Commit 653cd28
net: sched: always disable bh when taking tcf_lock
Recently, ops->init() and ops->dump() of all actions were modified to
always obtain tcf_lock when accessing private action state. Actions that
don't depend on tcf_lock for synchronization with their data path use
non-bh locking API. However, tcf_lock is also used to protect rate
estimator stats in softirq context by timer callback.
Change ops->init() and ops->dump() of all actions to disable bh when using
tcf_lock to prevent deadlock reported by following lockdep warning:
[ 105.470398] ================================
[ 105.475014] WARNING: inconsistent lock state
[ 105.479628] 4.18.0-rc8+ torvalds#664 Not tainted
[ 105.483897] --------------------------------
[ 105.488511] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 105.494871] swapper/16/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 105.500449] 00000000f86c012e (&(&p->tcfa_lock)->rlock){+.?.}, at: est_fetch_counters+0x3c/0xa0
[ 105.509696] {SOFTIRQ-ON-W} state was registered at:
[ 105.514925] _raw_spin_lock+0x2c/0x40
[ 105.519022] tcf_bpf_init+0x579/0x820 [act_bpf]
[ 105.523990] tcf_action_init_1+0x4e4/0x660
[ 105.528518] tcf_action_init+0x1ce/0x2d0
[ 105.532880] tcf_exts_validate+0x1d8/0x200
[ 105.537416] fl_change+0x55a/0x268b [cls_flower]
[ 105.542469] tc_new_tfilter+0x748/0xa20
[ 105.546738] rtnetlink_rcv_msg+0x56a/0x6d0
[ 105.551268] netlink_rcv_skb+0x18d/0x200
[ 105.555628] netlink_unicast+0x2d0/0x370
[ 105.559990] netlink_sendmsg+0x3b9/0x6a0
[ 105.564349] sock_sendmsg+0x6b/0x80
[ 105.568271] ___sys_sendmsg+0x4a1/0x520
[ 105.572547] __sys_sendmsg+0xd7/0x150
[ 105.576655] do_syscall_64+0x72/0x2c0
[ 105.580757] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 105.586243] irq event stamp: 489296
[ 105.590084] hardirqs last enabled at (489296): [<ffffffffb507e639>] _raw_spin_unlock_irq+0x29/0x40
[ 105.599765] hardirqs last disabled at (489295): [<ffffffffb507e745>] _raw_spin_lock_irq+0x15/0x50
[ 105.609277] softirqs last enabled at (489292): [<ffffffffb413a6a3>] irq_enter+0x83/0xa0
[ 105.618001] softirqs last disabled at (489293): [<ffffffffb413a800>] irq_exit+0x140/0x190
[ 105.626813]
other info that might help us debug this:
[ 105.633976] Possible unsafe locking scenario:
[ 105.640526] CPU0
[ 105.643325] ----
[ 105.646125] lock(&(&p->tcfa_lock)->rlock);
[ 105.650747] <Interrupt>
[ 105.653717] lock(&(&p->tcfa_lock)->rlock);
[ 105.658514]
*** DEADLOCK ***
[ 105.665349] 1 lock held by swapper/16/0:
[ 105.669629] #0: 00000000a640ad99 ((&est->timer)){+.-.}, at: call_timer_fn+0x10b/0x550
[ 105.678200]
stack backtrace:
[ 105.683194] CPU: 16 PID: 0 Comm: swapper/16 Not tainted 4.18.0-rc8+ torvalds#664
[ 105.690249] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[ 105.698626] Call Trace:
[ 105.701421] <IRQ>
[ 105.703791] dump_stack+0x92/0xeb
[ 105.707461] print_usage_bug+0x336/0x34c
[ 105.711744] mark_lock+0x7c9/0x980
[ 105.715500] ? print_shortest_lock_dependencies+0x2e0/0x2e0
[ 105.721424] ? check_usage_forwards+0x230/0x230
[ 105.726315] __lock_acquire+0x923/0x26f0
[ 105.730597] ? debug_show_all_locks+0x240/0x240
[ 105.735478] ? mark_lock+0x493/0x980
[ 105.739412] ? check_chain_key+0x140/0x1f0
[ 105.743861] ? __lock_acquire+0x836/0x26f0
[ 105.748323] ? lock_acquire+0x12e/0x290
[ 105.752516] lock_acquire+0x12e/0x290
[ 105.756539] ? est_fetch_counters+0x3c/0xa0
[ 105.761084] _raw_spin_lock+0x2c/0x40
[ 105.765099] ? est_fetch_counters+0x3c/0xa0
[ 105.769633] est_fetch_counters+0x3c/0xa0
[ 105.773995] est_timer+0x87/0x390
[ 105.777670] ? est_fetch_counters+0xa0/0xa0
[ 105.782210] ? lock_acquire+0x12e/0x290
[ 105.786410] call_timer_fn+0x161/0x550
[ 105.790512] ? est_fetch_counters+0xa0/0xa0
[ 105.795055] ? del_timer_sync+0xd0/0xd0
[ 105.799249] ? __lock_is_held+0x93/0x110
[ 105.803531] ? mark_held_locks+0x20/0xe0
[ 105.807813] ? _raw_spin_unlock_irq+0x29/0x40
[ 105.812525] ? est_fetch_counters+0xa0/0xa0
[ 105.817069] ? est_fetch_counters+0xa0/0xa0
[ 105.821610] run_timer_softirq+0x3c4/0x9f0
[ 105.826064] ? lock_acquire+0x12e/0x290
[ 105.830257] ? __bpf_trace_timer_class+0x10/0x10
[ 105.835237] ? __lock_is_held+0x25/0x110
[ 105.839517] __do_softirq+0x11d/0x7bf
[ 105.843542] irq_exit+0x140/0x190
[ 105.847208] smp_apic_timer_interrupt+0xac/0x3b0
[ 105.852182] apic_timer_interrupt+0xf/0x20
[ 105.856628] </IRQ>
[ 105.859081] RIP: 0010:cpuidle_enter_state+0xd8/0x4d0
[ 105.864395] Code: 46 ff 48 89 44 24 08 0f 1f 44 00 00 31 ff e8 cf ec 46 ff 80 7c 24 07 00 0f 85 1d 02 00 00 e8 9f 90 4b ff fb 66 0f 1f 44 00 00 <4c> 8b 6c 24 08 4d 29 fd 0f 80 36 03 00 00 4c 89 e8 48 ba cf f7 53
[ 105.884288] RSP: 0018:ffff8803ad94fd20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
[ 105.892494] RAX: 0000000000000000 RBX: ffffe8fb300829c0 RCX: ffffffffb41e19e1
[ 105.899988] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8803ad9358ac
[ 105.907503] RBP: ffffffffb6636300 R08: 0000000000000004 R09: 0000000000000000
[ 105.914997] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000004
[ 105.922487] R13: ffffffffb6636140 R14: ffffffffb66362d8 R15: 000000188d36091b
[ 105.929988] ? trace_hardirqs_on_caller+0x141/0x2d0
[ 105.935232] do_idle+0x28e/0x320
[ 105.938817] ? arch_cpu_idle_exit+0x40/0x40
[ 105.943361] ? mark_lock+0x8c1/0x980
[ 105.947295] ? _raw_spin_unlock_irqrestore+0x32/0x60
[ 105.952619] cpu_startup_entry+0xc2/0xd0
[ 105.956900] ? cpu_in_idle+0x20/0x20
[ 105.960830] ? _raw_spin_unlock_irqrestore+0x32/0x60
[ 105.966146] ? trace_hardirqs_on_caller+0x141/0x2d0
[ 105.971391] start_secondary+0x2b5/0x360
[ 105.975669] ? set_cpu_sibling_map+0x1330/0x1330
[ 105.980654] secondary_startup_64+0xa5/0xb0
Taking tcf_lock in sample action with bh disabled causes lockdep to issue a
warning regarding possible irq lock inversion dependency between tcf_lock,
and psample_groups_lock that is taken when holding tcf_lock in sample init:
[ 162.108959] Possible interrupt unsafe locking scenario:
[ 162.116386] CPU0 CPU1
[ 162.121277] ---- ----
[ 162.126162] lock(psample_groups_lock);
[ 162.130447] local_irq_disable();
[ 162.136772] lock(&(&p->tcfa_lock)->rlock);
[ 162.143957] lock(psample_groups_lock);
[ 162.150813] <Interrupt>
[ 162.153808] lock(&(&p->tcfa_lock)->rlock);
[ 162.158608]
*** DEADLOCK ***
In order to prevent potential lock inversion dependency between tcf_lock
and psample_groups_lock, extract call to psample_group_get() from tcf_lock
protected section in sample action init function.
Fixes: 4e23281 ("net: sched: act_mirred: remove dependency on rtnl lock")
Fixes: 764e9a2 ("net: sched: act_vlan: remove dependency on rtnl lock")
Fixes: 729e012 ("net: sched: act_tunnel_key: remove dependency on rtnl lock")
Fixes: d772849 ("net: sched: act_sample: remove dependency on rtnl lock")
Fixes: e8917f4 ("net: sched: act_gact: remove dependency on rtnl lock")
Fixes: b6a2b97 ("net: sched: act_csum: remove dependency on rtnl lock")
Fixes: 2142236 ("net: sched: act_bpf: remove dependency on rtnl lock")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>1 parent bb10745 commit 653cd28
File tree
7 files changed
+47
-44
lines changed- net/sched
7 files changed
+47
-44
lines changed| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
147 | 147 | | |
148 | 148 | | |
149 | 149 | | |
150 | | - | |
| 150 | + | |
151 | 151 | | |
152 | 152 | | |
153 | 153 | | |
| |||
164 | 164 | | |
165 | 165 | | |
166 | 166 | | |
167 | | - | |
| 167 | + | |
168 | 168 | | |
169 | 169 | | |
170 | 170 | | |
171 | | - | |
| 171 | + | |
172 | 172 | | |
173 | 173 | | |
174 | 174 | | |
| |||
340 | 340 | | |
341 | 341 | | |
342 | 342 | | |
343 | | - | |
| 343 | + | |
344 | 344 | | |
345 | 345 | | |
346 | 346 | | |
| |||
352 | 352 | | |
353 | 353 | | |
354 | 354 | | |
355 | | - | |
| 355 | + | |
356 | 356 | | |
357 | 357 | | |
358 | 358 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
96 | 96 | | |
97 | 97 | | |
98 | 98 | | |
99 | | - | |
| 99 | + | |
100 | 100 | | |
101 | 101 | | |
102 | 102 | | |
103 | | - | |
| 103 | + | |
104 | 104 | | |
105 | 105 | | |
106 | 106 | | |
| |||
604 | 604 | | |
605 | 605 | | |
606 | 606 | | |
607 | | - | |
| 607 | + | |
608 | 608 | | |
609 | 609 | | |
610 | 610 | | |
| |||
616 | 616 | | |
617 | 617 | | |
618 | 618 | | |
619 | | - | |
| 619 | + | |
620 | 620 | | |
621 | 621 | | |
622 | 622 | | |
623 | 623 | | |
624 | | - | |
| 624 | + | |
625 | 625 | | |
626 | 626 | | |
627 | 627 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
113 | 113 | | |
114 | 114 | | |
115 | 115 | | |
116 | | - | |
| 116 | + | |
117 | 117 | | |
118 | 118 | | |
119 | 119 | | |
| |||
126 | 126 | | |
127 | 127 | | |
128 | 128 | | |
129 | | - | |
| 129 | + | |
130 | 130 | | |
131 | 131 | | |
132 | 132 | | |
| |||
183 | 183 | | |
184 | 184 | | |
185 | 185 | | |
186 | | - | |
| 186 | + | |
187 | 187 | | |
188 | 188 | | |
189 | 189 | | |
| |||
202 | 202 | | |
203 | 203 | | |
204 | 204 | | |
205 | | - | |
| 205 | + | |
206 | 206 | | |
207 | 207 | | |
208 | 208 | | |
209 | 209 | | |
210 | | - | |
| 210 | + | |
211 | 211 | | |
212 | 212 | | |
213 | 213 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
159 | 159 | | |
160 | 160 | | |
161 | 161 | | |
162 | | - | |
| 162 | + | |
163 | 163 | | |
164 | 164 | | |
165 | 165 | | |
166 | 166 | | |
167 | 167 | | |
168 | 168 | | |
169 | | - | |
| 169 | + | |
170 | 170 | | |
171 | 171 | | |
172 | 172 | | |
| |||
177 | 177 | | |
178 | 178 | | |
179 | 179 | | |
180 | | - | |
| 180 | + | |
181 | 181 | | |
182 | 182 | | |
183 | 183 | | |
| |||
305 | 305 | | |
306 | 306 | | |
307 | 307 | | |
308 | | - | |
| 308 | + | |
309 | 309 | | |
310 | 310 | | |
311 | 311 | | |
| |||
318 | 318 | | |
319 | 319 | | |
320 | 320 | | |
321 | | - | |
| 321 | + | |
322 | 322 | | |
323 | 323 | | |
324 | 324 | | |
325 | 325 | | |
326 | | - | |
| 326 | + | |
327 | 327 | | |
328 | 328 | | |
329 | 329 | | |
| |||
356 | 356 | | |
357 | 357 | | |
358 | 358 | | |
359 | | - | |
| 359 | + | |
360 | 360 | | |
361 | 361 | | |
362 | 362 | | |
363 | 363 | | |
364 | 364 | | |
365 | 365 | | |
366 | 366 | | |
367 | | - | |
| 367 | + | |
368 | 368 | | |
369 | 369 | | |
370 | 370 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
44 | 44 | | |
45 | 45 | | |
46 | 46 | | |
| 47 | + | |
47 | 48 | | |
48 | 49 | | |
49 | 50 | | |
| |||
78 | 79 | | |
79 | 80 | | |
80 | 81 | | |
81 | | - | |
82 | 82 | | |
83 | | - | |
84 | | - | |
85 | | - | |
86 | | - | |
87 | | - | |
| 83 | + | |
| 84 | + | |
88 | 85 | | |
89 | | - | |
90 | 86 | | |
91 | 87 | | |
92 | 88 | | |
| 89 | + | |
| 90 | + | |
| 91 | + | |
| 92 | + | |
| 93 | + | |
| 94 | + | |
| 95 | + | |
93 | 96 | | |
94 | 97 | | |
95 | 98 | | |
96 | 99 | | |
97 | 100 | | |
98 | 101 | | |
99 | | - | |
| 102 | + | |
100 | 103 | | |
101 | 104 | | |
102 | 105 | | |
| |||
183 | 186 | | |
184 | 187 | | |
185 | 188 | | |
186 | | - | |
| 189 | + | |
187 | 190 | | |
188 | 191 | | |
189 | 192 | | |
| |||
201 | 204 | | |
202 | 205 | | |
203 | 206 | | |
204 | | - | |
| 207 | + | |
205 | 208 | | |
206 | 209 | | |
207 | 210 | | |
208 | 211 | | |
209 | | - | |
| 212 | + | |
210 | 213 | | |
211 | 214 | | |
212 | 215 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
354 | 354 | | |
355 | 355 | | |
356 | 356 | | |
357 | | - | |
| 357 | + | |
358 | 358 | | |
359 | 359 | | |
360 | 360 | | |
361 | | - | |
| 361 | + | |
362 | 362 | | |
363 | 363 | | |
364 | 364 | | |
| |||
485 | 485 | | |
486 | 486 | | |
487 | 487 | | |
488 | | - | |
| 488 | + | |
489 | 489 | | |
490 | 490 | | |
491 | 491 | | |
| |||
520 | 520 | | |
521 | 521 | | |
522 | 522 | | |
523 | | - | |
| 523 | + | |
524 | 524 | | |
525 | 525 | | |
526 | 526 | | |
527 | 527 | | |
528 | | - | |
| 528 | + | |
529 | 529 | | |
530 | 530 | | |
531 | 531 | | |
| |||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
| |||
213 | 213 | | |
214 | 214 | | |
215 | 215 | | |
216 | | - | |
| 216 | + | |
217 | 217 | | |
218 | 218 | | |
219 | | - | |
| 219 | + | |
220 | 220 | | |
221 | 221 | | |
222 | 222 | | |
| |||
249 | 249 | | |
250 | 250 | | |
251 | 251 | | |
252 | | - | |
| 252 | + | |
253 | 253 | | |
254 | 254 | | |
255 | 255 | | |
| |||
268 | 268 | | |
269 | 269 | | |
270 | 270 | | |
271 | | - | |
| 271 | + | |
272 | 272 | | |
273 | 273 | | |
274 | 274 | | |
275 | 275 | | |
276 | | - | |
| 276 | + | |
277 | 277 | | |
278 | 278 | | |
279 | 279 | | |
| |||
0 commit comments