linux/include/net/tc_act
Vlad Buslov 67cbf7dedd net: sched: sample: allow accessing psample_group with rtnl
Recently implemented support for sample action in flow_offload infra leads
to following rcu usage warning:

[ 1938.234856] =============================
[ 1938.234858] WARNING: suspicious RCU usage
[ 1938.234863] 5.3.0-rc1+ #574 Not tainted
[ 1938.234866] -----------------------------
[ 1938.234869] include/net/tc_act/tc_sample.h:47 suspicious rcu_dereference_check() usage!
[ 1938.234872]
               other info that might help us debug this:

[ 1938.234875]
               rcu_scheduler_active = 2, debug_locks = 1
[ 1938.234879] 1 lock held by tc/19540:
[ 1938.234881]  #0: 00000000b03cb918 (rtnl_mutex){+.+.}, at: tc_new_tfilter+0x47c/0x970
[ 1938.234900]
               stack backtrace:
[ 1938.234905] CPU: 2 PID: 19540 Comm: tc Not tainted 5.3.0-rc1+ #574
[ 1938.234908] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[ 1938.234911] Call Trace:
[ 1938.234922]  dump_stack+0x85/0xc0
[ 1938.234930]  tc_setup_flow_action+0xed5/0x2040
[ 1938.234944]  fl_hw_replace_filter+0x11f/0x2e0 [cls_flower]
[ 1938.234965]  fl_change+0xd24/0x1b30 [cls_flower]
[ 1938.234990]  tc_new_tfilter+0x3e0/0x970
[ 1938.235021]  ? tc_del_tfilter+0x720/0x720
[ 1938.235028]  rtnetlink_rcv_msg+0x389/0x4b0
[ 1938.235038]  ? netlink_deliver_tap+0x95/0x400
[ 1938.235044]  ? rtnl_dellink+0x2d0/0x2d0
[ 1938.235053]  netlink_rcv_skb+0x49/0x110
[ 1938.235063]  netlink_unicast+0x171/0x200
[ 1938.235073]  netlink_sendmsg+0x224/0x3f0
[ 1938.235091]  sock_sendmsg+0x5e/0x60
[ 1938.235097]  ___sys_sendmsg+0x2ae/0x330
[ 1938.235111]  ? __handle_mm_fault+0x12cd/0x19e0
[ 1938.235125]  ? __handle_mm_fault+0x12cd/0x19e0
[ 1938.235138]  ? find_held_lock+0x2b/0x80
[ 1938.235147]  ? do_user_addr_fault+0x22d/0x490
[ 1938.235160]  __sys_sendmsg+0x59/0xa0
[ 1938.235178]  do_syscall_64+0x5c/0xb0
[ 1938.235187]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1938.235192] RIP: 0033:0x7ff9a4d597b8
[ 1938.235197] Code: 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 8f 0c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83
 ec 28 89 54
[ 1938.235200] RSP: 002b:00007ffcfe381c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1938.235205] RAX: ffffffffffffffda RBX: 000000005d4497f9 RCX: 00007ff9a4d597b8
[ 1938.235208] RDX: 0000000000000000 RSI: 00007ffcfe381cb0 RDI: 0000000000000003
[ 1938.235211] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000006
[ 1938.235214] R10: 0000000000404ec2 R11: 0000000000000246 R12: 0000000000000001
[ 1938.235217] R13: 0000000000480640 R14: 0000000000000012 R15: 0000000000000001

Change tcf_sample_psample_group() helper to allow using it from both rtnl
and rcu protected contexts.

Fixes: a7a7be6087 ("net/sched: add sample action to the hardware intermediate representation")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-06 14:15:39 -07:00
..
tc_bpf.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tc_connmark.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tc_csum.h net: Change TCA_ACT_* to TCA_ID_* to match that of TCA_ID_POLICE 2019-02-10 09:28:43 -08:00
tc_ct.h net/sched: Introduce action ct 2019-07-09 12:11:59 -07:00
tc_ctinfo.h net: sched: act_ctinfo: tidy UAPI definition 2019-06-19 17:11:01 -04:00
tc_defact.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tc_gact.h net/sched: don't dereference a->goto_chain to read the chain index 2019-03-21 13:26:42 -07:00
tc_ife.h net: tc_act: drop include of module.h from tc_ife.h 2019-04-22 21:50:53 -07:00
tc_ipt.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tc_mirred.h net: Change TCA_ACT_* to TCA_ID_* to match that of TCA_ID_POLICE 2019-02-10 09:28:43 -08:00
tc_mpls.h net: sched: add mpls manipulation actions to TC 2019-07-08 19:50:13 -07:00
tc_nat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tc_pedit.h net: Change TCA_ACT_* to TCA_ID_* to match that of TCA_ID_POLICE 2019-02-10 09:28:43 -08:00
tc_police.h net: sched: police: allow accessing police->params with rtnl 2019-08-06 14:15:39 -07:00
tc_sample.h net: sched: sample: allow accessing psample_group with rtnl 2019-08-06 14:15:39 -07:00
tc_skbedit.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
tc_skbmod.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tc_tunnel_key.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tc_vlan.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00