rbtree.rs - add support for searching neighbors #2
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Introduce various methods to search for neighboring nodes by key: - predecessor/successor - prev/next node, in sort order, of an extant node - lower_bound/upper_bound - next largest/smallest node given a bound - get_or_lower_bound/get_or_upper_bound - get the given key, else the lower/upper bound of that key
| } | ||
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| #[derive(PartialEq)] | ||
| enum NeighborSearchType { |
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Naming things is hard...
| @@ -301,6 +313,427 @@ impl<K, V> RBTree<K, V> { | |||
| None | |||
| } | |||
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| fn neighborhood_search_raw( | |||
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I realize this helper might appear overcomplicated...as I've gone beyond implementing the minimal things we need for binder...but couldn't resist it for completeness. With 2 directions and 3 "flavors" of methods as called out in the description, there was a lot of duplication happening without such a helper.
matthewtgilbride
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Patch series "mm/hugetlb: uffd-wp fixes for hugetlb_change_protection()". Playing with virtio-mem and background snapshots (using uffd-wp) on hugetlb in QEMU, I managed to trigger a VM_BUG_ON(). Looking into the details, hugetlb_change_protection() seems to not handle uffd-wp correctly in all cases. Patch #1 fixes my test case. I don't have reproducers for patch #2, as it requires running into migration entries. I did not yet check in detail yet if !hugetlb code requires similar care. This patch (of 2): There are two problematic cases when stumbling over a PTE marker in hugetlb_change_protection(): (1) We protect an uffd-wp PTE marker a second time using uffd-wp: we will end up in the "!huge_pte_none(pte)" case and mess up the PTE marker. (2) We unprotect a uffd-wp PTE marker: we will similarly end up in the "!huge_pte_none(pte)" case even though we cleared the PTE, because the "pte" variable is stale. We'll mess up the PTE marker. For example, if we later stumble over such a "wrongly modified" PTE marker, we'll treat it like a present PTE that maps some garbage page. This can, for example, be triggered by mapping a memfd backed by huge pages, registering uffd-wp, uffd-wp'ing an unmapped page and (a) uffd-wp'ing it a second time; or (b) uffd-unprotecting it; or (c) unregistering uffd-wp. Then, ff we trigger fallocate(FALLOC_FL_PUNCH_HOLE) on that file range, we will run into a VM_BUG_ON: [ 195.039560] page:00000000ba1f2987 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0 [ 195.039565] flags: 0x7ffffc0001000(reserved|node=0|zone=0|lastcpupid=0x1fffff) [ 195.039568] raw: 0007ffffc0001000 ffffe742c0000008 ffffe742c0000008 0000000000000000 [ 195.039569] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 195.039569] page dumped because: VM_BUG_ON_PAGE(compound && !PageHead(page)) [ 195.039573] ------------[ cut here ]------------ [ 195.039574] kernel BUG at mm/rmap.c:1346! [ 195.039579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 195.039581] CPU: 7 PID: 4777 Comm: qemu-system-x86 Not tainted 6.0.12-200.fc36.x86_64 #1 [ 195.039583] Hardware name: LENOVO 20WNS1F81N/20WNS1F81N, BIOS N35ET50W (1.50 ) 09/15/2022 [ 195.039584] RIP: 0010:page_remove_rmap+0x45b/0x550 [ 195.039588] Code: [...] [ 195.039589] RSP: 0018:ffffbc03c3633ba8 EFLAGS: 00010292 [ 195.039591] RAX: 0000000000000040 RBX: ffffe742c0000000 RCX: 0000000000000000 [ 195.039592] RDX: 0000000000000002 RSI: ffffffff8e7aac1a RDI: 00000000ffffffff [ 195.039592] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffbc03c3633a08 [ 195.039593] R10: 0000000000000003 R11: ffffffff8f146328 R12: ffff9b04c42754b0 [ 195.039594] R13: ffffffff8fcc6328 R14: ffffbc03c3633c80 R15: ffff9b0484ab9100 [ 195.039595] FS: 00007fc7aaf68640(0000) GS:ffff9b0bbf7c0000(0000) knlGS:0000000000000000 [ 195.039596] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 195.039597] CR2: 000055d402c49110 CR3: 0000000159392003 CR4: 0000000000772ee0 [ 195.039598] PKRU: 55555554 [ 195.039599] Call Trace: [ 195.039600] <TASK> [ 195.039602] __unmap_hugepage_range+0x33b/0x7d0 [ 195.039605] unmap_hugepage_range+0x55/0x70 [ 195.039608] hugetlb_vmdelete_list+0x77/0xa0 [ 195.039611] hugetlbfs_fallocate+0x410/0x550 [ 195.039612] ? _raw_spin_unlock_irqrestore+0x23/0x40 [ 195.039616] vfs_fallocate+0x12e/0x360 [ 195.039618] __x64_sys_fallocate+0x40/0x70 [ 195.039620] do_syscall_64+0x58/0x80 [ 195.039623] ? syscall_exit_to_user_mode+0x17/0x40 [ 195.039624] ? do_syscall_64+0x67/0x80 [ 195.039626] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 195.039628] RIP: 0033:0x7fc7b590651f [ 195.039653] Code: [...] [ 195.039654] RSP: 002b:00007fc7aaf66e70 EFLAGS: 00000293 ORIG_RAX: 000000000000011d [ 195.039655] RAX: ffffffffffffffda RBX: 0000558ef4b7f370 RCX: 00007fc7b590651f [ 195.039656] RDX: 0000000018000000 RSI: 0000000000000003 RDI: 000000000000000c [ 195.039657] RBP: 0000000008000000 R08: 0000000000000000 R09: 0000000000000073 [ 195.039658] R10: 0000000008000000 R11: 0000000000000293 R12: 0000000018000000 [ 195.039658] R13: 00007fb8bbe00000 R14: 000000000000000c R15: 0000000000001000 [ 195.039661] </TASK> Fix it by not going into the "!huge_pte_none(pte)" case if we stumble over an exclusive marker. spin_unlock() + continue would get the job done. However, instead, make it clearer that there are no fall-through statements: we process each case (hwpoison, migration, marker, !none, none) and then unlock the page table to continue with the next PTE. Let's avoid "continue" statements and use a single spin_unlock() at the end. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: 60dfaad ("mm/hugetlb: allow uffd wr-protect none ptes") Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Peter Xu <[email protected]> Reviewed-by: Mike Kravetz <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Muchun Song <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
matthewtgilbride
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This lockdep splat says it better than I could: ================================ WARNING: inconsistent lock state 6.2.0-rc2-07010-ga9b9500ffaac-dirty Rust-for-Linux#967 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kworker/1:3/179 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff3ec4036ce098 (_xmit_ETHER#2){+.?.}-{3:3}, at: netif_freeze_queues+0x5c/0xc0 {IN-SOFTIRQ-W} state was registered at: _raw_spin_lock+0x5c/0xc0 sch_direct_xmit+0x148/0x37c __dev_queue_xmit+0x528/0x111c ip6_finish_output2+0x5ec/0xb7c ip6_finish_output+0x240/0x3f0 ip6_output+0x78/0x360 ndisc_send_skb+0x33c/0x85c ndisc_send_rs+0x54/0x12c addrconf_rs_timer+0x154/0x260 call_timer_fn+0xb8/0x3a0 __run_timers.part.0+0x214/0x26c run_timer_softirq+0x3c/0x74 __do_softirq+0x14c/0x5d8 ____do_softirq+0x10/0x20 call_on_irq_stack+0x2c/0x5c do_softirq_own_stack+0x1c/0x30 __irq_exit_rcu+0x168/0x1a0 irq_exit_rcu+0x10/0x40 el1_interrupt+0x38/0x64 irq event stamp: 7825 hardirqs last enabled at (7825): [<ffffdf1f7200cae4>] exit_to_kernel_mode+0x34/0x130 hardirqs last disabled at (7823): [<ffffdf1f708105f0>] __do_softirq+0x550/0x5d8 softirqs last enabled at (7824): [<ffffdf1f7081050c>] __do_softirq+0x46c/0x5d8 softirqs last disabled at (7811): [<ffffdf1f708166e0>] ____do_softirq+0x10/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); <Interrupt> lock(_xmit_ETHER#2); *** DEADLOCK *** 3 locks held by kworker/1:3/179: #0: ffff3ec400004748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0 #1: ffff80000a0bbdc8 ((work_completion)(&priv->tx_onestep_tstamp)){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0 #2: ffff3ec4036cd438 (&dev->tx_global_lock){+.+.}-{3:3}, at: netif_tx_lock+0x1c/0x34 Workqueue: events enetc_tx_onestep_tstamp Call trace: print_usage_bug.part.0+0x208/0x22c mark_lock+0x7f0/0x8b0 __lock_acquire+0x7c4/0x1ce0 lock_acquire.part.0+0xe0/0x220 lock_acquire+0x68/0x84 _raw_spin_lock+0x5c/0xc0 netif_freeze_queues+0x5c/0xc0 netif_tx_lock+0x24/0x34 enetc_tx_onestep_tstamp+0x20/0x100 process_one_work+0x28c/0x6c0 worker_thread+0x74/0x450 kthread+0x118/0x11c but I'll say it anyway: the enetc_tx_onestep_tstamp() work item runs in process context, therefore with softirqs enabled (i.o.w., it can be interrupted by a softirq). If we hold the netif_tx_lock() when there is an interrupt, and the NET_TX softirq then gets scheduled, this will take the netif_tx_lock() a second time and deadlock the kernel. To solve this, use netif_tx_lock_bh(), which blocks softirqs from running. Fixes: 7294380 ("enetc: support PTP Sync packet one-step timestamping") Signed-off-by: Vladimir Oltean <[email protected]> Reviewed-by: Alexander Duyck <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
matthewtgilbride
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This fixes the following trace caused by attempting to lock
cmd_sync_work_lock while holding the rcu_read_lock:
kworker/u3:2/212 is trying to lock:
ffff888002600910 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at:
hci_cmd_sync_queue+0xad/0x140
other info that might help us debug this:
context-{4:4}
4 locks held by kworker/u3:2/212:
#0: ffff8880028c6530 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
process_one_work+0x4dc/0x9a0
#1: ffff888001aafde0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0},
at: process_one_work+0x4dc/0x9a0
#2: ffff888002600070 (&hdev->lock){+.+.}-{3:3}, at:
hci_cc_le_set_cig_params+0x64/0x4f0
#3: ffffffffa5994b00 (rcu_read_lock){....}-{1:2}, at:
hci_cc_le_set_cig_params+0x2f9/0x4f0
Fixes: 26afbd8 ("Bluetooth: Add initial implementation of CIS connections")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
matthewtgilbride
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This attempts to fix the following trace:
iso-tester/52 is trying to acquire lock:
ffff8880024e0070 (&hdev->lock){+.+.}-{3:3}, at:
iso_sock_listen+0x29e/0x440
but task is already holding lock:
ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_sock_listen+0x8b/0x440
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
lock_acquire+0x176/0x3d0
lock_sock_nested+0x32/0x80
iso_connect_cfm+0x1a3/0x630
hci_cc_le_setup_iso_path+0x195/0x340
hci_cmd_complete_evt+0x1ae/0x500
hci_event_packet+0x38e/0x7c0
hci_rx_work+0x34c/0x980
process_one_work+0x5a5/0x9a0
worker_thread+0x89/0x6f0
kthread+0x14e/0x180
ret_from_fork+0x22/0x30
-> #1 (hci_cb_list_lock){+.+.}-{3:3}:
lock_acquire+0x176/0x3d0
__mutex_lock+0x13b/0xf50
hci_le_remote_feat_complete_evt+0x17e/0x320
hci_event_packet+0x38e/0x7c0
hci_rx_work+0x34c/0x980
process_one_work+0x5a5/0x9a0
worker_thread+0x89/0x6f0
kthread+0x14e/0x180
ret_from_fork+0x22/0x30
-> #0 (&hdev->lock){+.+.}-{3:3}:
check_prev_add+0xfc/0x1190
__lock_acquire+0x1e27/0x2750
lock_acquire+0x176/0x3d0
__mutex_lock+0x13b/0xf50
iso_sock_listen+0x29e/0x440
__sys_listen+0xe6/0x160
__x64_sys_listen+0x25/0x30
do_syscall_64+0x42/0x90
entry_SYSCALL_64_after_hwframe+0x62/0xcc
other info that might help us debug this:
Chain exists of:
&hdev->lock --> hci_cb_list_lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
lock(hci_cb_list_lock);
lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
lock(&hdev->lock);
*** DEADLOCK ***
1 lock held by iso-tester/52:
#0: ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_sock_listen+0x8b/0x440
Fixes: f764a6c ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
matthewtgilbride
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The cited commit changed class of tc_ht internal mutex in order to avoid false lock dependency with fs_core node and flow_table hash table structures. However, hash table implementation internally also includes a workqueue task with its own lockdep map which causes similar bogus lockdep splat[0]. Fix it by also adding dedicated class for hash table workqueue work structure of tc_ht. [0]: [ 1139.672465] ====================================================== [ 1139.673552] WARNING: possible circular locking dependency detected [ 1139.674635] 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 Not tainted [ 1139.675734] ------------------------------------------------------ [ 1139.676801] modprobe/5998 is trying to acquire lock: [ 1139.677726] ffff88811e7b93b8 (&node->lock){++++}-{3:3}, at: down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.679662] but task is already holding lock: [ 1139.680703] ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0 [ 1139.682223] which lock already depends on the new lock. [ 1139.683640] the existing dependency chain (in reverse order) is: [ 1139.684887] -> #2 (&tc_ht_lock_key){+.+.}-{3:3}: [ 1139.685975] __mutex_lock+0x12c/0x14b0 [ 1139.686659] rht_deferred_worker+0x35/0x1540 [ 1139.687405] process_one_work+0x7c2/0x1310 [ 1139.688134] worker_thread+0x59d/0xec0 [ 1139.688820] kthread+0x28f/0x330 [ 1139.689444] ret_from_fork+0x1f/0x30 [ 1139.690106] -> #1 ((work_completion)(&ht->run_work)){+.+.}-{0:0}: [ 1139.691250] __flush_work+0xe8/0x900 [ 1139.691915] __cancel_work_timer+0x2ca/0x3f0 [ 1139.692655] rhashtable_free_and_destroy+0x22/0x6f0 [ 1139.693472] del_sw_flow_table+0x22/0xb0 [mlx5_core] [ 1139.694592] tree_put_node+0x24c/0x450 [mlx5_core] [ 1139.695686] tree_remove_node+0x6e/0x100 [mlx5_core] [ 1139.696803] mlx5_destroy_flow_table+0x187/0x690 [mlx5_core] [ 1139.698017] mlx5e_tc_nic_cleanup+0x2f8/0x400 [mlx5_core] [ 1139.699217] mlx5e_cleanup_nic_rx+0x2b/0x210 [mlx5_core] [ 1139.700397] mlx5e_detach_netdev+0x19d/0x2b0 [mlx5_core] [ 1139.701571] mlx5e_suspend+0xdb/0x140 [mlx5_core] [ 1139.702665] mlx5e_remove+0x89/0x190 [mlx5_core] [ 1139.703756] auxiliary_bus_remove+0x52/0x70 [ 1139.704492] device_release_driver_internal+0x3c1/0x600 [ 1139.705360] bus_remove_device+0x2a5/0x560 [ 1139.706080] device_del+0x492/0xb80 [ 1139.706724] mlx5_rescan_drivers_locked+0x194/0x6a0 [mlx5_core] [ 1139.707961] mlx5_unregister_device+0x7a/0xa0 [mlx5_core] [ 1139.709138] mlx5_uninit_one+0x5f/0x160 [mlx5_core] [ 1139.710252] remove_one+0xd1/0x160 [mlx5_core] [ 1139.711297] pci_device_remove+0x96/0x1c0 [ 1139.722721] device_release_driver_internal+0x3c1/0x600 [ 1139.723590] unbind_store+0x1b1/0x200 [ 1139.724259] kernfs_fop_write_iter+0x348/0x520 [ 1139.725019] vfs_write+0x7b2/0xbf0 [ 1139.725658] ksys_write+0xf3/0x1d0 [ 1139.726292] do_syscall_64+0x3d/0x90 [ 1139.726942] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.727769] -> #0 (&node->lock){++++}-{3:3}: [ 1139.728698] __lock_acquire+0x2cf5/0x62f0 [ 1139.729415] lock_acquire+0x1c1/0x540 [ 1139.730076] down_write+0x8e/0x1f0 [ 1139.730709] down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.731841] mlx5_del_flow_rules+0x6f/0x610 [mlx5_core] [ 1139.732982] __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core] [ 1139.734207] mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core] [ 1139.735491] mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core] [ 1139.736716] mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core] [ 1139.738007] mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core] [ 1139.739213] mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core] [ 1139.740377] _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core] [ 1139.741534] rhashtable_free_and_destroy+0x3be/0x6f0 [ 1139.742351] mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core] [ 1139.743512] mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core] [ 1139.744683] mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core] [ 1139.745860] mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core] [ 1139.747098] mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core] [ 1139.748372] mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core] [ 1139.749590] __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core] [ 1139.750813] mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core] [ 1139.752147] mlx5e_rep_remove+0x62/0x80 [mlx5_core] [ 1139.753293] auxiliary_bus_remove+0x52/0x70 [ 1139.754028] device_release_driver_internal+0x3c1/0x600 [ 1139.754885] driver_detach+0xc1/0x180 [ 1139.755553] bus_remove_driver+0xef/0x2e0 [ 1139.756260] auxiliary_driver_unregister+0x16/0x50 [ 1139.757059] mlx5e_rep_cleanup+0x19/0x30 [mlx5_core] [ 1139.758207] mlx5e_cleanup+0x12/0x30 [mlx5_core] [ 1139.759295] mlx5_cleanup+0xc/0x49 [mlx5_core] [ 1139.760384] __x64_sys_delete_module+0x2b5/0x450 [ 1139.761166] do_syscall_64+0x3d/0x90 [ 1139.761827] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.762663] other info that might help us debug this: [ 1139.763925] Chain exists of: &node->lock --> (work_completion)(&ht->run_work) --> &tc_ht_lock_key [ 1139.765743] Possible unsafe locking scenario: [ 1139.766688] CPU0 CPU1 [ 1139.767399] ---- ---- [ 1139.768111] lock(&tc_ht_lock_key); [ 1139.768704] lock((work_completion)(&ht->run_work)); [ 1139.769869] lock(&tc_ht_lock_key); [ 1139.770770] lock(&node->lock); [ 1139.771326] *** DEADLOCK *** [ 1139.772345] 2 locks held by modprobe/5998: [ 1139.772994] #0: ffff88813c1ff0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600 [ 1139.774399] #1: ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0 [ 1139.775822] stack backtrace: [ 1139.776579] CPU: 3 PID: 5998 Comm: modprobe Not tainted 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 [ 1139.777935] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 1139.779529] Call Trace: [ 1139.779992] <TASK> [ 1139.780409] dump_stack_lvl+0x57/0x7d [ 1139.781015] check_noncircular+0x278/0x300 [ 1139.781687] ? print_circular_bug+0x460/0x460 [ 1139.782381] ? rcu_read_lock_sched_held+0x3f/0x70 [ 1139.783121] ? lock_release+0x487/0x7c0 [ 1139.783759] ? orc_find.part.0+0x1f1/0x330 [ 1139.784423] ? mark_lock.part.0+0xef/0x2fc0 [ 1139.785091] __lock_acquire+0x2cf5/0x62f0 [ 1139.785754] ? register_lock_class+0x18e0/0x18e0 [ 1139.786483] lock_acquire+0x1c1/0x540 [ 1139.787093] ? down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.788195] ? lockdep_hardirqs_on_prepare+0x3f0/0x3f0 [ 1139.788978] ? register_lock_class+0x18e0/0x18e0 [ 1139.789715] down_write+0x8e/0x1f0 [ 1139.790292] ? down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.791380] ? down_write_killable+0x220/0x220 [ 1139.792080] ? find_held_lock+0x2d/0x110 [ 1139.792713] down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.793795] mlx5_del_flow_rules+0x6f/0x610 [mlx5_core] [ 1139.794879] __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core] [ 1139.796032] ? __esw_offloads_unload_rep+0xd0/0xd0 [mlx5_core] [ 1139.797227] ? xa_load+0x11a/0x200 [ 1139.797800] ? __xa_clear_mark+0xf0/0xf0 [ 1139.798438] mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core] [ 1139.799660] mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core] [ 1139.800821] mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core] [ 1139.802049] ? mlx5_eswitch_get_uplink_priv+0x25/0x80 [mlx5_core] [ 1139.803260] mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core] [ 1139.804398] ? __cancel_work_timer+0x1c2/0x3f0 [ 1139.805099] ? mlx5e_tc_unoffload_from_slow_path+0x460/0x460 [mlx5_core] [ 1139.806387] mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core] [ 1139.807481] _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core] [ 1139.808564] rhashtable_free_and_destroy+0x3be/0x6f0 [ 1139.809336] ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core] [ 1139.809336] ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core] [ 1139.810455] mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core] [ 1139.811552] mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core] [ 1139.812655] mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core] [ 1139.813768] mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core] [ 1139.814952] mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core] [ 1139.816166] mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core] [ 1139.817336] __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core] [ 1139.818507] mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core] [ 1139.819788] ? mlx5_eswitch_uplink_get_proto_dev+0x30/0x30 [mlx5_core] [ 1139.821051] ? kernfs_find_ns+0x137/0x310 [ 1139.821705] mlx5e_rep_remove+0x62/0x80 [mlx5_core] [ 1139.822778] auxiliary_bus_remove+0x52/0x70 [ 1139.823449] device_release_driver_internal+0x3c1/0x600 [ 1139.824240] driver_detach+0xc1/0x180 [ 1139.824842] bus_remove_driver+0xef/0x2e0 [ 1139.825504] auxiliary_driver_unregister+0x16/0x50 [ 1139.826245] mlx5e_rep_cleanup+0x19/0x30 [mlx5_core] [ 1139.827322] mlx5e_cleanup+0x12/0x30 [mlx5_core] [ 1139.828345] mlx5_cleanup+0xc/0x49 [mlx5_core] [ 1139.829382] __x64_sys_delete_module+0x2b5/0x450 [ 1139.830119] ? module_flags+0x300/0x300 [ 1139.830750] ? task_work_func_match+0x50/0x50 [ 1139.831440] ? task_work_cancel+0x20/0x20 [ 1139.832088] ? lockdep_hardirqs_on_prepare+0x273/0x3f0 [ 1139.832873] ? syscall_enter_from_user_mode+0x1d/0x50 [ 1139.833661] ? trace_hardirqs_on+0x2d/0x100 [ 1139.834328] do_syscall_64+0x3d/0x90 [ 1139.834922] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.835700] RIP: 0033:0x7f153e71288b [ 1139.836302] Code: 73 01 c3 48 8b 0d 9d 75 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6d 75 0e 00 f7 d8 64 89 01 48 [ 1139.838866] RSP: 002b:00007ffe0a3ed938 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 1139.840020] RAX: ffffffffffffffda RBX: 0000564c2cbf8220 RCX: 00007f153e71288b [ 1139.841043] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000564c2cbf8288 [ 1139.842072] RBP: 0000564c2cbf8220 R08: 0000000000000000 R09: 0000000000000000 [ 1139.843094] R10: 00007f153e7a3ac0 R11: 0000000000000206 R12: 0000564c2cbf8288 [ 1139.844118] R13: 0000000000000000 R14: 0000564c2cbf7ae8 R15: 00007ffe0a3efcb8 Fixes: 9ba3333 ("net/mlx5e: Avoid false lock depenency warning on tc_ht") Signed-off-by: Vlad Buslov <[email protected]> Reviewed-by: Eli Cohen <[email protected]> Reviewed-by: Roi Dayan <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>
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Mar 7, 2023
The commit 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura free") uses the get/put_cpu() to protect the usage of percpu pointer in ->aura_freeptr() callback, but it also unnecessarily disable the preemption for the blockable memory allocation. The commit 87b93b6 ("octeontx2-pf: Avoid use of GFP_KERNEL in atomic context") tried to fix these sleep inside atomic warnings. But it only fix the one for the non-rt kernel. For the rt kernel, we still get the similar warnings like below. BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by swapper/0/1: #0: ffff800009fc5fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30 #1: ffff000100c276c0 (&mbox->lock){+.+.}-{3:3}, at: otx2_init_hw_resources+0x8c/0x3a4 #2: ffffffbfef6537e0 (&cpu_rcache->lock){+.+.}-{2:2}, at: alloc_iova_fast+0x1ac/0x2ac Preemption disabled at: [<ffff800008b1908c>] otx2_rq_aura_pool_init+0x14c/0x284 CPU: 20 PID: 1 Comm: swapper/0 Tainted: G W 6.2.0-rc3-rt1-yocto-preempt-rt #1 Hardware name: Marvell OcteonTX CN96XX board (DT) Call trace: dump_backtrace.part.0+0xe8/0xf4 show_stack+0x20/0x30 dump_stack_lvl+0x9c/0xd8 dump_stack+0x18/0x34 __might_resched+0x188/0x224 rt_spin_lock+0x64/0x110 alloc_iova_fast+0x1ac/0x2ac iommu_dma_alloc_iova+0xd4/0x110 __iommu_dma_map+0x80/0x144 iommu_dma_map_page+0xe8/0x260 dma_map_page_attrs+0xb4/0xc0 __otx2_alloc_rbuf+0x90/0x150 otx2_rq_aura_pool_init+0x1c8/0x284 otx2_init_hw_resources+0xe4/0x3a4 otx2_open+0xf0/0x610 __dev_open+0x104/0x224 __dev_change_flags+0x1e4/0x274 dev_change_flags+0x2c/0x7c ic_open_devs+0x124/0x2f8 ip_auto_config+0x180/0x42c do_one_initcall+0x90/0x4dc do_basic_setup+0x10c/0x14c kernel_init_freeable+0x10c/0x13c kernel_init+0x2c/0x140 ret_from_fork+0x10/0x20 Of course, we can shuffle the get/put_cpu() to only wrap the invocation of ->aura_freeptr() as what commit 87b93b6 does. But there are only two ->aura_freeptr() callbacks, otx2_aura_freeptr() and cn10k_aura_freeptr(). There is no usage of perpcu variable in the otx2_aura_freeptr() at all, so the get/put_cpu() seems redundant to it. We can move the get/put_cpu() into the corresponding callback which really has the percpu variable usage and avoid the sprinkling of get/put_cpu() in several places. Fixes: 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura free") Signed-off-by: Kevin Hao <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
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…kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.2, take #2 - Pass the correct address to mte_clear_page_tags() on initialising a tagged page - Plug a race against a GICv4.1 doorbell interrupt while saving the vgic-v3 pending state.
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Jakub Sitnicki says: ==================== This patch set addresses the syzbot report in [1]. Patch #1 has been suggested by Eric [2]. I extended it to cover the rest of sock_map proto callbacks. Otherwise we would still overflow the stack. Patch #2 contains the actual fix and bug analysis. Patches #3 & Rust-for-Linux#4 add coverage to selftests to trigger the bug. [1] https://lore.kernel.org/all/[email protected]/ [2] https://lore.kernel.org/all/CANn89iK2UN1FmdUcH12fv_xiZkv2G+Nskvmq7fG6aA_6VKRf6g@mail.gmail.com/ --- v1 -> v2: v1: https://lore.kernel.org/r/[email protected] [v1 didn't hit bpf@ ML by mistake] * pull in Eric's patch to protect against recursion loop bugs (Eric) * add a macro helper to check if pointer is inside a memory range (Eric) ==================== Signed-off-by: Alexei Starovoitov <[email protected]>
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…eues(). Christoph Paasch reported that commit b5fc292 ("inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().") started triggering WARN_ON_ONCE(sk->sk_forward_alloc) in sk_stream_kill_queues(). [0 - 2] Also, we can reproduce it by a program in [3]. In the commit, we delay freeing ipv6_pinfo.pktoptions from sk->destroy() to sk->sk_destruct(), so sk->sk_forward_alloc is no longer zero in inet_csk_destroy_sock(). The same check has been in inet_sock_destruct() from at least v2.6, we can just remove the WARN_ON_ONCE(). However, among the users of sk_stream_kill_queues(), only CAIF is not calling inet_sock_destruct(). Thus, we add the same WARN_ON_ONCE() to caif_sock_destructor(). [0]: https://lore.kernel.org/netdev/[email protected]/ [1]: multipath-tcp/mptcp_net-next#341 [2]: WARNING: CPU: 0 PID: 3232 at net/core/stream.c:212 sk_stream_kill_queues+0x2f9/0x3e0 Modules linked in: CPU: 0 PID: 3232 Comm: syz-executor.0 Not tainted 6.2.0-rc5ab24eb4698afbe147b424149c529e2a43ec24eb5 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:sk_stream_kill_queues+0x2f9/0x3e0 Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e ec 00 00 00 8b ab 08 01 00 00 e9 60 ff ff ff e8 d0 5f b6 fe 0f 0b eb 97 e8 c7 5f b6 fe <0f> 0b eb a0 e8 be 5f b6 fe 0f 0b e9 6a fe ff ff e8 02 07 e3 fe e9 RSP: 0018:ffff88810570fc68 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888101f38f40 RSI: ffffffff8285e529 RDI: 0000000000000005 RBP: 0000000000000ce0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000ce0 R11: 0000000000000001 R12: ffff8881009e9488 R13: ffffffff84af2cc0 R14: 0000000000000000 R15: ffff8881009e9458 FS: 00007f7fdfbd5800(0000) GS:ffff88811b600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32923000 CR3: 00000001062fc006 CR4: 0000000000170ef0 Call Trace: <TASK> inet_csk_destroy_sock+0x1a1/0x320 __tcp_close+0xab6/0xe90 tcp_close+0x30/0xc0 inet_release+0xe9/0x1f0 inet6_release+0x4c/0x70 __sock_release+0xd2/0x280 sock_close+0x15/0x20 __fput+0x252/0xa20 task_work_run+0x169/0x250 exit_to_user_mode_prepare+0x113/0x120 syscall_exit_to_user_mode+0x1d/0x40 do_syscall_64+0x48/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f7fdf7ae28d Code: c1 20 00 00 75 10 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 37 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00000000007dfbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f7fdf7ae28d RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000007f338e0f R09: 0000000000000e0f R10: 000000007f338e13 R11: 0000000000000293 R12: 00007f7fdefff000 R13: 00007f7fdefffcd8 R14: 00007f7fdefffce0 R15: 00007f7fdefffcd8 </TASK> [3]: https://lore.kernel.org/netdev/[email protected]/ Fixes: b5fc292 ("inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().") Reported-by: syzbot <[email protected]> Reported-by: Christoph Paasch <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
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Jun 21, 2023
xfs/170 on a filesystem with su=128k,sw=4 produces this splat: BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP CPU: 1 PID: 4022907 Comm: dd Tainted: G W 6.3.0-xfsx #2 6ebeeffbe9577d32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20171121_152543-x86-ol7-bu RIP: 0010:xfs_perag_rele+0x10/0x70 [xfs] RSP: 0018:ffffc90001e43858 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: ffffffffa054e717 RSI: 0000000000000005 RDI: 0000000000000000 RBP: ffff888194eea000 R08: 0000000000000000 R09: 0000000000000037 R10: ffff888100ac1cb0 R11: 0000000000000018 R12: 0000000000000000 R13: ffffc90001e43a38 R14: ffff888194eea000 R15: ffff888194eea000 FS: 00007f93d1a0e740(0000) GS:ffff88843fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000018a34f000 CR4: 00000000003506e0 Call Trace: <TASK> xfs_bmap_btalloc+0x1a7/0x5d0 [xfs f85291d6841cbb3dc740083f1f331c0327394518] xfs_bmapi_allocate+0xee/0x470 [xfs f85291d6841cbb3dc740083f1f331c0327394518] xfs_bmapi_write+0x539/0x9e0 [xfs f85291d6841cbb3dc740083f1f331c0327394518] xfs_iomap_write_direct+0x1bb/0x2b0 [xfs f85291d6841cbb3dc740083f1f331c0327394518] xfs_direct_write_iomap_begin+0x51c/0x710 [xfs f85291d6841cbb3dc740083f1f331c0327394518] iomap_iter+0x132/0x2f0 __iomap_dio_rw+0x2f8/0x840 iomap_dio_rw+0xe/0x30 xfs_file_dio_write_aligned+0xad/0x180 [xfs f85291d6841cbb3dc740083f1f331c0327394518] xfs_file_write_iter+0xfb/0x190 [xfs f85291d6841cbb3dc740083f1f331c0327394518] vfs_write+0x2eb/0x410 ksys_write+0x65/0xe0 do_syscall_64+0x2b/0x80 This crash occurs under the "out_low_space" label. We grabbed a perag reference, passed it via args->pag into xfs_bmap_btalloc_at_eof, and afterwards args->pag is NULL. Fix the second function not to clobber args->pag if the caller had passed one in. Fixes: 8584332 ("xfs: factor xfs_bmap_btalloc()") Signed-off-by: Darrick J. Wong <[email protected]> Reviewed-by: Dave Chinner <[email protected]> Signed-off-by: Dave Chinner <[email protected]>
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Jun 21, 2023
KCSAN found a data race in sock_recv_cmsgs() where the read access to sk->sk_stamp needs READ_ONCE(). BUG: KCSAN: data-race in packet_recvmsg / packet_recvmsg write (marked) to 0xffff88803c81f258 of 8 bytes by task 19171 on cpu 0: sock_write_timestamp include/net/sock.h:2670 [inline] sock_recv_cmsgs include/net/sock.h:2722 [inline] packet_recvmsg+0xb97/0xd00 net/packet/af_packet.c:3489 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg+0x11a/0x130 net/socket.c:1040 sock_read_iter+0x176/0x220 net/socket.c:1118 call_read_iter include/linux/fs.h:1845 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x5e0/0x630 fs/read_write.c:470 ksys_read+0x163/0x1a0 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x41/0x50 fs/read_write.c:621 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88803c81f258 of 8 bytes by task 19183 on cpu 1: sock_recv_cmsgs include/net/sock.h:2721 [inline] packet_recvmsg+0xb64/0xd00 net/packet/af_packet.c:3489 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg+0x11a/0x130 net/socket.c:1040 sock_read_iter+0x176/0x220 net/socket.c:1118 call_read_iter include/linux/fs.h:1845 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x5e0/0x630 fs/read_write.c:470 ksys_read+0x163/0x1a0 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x41/0x50 fs/read_write.c:621 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0xffffffffc4653600 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19183 Comm: syz-executor.5 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 6c7c98b ("sock: avoid dirtying sk_stamp, if possible") Reported-by: syzbot <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
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KCSAN found a data race of sk->sk_receive_queue->qlen where recvmsg() updates qlen under the queue lock and sendmsg() checks qlen under unix_state_sock(), not the queue lock, so the reader side needs READ_ONCE(). BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_wait_for_peer write (marked) to 0xffff888019fe7c68 of 4 bytes by task 49792 on cpu 0: __skb_unlink include/linux/skbuff.h:2347 [inline] __skb_try_recv_from_queue+0x3de/0x470 net/core/datagram.c:197 __skb_try_recv_datagram+0xf7/0x390 net/core/datagram.c:263 __unix_dgram_recvmsg+0x109/0x8a0 net/unix/af_unix.c:2452 unix_dgram_recvmsg+0x94/0xa0 net/unix/af_unix.c:2549 sock_recvmsg_nosec net/socket.c:1019 [inline] ____sys_recvmsg+0x3a3/0x3b0 net/socket.c:2720 ___sys_recvmsg+0xc8/0x150 net/socket.c:2764 do_recvmmsg+0x182/0x560 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x153/0x170 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff888019fe7c68 of 4 bytes by task 49793 on cpu 1: skb_queue_len include/linux/skbuff.h:2127 [inline] unix_recvq_full net/unix/af_unix.c:229 [inline] unix_wait_for_peer+0x154/0x1a0 net/unix/af_unix.c:1445 unix_dgram_sendmsg+0x13bc/0x14b0 net/unix/af_unix.c:2048 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x148/0x160 net/socket.c:747 ____sys_sendmsg+0x20e/0x620 net/socket.c:2503 ___sys_sendmsg+0xc6/0x140 net/socket.c:2557 __sys_sendmmsg+0x11d/0x370 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x58/0x70 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x0000000b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 49793 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Reviewed-by: Michal Kubiak <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
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KCSAN found a data race around sk->sk_shutdown where unix_release_sock() and unix_shutdown() update it under unix_state_lock(), OTOH unix_poll() and unix_dgram_poll() read it locklessly. We need to annotate the writes and reads with WRITE_ONCE() and READ_ONCE(). BUG: KCSAN: data-race in unix_poll / unix_release_sock write to 0xffff88800d0f8aec of 1 bytes by task 264 on cpu 0: unix_release_sock+0x75c/0x910 net/unix/af_unix.c:631 unix_release+0x59/0x80 net/unix/af_unix.c:1042 __sock_release+0x7d/0x170 net/socket.c:653 sock_close+0x19/0x30 net/socket.c:1397 __fput+0x179/0x5e0 fs/file_table.c:321 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x116/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88800d0f8aec of 1 bytes by task 222 on cpu 1: unix_poll+0xa3/0x2a0 net/unix/af_unix.c:3170 sock_poll+0xcf/0x2b0 net/socket.c:1385 vfs_poll include/linux/poll.h:88 [inline] ep_item_poll.isra.0+0x78/0xc0 fs/eventpoll.c:855 ep_send_events fs/eventpoll.c:1694 [inline] ep_poll fs/eventpoll.c:1823 [inline] do_epoll_wait+0x6c4/0xea0 fs/eventpoll.c:2258 __do_sys_epoll_wait fs/eventpoll.c:2270 [inline] __se_sys_epoll_wait fs/eventpoll.c:2265 [inline] __x64_sys_epoll_wait+0xcc/0x190 fs/eventpoll.c:2265 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x00 -> 0x03 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 222 Comm: dbus-broker Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 3c73419 ("af_unix: fix 'poll for write'/ connected DGRAM sockets") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Reviewed-by: Michal Kubiak <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
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In the function ieee80211_tx_dequeue() there is a particular locking sequence: begin: spin_lock(&local->queue_stop_reason_lock); q_stopped = local->queue_stop_reasons[q]; spin_unlock(&local->queue_stop_reason_lock); However small the chance (increased by ftracetest), an asynchronous interrupt can occur in between of spin_lock() and spin_unlock(), and the interrupt routine will attempt to lock the same &local->queue_stop_reason_lock again. This will cause a costly reset of the CPU and the wifi device or an altogether hang in the single CPU and single core scenario. The only remaining spin_lock(&local->queue_stop_reason_lock) that did not disable interrupts was patched, which should prevent any deadlocks on the same CPU/core and the same wifi device. This is the probable trace of the deadlock: kernel: ================================ kernel: WARNING: inconsistent lock state kernel: 6.3.0-rc6-mt-20230401-00001-gf86822a1170f Rust-for-Linux#4 Tainted: G W kernel: -------------------------------- kernel: inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kernel: kworker/5:0/25656 [HC0[0]:SC0[0]:HE1:SE1] takes: kernel: ffff9d6190779478 (&local->queue_stop_reason_lock){+.?.}-{2:2}, at: return_to_handler+0x0/0x40 kernel: {IN-SOFTIRQ-W} state was registered at: kernel: lock_acquire+0xc7/0x2d0 kernel: _raw_spin_lock+0x36/0x50 kernel: ieee80211_tx_dequeue+0xb4/0x1330 [mac80211] kernel: iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm] kernel: iwl_mvm_mac_wake_tx_queue+0x2d/0xd0 [iwlmvm] kernel: ieee80211_queue_skb+0x450/0x730 [mac80211] kernel: __ieee80211_xmit_fast.constprop.66+0x834/0xa50 [mac80211] kernel: __ieee80211_subif_start_xmit+0x217/0x530 [mac80211] kernel: ieee80211_subif_start_xmit+0x60/0x580 [mac80211] kernel: dev_hard_start_xmit+0xb5/0x260 kernel: __dev_queue_xmit+0xdbe/0x1200 kernel: neigh_resolve_output+0x166/0x260 kernel: ip_finish_output2+0x216/0xb80 kernel: __ip_finish_output+0x2a4/0x4d0 kernel: ip_finish_output+0x2d/0xd0 kernel: ip_output+0x82/0x2b0 kernel: ip_local_out+0xec/0x110 kernel: igmpv3_sendpack+0x5c/0x90 kernel: igmp_ifc_timer_expire+0x26e/0x4e0 kernel: call_timer_fn+0xa5/0x230 kernel: run_timer_softirq+0x27f/0x550 kernel: __do_softirq+0xb4/0x3a4 kernel: irq_exit_rcu+0x9b/0xc0 kernel: sysvec_apic_timer_interrupt+0x80/0xa0 kernel: asm_sysvec_apic_timer_interrupt+0x1f/0x30 kernel: _raw_spin_unlock_irqrestore+0x3f/0x70 kernel: free_to_partial_list+0x3d6/0x590 kernel: __slab_free+0x1b7/0x310 kernel: kmem_cache_free+0x52d/0x550 kernel: putname+0x5d/0x70 kernel: do_sys_openat2+0x1d7/0x310 kernel: do_sys_open+0x51/0x80 kernel: __x64_sys_openat+0x24/0x30 kernel: do_syscall_64+0x5c/0x90 kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc kernel: irq event stamp: 5120729 kernel: hardirqs last enabled at (5120729): [<ffffffff9d149936>] trace_graph_return+0xd6/0x120 kernel: hardirqs last disabled at (5120728): [<ffffffff9d149950>] trace_graph_return+0xf0/0x120 kernel: softirqs last enabled at (5069900): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40 kernel: softirqs last disabled at (5067555): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40 kernel: other info that might help us debug this: kernel: Possible unsafe locking scenario: kernel: CPU0 kernel: ---- kernel: lock(&local->queue_stop_reason_lock); kernel: <Interrupt> kernel: lock(&local->queue_stop_reason_lock); kernel: *** DEADLOCK *** kernel: 8 locks held by kworker/5:0/25656: kernel: #0: ffff9d618009d138 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1ca/0x530 kernel: #1: ffffb1ef4637fe68 ((work_completion)(&local->restart_work)){+.+.}-{0:0}, at: process_one_work+0x1ce/0x530 kernel: #2: ffffffff9f166548 (rtnl_mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: #3: ffff9d6190778728 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: Rust-for-Linux#4: ffff9d619077b480 (&mvm->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: Rust-for-Linux#5: ffff9d61907bacd8 (&trans_pcie->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: Rust-for-Linux#6: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_queue_state_change+0x59/0x3a0 [iwlmvm] kernel: Rust-for-Linux#7: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm] kernel: stack backtrace: kernel: CPU: 5 PID: 25656 Comm: kworker/5:0 Tainted: G W 6.3.0-rc6-mt-20230401-00001-gf86822a1170f Rust-for-Linux#4 kernel: Hardware name: LENOVO 82H8/LNVNB161216, BIOS GGCN51WW 11/16/2022 kernel: Workqueue: events_freezable ieee80211_restart_work [mac80211] kernel: Call Trace: kernel: <TASK> kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: dump_stack_lvl+0x5f/0xa0 kernel: dump_stack+0x14/0x20 kernel: print_usage_bug.part.46+0x208/0x2a0 kernel: mark_lock.part.47+0x605/0x630 kernel: ? sched_clock+0xd/0x20 kernel: ? trace_clock_local+0x14/0x30 kernel: ? __rb_reserve_next+0x5f/0x490 kernel: ? _raw_spin_lock+0x1b/0x50 kernel: __lock_acquire+0x464/0x1990 kernel: ? mark_held_locks+0x4e/0x80 kernel: lock_acquire+0xc7/0x2d0 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ? ftrace_return_to_handler+0x8b/0x100 kernel: ? preempt_count_add+0x4/0x70 kernel: _raw_spin_lock+0x36/0x50 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_tx_dequeue+0xb4/0x1330 [mac80211] kernel: ? prepare_ftrace_return+0xc5/0x190 kernel: ? ftrace_graph_func+0x16/0x20 kernel: ? 0xffffffffc02ab0b1 kernel: ? lock_acquire+0xc7/0x2d0 kernel: ? iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm] kernel: ? ieee80211_tx_dequeue+0x9/0x1330 [mac80211] kernel: ? __rcu_read_lock+0x4/0x40 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_queue_state_change+0x311/0x3a0 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_wake_sw_queue+0x17/0x20 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_unmap+0x1c9/0x1f0 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_free+0x55/0x130 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_tx_free+0x63/0x80 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: _iwl_trans_pcie_gen2_stop_device+0x3f3/0x5b0 [iwlwifi] kernel: ? _iwl_trans_pcie_gen2_stop_device+0x9/0x5b0 [iwlwifi] kernel: ? mutex_lock_nested+0x4/0x30 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_trans_pcie_gen2_stop_device+0x5f/0x90 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_stop_device+0x78/0xd0 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: __iwl_mvm_mac_start+0x114/0x210 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_mac_start+0x76/0x150 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: drv_start+0x79/0x180 [mac80211] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_reconfig+0x1523/0x1ce0 [mac80211] kernel: ? synchronize_net+0x4/0x50 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_restart_work+0x108/0x170 [mac80211] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: process_one_work+0x250/0x530 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: worker_thread+0x48/0x3a0 kernel: ? __pfx_worker_thread+0x10/0x10 kernel: kthread+0x10f/0x140 kernel: ? __pfx_kthread+0x10/0x10 kernel: ret_from_fork+0x29/0x50 kernel: </TASK> Fixes: 4444bc2 ("wifi: mac80211: Proper mark iTXQs for resumption") Link: https://lore.kernel.org/all/[email protected]/ Reported-by: Mirsad Goran Todorovac <[email protected]> Cc: Gregory Greenman <[email protected]> Cc: Johannes Berg <[email protected]> Link: https://lore.kernel.org/all/[email protected]/ Cc: David S. Miller <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Paolo Abeni <[email protected]> Cc: Leon Romanovsky <[email protected]> Cc: Alexander Wetzel <[email protected]> Signed-off-by: Mirsad Goran Todorovac <[email protected]> Reviewed-by: Leon Romanovsky <[email protected]> Reviewed-by: tag, or it goes automatically? Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Johannes Berg <[email protected]>
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Jun 21, 2023
Our CI system caught a lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc7+ Rust-for-Linux#1167 Not tainted ------------------------------------------------------ kswapd0/46 is trying to acquire lock: ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120 but task is already holding lock: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire+0xa5/0xe0 kmem_cache_alloc+0x31/0x2c0 alloc_extent_state+0x1d/0xd0 __clear_extent_bit+0x2e0/0x4f0 try_release_extent_mapping+0x216/0x280 btrfs_release_folio+0x2e/0x90 invalidate_inode_pages2_range+0x397/0x470 btrfs_cleanup_dirty_bgs+0x9e/0x210 btrfs_cleanup_one_transaction+0x22/0x760 btrfs_commit_transaction+0x3b7/0x13a0 create_subvol+0x59b/0x970 btrfs_mksubvol+0x435/0x4f0 __btrfs_ioctl_snap_create+0x11e/0x1b0 btrfs_ioctl_snap_create_v2+0xbf/0x140 btrfs_ioctl+0xa45/0x28f0 __x64_sys_ioctl+0x88/0xc0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #0 (sb_internal#2){++++}-{0:0}: __lock_acquire+0x1435/0x21a0 lock_acquire+0xc2/0x2b0 start_transaction+0x401/0x730 btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_evict_inode+0x292/0x3d0 evict+0xcc/0x1d0 inode_lru_isolate+0x14d/0x1e0 __list_lru_walk_one+0xbe/0x1c0 list_lru_walk_one+0x58/0x80 prune_icache_sb+0x39/0x60 super_cache_scan+0x161/0x1f0 do_shrink_slab+0x163/0x340 shrink_slab+0x1d3/0x290 shrink_node+0x300/0x720 balance_pgdat+0x35c/0x7a0 kswapd+0x205/0x410 kthread+0xf0/0x120 ret_from_fork+0x29/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(sb_internal#2); lock(fs_reclaim); lock(sb_internal#2); *** DEADLOCK *** 3 locks held by kswapd0/46: #0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0 #1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290 #2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0 stack backtrace: CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ Rust-for-Linux#1167 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x58/0x90 check_noncircular+0xd6/0x100 ? save_trace+0x3f/0x310 ? add_lock_to_list+0x97/0x120 __lock_acquire+0x1435/0x21a0 lock_acquire+0xc2/0x2b0 ? btrfs_commit_inode_delayed_inode+0x5f/0x120 start_transaction+0x401/0x730 ? btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_commit_inode_delayed_inode+0x5f/0x120 btrfs_evict_inode+0x292/0x3d0 ? lock_release+0x134/0x270 ? __pfx_wake_bit_function+0x10/0x10 evict+0xcc/0x1d0 inode_lru_isolate+0x14d/0x1e0 __list_lru_walk_one+0xbe/0x1c0 ? __pfx_inode_lru_isolate+0x10/0x10 ? __pfx_inode_lru_isolate+0x10/0x10 list_lru_walk_one+0x58/0x80 prune_icache_sb+0x39/0x60 super_cache_scan+0x161/0x1f0 do_shrink_slab+0x163/0x340 shrink_slab+0x1d3/0x290 shrink_node+0x300/0x720 balance_pgdat+0x35c/0x7a0 kswapd+0x205/0x410 ? __pfx_autoremove_wake_function+0x10/0x10 ? __pfx_kswapd+0x10/0x10 kthread+0xf0/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 </TASK> This happens because when we abort the transaction in the transaction commit path we call invalidate_inode_pages2_range on our block group cache inodes (if we have space cache v1) and any delalloc inodes we may have. The plain invalidate_inode_pages2_range() call passes through GFP_KERNEL, which makes sense in most cases, but not here. Wrap these two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to make sure we don't end up with the fs reclaim dependency under the transaction dependency. CC: [email protected] # 4.14+ Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
matthewtgilbride
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Jun 21, 2023
Cited commit causes ABBA deadlock[0] when peer flows are created while
holding the devcom rw semaphore. Due to peer flows offload implementation
the lock is taken much higher up the call chain and there is no obvious way
to easily fix the deadlock. Instead, since tc route query code needs the
peer eswitch structure only to perform a lookup in xarray and doesn't
perform any sleeping operations with it, refactor the code for lockless
execution in following ways:
- RCUify the devcom 'data' pointer. When resetting the pointer
synchronously wait for RCU grace period before returning. This is fine
since devcom is currently only used for synchronization of
pairing/unpairing of eswitches which is rare and already expensive as-is.
- Wrap all usages of 'paired' boolean in {READ|WRITE}_ONCE(). The flag has
already been used in some unlocked contexts without proper
annotations (e.g. users of mlx5_devcom_is_paired() function), but it wasn't
an issue since all relevant code paths checked it again after obtaining the
devcom semaphore. Now it is also used by mlx5_devcom_get_peer_data_rcu() as
"best effort" check to return NULL when devcom is being unpaired. Note that
while RCU read lock doesn't prevent the unpaired flag from being changed
concurrently it still guarantees that reader can continue to use 'data'.
- Refactor mlx5e_tc_query_route_vport() function to use new
mlx5_devcom_get_peer_data_rcu() API which fixes the deadlock.
[0]:
[ 164.599612] ======================================================
[ 164.600142] WARNING: possible circular locking dependency detected
[ 164.600667] 6.3.0-rc3+ #1 Not tainted
[ 164.601021] ------------------------------------------------------
[ 164.601557] handler1/3456 is trying to acquire lock:
[ 164.601998] ffff88811f1714b0 (&esw->offloads.encap_tbl_lock){+.+.}-{3:3}, at: mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.603078]
but task is already holding lock:
[ 164.603617] ffff88810137fc98 (&comp->sem){++++}-{3:3}, at: mlx5_devcom_get_peer_data+0x37/0x80 [mlx5_core]
[ 164.604459]
which lock already depends on the new lock.
[ 164.605190]
the existing dependency chain (in reverse order) is:
[ 164.605848]
-> #1 (&comp->sem){++++}-{3:3}:
[ 164.606380] down_read+0x39/0x50
[ 164.606772] mlx5_devcom_get_peer_data+0x37/0x80 [mlx5_core]
[ 164.607336] mlx5e_tc_query_route_vport+0x86/0xc0 [mlx5_core]
[ 164.607914] mlx5e_tc_tun_route_lookup+0x1a4/0x1d0 [mlx5_core]
[ 164.608495] mlx5e_attach_decap_route+0xc6/0x1e0 [mlx5_core]
[ 164.609063] mlx5e_tc_add_fdb_flow+0x1ea/0x360 [mlx5_core]
[ 164.609627] __mlx5e_add_fdb_flow+0x2d2/0x430 [mlx5_core]
[ 164.610175] mlx5e_configure_flower+0x952/0x1a20 [mlx5_core]
[ 164.610741] tc_setup_cb_add+0xd4/0x200
[ 164.611146] fl_hw_replace_filter+0x14c/0x1f0 [cls_flower]
[ 164.611661] fl_change+0xc95/0x18a0 [cls_flower]
[ 164.612116] tc_new_tfilter+0x3fc/0xd20
[ 164.612516] rtnetlink_rcv_msg+0x418/0x5b0
[ 164.612936] netlink_rcv_skb+0x54/0x100
[ 164.613339] netlink_unicast+0x190/0x250
[ 164.613746] netlink_sendmsg+0x245/0x4a0
[ 164.614150] sock_sendmsg+0x38/0x60
[ 164.614522] ____sys_sendmsg+0x1d0/0x1e0
[ 164.614934] ___sys_sendmsg+0x80/0xc0
[ 164.615320] __sys_sendmsg+0x51/0x90
[ 164.615701] do_syscall_64+0x3d/0x90
[ 164.616083] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 164.616568]
-> #0 (&esw->offloads.encap_tbl_lock){+.+.}-{3:3}:
[ 164.617210] __lock_acquire+0x159e/0x26e0
[ 164.617638] lock_acquire+0xc2/0x2a0
[ 164.618018] __mutex_lock+0x92/0xcd0
[ 164.618401] mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.618943] post_process_attr+0x153/0x2d0 [mlx5_core]
[ 164.619471] mlx5e_tc_add_fdb_flow+0x164/0x360 [mlx5_core]
[ 164.620021] __mlx5e_add_fdb_flow+0x2d2/0x430 [mlx5_core]
[ 164.620564] mlx5e_configure_flower+0xe33/0x1a20 [mlx5_core]
[ 164.621125] tc_setup_cb_add+0xd4/0x200
[ 164.621531] fl_hw_replace_filter+0x14c/0x1f0 [cls_flower]
[ 164.622047] fl_change+0xc95/0x18a0 [cls_flower]
[ 164.622500] tc_new_tfilter+0x3fc/0xd20
[ 164.622906] rtnetlink_rcv_msg+0x418/0x5b0
[ 164.623324] netlink_rcv_skb+0x54/0x100
[ 164.623727] netlink_unicast+0x190/0x250
[ 164.624138] netlink_sendmsg+0x245/0x4a0
[ 164.624544] sock_sendmsg+0x38/0x60
[ 164.624919] ____sys_sendmsg+0x1d0/0x1e0
[ 164.625340] ___sys_sendmsg+0x80/0xc0
[ 164.625731] __sys_sendmsg+0x51/0x90
[ 164.626117] do_syscall_64+0x3d/0x90
[ 164.626502] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 164.626995]
other info that might help us debug this:
[ 164.627725] Possible unsafe locking scenario:
[ 164.628268] CPU0 CPU1
[ 164.628683] ---- ----
[ 164.629098] lock(&comp->sem);
[ 164.629421] lock(&esw->offloads.encap_tbl_lock);
[ 164.630066] lock(&comp->sem);
[ 164.630555] lock(&esw->offloads.encap_tbl_lock);
[ 164.630993]
*** DEADLOCK ***
[ 164.631575] 3 locks held by handler1/3456:
[ 164.631962] #0: ffff888124b75130 (&block->cb_lock){++++}-{3:3}, at: tc_setup_cb_add+0x5b/0x200
[ 164.632703] #1: ffff888116e512b8 (&esw->mode_lock){++++}-{3:3}, at: mlx5_esw_hold+0x39/0x50 [mlx5_core]
[ 164.633552] #2: ffff88810137fc98 (&comp->sem){++++}-{3:3}, at: mlx5_devcom_get_peer_data+0x37/0x80 [mlx5_core]
[ 164.634435]
stack backtrace:
[ 164.634883] CPU: 17 PID: 3456 Comm: handler1 Not tainted 6.3.0-rc3+ #1
[ 164.635431] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 164.636340] Call Trace:
[ 164.636616] <TASK>
[ 164.636863] dump_stack_lvl+0x47/0x70
[ 164.637217] check_noncircular+0xfe/0x110
[ 164.637601] __lock_acquire+0x159e/0x26e0
[ 164.637977] ? mlx5_cmd_set_fte+0x5b0/0x830 [mlx5_core]
[ 164.638472] lock_acquire+0xc2/0x2a0
[ 164.638828] ? mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.639339] ? lock_is_held_type+0x98/0x110
[ 164.639728] __mutex_lock+0x92/0xcd0
[ 164.640074] ? mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.640576] ? __lock_acquire+0x382/0x26e0
[ 164.640958] ? mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.641468] ? mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.641965] mlx5e_attach_encap+0xd8/0x8b0 [mlx5_core]
[ 164.642454] ? lock_release+0xbf/0x240
[ 164.642819] post_process_attr+0x153/0x2d0 [mlx5_core]
[ 164.643318] mlx5e_tc_add_fdb_flow+0x164/0x360 [mlx5_core]
[ 164.643835] __mlx5e_add_fdb_flow+0x2d2/0x430 [mlx5_core]
[ 164.644340] mlx5e_configure_flower+0xe33/0x1a20 [mlx5_core]
[ 164.644862] ? lock_acquire+0xc2/0x2a0
[ 164.645219] tc_setup_cb_add+0xd4/0x200
[ 164.645588] fl_hw_replace_filter+0x14c/0x1f0 [cls_flower]
[ 164.646067] fl_change+0xc95/0x18a0 [cls_flower]
[ 164.646488] tc_new_tfilter+0x3fc/0xd20
[ 164.646861] ? tc_del_tfilter+0x810/0x810
[ 164.647236] rtnetlink_rcv_msg+0x418/0x5b0
[ 164.647621] ? rtnl_setlink+0x160/0x160
[ 164.647982] netlink_rcv_skb+0x54/0x100
[ 164.648348] netlink_unicast+0x190/0x250
[ 164.648722] netlink_sendmsg+0x245/0x4a0
[ 164.649090] sock_sendmsg+0x38/0x60
[ 164.649434] ____sys_sendmsg+0x1d0/0x1e0
[ 164.649804] ? copy_msghdr_from_user+0x6d/0xa0
[ 164.650213] ___sys_sendmsg+0x80/0xc0
[ 164.650563] ? lock_acquire+0xc2/0x2a0
[ 164.650926] ? lock_acquire+0xc2/0x2a0
[ 164.651286] ? __fget_files+0x5/0x190
[ 164.651644] ? find_held_lock+0x2b/0x80
[ 164.652006] ? __fget_files+0xb9/0x190
[ 164.652365] ? lock_release+0xbf/0x240
[ 164.652723] ? __fget_files+0xd3/0x190
[ 164.653079] __sys_sendmsg+0x51/0x90
[ 164.653435] do_syscall_64+0x3d/0x90
[ 164.653784] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 164.654229] RIP: 0033:0x7f378054f8bd
[ 164.654577] Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 6a c3 f4 ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 44 24 08 e8 be c3 f4 ff 48
[ 164.656041] RSP: 002b:00007f377fa114b0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
[ 164.656701] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f378054f8bd
[ 164.657297] RDX: 0000000000000000 RSI: 00007f377fa11540 RDI: 0000000000000014
[ 164.657885] RBP: 00007f377fa12278 R08: 0000000000000000 R09: 000000000000015c
[ 164.658472] R10: 00007f377fa123d0 R11: 0000000000000293 R12: 0000560962d99bd0
[ 164.665317] R13: 0000000000000000 R14: 0000560962d99bd0 R15: 00007f377fa11540
Fixes: f9d196b ("net/mlx5e: Use correct eswitch for stack devices with lag")
Signed-off-by: Vlad Buslov <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Reviewed-by: Shay Drory <[email protected]>
Reviewed-by: Tariq Toukan <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
matthewtgilbride
pushed a commit
that referenced
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Aug 18, 2024
Currently the dma debugging code can end up indirectly calling printk under the radix_lock. This happens when a radix tree node allocation fails. This is a problem because the printk code, when used together with netconsole, can end up inside the dma debugging code while trying to transmit a message over netcons. This creates the possibility of either a circular deadlock on the same CPU, with that CPU trying to grab the radix_lock twice, or an ABBA deadlock between different CPUs, where one CPU grabs the console lock first and then waits for the radix_lock, while the other CPU is holding the radix_lock and is waiting for the console lock. The trace captured by lockdep is of the ABBA variant. -> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x5a/0x90 debug_dma_map_page+0x79/0x180 dma_map_page_attrs+0x1d2/0x2f0 bnxt_start_xmit+0x8c6/0x1540 netpoll_start_xmit+0x13f/0x180 netpoll_send_skb+0x20d/0x320 netpoll_send_udp+0x453/0x4a0 write_ext_msg+0x1b9/0x460 console_flush_all+0x2ff/0x5a0 console_unlock+0x55/0x180 vprintk_emit+0x2e3/0x3c0 devkmsg_emit+0x5a/0x80 devkmsg_write+0xfd/0x180 do_iter_readv_writev+0x164/0x1b0 vfs_writev+0xf9/0x2b0 do_writev+0x6d/0x110 do_syscall_64+0x80/0x150 entry_SYSCALL_64_after_hwframe+0x4b/0x53 -> #0 (console_owner){-.-.}-{0:0}: __lock_acquire+0x15d1/0x31a0 lock_acquire+0xe8/0x290 console_flush_all+0x2ea/0x5a0 console_unlock+0x55/0x180 vprintk_emit+0x2e3/0x3c0 _printk+0x59/0x80 warn_alloc+0x122/0x1b0 __alloc_pages_slowpath+0x1101/0x1120 __alloc_pages+0x1eb/0x2c0 alloc_slab_page+0x5f/0x150 new_slab+0x2dc/0x4e0 ___slab_alloc+0xdcb/0x1390 kmem_cache_alloc+0x23d/0x360 radix_tree_node_alloc+0x3c/0xf0 radix_tree_insert+0xf5/0x230 add_dma_entry+0xe9/0x360 dma_map_page_attrs+0x1d2/0x2f0 __bnxt_alloc_rx_frag+0x147/0x180 bnxt_alloc_rx_data+0x79/0x160 bnxt_rx_skb+0x29/0xc0 bnxt_rx_pkt+0xe22/0x1570 __bnxt_poll_work+0x101/0x390 bnxt_poll+0x7e/0x320 __napi_poll+0x29/0x160 net_rx_action+0x1e0/0x3e0 handle_softirqs+0x190/0x510 run_ksoftirqd+0x4e/0x90 smpboot_thread_fn+0x1a8/0x270 kthread+0x102/0x120 ret_from_fork+0x2f/0x40 ret_from_fork_asm+0x11/0x20 This bug is more likely than it seems, because when one CPU has run out of memory, chances are the other has too. The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so not many users are likely to trigger it. Signed-off-by: Rik van Riel <[email protected]> Reported-by: Konstantin Ovsepian <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]>
matthewtgilbride
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Aug 18, 2024
linkwatch_event() grabs possibly very contended RTNL mutex.
system_wq is not suitable for such work.
Inspired by many noisy syzbot reports.
3 locks held by kworker/0:7/5266:
#0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
#0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
#1: ffffc90003f6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
#2: ffffffff8fa6f208 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
Reported-by: syzbot <[email protected]>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
matthewtgilbride
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Aug 18, 2024
When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/[email protected]/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ Rust-for-Linux#34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 Rust-for-Linux#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 Rust-for-Linux#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 Rust-for-Linux#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Rust-for-Linux#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Rust-for-Linux#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 Rust-for-Linux#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ Rust-for-Linux#34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <[email protected]> Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: [email protected] CC: [email protected] Signed-off-by: James Chapman <[email protected]> Signed-off-by: Tom Parkin <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
matthewtgilbride
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Aug 19, 2024
…on array The out-of-bounds access is reported by UBSAN: [ 0.000000] UBSAN: array-index-out-of-bounds in ../arch/riscv/kernel/vendor_extensions.c:41:66 [ 0.000000] index -1 is out of range for type 'riscv_isavendorinfo [32]' [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.11.0-rc2ubuntu-defconfig #2 [ 0.000000] Hardware name: riscv-virtio,qemu (DT) [ 0.000000] Call Trace: [ 0.000000] [<ffffffff94e078ba>] dump_backtrace+0x32/0x40 [ 0.000000] [<ffffffff95c83c1a>] show_stack+0x38/0x44 [ 0.000000] [<ffffffff95c94614>] dump_stack_lvl+0x70/0x9c [ 0.000000] [<ffffffff95c94658>] dump_stack+0x18/0x20 [ 0.000000] [<ffffffff95c8bbb2>] ubsan_epilogue+0x10/0x46 [ 0.000000] [<ffffffff95485a82>] __ubsan_handle_out_of_bounds+0x94/0x9c [ 0.000000] [<ffffffff94e09442>] __riscv_isa_vendor_extension_available+0x90/0x92 [ 0.000000] [<ffffffff94e043b6>] riscv_cpufeature_patch_func+0xc4/0x148 [ 0.000000] [<ffffffff94e035f8>] _apply_alternatives+0x42/0x50 [ 0.000000] [<ffffffff95e04196>] apply_boot_alternatives+0x3c/0x100 [ 0.000000] [<ffffffff95e05b52>] setup_arch+0x85a/0x8bc [ 0.000000] [<ffffffff95e00ca0>] start_kernel+0xa4/0xfb6 The dereferencing using cpu should actually not happen, so remove it. Fixes: 23c996f ("riscv: Extend cpufeature.c to detect vendor extensions") Signed-off-by: Alexandre Ghiti <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
matthewtgilbride
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Aug 19, 2024
Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda Rust-for-Linux#6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda Rust-for-Linux#6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] Rust-for-Linux#4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda Rust-for-Linux#6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Yu Kuai <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
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Introduce various methods to search for neighboring nodes by key: