.171367] tcf_proto_destroy+0x1d/0xa0 > [ 197.171367] tc_del_tfilter+0x3c9/0x7b0 > [ 197.171367] ? tc_dump_tfilter+0x310/0x310 > [ 197.171367] rtnetlink_rcv_msg+0x2bf/0x370 > [ 197.171367] ? preempt_count_add+0x68/0xa0 > [ 197.171367] ? _raw_spin_lock_irqsave+0x19/0x40 > [ 197.171367] ? _raw_spin_unlock_irqrestore+0x1f/0x31 > [ 197.171367] ? rtnl_calcit.isra.0+0x130/0x130 > [ 197.171367] netlink_rcv_skb+0x4e/0x100 > [ 197.171367] netlink_unicast+0x18e/0x230 > [ 197.171367] netlink_sendmsg+0x245/0x480 > [ 197.171367] sock_sendmsg+0x5b/0x60 > [ 197.171367] ____sys_sendmsg+0x20b/0x280 > [ 197.171367] ? copy_msghdr_from_user+0x5c/0x90 > [ 197.171367] ___sys_sendmsg+0x7c/0xc0 > [ 197.171367] ? folio_add_lru+0x52/0x80 > [ 197.171367] ? __sys_sendto+0xee/0x160 > [ 197.171367] __sys_sendmsg+0x59/0xa0 > [ 197.171367] do_syscall_64+0x40/0x90 > [ 197.171367] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 197.171367] RIP: 0033:0x7fa7b0d64397 > [ 197.171367] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 > [ 197.171367] RSP: 002b:00007ffdd88b58e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > [ 197.171367] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa7b0d64397 > [ 197.171367] RDX: 0000000000000000 RSI: 00007ffdd88b5960 RDI: 0000000000000003 > [ 197.171367] RBP: 0000000061b05c21 R08: 0000000000000001 R09: 0000564584e47890 > [ 197.171367] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 > [ 197.171367] R13: 00007ffdd88b9a80 R14: 00000000bfff0000 R15: 0000564584e3e420 > [ 197.171367] > [ 197.171367] Modules linked in: cls_flower sch_mqprio sch_ingress dwmac_intel(E) stmmac(E) pcs_xpcs phylink marvell marvell10g libphy 8021q bnep bluetooth ecryptfs nfsd sch_fq_codel uio uhid snd_soc_dmic snd_sof_pci_intel_tgl x86_pkg_temp_thermal snd_sof_intel_hda_common kvm_intel iTCO_wdt iTCO_vendor_support soundwire_intel mei_hdcp kvm soundwire_generic_allocation soundwire_cadence soundwire_bus irqbypass snd_sof_xtensa_dsp ax88179_178a snd_soc_acpi_intel_match intel_rapl_msr pcspkr usbnet snd_soc_acpi mii snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec i2c_i801 snd_hda_core intel_ish_ipc tpm_crb 8250_lpss intel_ishtp tpm_tis i915 mei_me i2c_smbus mei tpm_tis_core dw_dmac_core tpm spi_dw_pci parport_pc intel_pmc_core spi_dw thermal parport ttm fuse configfs snd_sof_pci snd_sof snd_soc_core snd_compress ac97_bus ledtrig_audio snd_pcm snd_timer snd soundcore [last unloaded: libphy] > [ 197.171367] CR2: 0000000000000000 > [ 197.171367] ---[ end trace 8b8d1c617c39093d ]--- > > This patch reimplements the tc flower rx frame steering for VLAN priority > by keeping a record of flow_cls_offload added. The implementation also > makes way to support EtherType based RX frame steering later. > > Fixes: 0e039f5cf86c ("net: stmmac: add RX frame steering based on VLAN priority in tc flower") > Tested-by: Kurt Kanzenbach > Signed-off-by: Ong Boon Leong You submitted this patch to net as well. I guess, it should be merged to net. After net is merged into net-next we can proceed with the EtherType steering? Thanks, Kurt