reduce hooking in TCP code #2

pabeni · 2020-03-19T10:41:04Z

the mptcp_rcv_synsent() hook can be dropped moving the related code in subflow_finish_connect()

sel_lock cannot nest in the console lock. Thanks to syzkaller, the kernel states firmly: > WARNING: possible circular locking dependency detected > 5.6.0-rc3-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor.4/20336 is trying to acquire lock: > ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > > but task is already holding lock: > ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> multipath-tcp#2 (sel_lock){+.+.}: > mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 > set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217 > set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181 > tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_SETSEL). Locks held on the path: console_lock -> sel_lock > -> multipath-tcp#1 (console_lock){+.+.}: > console_lock+0x46/0x70 kernel/printk/printk.c:2289 > con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223 > n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350 > do_tty_write drivers/tty/tty_io.c:962 [inline] > tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046 This is write(). Locks held on the path: termios_rwsem -> console_lock > -> #0 (&tty->termios_rwsem){++++}: > down_write+0x57/0x140 kernel/locking/rwsem.c:1534 > tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902 > tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465 > paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389 > tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_PASTESEL). Locks held on the path: sel_lock -> termios_rwsem > other info that might help us debug this: > > Chain exists of: > &tty->termios_rwsem --> console_lock --> sel_lock Clearly. From the above, we have: console_lock -> sel_lock sel_lock -> termios_rwsem termios_rwsem -> console_lock Fix this by reversing the console_lock -> sel_lock dependency in ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock. Signed-off-by: Jiri Slaby <[email protected]> Reported-by: [email protected] Fixes: 07e6124 ("vt: selection, close sel_buffer race") Cc: stable <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

journal_head::b_transaction and journal_head::b_next_transaction could be accessed concurrently as noticed by KCSAN, LTP: starting fsync04 /dev/zero: Can't open blockdev EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null) ================================================================== BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2] write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70: __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2] __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569 jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2] (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034 kjournald2+0x13b/0x450 [jbd2] kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68: jbd2_write_access_granted+0x1b2/0x250 [jbd2] jbd2_write_access_granted at fs/jbd2/transaction.c:1155 jbd2_journal_get_write_access+0x2c/0x60 [jbd2] __ext4_journal_get_write_access+0x50/0x90 [ext4] ext4_mb_mark_diskspace_used+0x158/0x620 [ext4] ext4_mb_new_blocks+0x54f/0xca0 [ext4] ext4_ind_map_blocks+0xc79/0x1b40 [ext4] ext4_map_blocks+0x3b4/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block+0x3b/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe 5 locks held by fsync04/25724: #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260 multipath-tcp#1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4] multipath-tcp#2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] multipath-tcp#3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4] multipath-tcp#4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2] irq event stamp: 1407125 hardirqs last enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ multipath-tcp#7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 The plain reads are outside of jh->b_state_lock critical section which result in data races. Fix them by adding pairs of READ|WRITE_ONCE(). Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Qian Cai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>

Fix NULL pointer dereference in the error flow of ib_create_qp_user when accessing to uninitialized list pointers - rdma_mrs and sig_mrs. The following crash from syzkaller revealed it. kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [multipath-tcp#1] SMP KASAN PTI CPU: 1 PID: 23167 Comm: syz-executor.1 Not tainted 5.5.0-rc5 multipath-tcp#2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 RIP: 0010:ib_mr_pool_destroy+0x81/0x1f0 Code: 00 00 fc ff df 49 c1 ec 03 4d 01 fc e8 a8 ea 72 fe 41 80 3c 24 00 0f 85 62 01 00 00 48 8b 13 48 89 d6 4c 8d 6a c8 48 c1 ee 03 <42> 80 3c 3e 00 0f 85 34 01 00 00 48 8d 7a 08 4c 8b 02 48 89 fe 48 RSP: 0018:ffffc9000951f8b0 EFLAGS: 00010046 RAX: 0000000000040000 RBX: ffff88810f268038 RCX: ffffffff82c41628 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000951f850 RBP: ffff88810f268020 R08: 0000000000000004 R09: fffff520012a3f0a R10: 0000000000000001 R11: fffff520012a3f0a R12: ffffed1021e4d007 R13: ffffffffffffffc8 R14: 0000000000000246 R15: dffffc0000000000 FS: 00007f54bc788700(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000116920002 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rdma_rw_cleanup_mrs+0x15/0x30 ib_destroy_qp_user+0x674/0x7d0 ib_create_qp_user+0xb01/0x11c0 create_qp+0x1517/0x2130 ib_uverbs_create_qp+0x13e/0x190 ib_uverbs_write+0xaa5/0xdf0 __vfs_write+0x7c/0x100 vfs_write+0x168/0x4a0 ksys_write+0xc8/0x200 do_syscall_64+0x9c/0x390 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b49 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54bc787c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000465b49 RDX: 0000000000000040 RSI: 0000000020000540 RDI: 0000000000000003 RBP: 00007f54bc787c70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f54bc7886bc R13: 00000000004ca2ec R14: 000000000070ded0 R15: 0000000000000005 Fixes: a060b56 ("IB/core: generic RDMA READ/WRITE API") Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Maor Gottlieb <[email protected]> Signed-off-by: Leon Romanovsky <[email protected]> Reviewed-by: Jason Gunthorpe <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>

the following packetdrill script socket(..., SOCK_STREAM, IPPROTO_MPTCP) = 3 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) > S 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8,mpcapable v1 flags[flag_h] nokey> < S. 0:0(0) ack 1 win 65535 <mss 1460,sackOK,TS val 700 ecr 100,nop,wscale 8,mpcapable v1 flags[flag_h] key[skey=2]> > . 1:1(0) ack 1 win 256 <nop, nop, TS val 100 ecr 700,mpcapable v1 flags[flag_h] key[ckey,skey]> getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0 fcntl(3, F_SETFL, O_RDWR) = 0 write(3, ..., 1000) = 1000 doesn't transmit 1KB data packet after a successful three-way-handshake, using mp_capable with data as required by protocol v1, and write() hangs forever: PID: 973 TASK: ffff97dd399cae80 CPU: 1 COMMAND: "packetdrill" #0 [ffffa9b94062fb78] __schedule at ffffffff9c90a000 multipath-tcp#1 [ffffa9b94062fc08] schedule at ffffffff9c90a4a0 multipath-tcp#2 [ffffa9b94062fc18] schedule_timeout at ffffffff9c90e00d multipath-tcp#3 [ffffa9b94062fc90] wait_woken at ffffffff9c120184 multipath-tcp#4 [ffffa9b94062fcb0] sk_stream_wait_connect at ffffffff9c75b064 multipath-tcp#5 [ffffa9b94062fd20] mptcp_sendmsg at ffffffff9c8e801c multipath-tcp#6 [ffffa9b94062fdc0] sock_sendmsg at ffffffff9c747324 multipath-tcp#7 [ffffa9b94062fdd8] sock_write_iter at ffffffff9c7473c7 multipath-tcp#8 [ffffa9b94062fe48] new_sync_write at ffffffff9c302976 multipath-tcp#9 [ffffa9b94062fed0] vfs_write at ffffffff9c305685 multipath-tcp#10 [ffffa9b94062ff00] ksys_write at ffffffff9c305985 multipath-tcp#11 [ffffa9b94062ff38] do_syscall_64 at ffffffff9c004475 multipath-tcp#12 [ffffa9b94062ff50] entry_SYSCALL_64_after_hwframe at ffffffff9ca0008c RIP: 00007f959407eaf7 RSP: 00007ffe9e95a910 RFLAGS: 00000293 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f959407eaf7 RDX: 00000000000003e8 RSI: 0000000001785fe0 RDI: 0000000000000008 RBP: 0000000001785fe0 R8: 0000000000000000 R9: 0000000000000003 R10: 0000000000000007 R11: 0000000000000293 R12: 00000000000003e8 R13: 00007ffe9e95ae30 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b Fix it ensuring that socket state is TCP_ESTABLISHED on reception of the third ack. Fixes: 1954b86 ("mptcp: Check connection state before attempting send") Suggested-by: Paolo Abeni <[email protected]> Signed-off-by: Davide Caratti <[email protected]> Signed-off-by: David S. Miller <[email protected]>

Paul Blakey says: ==================== Introduce connection tracking offload Background ---------- The connection tracking action provides the ability to associate connection state to a packet. The connection state may be used for stateful packet processing such as stateful firewalls and NAT operations. Connection tracking in TC SW ---------------------------- The CT state may be matched only after the CT action is performed. As such, CT use cases are commonly implemented using multiple chains. Consider the following TC filters, as an example: 1. tc filter add dev ens1f0_0 ingress prio 1 chain 0 proto ip flower \ src_mac 24:8a:07:a5:28:01 ct_state -trk \ action ct \ pipe action goto chain 2 2. tc filter add dev ens1f0_0 ingress prio 1 chain 2 proto ip flower \ ct_state +trk+new \ action ct commit \ pipe action tunnel_key set \ src_ip 0.0.0.0 \ dst_ip 7.7.7.8 \ id 98 \ dst_port 4789 \ action mirred egress redirect dev vxlan0 3. tc filter add dev ens1f0_0 ingress prio 1 chain 2 proto ip flower \ ct_state +trk+est \ action tunnel_key set \ src_ip 0.0.0.0 \ dst_ip 7.7.7.8 \ id 98 \ dst_port 4789 \ action mirred egress redirect dev vxlan0 Filter multipath-tcp#1 (chain 0) decides, after initial packet classification, to send the packet to the connection tracking module (ct action). Once the ct_state is initialized by the CT action the packet processing continues on chain 2. Chain 2 classifies the packet based on the ct_state. Filter multipath-tcp#2 matches on the +trk+new CT state while filter multipath-tcp#3 matches on the +trk+est ct_state. MLX5 Connection tracking HW offload - MLX5 driver patches ------------------------------ The MLX5 hardware model aligns with the software model by realizing a multi-table architecture. In SW the TC CT action sets the CT state on the skb. Similarly, HW sets the CT state on a HW register. Driver gets this CT state while offloading a tuple with a new ct_metadata action that provides it. Matches on ct_state are translated to HW register matches. TC filter with CT action broken to two rules, a pre_ct rule, and a post_ct rule. pre_ct rule: Inserted on the corrosponding tc chain table, matches on original tc match, with actions: any pre ct actions, set fte_id, set zone, and goto the ct table. The fte_id is a register mapping uniquely identifying this filter. post_ct_rule: Inserted in a post_ct table, matches on the fte_id register mapping, with actions: counter + any post ct actions (this is usally 'goto chain X') post_ct table is a table that all the tuples inserted to the ct table goto, so if there is a tuple hit, packet will continue from ct table to post_ct table, after being marked with the CT state (mark/label..) This design ensures that the rule's actions and counters will be executed only after a CT hit. HW misses will continue processing in SW from the last chain ID that was processed in hardware. The following illustrates the HW model: +-------------------+ +--------------------+ +--------------+ + pre_ct (tc chain) +----->+ CT (nat or no nat) +--->+ post_ct +-----> + original match + | + tuple + zone match + | + fte_id match + | +-------------------+ | +--------------------+ | +--------------+ | v v v set chain miss mapping set mark original set fte_id set label filter set zone set established actions set tunnel_id do nat (if needed) do decap To fill CT table, driver registers a CB for flow offload events, for each new flow table that is passed to it from offloading ct actions. Once a flow offload event is triggered on this CB, offload this flow to the hardware CT table. Established events offload -------------------------- Currently, act_ct maintains an FT instance per ct zone. Flow table entries are created, per ct connection, when connections enter an established state and deleted otherwise. Once an entry is created, the FT assumes ownership of the entries, and manages their aging. FT is used for software offload of conntrack. FT entries associate 5-tuples with an action list. The act_ct changes in this patchset: Populate the action list with a (new) ct_metadata action, providing the connection's ct state (zone,mark and label), and mangle actions if NAT is configured. Pass the action's flow table instance as ct action entry parameter, so when the action is offloaded, the driver may register a callback on it's block to receive FT flow offload add/del/stats events. Netilter changes -------------------------- The netfilter changes export the relevant bits, and add the relevant CBs to support the above. Applying this patchset -------------------------- On top of current net-next ("r8169: simplify getting stats by using netdev_stats_to_stats64"), pull Saeed's ct-offload branch, from git git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux.git and fix the following non trivial conflict in fs_core.c as follows: Then apply this patchset. Changelog: v2->v3: Added the first two patches needed after rebasing on net-next: "net/mlx5: E-Switch, Enable reg c1 loopback when possible" "net/mlx5e: en_rep: Create uplink rep root table after eswitch offloads table" ==================== Signed-off-by: David S. Miller <[email protected]>

Sigh, this is mostly my fault for not giving commit cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") enough scrutiny during review. The way we're checking bandwidth limitations here is mostly wrong: For starters, drm_dp_mst_atomic_check_bw_limit() determines the pbn_limit of a branch by simply scanning each port on the current branch device, then uses the last non-zero full_pbn value that it finds. It then counts the sum of the PBN used on each branch device for that level, and compares against the full_pbn value it found before. This is wrong because ports can and will have different PBN limitations on many hubs, especially since a number of DisplayPort hubs out there will be clever and only use the smallest link rate required for each downstream sink - potentially giving every port a different full_pbn value depending on what link rate it's trained at. This means with our current code, which max PBN value we end up with is not well defined. Additionally, we also need to remember when checking bandwidth limitations that the top-most device in any MST topology is a branch device, not a port. This means that the first level of a topology doesn't technically have a full_pbn value that needs to be checked. Instead, we should assume that so long as our VCPI allocations fit we're within the bandwidth limitations of the primary MSTB. We do however, want to check full_pbn on every port including those of the primary MSTB. However, it's important to keep in mind that this value represents the minimum link rate /between a port's sink or mstb, and the mstb itself/. A quick diagram to explain: MSTB multipath-tcp#1 / \ / \ Port multipath-tcp#1 Port multipath-tcp#2 full_pbn for Port multipath-tcp#1 → | | ← full_pbn for Port multipath-tcp#2 Sink multipath-tcp#1 MSTB multipath-tcp#2 | etc... Note that in the above diagram, the combined PBN from all VCPI allocations on said hub should not exceed the full_pbn value of port multipath-tcp#2, and the display configuration on sink multipath-tcp#1 should not exceed the full_pbn value of port multipath-tcp#1. However, port multipath-tcp#1 and port multipath-tcp#2 can otherwise consume as much bandwidth as they want so long as their VCPI allocations still fit. And finally - our current bandwidth checking code also makes the mistake of not checking whether something is an end device or not before trying to traverse down it. So, let's fix it by rewriting our bandwidth checking helpers. We split the function into one part for handling branches which simply adds up the total PBN on each branch and returns it, and one for checking each port to ensure we're not going over its PBN limit. Phew. This should fix regressions seen, where we erroneously reject display configurations due to thinking they're going over our bandwidth limits when they're not. Changes since v1: * Took an even closer look at how PBN limitations are supposed to be handled, and did some experimenting with Sean Paul. Ended up rewriting these helpers again, but this time they should actually be correct! Changes since v2: * Small indenting fix * Fix pbn_used check in drm_dp_mst_atomic_check_port_bw_limit() Signed-off-by: Lyude Paul <[email protected]> Fixes: cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") Cc: Sean Paul <[email protected]> Acked-by: Alex Deucher <[email protected]> Reviewed-by: Mikita Lipski <[email protected]> Tested-by: Hans de Goede <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Petr Machata says: ==================== RED: Introduce an ECN tail-dropping mode When the RED qdisc is currently configured to enable ECN, the RED algorithm is used to decide whether a certain SKB should be marked. If that SKB is not ECN-capable, it is early-dropped. It is also possible to keep all traffic in the queue, and just mark the ECN-capable subset of it, as appropriate under the RED algorithm. Some switches support this mode, and some installations make use of it. There is currently no way to put the RED qdiscs to this mode. Therefore this patchset adds a new RED flag, TC_RED_TAILDROP. When the qdisc is configured with this flag, non-ECT traffic is enqueued (and tail-dropped when the queue size is exhausted) instead of being early-dropped. Unfortunately, adding a new RED flag is not as simple as it sounds. RED flags are passed in tc_red_qopt.flags. However RED neglects to validate the flag field, and just copies it over wholesale to its internal structure, and later dumps it back. A broken userspace can therefore configure a RED qdisc with arbitrary unsupported flags, and later expect to see the flags on qdisc dump. The current ABI thus allows storage of 5 bits of custom data along with the qdisc instance. GRED, SFQ and CHOKE qdiscs are in the same situation. (GRED validates VQ flags, but not the flags for the main queue.) E.g. if SFQ ever needs to support TC_RED_ADAPTATIVE, it needs another way of doing it, and at the same time it needs to retain the possibility to store 6 bits of uninterpreted data. For RED, this problem is resolved in patch multipath-tcp#2, which adds a new attribute, and a way to separate flags from userbits that can be reused by other qdiscs. The flag itself and related behavioral changes are added in patch To test the new feature, patch multipath-tcp#1 first introduces a TDC testsuite that covers the existing RED flags. Patch multipath-tcp#5 later extends it with taildrop coverage. Patch multipath-tcp#6 contains a forwarding selftest for the offloaded datapath. To test the SW datapath, I took the mlxsw selftest and adapted it in mostly obvious ways. The test is stable enough to verify that RED, ECN and ECN taildrop actually work. However, I have no confidence in its portability to other people's machines or mildly different configurations. I therefore do not find it suitable for upstreaming. GRED and CHOKE can use the same method as RED if they ever need to support extra flags. SFQ uses the length of TCA_OPTIONS to dispatch on binary control structure version, and would therefore need a different approach. v2: - Patch multipath-tcp#1 - Require nsPlugin in each RED test - Match end-of-line to catch cases of more flags reported than requested - Patch multipath-tcp#2: - Replaced with another patch. - Patch multipath-tcp#3: - Fix red_use_taildrop() condition in red_enqueue switch for probabilistic case. - Patch multipath-tcp#5: - Require nsPlugin in each RED test - Match end-of-line to catch cases of more flags reported than requested - Add a test for creation of non-ECN taildrop, which should fail ==================== Signed-off-by: David S. Miller <[email protected]>

Ido Schimmel says: ==================== mlxsw: Offload TC action skbedit priority Petr says: The TC action "skbedit priority P" has the effect of assigning skbprio of P to SKBs that it's applied on. In HW datapath of a switch, the corresponding action is assignment of internal switch priority. Spectrum switches allow setting of packet priority based on an ACL action, which is good match for the skbedit priority gadget. This patchset therefore implements offloading of this action to the Spectrum ACL engine. After a bit of refactoring in patch #1, patch #2 extends the skbedit action to support offloading of "priority" subcommand. On mlxsw side, in patch #3, the QOS_ACTION flexible action is added, with fields necessary for priority adjustment. In patch #4, "skbedit priority" is connected to that action. Patch #5 implements a new forwarding selftest, suitable for both SW- and HW-datapath testing. ==================== Signed-off-by: David S. Miller <[email protected]>

The DMA error handler routine is currently a tasklet, scheduled to run after the DMA error IRQ was handled. However it needs to take the MDIO mutex, which is not allowed to do in a tasklet. A kernel (with debug options) complains consequently: [ 614.050361] net eth0: DMA Tx error 0x174019 [ 614.064002] net eth0: Current BD is at: 0x8f84aa0ce [ 614.080195] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [ 614.109484] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 40, name: kworker/u4:4 [ 614.135428] 3 locks held by kworker/u4:4/40: [ 614.149075] #0: ffff000879863328 ((wq_completion)rpciod){....}, at: process_one_work+0x1f0/0x6a8 [ 614.177528] #1: ffff80001251bdf8 ((work_completion)(&task->u.tk_work)){....}, at: process_one_work+0x1f0/0x6a8 [ 614.209033] #2: ffff0008784e0110 (sk_lock-AF_INET-RPC){....}, at: tcp_sendmsg+0x24/0x58 [ 614.235429] CPU: 0 PID: 40 Comm: kworker/u4:4 Not tainted 5.6.0-rc3-00926-g4a165a9d5921 #26 [ 614.260854] Hardware name: ARM Test FPGA (DT) [ 614.274734] Workqueue: rpciod rpc_async_schedule [ 614.289022] Call trace: [ 614.296871] dump_backtrace+0x0/0x1a0 [ 614.308311] show_stack+0x14/0x20 [ 614.318751] dump_stack+0xbc/0x100 [ 614.329403] ___might_sleep+0xf0/0x140 [ 614.341018] __might_sleep+0x4c/0x80 [ 614.352201] __mutex_lock+0x5c/0x8a8 [ 614.363348] mutex_lock_nested+0x1c/0x28 [ 614.375654] axienet_dma_err_handler+0x38/0x388 [ 614.389999] tasklet_action_common.isra.15+0x160/0x1a8 [ 614.405894] tasklet_action+0x24/0x30 [ 614.417297] efi_header_end+0xe0/0x494 [ 614.429020] irq_exit+0xd0/0xd8 [ 614.439047] __handle_domain_irq+0x60/0xb0 [ 614.451877] gic_handle_irq+0xdc/0x2d0 [ 614.463486] el1_irq+0xcc/0x180 [ 614.473451] __tcp_transmit_skb+0x41c/0xb58 [ 614.486513] tcp_write_xmit+0x224/0x10a0 [ 614.498792] __tcp_push_pending_frames+0x38/0xc8 [ 614.513126] tcp_rcv_established+0x41c/0x820 [ 614.526301] tcp_v4_do_rcv+0x8c/0x218 [ 614.537784] __release_sock+0x5c/0x108 [ 614.549466] release_sock+0x34/0xa0 [ 614.560318] tcp_sendmsg+0x40/0x58 [ 614.571053] inet_sendmsg+0x40/0x68 [ 614.582061] sock_sendmsg+0x18/0x30 [ 614.593074] xs_sendpages+0x218/0x328 [ 614.604506] xs_tcp_send_request+0xa0/0x1b8 [ 614.617461] xprt_transmit+0xc8/0x4f0 [ 614.628943] call_transmit+0x8c/0xa0 [ 614.640028] __rpc_execute+0xbc/0x6f8 [ 614.651380] rpc_async_schedule+0x28/0x48 [ 614.663846] process_one_work+0x298/0x6a8 [ 614.676299] worker_thread+0x40/0x490 [ 614.687687] kthread+0x134/0x138 [ 614.697804] ret_from_fork+0x10/0x18 [ 614.717319] xilinx_axienet 7fe00000.ethernet eth0: Link is Down [ 615.748343] xilinx_axienet 7fe00000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off Since tasklets are not really popular anymore anyway, lets convert this over to a work queue, which can sleep and thus can take the MDIO mutex. Signed-off-by: Andre Przywara <[email protected]> Signed-off-by: David S. Miller <[email protected]>

Yonghong Song says: ==================== Commit 8b401f9 ("bpf: implement bpf_send_signal() helper") introduced bpf_send_signal() helper and Commit 8482941 ("bpf: Add bpf_send_signal_thread() helper") added bpf_send_signal_thread() helper. Both helpers try to send a signel to current process or thread. When bpf_prog is called with scheduler rq_lock held, a deadlock could happen since bpf_send_signal() and bpf_send_signal_thread() will call group_send_sig_info() which may ultimately want to acquire rq_lock() again. This happens in 5.2 and 4.16 based kernels in our production environment with perf_sw_event. In a different scenario, the following is also possible in the last kernel: cpu 1: do_task_stat <- holding sighand->siglock ... task_sched_runtime <- trying to grab rq_lock cpu 2: __schedule <- holding rq_lock ... do_send_sig_info <- trying to grab sighand->siglock Commit eac9153 ("bpf/stackmap: Fix deadlock with rq_lock in bpf_get_stack()") has a similar issue with above rq_lock() deadlock. This patch set addressed the issue in a similar way. Patch #1 provided kernel solution and Patch #2 added a selftest. Changelogs: v2 -> v3: . simplify selftest send_signal_sched_switch(). The previous version has mmap/munmap inherited from Song's reproducer. They are not necessary in this context. v1 -> v2: . previous fix using task_work in nmi() is incorrect. there is no nmi() involvement here. Using task_work in all cases might be a solution. But decided to use a similar fix as in Commit eac9153. ==================== Signed-off-by: Alexei Starovoitov <[email protected]>

The bucket->lock is not needed in the sock_hash_free and sock_map_free calls, in fact it is causing a splat due to being inside rcu block. | BUG: sleeping function called from invalid context at net/core/sock.c:2935 | in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 62, name: kworker/0:1 | 3 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffff8881381f6df8 (&stab->lock){+...}, at: sock_map_free+0x26/0x180 | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04008-g7b083332376e #454 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep.cold+0xa6/0xb6 | lock_sock_nested+0x28/0x90 | sock_map_free+0x5f/0x180 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 The reason we have stab->lock and bucket->locks in sockmap code is to handle checking EEXIST in update/delete cases. We need to be careful during an update operation that we check for EEXIST and we need to ensure that the psock object is not in some partial state of removal/insertion while we do this. So both map_update_common and sock_map_delete need to guard from being run together potentially deleting an entry we are checking, etc. But by the time we get to the tear-down code in sock_{ma[|hash}_free we have already disconnected the map and we just did synchronize_rcu() in the line above so no updates/deletes should be in flight. Because of this we can drop the bucket locks from the map free'ing code, noting no update/deletes can be in-flight. Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface") Reported-by: Jakub Sitnicki <[email protected]> Suggested-by: Jakub Sitnicki <[email protected]> Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/158385850787.30597.8346421465837046618.stgit@john-Precision-5820-Tower

The vector management code assumes that managed interrupts cannot be migrated away from an online CPU. free_moved_vector() has a WARN_ON_ONCE() which triggers when a managed interrupt vector association on a online CPU is cleared. The CPU offline code uses a different mechanism which cannot trigger this. This assumption is not longer correct because the new CPU isolation feature which affects the placement of managed interrupts must be able to move a managed interrupt away from an online CPU. There are two reasons why this can happen: 1) When the interrupt is activated the affinity mask which was established in irq_create_affinity_masks() is handed in to the vector allocation code. This mask contains all CPUs to which the interrupt can be made affine to, but this does not take the CPU isolation 'managed_irq' mask into account. When the interrupt is finally requested by the device driver then the affinity is checked again and the CPU isolation 'managed_irq' mask is taken into account, which moves the interrupt to a non-isolated CPU if possible. 2) The interrupt can be affine to an isolated CPU because the non-isolated CPUs in the calculated affinity mask are not online. Once a non-isolated CPU which is in the mask comes online the interrupt is migrated to this non-isolated CPU In both cases the regular online migration mechanism is used which triggers the WARN_ON_ONCE() in free_moved_vector(). Case #1 could have been addressed by taking the isolation mask into account, but that would require a massive code change in the activation logic and the eventual migration event was accepted as a reasonable tradeoff when the isolation feature was developed. But even if #1 would be addressed, #2 would still trigger it. Of course the warning in free_moved_vector() was overlooked at that time and the above two cases which have been discussed during patch review have obviously never been tested before the final submission. So keep it simple and remove the warning. [ tglx: Rewrote changelog and added a comment to free_moved_vector() ] Fixes: 11ea68f ("genirq, sched/isolation: Isolate from handling managed interrupts") Signed-off-by: Peter Xu <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lkml.kernel.org/r/[email protected]

It is safe to traverse mm->notifier_subscriptions->list either under SRCU read lock or mm->notifier_subscriptions->lock using hlist_for_each_entry_rcu(). Silence the PROVE_RCU_LIST false positives, for example, WARNING: suspicious RCU usage ----------------------------- mm/mmu_notifier.c:484 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by libvirtd/802: #0: ffff9321e3f58148 (&mm->mmap_sem#2){++++}, at: do_mprotect_pkey+0xe1/0x3e0 #1: ffffffff91ae6160 (mmu_notifier_invalidate_range_start){+.+.}, at: change_p4d_range+0x5fa/0x800 #2: ffffffff91ae6e08 (srcu){....}, at: __mmu_notifier_invalidate_range_start+0x178/0x460 stack backtrace: CPU: 7 PID: 802 Comm: libvirtd Tainted: G I 5.6.0-rc6-next-20200317+ #2 Hardware name: HP ProLiant BL460c Gen8, BIOS I31 11/02/2014 Call Trace: dump_stack+0xa4/0xfe lockdep_rcu_suspicious+0xeb/0xf5 __mmu_notifier_invalidate_range_start+0x3ff/0x460 change_p4d_range+0x746/0x800 change_protection+0x1df/0x300 mprotect_fixup+0x245/0x3e0 do_mprotect_pkey+0x23b/0x3e0 __x64_sys_mprotect+0x51/0x70 do_syscall_64+0x91/0xae8 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Signed-off-by: Qian Cai <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Paul E. McKenney <[email protected]> Reviewed-by: Jason Gunthorpe <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>

Ido Schimmel says: ==================== mlxsw: Offload TC action pedit munge dsfield Petr says: The Spectrum switches allow packet prioritization based on DSCP on ingress, and update of DSCP on egress. This is configured through the DCB APP rules. For some use cases, assigning a custom DSCP value based on an ACL match is a better tool. To that end, offload FLOW_ACTION_MANGLE to permit changing of dsfield as a whole, or DSCP and ECN values in isolation. After fixing a commentary nit in patch #1, and mlxsw naming in patch #2, patches #3 and #4 add the offload to mlxsw. Patch #5 adds a forwarding selftest for pedit dsfield, applicable to SW as well as HW datapaths. Patch #6 adds a mlxsw-specific test to verify DSCP rewrite due to DCB APP rules is not performed on pedited packets. The tests only cover IPv4 dsfield setting. We have tests for IPv6 as well, but would like to postpone their contribution until the corresponding iproute patches have been accepted. ==================== Signed-off-by: David S. Miller <[email protected]>

Petr Machata says: ==================== Implement stats_update callback for pedit and skbedit The stats_update callback is used for adding HW counters to the SW ones. Both skbedit and pedit actions are actually recognized by flow_offload.h, but do not implement these callbacks. As a consequence, the reported values are only the SW ones, even where there is a HW counter available. Patch #1 adds the callback to action skbedit, patch #2 adds it to action pedit. Patch #3 tweaks an skbedit selftest with a check that would have caught this problem. The pedit test is not likewise tweaked, because the iproute2 pedit action currently does not support JSON dumping. This will be addressed later. ==================== Signed-off-by: David S. Miller <[email protected]>

Ido Schimmel says: ==================== mlxsw: Various static checkers fixes Jakub told me he gets some warnings with W=1, so I decided to check with sparse, smatch and coccinelle as well. This patch set fixes all the issues found. None are actual bugs / regressions and therefore not targeted at net. Patches #1-#2 add missing kernel-doc comments. Patch #3 removes dead code. Patch #4 reworks the ACL code to avoid defining a static variable in a header file. Patch #5 removes unnecessary conversion to bool that coccinelle warns about. Patch #6 avoids false-positive uninitialized symbol errors emitted by smatch. ==================== Signed-off-by: David S. Miller <[email protected]>

Ido Schimmel says: ==================== Add packet trap policers support Background ========== Devices capable of offloading the kernel's datapath and perform functions such as bridging and routing must also be able to send (trap) specific packets to the kernel (i.e., the CPU) for processing. For example, a device acting as a multicast-aware bridge must be able to trap IGMP membership reports to the kernel for processing by the bridge module. Motivation ========== In most cases, the underlying device is capable of handling packet rates that are several orders of magnitude higher compared to those that can be handled by the CPU. Therefore, in order to prevent the underlying device from overwhelming the CPU, devices usually include packet trap policers that are able to police the trapped packets to rates that can be handled by the CPU. Proposed solution ================= This patch set allows capable device drivers to register their supported packet trap policers with devlink. User space can then tune the parameters of these policers (currently, rate and burst size) and read from the device the number of packets that were dropped by the policer, if supported. These packet trap policers can then be bound to existing packet trap groups, which are used to aggregate logically related packet traps. As a result, trapped packets are policed to rates that can be handled the host CPU. Example usage ============= Instantiate netdevsim: Dump available packet trap policers: netdevsim/netdevsim10: policer 1 rate 1000 burst 128 policer 2 rate 2000 burst 256 policer 3 rate 3000 burst 512 Change the parameters of a packet trap policer: Bind a packet trap policer to a packet trap group: Dump parameters and statistics of a packet trap policer: netdevsim/netdevsim10: policer 3 rate 100 burst 16 stats: rx: dropped 92 Unbind a packet trap policer from a packet trap group: Patch set overview ================== Patch #1 adds the core infrastructure in devlink which allows capable device drivers to register their supported packet trap policers with devlink. Patch #2 extends the existing devlink-trap documentation. Patch #3 extends netdevsim to register a few dummy packet trap policers with devlink. Used later on to selftests the core infrastructure. Patches #4-#5 adds infrastructure in devlink to allow binding of packet trap policers to packet trap groups. Patch #6 extends netdevsim to allow such binding. Patch #7 adds a selftest over netdevsim that verifies the core devlink-trap policers functionality. Patches #8-#14 gradually add devlink-trap policers support in mlxsw. Patch #15 adds a selftest over mlxsw. All registered packet trap policers are verified to handle the configured rate and burst size. Future plans ============ * Allow changing default association between packet traps and packet trap groups * Add more packet traps. For example, for control packets (e.g., IGMP) v3: * Rebase v2 (address comments from Jiri and Jakub): * Patch #1: Add 'strict_start_type' in devlink policy * Patch #1: Have device drivers provide max/min rate/burst size for each policer. Use them to check validity of user provided parameters * Patch #3: Remove check about burst size being a power of 2 and instead add a debugfs knob to fail the operation * Patch #3: Provide max/min rate/burst size when registering policers and remove the validity checks from nsim_dev_devlink_trap_policer_set() * Patch #5: Check for presence of 'DEVLINK_ATTR_TRAP_POLICER_ID' in devlink_trap_group_set() and bail if not present * Patch #5: Add extack error message in case trap group was partially modified * Patch #7: Add test case with new 'fail_trap_policer_set' knob * Patch #7: Add test case for partially modified trap group * Patch #10: Provide max/min rate/burst size when registering policers * Patch #11: Remove the max/min validity checks from __mlxsw_sp_trap_policer_set() ==================== Signed-off-by: David S. Miller <[email protected]>

Florian Fainelli says: ==================== net: dsa: b53 & bcm_sf2 updates for 7278 This patch series contains some updates to the b53 and bcm_sf2 drivers specifically for the 7278 Ethernet switch. The first patch is technically a bug fix so it should ideally be backported to -stable, provided that Dan also agress with my resolution on this. Patches #2 through #4 are minor changes to the core b53 driver to restore VLAN configuration upon system resumption as well as deny specific bridge/VLAN operations on port 7 with the 7278 which is special and does not support VLANs. Patches #5 through #9 add support for matching VLAN TCI keys/masks to the CFP code. Changes in v2: - fixed some code comments and arrange some code for easier reading ==================== Signed-off-by: David S. Miller <[email protected]>

With the following patches: - btrfs: backref, only collect file extent items matching backref offset - btrfs: backref, not adding refs from shared block when resolving normal backref - btrfs: backref, only search backref entries from leaves of the same root we only collect the normal data refs we want, so the imprecise upper bound total_refs of that EXTENT_ITEM could now be changed to the count of the normal backref entry we want to search. Background and how the patches fit together: Btrfs has two types of data backref. For BTRFS_EXTENT_DATA_REF_KEY type of backref, we don't have the exact block number. Therefore, we need to call resolve_indirect_refs. It uses btrfs_search_slot to locate the leaf block. Then we need to walk through the leaves to search for the EXTENT_DATA items that have disk bytenr matching the extent item (add_all_parents). When resolving indirect refs, we could take entries that don't belong to the backref entry we are searching for right now. For that reason when searching backref entry, we always use total refs of that EXTENT_ITEM rather than individual count. For example: item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize extent refs 24 gen 7302 flags DATA shared data backref parent 394985472 count 10 #1 extent data backref root 257 objectid 260 offset 1048576 count 3 #2 extent data backref root 256 objectid 260 offset 65536 count 6 #3 extent data backref root 257 objectid 260 offset 65536 count 5 #4 For example, when searching backref entry #4, we'll use total_refs 24, a very loose loop ending condition, instead of total_refs = 5. But using total_refs = 24 is not accurate. Sometimes, we'll never find all the refs from specific root. As a result, the loop keeps on going until we reach the end of that inode. The first 3 patches, handle 3 different types refs we might encounter. These refs do not belong to the normal backref we are searching, and hence need to be skipped. This patch changes the total_refs to correct number so that we could end loop as soon as we find all the refs we want. btrfs send uses backref to find possible clone sources, the following is a simple test to compare the results with and without this patch: $ btrfs subvolume create /sub1 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=64K count=1 seek=$((i-1)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot /sub1 /sub2 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=4K count=1 seek=$(((i-1)*16+10)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot -r /sub1 /snap1 $ time btrfs send /snap1 | btrfs receive /volume2 Without this patch: real 69m48.124s user 0m50.199s sys 70m15.600s With this patch: real 1m59.683s user 0m35.421s sys 2m42.684s Reviewed-by: Josef Bacik <[email protected]> Reviewed-by: Johannes Thumshirn <[email protected]> Signed-off-by: ethanwu <[email protected]> [ add patchset cover letter with background and numbers ] Signed-off-by: David Sterba <[email protected]>

During unmount we can have a job from the delayed inode items work queue still running, that can lead to at least two bad things: 1) A crash, because the worker can try to create a transaction just after the fs roots were freed; 2) A transaction leak, because the worker can create a transaction before the fs roots are freed and just after we committed the last transaction and after we stopped the transaction kthread. A stack trace example of the crash: [79011.691214] kernel BUG at lib/radix-tree.c:982! [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2 (...) [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs] [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170 (...) [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001 [79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000 [79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [79011.715448] Call Trace: [79011.715925] record_root_in_trans+0x72/0xf0 [btrfs] [79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs] [79011.717925] start_transaction+0xdd/0x5c0 [btrfs] [79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs] [79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs] [79011.720773] process_one_work+0x26d/0x6a0 [79011.721497] worker_thread+0x4f/0x3e0 [79011.722153] ? process_one_work+0x6a0/0x6a0 [79011.722901] kthread+0x103/0x140 [79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70 [79011.724379] ret_from_fork+0x3a/0x50 (...) The following diagram shows a sequence of steps that lead to the crash during ummount of the filesystem: CPU 1 CPU 2 CPU 3 btrfs_punch_hole() btrfs_btree_balance_dirty() btrfs_balance_delayed_items() --> sees fs_info->delayed_root->items with value 200, which is greater than BTRFS_DELAYED_BACKGROUND (128) and smaller than BTRFS_DELAYED_WRITEBACK (512) btrfs_wq_run_delayed_node() --> queues a job for fs_info->delayed_workers to run btrfs_async_run_delayed_root() btrfs_async_run_delayed_root() --> job queued by CPU 1 --> starts picking and running delayed nodes from the prepare_list list close_ctree() btrfs_delete_unused_bgs() btrfs_commit_super() btrfs_join_transaction() --> gets transaction N btrfs_commit_transaction(N) --> set transaction state to TRANTS_STATE_COMMIT_START btrfs_first_prepared_delayed_node() --> picks delayed node X through the prepared_list list btrfs_run_delayed_items() btrfs_first_delayed_node() --> also picks delayed node X but through the node_list list __btrfs_commit_inode_delayed_items() --> runs all delayed items from this node and drops the node's item count to 0 through call to btrfs_release_delayed_inode() --> finishes running any remaining delayed nodes --> finishes transaction commit --> stops cleaner and transaction threads btrfs_free_fs_roots() --> frees all roots and removes them from the radix tree fs_info->fs_roots_radix btrfs_join_transaction() start_transaction() btrfs_record_root_in_trans() record_root_in_trans() radix_tree_tag_set() --> crashes because the root is not in the radix tree anymore If the worker is able to call btrfs_join_transaction() before the unmount task frees the fs roots, we end up leaking a transaction and all its resources, since after the call to btrfs_commit_super() and stopping the transaction kthread, we don't expect to have any transaction open anymore. When this situation happens the worker has a delayed node that has no more items to run, since the task calling btrfs_run_delayed_items(), which is doing a transaction commit, picks the same node and runs all its items first. We can not wait for the worker to complete when running delayed items through btrfs_run_delayed_items(), because we call that function in several phases of a transaction commit, and that could cause a deadlock because the worker calls btrfs_join_transaction() and the task doing the transaction commit may have already set the transaction state to TRANS_STATE_COMMIT_DOING. Also it's not possible to get into a situation where only some of the items of a delayed node are added to the fs/subvolume tree in the current transaction and the remaining ones in the next transaction, because when running the items of a delayed inode we lock its mutex, effectively waiting for the worker if the worker is running the items of the delayed node already. Since this can only cause issues when unmounting a filesystem, fix it in a simple way by waiting for any jobs on the delayed workers queue before calling btrfs_commit_supper() at close_ctree(). This works because at this point no one can call btrfs_btree_balance_dirty() or btrfs_balance_delayed_items(), and if we end up waiting for any worker to complete, btrfs_commit_super() will commit the transaction created by the worker. CC: [email protected] # 4.4+ Signed-off-by: Filipe Manana <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>

…during probe When booting j721e the following bug is printed: [ 1.154821] BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 [ 1.154827] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 12, name: kworker/0:1 [ 1.154832] 3 locks held by kworker/0:1/12: [ 1.154836] #0: ffff000840030728 ((wq_completion)events){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154852] #1: ffff80001214fdd8 (deferred_probe_work){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154860] #2: ffff00084060b170 (&dev->mutex){....}, at: __device_attach+0x38/0x138 [ 1.154872] irq event stamp: 63096 [ 1.154881] hardirqs last enabled at (63095): [<ffff800010b74318>] _raw_spin_unlock_irqrestore+0x70/0x78 [ 1.154887] hardirqs last disabled at (63096): [<ffff800010b740d8>] _raw_spin_lock_irqsave+0x28/0x80 [ 1.154893] softirqs last enabled at (62254): [<ffff800010080c88>] _stext+0x488/0x564 [ 1.154899] softirqs last disabled at (62247): [<ffff8000100fdb3c>] irq_exit+0x114/0x140 [ 1.154906] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.6.0-rc6-next-20200318-00094-g45e4089b0bd3 #221 [ 1.154911] Hardware name: Texas Instruments K3 J721E SoC (DT) [ 1.154917] Workqueue: events deferred_probe_work_func [ 1.154923] Call trace: [ 1.154928] dump_backtrace+0x0/0x190 [ 1.154933] show_stack+0x14/0x20 [ 1.154940] dump_stack+0xe0/0x148 [ 1.154946] ___might_sleep+0x150/0x1f0 [ 1.154952] __might_sleep+0x4c/0x80 [ 1.154957] wait_for_completion_timeout+0x40/0x140 [ 1.154964] ti_sci_set_device_state+0xa0/0x158 [ 1.154969] ti_sci_cmd_get_device_exclusive+0x14/0x20 [ 1.154977] ti_sci_dev_start+0x34/0x50 [ 1.154984] genpd_runtime_resume+0x78/0x1f8 [ 1.154991] __rpm_callback+0x3c/0x140 [ 1.154996] rpm_callback+0x20/0x80 [ 1.155001] rpm_resume+0x568/0x758 [ 1.155007] __pm_runtime_resume+0x44/0xb0 [ 1.155013] omap8250_probe+0x2b4/0x508 [ 1.155019] platform_drv_probe+0x50/0xa0 [ 1.155023] really_probe+0xd4/0x318 [ 1.155028] driver_probe_device+0x54/0xe8 [ 1.155033] __device_attach_driver+0x80/0xb8 [ 1.155039] bus_for_each_drv+0x74/0xc0 [ 1.155044] __device_attach+0xdc/0x138 [ 1.155049] device_initial_probe+0x10/0x18 [ 1.155053] bus_probe_device+0x98/0xa0 [ 1.155058] deferred_probe_work_func+0x74/0xb0 [ 1.155063] process_one_work+0x280/0x6e8 [ 1.155068] worker_thread+0x48/0x430 [ 1.155073] kthread+0x108/0x138 [ 1.155079] ret_from_fork+0x10/0x18 To fix the bug we need to first call pm_runtime_enable() prior to any pm_runtime calls. Reported-by: Tomi Valkeinen <[email protected]> Signed-off-by: Peter Ujfalusi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

Zygo reported the following lockdep splat while testing the balance patches ====================================================== WARNING: possible circular locking dependency detected 5.6.0-c6f0579d496a+ #53 Not tainted ------------------------------------------------------ kswapd0/1133 is trying to acquire lock: ffff888092f622c0 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node+0x7c/0x5b0 but task is already holding lock: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}: fs_reclaim_acquire.part.91+0x29/0x30 fs_reclaim_acquire+0x19/0x20 kmem_cache_alloc_trace+0x32/0x740 add_block_entry+0x45/0x260 btrfs_ref_tree_mod+0x6e2/0x8b0 btrfs_alloc_tree_block+0x789/0x880 alloc_tree_block_no_bg_flush+0xc6/0xf0 __btrfs_cow_block+0x270/0x940 btrfs_cow_block+0x1ba/0x3a0 btrfs_search_slot+0x999/0x1030 btrfs_insert_empty_items+0x81/0xe0 btrfs_insert_delayed_items+0x128/0x7d0 __btrfs_run_delayed_items+0xf4/0x2a0 btrfs_run_delayed_items+0x13/0x20 btrfs_commit_transaction+0x5cc/0x1390 insert_balance_item.isra.39+0x6b2/0x6e0 btrfs_balance+0x72d/0x18d0 btrfs_ioctl_balance+0x3de/0x4c0 btrfs_ioctl+0x30ab/0x44a0 ksys_ioctl+0xa1/0xe0 __x64_sys_ioctl+0x43/0x50 do_syscall_64+0x77/0x2c0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&delayed_node->mutex){+.+.}: __lock_acquire+0x197e/0x2550 lock_acquire+0x103/0x220 __mutex_lock+0x13d/0xce0 mutex_lock_nested+0x1b/0x20 __btrfs_release_delayed_node+0x7c/0x5b0 btrfs_remove_delayed_node+0x49/0x50 btrfs_evict_inode+0x6fc/0x900 evict+0x19a/0x2c0 dispose_list+0xa0/0xe0 prune_icache_sb+0xbd/0xf0 super_cache_scan+0x1b5/0x250 do_shrink_slab+0x1f6/0x530 shrink_slab+0x32e/0x410 shrink_node+0x2a5/0xba0 balance_pgdat+0x4bd/0x8a0 kswapd+0x35a/0x800 kthread+0x1e9/0x210 ret_from_fork+0x3a/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&delayed_node->mutex); lock(fs_reclaim); lock(&delayed_node->mutex); *** DEADLOCK *** 3 locks held by kswapd0/1133: #0: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 #1: ffffffff8fc380d8 (shrinker_rwsem){++++}, at: shrink_slab+0x1e8/0x410 #2: ffff8881e0e6c0e8 (&type->s_umount_key#42){++++}, at: trylock_super+0x1b/0x70 stack backtrace: CPU: 2 PID: 1133 Comm: kswapd0 Not tainted 5.6.0-c6f0579d496a+ #53 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0xc1/0x11a print_circular_bug.isra.38.cold.57+0x145/0x14a check_noncircular+0x2a9/0x2f0 ? print_circular_bug.isra.38+0x130/0x130 ? stack_trace_consume_entry+0x90/0x90 ? save_trace+0x3cc/0x420 __lock_acquire+0x197e/0x2550 ? btrfs_inode_clear_file_extent_range+0x9b/0xb0 ? register_lock_class+0x960/0x960 lock_acquire+0x103/0x220 ? __btrfs_release_delayed_node+0x7c/0x5b0 __mutex_lock+0x13d/0xce0 ? __btrfs_release_delayed_node+0x7c/0x5b0 ? __asan_loadN+0xf/0x20 ? pvclock_clocksource_read+0xeb/0x190 ? __btrfs_release_delayed_node+0x7c/0x5b0 ? mutex_lock_io_nested+0xc20/0xc20 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x1e6/0x2e0 mutex_lock_nested+0x1b/0x20 ? mutex_lock_nested+0x1b/0x20 __btrfs_release_delayed_node+0x7c/0x5b0 btrfs_remove_delayed_node+0x49/0x50 btrfs_evict_inode+0x6fc/0x900 ? btrfs_setattr+0x840/0x840 ? do_raw_spin_unlock+0xa8/0x140 evict+0x19a/0x2c0 dispose_list+0xa0/0xe0 prune_icache_sb+0xbd/0xf0 ? invalidate_inodes+0x310/0x310 super_cache_scan+0x1b5/0x250 do_shrink_slab+0x1f6/0x530 shrink_slab+0x32e/0x410 ? do_shrink_slab+0x530/0x530 ? do_shrink_slab+0x530/0x530 ? __kasan_check_read+0x11/0x20 ? mem_cgroup_protected+0x13d/0x260 shrink_node+0x2a5/0xba0 balance_pgdat+0x4bd/0x8a0 ? mem_cgroup_shrink_node+0x490/0x490 ? _raw_spin_unlock_irq+0x27/0x40 ? finish_task_switch+0xce/0x390 ? rcu_read_lock_bh_held+0xb0/0xb0 kswapd+0x35a/0x800 ? _raw_spin_unlock_irqrestore+0x4c/0x60 ? balance_pgdat+0x8a0/0x8a0 ? finish_wait+0x110/0x110 ? __kasan_check_read+0x11/0x20 ? __kthread_parkme+0xc6/0xe0 ? balance_pgdat+0x8a0/0x8a0 kthread+0x1e9/0x210 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x50 This is because we hold that delayed node's mutex while doing tree operations. Fix this by just wrapping the searches in nofs. CC: [email protected] # 4.4+ Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>

A lockdep circular locking dependency report was seen when running a keyutils test: [12537.027242] ====================================================== [12537.059309] WARNING: possible circular locking dependency detected [12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE --------- - - [12537.125253] ------------------------------------------------------ [12537.153189] keyctl/25598 is trying to acquire lock: [12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0 [12537.208365] [12537.208365] but task is already holding lock: [12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12537.270476] [12537.270476] which lock already depends on the new lock. [12537.270476] [12537.307209] [12537.307209] the existing dependency chain (in reverse order) is: [12537.340754] [12537.340754] -> #3 (&type->lock_class){++++}: [12537.367434] down_write+0x4d/0x110 [12537.385202] __key_link_begin+0x87/0x280 [12537.405232] request_key_and_link+0x483/0xf70 [12537.427221] request_key+0x3c/0x80 [12537.444839] dns_query+0x1db/0x5a5 [dns_resolver] [12537.468445] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.496731] cifs_reconnect+0xe04/0x2500 [cifs] [12537.519418] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.546263] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.573551] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.601045] kthread+0x30c/0x3d0 [12537.617906] ret_from_fork+0x3a/0x50 [12537.636225] [12537.636225] -> #2 (root_key_user.cons_lock){+.+.}: [12537.664525] __mutex_lock+0x105/0x11f0 [12537.683734] request_key_and_link+0x35a/0xf70 [12537.705640] request_key+0x3c/0x80 [12537.723304] dns_query+0x1db/0x5a5 [dns_resolver] [12537.746773] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.775607] cifs_reconnect+0xe04/0x2500 [cifs] [12537.798322] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.823369] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.847262] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.873477] kthread+0x30c/0x3d0 [12537.890281] ret_from_fork+0x3a/0x50 [12537.908649] [12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}: [12537.935225] __mutex_lock+0x105/0x11f0 [12537.954450] cifs_call_async+0x102/0x7f0 [cifs] [12537.977250] smb2_async_readv+0x6c3/0xc90 [cifs] [12538.000659] cifs_readpages+0x120a/0x1e50 [cifs] [12538.023920] read_pages+0xf5/0x560 [12538.041583] __do_page_cache_readahead+0x41d/0x4b0 [12538.067047] ondemand_readahead+0x44c/0xc10 [12538.092069] filemap_fault+0xec1/0x1830 [12538.111637] __do_fault+0x82/0x260 [12538.129216] do_fault+0x419/0xfb0 [12538.146390] __handle_mm_fault+0x862/0xdf0 [12538.167408] handle_mm_fault+0x154/0x550 [12538.187401] __do_page_fault+0x42f/0xa60 [12538.207395] do_page_fault+0x38/0x5e0 [12538.225777] page_fault+0x1e/0x30 [12538.243010] [12538.243010] -> #0 (&mm->mmap_sem){++++}: [12538.267875] lock_acquire+0x14c/0x420 [12538.286848] __might_fault+0x119/0x1b0 [12538.306006] keyring_read_iterator+0x7e/0x170 [12538.327936] assoc_array_subtree_iterate+0x97/0x280 [12538.352154] keyring_read+0xe9/0x110 [12538.370558] keyctl_read_key+0x1b9/0x220 [12538.391470] do_syscall_64+0xa5/0x4b0 [12538.410511] entry_SYSCALL_64_after_hwframe+0x6a/0xdf [12538.435535] [12538.435535] other info that might help us debug this: [12538.435535] [12538.472829] Chain exists of: [12538.472829] &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class [12538.472829] [12538.524820] Possible unsafe locking scenario: [12538.524820] [12538.551431] CPU0 CPU1 [12538.572654] ---- ---- [12538.595865] lock(&type->lock_class); [12538.613737] lock(root_key_user.cons_lock); [12538.644234] lock(&type->lock_class); [12538.672410] lock(&mm->mmap_sem); [12538.687758] [12538.687758] *** DEADLOCK *** [12538.687758] [12538.714455] 1 lock held by keyctl/25598: [12538.732097] #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12538.770573] [12538.770573] stack backtrace: [12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G [12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015 [12538.881963] Call Trace: [12538.892897] dump_stack+0x9a/0xf0 [12538.907908] print_circular_bug.isra.25.cold.50+0x1bc/0x279 [12538.932891] ? save_trace+0xd6/0x250 [12538.948979] check_prev_add.constprop.32+0xc36/0x14f0 [12538.971643] ? keyring_compare_object+0x104/0x190 [12538.992738] ? check_usage+0x550/0x550 [12539.009845] ? sched_clock+0x5/0x10 [12539.025484] ? sched_clock_cpu+0x18/0x1e0 [12539.043555] __lock_acquire+0x1f12/0x38d0 [12539.061551] ? trace_hardirqs_on+0x10/0x10 [12539.080554] lock_acquire+0x14c/0x420 [12539.100330] ? __might_fault+0xc4/0x1b0 [12539.119079] __might_fault+0x119/0x1b0 [12539.135869] ? __might_fault+0xc4/0x1b0 [12539.153234] keyring_read_iterator+0x7e/0x170 [12539.172787] ? keyring_read+0x110/0x110 [12539.190059] assoc_array_subtree_iterate+0x97/0x280 [12539.211526] keyring_read+0xe9/0x110 [12539.227561] ? keyring_gc_check_iterator+0xc0/0xc0 [12539.249076] keyctl_read_key+0x1b9/0x220 [12539.266660] do_syscall_64+0xa5/0x4b0 [12539.283091] entry_SYSCALL_64_after_hwframe+0x6a/0xdf One way to prevent this deadlock scenario from happening is to not allow writing to userspace while holding the key semaphore. Instead, an internal buffer is allocated for getting the keys out from the read method first before copying them out to userspace without holding the lock. That requires taking out the __user modifier from all the relevant read methods as well as additional changes to not use any userspace write helpers. That is, 1) The put_user() call is replaced by a direct copy. 2) The copy_to_user() call is replaced by memcpy(). 3) All the fault handling code is removed. Compiling on a x86-64 system, the size of the rxrpc_read() function is reduced from 3795 bytes to 2384 bytes with this patch. Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Waiman Long <[email protected]> Signed-off-by: David Howells <[email protected]>

On some EFI systems, the video BIOS is provided by the EFI firmware. The boot stub code stores the physical address of the ROM image in pdev->rom. Currently we attempt to access this pointer using phys_to_virt(), which doesn't work with CONFIG_HIGHMEM. On these systems, attempting to load the radeon module on a x86_32 kernel can result in the following: BUG: unable to handle page fault for address: 3e8ed03c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 317 Comm: systemd-udevd Not tainted 5.6.0-rc3-next-20200228 #2 Hardware name: Apple Computer, Inc. MacPro1,1/Mac-F4208DC8, BIOS MP11.88Z.005C.B08.0707021221 07/02/07 EIP: radeon_get_bios+0x5ed/0xe50 [radeon] Code: 00 00 84 c0 0f 85 12 fd ff ff c7 87 64 01 00 00 00 00 00 00 8b 47 08 8b 55 b0 e8 1e 83 e1 d6 85 c0 74 1a 8b 55 c0 85 d2 74 13 <80> 38 55 75 0e 80 78 01 aa 0f 84 a4 03 00 00 8d 74 26 00 68 dc 06 EAX: 3e8ed03c EBX: 00000000 ECX: 3e8ed03c EDX: 00010000 ESI: 00040000 EDI: eec04000 EBP: eef3fc60 ESP: eef3fbe0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206 CR0: 80050033 CR2: 3e8ed03c CR3: 2ec77000 CR4: 000006d0 Call Trace: r520_init+0x26/0x240 [radeon] radeon_device_init+0x533/0xa50 [radeon] radeon_driver_load_kms+0x80/0x220 [radeon] drm_dev_register+0xa7/0x180 [drm] radeon_pci_probe+0x10f/0x1a0 [radeon] pci_device_probe+0xd4/0x140 Fix the issue by updating all drivers which can access a platform provided ROM. Instead of calling the helper function pci_platform_rom() which uses phys_to_virt(), call ioremap() directly on the pdev->rom. radeon_read_platform_bios() previously directly accessed an __iomem pointer. Avoid this by calling memcpy_fromio() instead of kmemdup(). pci_platform_rom() now has no remaining callers, so remove it. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mikel Rychliski <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Acked-by: Alex Deucher <[email protected]>

Patch series "mm: memcontrol: recursive memory.low protection", v3. The current memory.low (and memory.min) semantics require protection to be assigned to a cgroup in an untinterrupted chain from the top-level cgroup all the way to the leaf. In practice, we want to protect entire cgroup subtrees from each other (system management software vs. workload), but we would like the VM to balance memory optimally *within* each subtree, without having to make explicit weight allocations among individual components. The current semantics make that impossible. They also introduce unmanageable complexity into more advanced resource trees. For example: host root `- system.slice `- rpm upgrades `- logging `- workload.slice `- a container `- system.slice `- workload.slice `- job A `- component 1 `- component 2 `- job B At a host-level perspective, we would like to protect the outer workload.slice subtree as a whole from rpm upgrades, logging etc. But for that to be effective, right now we'd have to propagate it down through the container, the inner workload.slice, into the job cgroup and ultimately the component cgroups where memory is actually, physically allocated. This may cross several tree delegation points and namespace boundaries, which make such a setup near impossible. CPU and IO on the other hand are already distributed recursively. The user would simply configure allowances at the host level, and they would apply to the entire subtree without any downward propagation. To enable the above-mentioned usecases and bring memory in line with other resource controllers, this patch series extends memory.low/min such that settings apply recursively to the entire subtree. Users can still assign explicit shares in subgroups, but if they don't, any ancestral protection will be distributed such that children compete freely amongst each other - as if no memory control were enabled inside the subtree - but enjoy protection from neighboring trees. In the above example, the user would then be able to configure shares of CPU, IO and memory at the host level to comprehensively protect and isolate the workload.slice as a whole from system.slice activity. Patch #1 fixes an existing bug that can give a cgroup tree more protection than it should receive as per ancestor configuration. Patch #2 simplifies and documents the existing code to make it easier to reason about the changes in the next patch. Patch #3 finally implements recursive memory protection semantics. Because of a risk of regressing legacy setups, the new semantics are hidden behind a cgroup2 mount option, 'memory_recursiveprot'. More details in patch #3. This patch (of 3): When memory.low is overcommitted - i.e. the children claim more protection than their shared ancestor grants them - the allowance is distributed in proportion to how much each sibling uses their own declared protection: low_usage = min(memory.low, memory.current) elow = parent_elow * (low_usage / siblings_low_usage) However, siblings_low_usage is not the sum of all low_usages. It sums up the usages of *only those cgroups that are within their memory.low* That means that low_usage can be *bigger* than siblings_low_usage, and consequently the total protection afforded to the children can be bigger than what the ancestor grants the subtree. Consider three groups where two are in excess of their protection: A/memory.low = 10G A/A1/memory.low = 10G, memory.current = 20G A/A2/memory.low = 10G, memory.current = 20G A/A3/memory.low = 10G, memory.current = 8G siblings_low_usage = 8G (only A3 contributes) A1/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(8G) = 12.5G -> 10G A2/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(8G) = 12.5G -> 10G A3/elow = parent_elow(10G) * low_usage(8G) / siblings_low_usage(8G) = 10.0G (the 12.5G are capped to the explicit memory.low setting of 10G) With that, the sum of all awarded protection below A is 30G, when A only grants 10G for the entire subtree. What does this mean in practice? A1 and A2 would still be in excess of their 10G allowance and would be reclaimed, whereas A3 would not. As they eventually drop below their protection setting, they would be counted in siblings_low_usage again and the error would right itself. When reclaim was applied in a binary fashion (cgroup is reclaimed when it's above its protection, otherwise it's skipped) this would actually work out just fine. However, since 1bc63fb ("mm, memcg: make scan aggression always exclude protection"), reclaim pressure is scaled to how much a cgroup is above its protection. As a result this calculation error unduly skews pressure away from A1 and A2 toward the rest of the system. But why did we do it like this in the first place? The reasoning behind exempting groups in excess from siblings_low_usage was to go after them first during reclaim in an overcommitted subtree: A/memory.low = 2G, memory.current = 4G A/A1/memory.low = 3G, memory.current = 2G A/A2/memory.low = 1G, memory.current = 2G siblings_low_usage = 2G (only A1 contributes) A1/elow = parent_elow(2G) * low_usage(2G) / siblings_low_usage(2G) = 2G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G While the children combined are overcomitting A and are technically both at fault, A2 is actively declaring unprotected memory and we would like to reclaim that first. However, while this sounds like a noble goal on the face of it, it doesn't make much difference in actual memory distribution: Because A is overcommitted, reclaim will not stop once A2 gets pushed back to within its allowance; we'll have to reclaim A1 either way. The end result is still that protection is distributed proportionally, with A1 getting 3/4 (1.5G) and A2 getting 1/4 (0.5G) of A's allowance. [ If A weren't overcommitted, it wouldn't make a difference since each cgroup would just get the protection it declares: A/memory.low = 2G, memory.current = 3G A/A1/memory.low = 1G, memory.current = 1G A/A2/memory.low = 1G, memory.current = 2G With the current calculation: siblings_low_usage = 1G (only A1 contributes) A1/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(1G) = 2G -> 1G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(1G) = 2G -> 1G Including excess groups in siblings_low_usage: siblings_low_usage = 2G A1/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G -> 1G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G -> 1G ] Simplify the calculation and fix the proportional reclaim bug by including excess cgroups in siblings_low_usage. After this patch, the effective memory.low distribution from the example above would be as follows: A/memory.low = 10G A/A1/memory.low = 10G, memory.current = 20G A/A2/memory.low = 10G, memory.current = 20G A/A3/memory.low = 10G, memory.current = 8G siblings_low_usage = 28G A1/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(28G) = 3.5G A2/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(28G) = 3.5G A3/elow = parent_elow(10G) * low_usage(8G) / siblings_low_usage(28G) = 2.8G Fixes: 1bc63fb ("mm, memcg: make scan aggression always exclude protection") Fixes: 2306715 ("mm: memory.low hierarchical behavior") Signed-off-by: Johannes Weiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: Tejun Heo <[email protected]> Acked-by: Roman Gushchin <[email protected]> Acked-by: Chris Down <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Michal Koutný <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>

Similar to commit 0266d81 ("acpi/processor: Prevent cpu hotplug deadlock") except this is for acpi_processor_ffh_cstate_probe(): "The problem is that the work is scheduled on the current CPU from the hotplug thread associated with that CPU. It's not required to invoke these functions via the workqueue because the hotplug thread runs on the target CPU already. Check whether current is a per cpu thread pinned on the target CPU and invoke the function directly to avoid the workqueue." WARNING: possible circular locking dependency detected ------------------------------------------------------ cpuhp/1/15 is trying to acquire lock: ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630 but task is already holding lock: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x3e/0xc0 irq_calc_affinity_vectors+0x5f/0x91 __pci_enable_msix_range+0x10f/0x9a0 pci_alloc_irq_vectors_affinity+0x13e/0x1f0 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208 pqi_ctrl_init+0x72f/0x1618 [smartpqi] pqi_pci_probe.cold.63+0x882/0x892 [smartpqi] local_pci_probe+0x7a/0xc0 work_for_cpu_fn+0x2e/0x50 process_one_work+0x57e/0xb90 worker_thread+0x363/0x5b0 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}: __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 other info that might help us debug this: Chain exists of: (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(cpuidle_lock); lock(cpuhp_state-up); lock(cpuidle_lock); lock((work_completion)(&wfc.work)); *** DEADLOCK *** 3 locks held by cpuhp/1/15: #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 Call Trace: dump_stack+0xa0/0xea print_circular_bug.cold.52+0x147/0x14c check_noncircular+0x295/0x2d0 __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 Signed-off-by: Qian Cai <[email protected]> Tested-by: Borislav Petkov <[email protected]> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <[email protected]>

Patch series "mm: Fix misuse of parent anon_vma in dup_mmap path". This patchset fixes the misuse of parenet anon_vma, which mainly caused by child vma's vm_next and vm_prev are left same as its parent after duplicate vma. Finally, code reached parent vma's neighbor by referring pointer of child vma and executed wrong logic. The first two patches fix relevant issues, and the third patch sets vm_next and vm_prev to NULL when duplicate vma to prevent potential misuse in future. Effects of the first bug is that causes rmap code to check both parent and child's page table, although a page couldn't be mapped by both parent and child, because child vma has WIPEONFORK so all pages mapped by child are 'new' and not relevant to parent. Effects of the second bug is that the relationship of anon_vma of parent and child are totallyconvoluted. It would cause 'son', 'grandson', ..., etc, to share 'parent' anon_vma, which disobey the design rule of reusing anon_vma (the rule to be followed is that reusing should among vma of same process, and vma should not gone through fork). So, both issues should cause unnecessary rmap walking and have unexpected complexity. These two issues would not be directly visible, I used debugging code to check the anon_vma pointers of parent and child when inspecting the suspicious implementation of issue #2, then find the problem. This patch (of 3): In dup_mmap(), anon_vma_prepare() is called for vma has VM_WIPEONFORK, and parameter 'tmp' (i.e., the new vma of child) has same ->vm_next and ->vm_prev as its parent vma. That allows anon_vma used by parent been mistakenly shared by child (find_mergeable_anon_vma() will do this reuse work). Besides this issue, call anon_vma_prepare() should be avoided because we don't copy page for this vma. Preparing anon_vma will be handled during fault. Fixes: d2cd9ed ("mm,fork: introduce MADV_WIPEONFORK") Signed-off-by: Li Xinhai <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Johannes Weiner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>

Ido Schimmel says: ==================== mlxsw: Two small changes Patch #1 increases the scale of supported IPv6 nexthops groups when each group has one nexthop and all are using the same nexthop device, but with a different gateway IP. Patch #2 adjusts a register definition in accordance with recent firmware changes. ==================== Signed-off-by: David S. Miller <[email protected]>

Petr Machata says: ==================== Add selftests for pedit ex munge ip6 dsfield Patch #1 extends the existing generic forwarding selftests to cover pedit ex munge ip6 traffic_class as well. Patch #2 adds TDC test coverage. ==================== Signed-off-by: David S. Miller <[email protected]>

Ido Schimmel says: ==================== mlxsw: Mirroring cleanups This patch set contains various cleanups in SPAN (mirroring) code noticed by Amit and I while working on future enhancements in this area. No functional changes intended. Tested by current mirroring selftests. Patches #1-#2 from Amit reduce nesting in a certain function and rename a callback to a more meaningful name. Patch #3 removes debug prints that have little value. Patch #4 converts a reference count to 'refcount_t' in order to catch over/under flows. Patch #5 replaces a zero-length array with flexible-array member in order to get a compiler warning in case the flexible array does not occur last in the structure. ==================== Signed-off-by: David S. Miller <[email protected]>

Access to genmask field in struct nft_set_ext results in unaligned atomic read: [ 72.130109] Unable to handle kernel paging request at virtual address ffff0000c2bb708c [ 72.131036] Mem abort info: [ 72.131213] ESR = 0x0000000096000021 [ 72.131446] EC = 0x25: DABT (current EL), IL = 32 bits [ 72.132209] SET = 0, FnV = 0 [ 72.133216] EA = 0, S1PTW = 0 [ 72.134080] FSC = 0x21: alignment fault [ 72.135593] Data abort info: [ 72.137194] ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000 [ 72.142351] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 72.145989] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 72.150115] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000237d27000 [ 72.154893] [ffff0000c2bb708c] pgd=0000000000000000, p4d=180000023ffff403, pud=180000023f84b403, pmd=180000023f835403, +pte=0068000102bb7707 [ 72.163021] Internal error: Oops: 0000000096000021 [#1] SMP [...] [ 72.170041] CPU: 7 UID: 0 PID: 54 Comm: kworker/7:0 Tainted: G E 6.13.0-rc3+ #2 [ 72.170509] Tainted: [E]=UNSIGNED_MODULE [ 72.170720] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-stable202302-for-qemu 03/01/2023 [ 72.171192] Workqueue: events_power_efficient nft_rhash_gc [nf_tables] [ 72.171552] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 72.171915] pc : nft_rhash_gc+0x200/0x2d8 [nf_tables] [ 72.172166] lr : nft_rhash_gc+0x128/0x2d8 [nf_tables] [ 72.172546] sp : ffff800081f2bce0 [ 72.172724] x29: ffff800081f2bd40 x28: ffff0000c2bb708c x27: 0000000000000038 [ 72.173078] x26: ffff0000c6780ef0 x25: ffff0000c643df00 x24: ffff0000c6778f78 [ 72.173431] x23: 000000000000001a x22: ffff0000c4b1f000 x21: ffff0000c6780f78 [ 72.173782] x20: ffff0000c2bb70dc x19: ffff0000c2bb7080 x18: 0000000000000000 [ 72.174135] x17: ffff0000c0a4e1c0 x16: 0000000000003000 x15: 0000ac26d173b978 [ 72.174485] x14: ffffffffffffffff x13: 0000000000000030 x12: ffff0000c6780ef0 [ 72.174841] x11: 0000000000000000 x10: ffff800081f2bcf8 x9 : ffff0000c3000000 [ 72.175193] x8 : 00000000000004be x7 : 0000000000000000 x6 : 0000000000000000 [ 72.175544] x5 : 0000000000000040 x4 : ffff0000c3000010 x3 : 0000000000000000 [ 72.175871] x2 : 0000000000003a98 x1 : ffff0000c2bb708c x0 : 0000000000000004 [ 72.176207] Call trace: [ 72.176316] nft_rhash_gc+0x200/0x2d8 [nf_tables] (P) [ 72.176653] process_one_work+0x178/0x3d0 [ 72.176831] worker_thread+0x200/0x3f0 [ 72.176995] kthread+0xe8/0xf8 [ 72.177130] ret_from_fork+0x10/0x20 [ 72.177289] Code: 54fff984 d503201f d2800080 91003261 (f820303f) [ 72.177557] ---[ end trace 0000000000000000 ]--- Align struct nft_set_ext to word size to address this and documentation it. pahole reports that this increases the size of elements for rhash and pipapo in 8 bytes on x86_64. Fixes: 7ffc748 ("netfilter: nft_set_hash: skip duplicated elements pending gc run") Signed-off-by: Pablo Neira Ayuso <[email protected]>

The mapping VMA address is saved in VAS window struct when the paste address is mapped. This VMA address is used during migration to unmap the paste address if the window is active. The paste address mapping will be removed when the window is closed or with the munmap(). But the VMA address in the VAS window is not updated with munmap() which is causing invalid access during migration. The KASAN report shows: [16386.254991] BUG: KASAN: slab-use-after-free in reconfig_close_windows+0x1a0/0x4e8 [16386.255043] Read of size 8 at addr c00000014a819670 by task drmgr/696928 [16386.255096] CPU: 29 UID: 0 PID: 696928 Comm: drmgr Kdump: loaded Tainted: G B 6.11.0-rc5-nxgzip #2 [16386.255128] Tainted: [B]=BAD_PAGE [16386.255148] Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1110.00 (NH1110_016) hv:phyp pSeries [16386.255181] Call Trace: [16386.255202] [c00000016b297660] [c0000000018ad0ac] dump_stack_lvl+0x84/0xe8 (unreliable) [16386.255246] [c00000016b297690] [c0000000006e8a90] print_report+0x19c/0x764 [16386.255285] [c00000016b297760] [c0000000006e9490] kasan_report+0x128/0x1f8 [16386.255309] [c00000016b297880] [c0000000006eb5c8] __asan_load8+0xac/0xe0 [16386.255326] [c00000016b2978a0] [c00000000013f898] reconfig_close_windows+0x1a0/0x4e8 [16386.255343] [c00000016b297990] [c000000000140e58] vas_migration_handler+0x3a4/0x3fc [16386.255368] [c00000016b297a90] [c000000000128848] pseries_migrate_partition+0x4c/0x4c4 ... [16386.256136] Allocated by task 696554 on cpu 31 at 16377.277618s: [16386.256149] kasan_save_stack+0x34/0x68 [16386.256163] kasan_save_track+0x34/0x80 [16386.256175] kasan_save_alloc_info+0x58/0x74 [16386.256196] __kasan_slab_alloc+0xb8/0xdc [16386.256209] kmem_cache_alloc_noprof+0x200/0x3d0 [16386.256225] vm_area_alloc+0x44/0x150 [16386.256245] mmap_region+0x214/0x10c4 [16386.256265] do_mmap+0x5fc/0x750 [16386.256277] vm_mmap_pgoff+0x14c/0x24c [16386.256292] ksys_mmap_pgoff+0x20c/0x348 [16386.256303] sys_mmap+0xd0/0x160 ... [16386.256350] Freed by task 0 on cpu 31 at 16386.204848s: [16386.256363] kasan_save_stack+0x34/0x68 [16386.256374] kasan_save_track+0x34/0x80 [16386.256384] kasan_save_free_info+0x64/0x10c [16386.256396] __kasan_slab_free+0x120/0x204 [16386.256415] kmem_cache_free+0x128/0x450 [16386.256428] vm_area_free_rcu_cb+0xa8/0xd8 [16386.256441] rcu_do_batch+0x2c8/0xcf0 [16386.256458] rcu_core+0x378/0x3c4 [16386.256473] handle_softirqs+0x20c/0x60c [16386.256495] do_softirq_own_stack+0x6c/0x88 [16386.256509] do_softirq_own_stack+0x58/0x88 [16386.256521] __irq_exit_rcu+0x1a4/0x20c [16386.256533] irq_exit+0x20/0x38 [16386.256544] interrupt_async_exit_prepare.constprop.0+0x18/0x2c ... [16386.256717] Last potentially related work creation: [16386.256729] kasan_save_stack+0x34/0x68 [16386.256741] __kasan_record_aux_stack+0xcc/0x12c [16386.256753] __call_rcu_common.constprop.0+0x94/0xd04 [16386.256766] vm_area_free+0x28/0x3c [16386.256778] remove_vma+0xf4/0x114 [16386.256797] do_vmi_align_munmap.constprop.0+0x684/0x870 [16386.256811] __vm_munmap+0xe0/0x1f8 [16386.256821] sys_munmap+0x54/0x6c [16386.256830] system_call_exception+0x1a0/0x4a0 [16386.256841] system_call_vectored_common+0x15c/0x2ec [16386.256868] The buggy address belongs to the object at c00000014a819670 which belongs to the cache vm_area_struct of size 168 [16386.256887] The buggy address is located 0 bytes inside of freed 168-byte region [c00000014a819670, c00000014a819718) [16386.256915] The buggy address belongs to the physical page: [16386.256928] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14a81 [16386.256950] memcg:c0000000ba430001 [16386.256961] anon flags: 0x43ffff800000000(node=4|zone=0|lastcpupid=0x7ffff) [16386.256975] page_type: 0xfdffffff(slab) [16386.256990] raw: 043ffff800000000 c00000000501c080 0000000000000000 5deadbee00000001 [16386.257003] raw: 0000000000000000 00000000011a011a 00000001fdffffff c0000000ba430001 [16386.257018] page dumped because: kasan: bad access detected This patch adds close() callback in vas_vm_ops vm_operations_struct which will be executed during munmap() before freeing VMA. The VMA address in the VAS window is set to NULL after holding the window mmap_mutex. Fixes: 37e6764 ("powerpc/pseries/vas: Add VAS migration handler") Signed-off-by: Haren Myneni <[email protected]> Signed-off-by: Madhavan Srinivasan <[email protected]> Link: https://patch.msgid.link/[email protected]

syzbot reports that a recent fix causes nesting issues between the (now) raw timeoutlock and the eventfd locking: ============================= [ BUG: Invalid wait context ] 6.13.0-rc4-00080-g9828a4c0901f #29 Not tainted ----------------------------- kworker/u32:0/68094 is trying to lock: ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180 other info that might help us debug this: context-{5:5} 6 locks held by kworker/u32:0/68094: #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 stack backtrace: CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f #29 Hardware name: linux,dummy-virt (DT) Workqueue: iou_exit io_ring_exit_work Call trace: show_stack+0x1c/0x30 (C) __dump_stack+0x24/0x30 dump_stack_lvl+0x60/0x80 dump_stack+0x14/0x20 __lock_acquire+0x19f8/0x60c8 lock_acquire+0x1a4/0x540 _raw_spin_lock_irqsave+0x90/0xd0 eventfd_signal_mask+0x64/0x180 io_eventfd_signal+0x64/0x108 io_req_local_work_add+0x294/0x430 __io_req_task_work_add+0x1c0/0x270 io_kill_timeout+0x1f0/0x288 io_kill_timeouts+0xd4/0x180 io_uring_try_cancel_requests+0x2e8/0x388 io_ring_exit_work+0x150/0x550 process_one_work+0x5e8/0xfc0 worker_thread+0x7ec/0xc80 kthread+0x24c/0x300 ret_from_fork+0x10/0x20 because after the preempt-rt fix for the timeout lock nesting inside the io-wq lock, we now have the eventfd spinlock nesting inside the raw timeout spinlock. Rather than play whack-a-mole with other nesting on the timeout lock, split the deletion and killing of timeouts so queueing the task_work for the timeout cancelations can get done outside of the timeout lock. Reported-by: [email protected] Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock") Signed-off-by: Jens Axboe <[email protected]>

…le_direct_reclaim() The task sometimes continues looping in throttle_direct_reclaim() because allow_direct_reclaim(pgdat) keeps returning false. #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c #2 [ffff80002cb6f990] schedule at ffff800008abc50c #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4 At this point, the pgdat contains the following two zones: NODE: 4 ZONE: 0 ADDR: ffff00817fffe540 NAME: "DMA32" SIZE: 20480 MIN/LOW/HIGH: 11/28/45 VM_STAT: NR_FREE_PAGES: 359 NR_ZONE_INACTIVE_ANON: 18813 NR_ZONE_ACTIVE_ANON: 0 NR_ZONE_INACTIVE_FILE: 50 NR_ZONE_ACTIVE_FILE: 0 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 NODE: 4 ZONE: 1 ADDR: ffff00817fffec00 NAME: "Normal" SIZE: 8454144 PRESENT: 98304 MIN/LOW/HIGH: 68/166/264 VM_STAT: NR_FREE_PAGES: 146 NR_ZONE_INACTIVE_ANON: 94668 NR_ZONE_ACTIVE_ANON: 3 NR_ZONE_INACTIVE_FILE: 735 NR_ZONE_ACTIVE_FILE: 78 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of inactive/active file-backed pages calculated in zone_reclaimable_pages() based on the result of zone_page_state_snapshot() is zero. Additionally, since this system lacks swap, the calculation of inactive/ active anonymous pages is skipped. crash> p nr_swap_pages nr_swap_pages = $1937 = { counter = 0 } As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having free pages significantly exceeding the high watermark. The problem is that the pgdat->kswapd_failures hasn't been incremented. crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures $1935 = 0x0 This is because the node deemed balanced. The node balancing logic in balance_pgdat() evaluates all zones collectively. If one or more zones (e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the entire node is deemed balanced. This causes balance_pgdat() to exit early before incrementing the kswapd_failures, as it considers the overall memory state acceptable, even though some zones (like ZONE_NORMAL) remain under significant pressure. The patch ensures that zone_reclaimable_pages() includes free pages (NR_FREE_PAGES) in its calculation when no other reclaimable pages are available (e.g., file-backed or anonymous pages). This change prevents zones like ZONE_DMA32, which have sufficient free pages, from being mistakenly deemed unreclaimable. By doing so, the patch ensures proper node balancing, avoids masking pressure on other zones like ZONE_NORMAL, and prevents infinite loops in throttle_direct_reclaim() caused by allow_direct_reclaim(pgdat) repeatedly returning false. The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused by a node being incorrectly deemed balanced despite pressure in certain zones, such as ZONE_NORMAL. This issue arises from zone_reclaimable_pages() returning 0 for zones without reclaimable file- backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient free pages to be skipped. The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored during reclaim, masking pressure in other zones. Consequently, pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback mechanisms in allow_direct_reclaim() from being triggered, leading to an infinite loop in throttle_direct_reclaim(). This patch modifies zone_reclaimable_pages() to account for free pages (NR_FREE_PAGES) when no other reclaimable pages exist. This ensures zones with sufficient free pages are not skipped, enabling proper balancing and reclaim behavior. [[email protected]: coding-style cleanups] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations") Signed-off-by: Seiji Nishikawa <[email protected]> Cc: Mel Gorman <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

We found a timeout problem with the pldm command on our system. The reason is that the MCTP-I3C driver has a race condition when receiving multiple-packet messages in multi-thread, resulting in a wrong packet order problem. We identified this problem by adding a debug message to the mctp_i3c_read function. According to the MCTP spec, a multiple-packet message must be composed in sequence, and if there is a wrong sequence, the whole message will be discarded and wait for the next SOM. For example, SOM → Pkt Seq #2 → Pkt Seq #1 → Pkt Seq #3 → EOM. Therefore, we try to solve this problem by adding a mutex to the mctp_i3c_read function. Before the modification, when a command requesting a multiple-packet message response is sent consecutively, an error usually occurs within 100 loops. After the mutex, it can go through 40000 loops without any error, and it seems to run well. Fixes: c8755b2 ("mctp i3c: MCTP I3C driver") Signed-off-by: Leo Yang <[email protected]> Link: https://patch.msgid.link/[email protected] [[email protected]: dropped already answered question from changelog] Signed-off-by: Paolo Abeni <[email protected]>

Daniel Machon says: ==================== net: lan969x: add FDMA support == Description: This series is the last of a multi-part series, that prepares and adds support for the new lan969x switch driver. The upstreaming efforts has been split into multiple series: 1) Prepare the Sparx5 driver for lan969x (merged) 2) Add support for lan969x (same basic features as Sparx5 provides excl. FDMA and VCAP, merged). 3) Add lan969x VCAP functionality (merged). 4) Add RGMII support (merged). --> 5) Add FDMA support. == FDMA support: The lan969x switch device uses the same FDMA engine as the Sparx5 switch device, with the same number of channels etc. This means we can utilize the newly added FDMA library, that is already in use by the lan966x and sparx5 drivers. As previous lan969x series, the FDMA implementation will hook into the Sparx5 implementation where possible, however both RX and TX handling will be done differently on lan969x and therefore requires a separate implementation of the RX and TX path. Details are in the commit description of the individual patches == Patch breakdown: Patch #1: Enable FDMA support on lan969x Patch #2: Split start()/stop() functions Patch #3: Activate TX FDMA in start() Patch #4: Ops out a few functions that differ on the two platforms Patch #5: Add FDMA implementation for lan969x v1: https://lore.kernel.org/20250109-sparx5-lan969x-switch-driver-5-v1-0-13d6d8451e63@microchip.com ==================== Link: https://patch.msgid.link/20250113-sparx5-lan969x-switch-driver-5-v2-0-c468f02fd623@microchip.com Signed-off-by: Jakub Kicinski <[email protected]>

Tariq Toukan says: ==================== net/mlx5e: CT: Add support for hardware steering This series start with one more HWS patch by Yevgeny, followed by patches that add support for connection tracking in hardware steering mode. It consists of: - patch #2 hooks up the CT ops for the new mode in the right places. - patch #3 moves a function into a common file, so it can be reused. - patch #4 uses the HWS API to implement connection tracking. The main advantage of hardware steering compared to software steering is vastly improved performance when adding/removing/updating rules. Using the T-Rex traffic generator to initiate multi-million UDP flows per second, a kernel running with these patches was able to offload ~600K unique UDP flows per second, a number around ~7x larger than software steering was able to achieve on the same hardware (256-thread AMD EPYC, 512 GB RAM, ConnectX 7 b2b). ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>

Fix a lockdep warning [1] observed during the write combining test. The warning indicates a potential nested lock scenario that could lead to a deadlock. However, this is a false positive alarm because the SF lock and its parent lock are distinct ones. The lockdep confusion arises because the locks belong to the same object class (i.e., struct mlx5_core_dev). To resolve this, the code has been refactored to avoid taking both locks. Instead, only the parent lock is acquired. [1] raw_ethernet_bw/2118 is trying to acquire lock: [ 213.619032] ffff88811dd75e08 (&dev->wc_state_lock){+.+.}-{3:3}, at: mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.620270] [ 213.620270] but task is already holding lock: [ 213.620943] ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3}, at: mlx5_wc_support_get+0x10c/0x210 [mlx5_core] [ 213.622045] [ 213.622045] other info that might help us debug this: [ 213.622778] Possible unsafe locking scenario: [ 213.622778] [ 213.623465] CPU0 [ 213.623815] ---- [ 213.624148] lock(&dev->wc_state_lock); [ 213.624615] lock(&dev->wc_state_lock); [ 213.625071] [ 213.625071] *** DEADLOCK *** [ 213.625071] [ 213.625805] May be due to missing lock nesting notation [ 213.625805] [ 213.626522] 4 locks held by raw_ethernet_bw/2118: [ 213.627019] #0: ffff88813f80d578 (&uverbs_dev->disassociate_srcu){.+.+}-{0:0}, at: ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs] [ 213.628088] #1: ffff88810fb23930 (&file->hw_destroy_rwsem){.+.+}-{3:3}, at: ib_init_ucontext+0x2d/0xf0 [ib_uverbs] [ 213.629094] #2: ffff88810fb23878 (&file->ucontext_lock){+.+.}-{3:3}, at: ib_init_ucontext+0x49/0xf0 [ib_uverbs] [ 213.630106] #3: ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3}, at: mlx5_wc_support_get+0x10c/0x210 [mlx5_core] [ 213.631185] [ 213.631185] stack backtrace: [ 213.631718] CPU: 1 UID: 0 PID: 2118 Comm: raw_ethernet_bw Not tainted 6.12.0-rc7_internal_net_next_mlx5_89a0ad0 #1 [ 213.632722] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 213.633785] Call Trace: [ 213.634099] [ 213.634393] dump_stack_lvl+0x7e/0xc0 [ 213.634806] print_deadlock_bug+0x278/0x3c0 [ 213.635265] __lock_acquire+0x15f4/0x2c40 [ 213.635712] lock_acquire+0xcd/0x2d0 [ 213.636120] ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.636722] ? mlx5_ib_enable_lb+0x24/0xa0 [mlx5_ib] [ 213.637277] __mutex_lock+0x81/0xda0 [ 213.637697] ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.638305] ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.638902] ? rcu_read_lock_sched_held+0x3f/0x70 [ 213.639400] ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.640016] mlx5_wc_support_get+0x18c/0x210 [mlx5_core] [ 213.640615] set_ucontext_resp+0x68/0x2b0 [mlx5_ib] [ 213.641144] ? debug_mutex_init+0x33/0x40 [ 213.641586] mlx5_ib_alloc_ucontext+0x18e/0x7b0 [mlx5_ib] [ 213.642145] ib_init_ucontext+0xa0/0xf0 [ib_uverbs] [ 213.642679] ib_uverbs_handler_UVERBS_METHOD_GET_CONTEXT+0x95/0xc0 [ib_uverbs] [ 213.643426] ? _copy_from_user+0x46/0x80 [ 213.643878] ib_uverbs_cmd_verbs+0xa6b/0xc80 [ib_uverbs] [ 213.644426] ? ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x130/0x130 [ib_uverbs] [ 213.645213] ? __lock_acquire+0xa99/0x2c40 [ 213.645675] ? lock_acquire+0xcd/0x2d0 [ 213.646101] ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs] [ 213.646625] ? reacquire_held_locks+0xcf/0x1f0 [ 213.647102] ? do_user_addr_fault+0x45d/0x770 [ 213.647586] ib_uverbs_ioctl+0xe0/0x170 [ib_uverbs] [ 213.648102] ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs] [ 213.648632] __x64_sys_ioctl+0x4d3/0xaa0 [ 213.649060] ? do_user_addr_fault+0x4a8/0x770 [ 213.649528] do_syscall_64+0x6d/0x140 [ 213.649947] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 213.650478] RIP: 0033:0x7fa179b0737b [ 213.650893] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7d 2a 0f 00 f7 d8 64 89 01 48 [ 213.652619] RSP: 002b:00007ffd2e6d46e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 213.653390] RAX: ffffffffffffffda RBX: 00007ffd2e6d47f8 RCX: 00007fa179b0737b [ 213.654084] RDX: 00007ffd2e6d47e0 RSI: 00000000c0181b01 RDI: 0000000000000003 [ 213.654767] RBP: 00007ffd2e6d47c0 R08: 00007fa1799be010 R09: 0000000000000002 [ 213.655453] R10: 00007ffd2e6d4960 R11: 0000000000000246 R12: 00007ffd2e6d487c [ 213.656170] R13: 0000000000000027 R14: 0000000000000001 R15: 00007ffd2e6d4f70 Fixes: d98995b ("net/mlx5: Reimplement write combining test") Signed-off-by: Yishai Hadas <[email protected]> Reviewed-by: Michael Guralnik <[email protected]> Reviewed-by: Larysa Zaremba <[email protected]> Signed-off-by: Tariq Toukan <[email protected]> Signed-off-by: Paolo Abeni <[email protected]>

Clear the port select structure on error so no stale values left after definers are destroyed. That's because the mlx5_lag_destroy_definers() always try to destroy all lag definers in the tt_map, so in the flow below lag definers get double-destroyed and cause kernel crash: mlx5_lag_port_sel_create() mlx5_lag_create_definers() mlx5_lag_create_definer() <- Failed on tt 1 mlx5_lag_destroy_definers() <- definers[tt=0] gets destroyed mlx5_lag_port_sel_create() mlx5_lag_create_definers() mlx5_lag_create_definer() <- Failed on tt 0 mlx5_lag_destroy_definers() <- definers[tt=0] gets double-destroyed Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 64k pages, 48-bit VAs, pgdp=0000000112ce2e00 [0000000000000008] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: iptable_raw bonding ip_gre ip6_gre gre ip6_tunnel tunnel6 geneve ip6_udp_tunnel udp_tunnel ipip tunnel4 ip_tunnel rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) ib_uverbs(OE) mlx5_fwctl(OE) fwctl(OE) mlx5_core(OE) mlxdevm(OE) ib_core(OE) mlxfw(OE) memtrack(OE) mlx_compat(OE) openvswitch nsh nf_conncount psample xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc netconsole overlay efi_pstore sch_fq_codel zram ip_tables crct10dif_ce qemu_fw_cfg fuse ipv6 crc_ccitt [last unloaded: mlx_compat(OE)] CPU: 3 UID: 0 PID: 217 Comm: kworker/u53:2 Tainted: G OE 6.11.0+ #2 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 Workqueue: mlx5_lag mlx5_do_bond_work [mlx5_core] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core] lr : mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core] sp : ffff800085fafb00 x29: ffff800085fafb00 x28: ffff0000da0c8000 x27: 0000000000000000 x26: ffff0000da0c8000 x25: ffff0000da0c8000 x24: ffff0000da0c8000 x23: ffff0000c31f81a0 x22: 0400000000000000 x21: ffff0000da0c8000 x20: 0000000000000000 x19: 0000000000000001 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffff8b0c9350 x14: 0000000000000000 x13: ffff800081390d18 x12: ffff800081dc3cc0 x11: 0000000000000001 x10: 0000000000000b10 x9 : ffff80007ab7304c x8 : ffff0000d00711f0 x7 : 0000000000000004 x6 : 0000000000000190 x5 : ffff00027edb3010 x4 : 0000000000000000 x3 : 0000000000000000 x2 : ffff0000d39b8000 x1 : ffff0000d39b8000 x0 : 0400000000000000 Call trace: mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core] mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core] mlx5_lag_destroy_definers+0xa0/0x108 [mlx5_core] mlx5_lag_port_sel_create+0x2d4/0x6f8 [mlx5_core] mlx5_activate_lag+0x60c/0x6f8 [mlx5_core] mlx5_do_bond_work+0x284/0x5c8 [mlx5_core] process_one_work+0x170/0x3e0 worker_thread+0x2d8/0x3e0 kthread+0x11c/0x128 ret_from_fork+0x10/0x20 Code: a9025bf5 aa0003f6 a90363f7 f90023f9 (f9400400) ---[ end trace 0000000000000000 ]--- Fixes: dc48516 ("net/mlx5: Lag, add support to create definers for LAG") Signed-off-by: Mark Zhang <[email protected]> Reviewed-by: Leon Romanovsky <[email protected]> Reviewed-by: Mark Bloch <[email protected]> Reviewed-by: Jacob Keller <[email protected]> Signed-off-by: Tariq Toukan <[email protected]> Signed-off-by: Paolo Abeni <[email protected]>

Petr Machata says: ==================== mlxsw: Move Tx header handling to PCI driver Amit Cohen writes: Tx header should be added to all packets transmitted from the CPU to Spectrum ASICs. Historically, handling this header was added as a driver function, as Tx header is different between Spectrum and Switch-X. From May 2021, there is no support for SwitchX-2 ASIC, and all the relevant code was removed. For now, there is no justification to handle Tx header as part of spectrum.c, we can handle this as part of PCI, in skb_transmit(). This change will also be useful when XDP support will be added to mlxsw, as for XDP_TX and XDP_REDIRECT actions, Tx header should be added before transmitting the packet. Patch set overview: Patches #1-#2 add structure to store Tx header info and initialize it Patch #3 moves definitions of Tx header fields to txheader.h Patch #4 moves Tx header handling to PCI driver Patch #5 removes unnecessary attribute ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>

irq_chip functions may be called in raw spinlock context. Therefore, we must also use a raw spinlock for our own internal locking. This fixes the following lockdep splat: [ 5.349336] ============================= [ 5.353349] [ BUG: Invalid wait context ] [ 5.357361] 6.13.0-rc5+ #69 Tainted: G W [ 5.363031] ----------------------------- [ 5.367045] kworker/u17:1/44 is trying to lock: [ 5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.380079] other info that might help us debug this: [ 5.385138] context-{5:5} [ 5.387762] 5 locks held by kworker/u17:1/44: [ 5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204) [ 5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205) [ 5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006) [ 5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596) [ 5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614) [ 5.436472] stack backtrace: [ 5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G W 6.13.0-rc5+ #69 [ 5.448690] Tainted: [W]=WARN [ 5.451656] Hardware name: xlnx,zynqmp (DT) [ 5.455845] Workqueue: events_unbound deferred_probe_work_func [ 5.461699] Call trace: [ 5.464147] show_stack+0x18/0x24 C [ 5.467821] dump_stack_lvl (lib/dump_stack.c:123) [ 5.471501] dump_stack (lib/dump_stack.c:130) [ 5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176) [ 5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814) [ 5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345) [ 5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250) [ 5.497645] irq_startup (kernel/irq/chip.c:270) [ 5.501143] __setup_irq (kernel/irq/manage.c:1807) [ 5.504728] request_threaded_irq (kernel/irq/manage.c:2208) Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support") Signed-off-by: Sean Anderson <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Bartosz Golaszewski <[email protected]>

This commit addresses a circular locking dependency issue within the GFX isolation mechanism. The problem was identified by a warning indicating a potential deadlock due to inconsistent lock acquisition order. - The `amdgpu_gfx_enforce_isolation_ring_begin_use` and `amdgpu_gfx_enforce_isolation_ring_end_use` functions previously acquired `enforce_isolation_mutex` and called `amdgpu_gfx_kfd_sch_ctrl`, leading to potential deadlocks. ie., If `amdgpu_gfx_kfd_sch_ctrl` is called while `enforce_isolation_mutex` is held, and `amdgpu_gfx_enforce_isolation_handler` is called while `kfd_sch_mutex` is held, it can create a circular dependency. By ensuring consistent lock usage, this fix resolves the issue: [ 606.297333] ====================================================== [ 606.297343] WARNING: possible circular locking dependency detected [ 606.297353] 6.10.0-amd-mlkd-610-311224-lof #19 Tainted: G OE [ 606.297365] ------------------------------------------------------ [ 606.297375] kworker/u96:3/3825 is trying to acquire lock: [ 606.297385] ffff9aa64e431cb8 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}, at: __flush_work+0x232/0x610 [ 606.297413] but task is already holding lock: [ 606.297423] ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu] [ 606.297725] which lock already depends on the new lock. [ 606.297738] the existing dependency chain (in reverse order) is: [ 606.297749] -> #2 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}: [ 606.297765] __mutex_lock+0x85/0x930 [ 606.297776] mutex_lock_nested+0x1b/0x30 [ 606.297786] amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu] [ 606.298007] amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu] [ 606.298225] amdgpu_ring_alloc+0x48/0x70 [amdgpu] [ 606.298412] amdgpu_ib_schedule+0x176/0x8a0 [amdgpu] [ 606.298603] amdgpu_job_run+0xac/0x1e0 [amdgpu] [ 606.298866] drm_sched_run_job_work+0x24f/0x430 [gpu_sched] [ 606.298880] process_one_work+0x21e/0x680 [ 606.298890] worker_thread+0x190/0x350 [ 606.298899] kthread+0xe7/0x120 [ 606.298908] ret_from_fork+0x3c/0x60 [ 606.298919] ret_from_fork_asm+0x1a/0x30 [ 606.298929] -> #1 (&adev->enforce_isolation_mutex){+.+.}-{3:3}: [ 606.298947] __mutex_lock+0x85/0x930 [ 606.298956] mutex_lock_nested+0x1b/0x30 [ 606.298966] amdgpu_gfx_enforce_isolation_handler+0x87/0x370 [amdgpu] [ 606.299190] process_one_work+0x21e/0x680 [ 606.299199] worker_thread+0x190/0x350 [ 606.299208] kthread+0xe7/0x120 [ 606.299217] ret_from_fork+0x3c/0x60 [ 606.299227] ret_from_fork_asm+0x1a/0x30 [ 606.299236] -> #0 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}: [ 606.299257] __lock_acquire+0x16f9/0x2810 [ 606.299267] lock_acquire+0xd1/0x300 [ 606.299276] __flush_work+0x250/0x610 [ 606.299286] cancel_delayed_work_sync+0x71/0x80 [ 606.299296] amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu] [ 606.299509] amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu] [ 606.299723] amdgpu_ring_alloc+0x48/0x70 [amdgpu] [ 606.299909] amdgpu_ib_schedule+0x176/0x8a0 [amdgpu] [ 606.300101] amdgpu_job_run+0xac/0x1e0 [amdgpu] [ 606.300355] drm_sched_run_job_work+0x24f/0x430 [gpu_sched] [ 606.300369] process_one_work+0x21e/0x680 [ 606.300378] worker_thread+0x190/0x350 [ 606.300387] kthread+0xe7/0x120 [ 606.300396] ret_from_fork+0x3c/0x60 [ 606.300406] ret_from_fork_asm+0x1a/0x30 [ 606.300416] other info that might help us debug this: [ 606.300428] Chain exists of: (work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work) --> &adev->enforce_isolation_mutex --> &adev->gfx.kfd_sch_mutex [ 606.300458] Possible unsafe locking scenario: [ 606.300468] CPU0 CPU1 [ 606.300476] ---- ---- [ 606.300484] lock(&adev->gfx.kfd_sch_mutex); [ 606.300494] lock(&adev->enforce_isolation_mutex); [ 606.300508] lock(&adev->gfx.kfd_sch_mutex); [ 606.300521] lock((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)); [ 606.300536] *** DEADLOCK *** [ 606.300546] 5 locks held by kworker/u96:3/3825: [ 606.300555] #0: ffff9aa5aa1f5d58 ((wq_completion)comp_1.1.0){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680 [ 606.300577] #1: ffffaa53c3c97e40 ((work_completion)(&sched->work_run_job)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680 [ 606.300600] #2: ffff9aa64e463c98 (&adev->enforce_isolation_mutex){+.+.}-{3:3}, at: amdgpu_gfx_enforce_isolation_ring_begin_use+0x1c3/0x5d0 [amdgpu] [ 606.300837] #3: ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu] [ 606.301062] #4: ffffffff8c1a5660 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x70/0x610 [ 606.301083] stack backtrace: [ 606.301092] CPU: 14 PID: 3825 Comm: kworker/u96:3 Tainted: G OE 6.10.0-amd-mlkd-610-311224-lof #19 [ 606.301109] Hardware name: Gigabyte Technology Co., Ltd. X570S GAMING X/X570S GAMING X, BIOS F7 03/22/2024 [ 606.301124] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched] [ 606.301140] Call Trace: [ 606.301146] <TASK> [ 606.301154] dump_stack_lvl+0x9b/0xf0 [ 606.301166] dump_stack+0x10/0x20 [ 606.301175] print_circular_bug+0x26c/0x340 [ 606.301187] check_noncircular+0x157/0x170 [ 606.301197] ? register_lock_class+0x48/0x490 [ 606.301213] __lock_acquire+0x16f9/0x2810 [ 606.301230] lock_acquire+0xd1/0x300 [ 606.301239] ? __flush_work+0x232/0x610 [ 606.301250] ? srso_alias_return_thunk+0x5/0xfbef5 [ 606.301261] ? mark_held_locks+0x54/0x90 [ 606.301274] ? __flush_work+0x232/0x610 [ 606.301284] __flush_work+0x250/0x610 [ 606.301293] ? __flush_work+0x232/0x610 [ 606.301305] ? __pfx_wq_barrier_func+0x10/0x10 [ 606.301318] ? mark_held_locks+0x54/0x90 [ 606.301331] ? srso_alias_return_thunk+0x5/0xfbef5 [ 606.301345] cancel_delayed_work_sync+0x71/0x80 [ 606.301356] amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu] [ 606.301661] amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu] [ 606.302050] ? srso_alias_return_thunk+0x5/0xfbef5 [ 606.302069] amdgpu_ring_alloc+0x48/0x70 [amdgpu] [ 606.302452] amdgpu_ib_schedule+0x176/0x8a0 [amdgpu] [ 606.302862] ? drm_sched_entity_error+0x82/0x190 [gpu_sched] [ 606.302890] amdgpu_job_run+0xac/0x1e0 [amdgpu] [ 606.303366] drm_sched_run_job_work+0x24f/0x430 [gpu_sched] [ 606.303388] process_one_work+0x21e/0x680 [ 606.303409] worker_thread+0x190/0x350 [ 606.303424] ? __pfx_worker_thread+0x10/0x10 [ 606.303437] kthread+0xe7/0x120 [ 606.303449] ? __pfx_kthread+0x10/0x10 [ 606.303463] ret_from_fork+0x3c/0x60 [ 606.303476] ? __pfx_kthread+0x10/0x10 [ 606.303489] ret_from_fork_asm+0x1a/0x30 [ 606.303512] </TASK> v2: Refactor lock handling to resolve circular dependency (Alex) - Introduced a `sched_work` flag to defer the call to `amdgpu_gfx_kfd_sch_ctrl` until after releasing `enforce_isolation_mutex`. - This change ensures that `amdgpu_gfx_kfd_sch_ctrl` is called outside the critical section, preventing the circular dependency and deadlock. - The `sched_work` flag is set within the mutex-protected section if conditions are met, and the actual function call is made afterward. - This approach ensures consistent lock acquisition order. Fixes: afefd6f ("drm/amdgpu: Implement Enforce Isolation Handler for KGD/KFD serialization") Cc: Christian König <[email protected]> Cc: Alex Deucher <[email protected]> Signed-off-by: Srinivasan Shanmugam <[email protected]> Suggested-by: Alex Deucher <[email protected]> Reviewed-by: Alex Deucher <[email protected]> Signed-off-by: Alex Deucher <[email protected]> (cherry picked from commit 0b6b2dd) Cc: [email protected]

syz reports an out of bounds read: ================================================================== BUG: KASAN: slab-out-of-bounds in ocfs2_match fs/ocfs2/dir.c:334 [inline] BUG: KASAN: slab-out-of-bounds in ocfs2_search_dirblock+0x283/0x6e0 fs/ocfs2/dir.c:367 Read of size 1 at addr ffff88804d8b9982 by task syz-executor.2/14802 CPU: 0 UID: 0 PID: 14802 Comm: syz-executor.2 Not tainted 6.13.0-rc4 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Sched_ext: serialise (enabled+all), task: runnable_at=-10ms Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x229/0x350 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x164/0x530 mm/kasan/report.c:489 kasan_report+0x147/0x180 mm/kasan/report.c:602 ocfs2_match fs/ocfs2/dir.c:334 [inline] ocfs2_search_dirblock+0x283/0x6e0 fs/ocfs2/dir.c:367 ocfs2_find_entry_id fs/ocfs2/dir.c:414 [inline] ocfs2_find_entry+0x1143/0x2db0 fs/ocfs2/dir.c:1078 ocfs2_find_files_on_disk+0x18e/0x530 fs/ocfs2/dir.c:1981 ocfs2_lookup_ino_from_name+0xb6/0x110 fs/ocfs2/dir.c:2003 ocfs2_lookup+0x30a/0xd40 fs/ocfs2/namei.c:122 lookup_open fs/namei.c:3627 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x145a/0x3870 fs/namei.c:3984 do_filp_open+0xe9/0x1c0 fs/namei.c:4014 do_sys_openat2+0x135/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x15d/0x1c0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f01076903ad Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f01084acfc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f01077cbf80 RCX: 00007f01076903ad RDX: 0000000000105042 RSI: 0000000020000080 RDI: ffffffffffffff9c RBP: 00007f01077cbf80 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f01077cbf80 R14: 00007f010764fc90 R15: 00007f010848d000 </TASK> ================================================================== And a general protection fault in ocfs2_prepare_dir_for_insert: ================================================================== loop0: detected capacity change from 0 to 32768 JBD2: Ignoring recovery information on journal ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 5096 Comm: syz-executor792 Not tainted 6.11.0-rc4-syzkaller-00002-gb0da640826ba #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:ocfs2_find_dir_space_id fs/ocfs2/dir.c:3406 [inline] RIP: 0010:ocfs2_prepare_dir_for_insert+0x3309/0x5c70 fs/ocfs2/dir.c:4280 Code: 00 00 e8 2a 25 13 fe e9 ba 06 00 00 e8 20 25 13 fe e9 4f 01 00 00 e8 16 25 13 fe 49 8d 7f 08 49 8d 5f 09 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 bd 23 00 00 48 89 d8 48 c1 e8 03 42 0f RSP: 0018:ffffc9000af9f020 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000009 RCX: ffff88801e27a440 RDX: 0000000000000000 RSI: 0000000000000400 RDI: 0000000000000008 RBP: ffffc9000af9f830 R08: ffffffff8380395b R09: ffffffff838090a7 R10: 0000000000000002 R11: ffff88801e27a440 R12: dffffc0000000000 R13: ffff88803c660878 R14: f700000000000088 R15: 0000000000000000 FS: 000055555a677380(0000) GS:ffff888020800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560bce569178 CR3: 000000001de5a000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292 vfs_mknod+0x36d/0x3b0 fs/namei.c:4088 do_mknodat+0x3ec/0x5b0 __do_sys_mknodat fs/namei.c:4166 [inline] __se_sys_mknodat fs/namei.c:4163 [inline] __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:4163 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2dafda3a99 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe336a6658 EFLAGS: 00000246 ORIG_RAX: 0000000000000103 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2dafda3a99 RDX: 00000000000021c0 RSI: 0000000020000040 RDI: 00000000ffffff9c RBP: 00007f2dafe1b5f0 R08: 0000000000004480 R09: 000055555a6784c0 R10: 0000000000000103 R11: 0000000000000246 R12: 00007ffe336a6680 R13: 00007ffe336a68a8 R14: 431bde82d7b634db R15: 00007f2dafdec03b </TASK> ================================================================== The two reports are all caused invalid negative i_size of dir inode. For ocfs2, dir_inode can't be negative or zero. Here add a check in which is called by ocfs2_check_dir_for_entry(). It fixes the second report as ocfs2_check_dir_for_entry() must be called before ocfs2_prepare_dir_for_insert(). Also set a up limit for dir with OCFS2_INLINE_DATA_FL. The i_size can't be great than blocksize. Link: https://lkml.kernel.org/r/[email protected] Reported-by: Jiacheng Xu <[email protected]> Link: https://lore.kernel.org/ocfs2-devel/[email protected]/T/#u Reported-by: [email protected] Link: https://lore.kernel.org/all/[email protected]/T/ Signed-off-by: Su Yue <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Jun Piao <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

Add read memory barrier to ensure the order of operations when accessing control queue descriptors. Specifically, we want to avoid cases where loads can be reordered: 1. Load #1 is dispatched to read descriptor flags. 2. Load #2 is dispatched to read some other field from the descriptor. 3. Load #2 completes, accessing memory/cache at a point in time when the DD flag is zero. 4. NIC DMA overwrites the descriptor, now the DD flag is one. 5. Any fields loaded before step 4 are now inconsistent with the actual descriptor state. Add read memory barrier between steps 1 and 2, so that load #2 is not executed until load #1 has completed. Fixes: 8077c72 ("idpf: add controlq init and reset checks") Reviewed-by: Przemek Kitszel <[email protected]> Reviewed-by: Sridhar Samudrala <[email protected]> Suggested-by: Lance Richardson <[email protected]> Signed-off-by: Emil Tantilov <[email protected]> Tested-by: Krishneil Singh <[email protected]> Signed-off-by: Tony Nguyen <[email protected]>

It isn't guaranteed that NETWORK_INTERFACE_INFO::LinkSpeed will always be set by the server, so the client must handle any values and then prevent oopses like below from happening: Oops: divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 UID: 0 PID: 1323 Comm: cat Not tainted 6.13.0-rc7 #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41 04/01/2014 RIP: 0010:cifs_debug_data_proc_show+0xa45/0x1460 [cifs] Code: 00 00 48 89 df e8 3b cd 1b c1 41 f6 44 24 2c 04 0f 84 50 01 00 00 48 89 ef e8 e7 d0 1b c1 49 8b 44 24 18 31 d2 49 8d 7c 24 28 <48> f7 74 24 18 48 89 c3 e8 6e cf 1b c1 41 8b 6c 24 28 49 8d 7c 24 RSP: 0018:ffffc90001817be0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88811230022c RCX: ffffffffc041bd99 RDX: 0000000000000000 RSI: 0000000000000567 RDI: ffff888112300228 RBP: ffff888112300218 R08: fffff52000302f5f R09: ffffed1022fa58ac R10: ffff888117d2c566 R11: 00000000fffffffe R12: ffff888112300200 R13: 000000012a15343f R14: 0000000000000001 R15: ffff888113f2db58 FS: 00007fe27119e740(0000) GS:ffff888148600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2633c5000 CR3: 0000000124da0000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0x159/0x1b0 ? cifs_debug_data_proc_show+0xa45/0x1460 [cifs] ? do_error_trap+0x90/0x130 ? cifs_debug_data_proc_show+0xa45/0x1460 [cifs] ? exc_divide_error+0x39/0x50 ? cifs_debug_data_proc_show+0xa45/0x1460 [cifs] ? asm_exc_divide_error+0x1a/0x20 ? cifs_debug_data_proc_show+0xa39/0x1460 [cifs] ? cifs_debug_data_proc_show+0xa45/0x1460 [cifs] ? seq_read_iter+0x42e/0x790 seq_read_iter+0x19a/0x790 proc_reg_read_iter+0xbe/0x110 ? __pfx_proc_reg_read_iter+0x10/0x10 vfs_read+0x469/0x570 ? do_user_addr_fault+0x398/0x760 ? __pfx_vfs_read+0x10/0x10 ? find_held_lock+0x8a/0xa0 ? __pfx_lock_release+0x10/0x10 ksys_read+0xd3/0x170 ? __pfx_ksys_read+0x10/0x10 ? __rcu_read_unlock+0x50/0x270 ? mark_held_locks+0x1a/0x90 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe271288911 Code: 00 48 8b 15 01 25 10 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 20 ad 01 00 f3 0f 1e fa 80 3d b5 a7 10 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec RSP: 002b:00007ffe87c079d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007fe271288911 RDX: 0000000000040000 RSI: 00007fe2633c6000 RDI: 0000000000000003 RBP: 00007ffe87c07a00 R08: 0000000000000000 R09: 00007fe2713e6380 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000040000 R13: 00007fe2633c6000 R14: 0000000000000003 R15: 0000000000000000 </TASK> Fix this by setting cifs_server_iface::speed to a sane value (1Gbps) by default when link speed is unset. Cc: Shyam Prasad N <[email protected]> Cc: Tom Talpey <[email protected]> Fixes: a6d8fb5 ("cifs: distribute channels across interfaces based on speed") Reported-by: Frank Sorenson <[email protected]> Reported-by: Jay Shin <[email protected]> Signed-off-by: Paulo Alcantara (Red Hat) <[email protected]> Signed-off-by: Steve French <[email protected]>

Function xen_pin_page calls xen_pte_lock, which in turn grab page table lock (ptlock). When locking, xen_pte_lock expect mm->page_table_lock to be held before grabbing ptlock, but this does not happen when pinning is caused by xen_mm_pin_all. This commit addresses lockdep warning below, which shows up when suspending a Xen VM. [ 3680.658422] Freezing user space processes [ 3680.660156] Freezing user space processes completed (elapsed 0.001 seconds) [ 3680.660182] OOM killer disabled. [ 3680.660192] Freezing remaining freezable tasks [ 3680.661485] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) [ 3680.685254] [ 3680.685265] ================================== [ 3680.685269] WARNING: Nested lock was not taken [ 3680.685274] 6.12.0+ #16 Tainted: G W [ 3680.685279] ---------------------------------- [ 3680.685283] migration/0/19 is trying to lock: [ 3680.685288] ffff88800bac33c0 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: xen_pin_page+0x175/0x1d0 [ 3680.685303] [ 3680.685303] but this task is not holding: [ 3680.685308] init_mm.page_table_lock [ 3680.685311] [ 3680.685311] stack backtrace: [ 3680.685316] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Tainted: G W 6.12.0+ #16 [ 3680.685324] Tainted: [W]=WARN [ 3680.685328] Stopper: multi_cpu_stop+0x0/0x120 <- __stop_cpus.constprop.0+0x8c/0xd0 [ 3680.685339] Call Trace: [ 3680.685344] <TASK> [ 3680.685347] dump_stack_lvl+0x77/0xb0 [ 3680.685356] __lock_acquire+0x917/0x2310 [ 3680.685364] lock_acquire+0xce/0x2c0 [ 3680.685369] ? xen_pin_page+0x175/0x1d0 [ 3680.685373] _raw_spin_lock_nest_lock+0x2f/0x70 [ 3680.685381] ? xen_pin_page+0x175/0x1d0 [ 3680.685386] xen_pin_page+0x175/0x1d0 [ 3680.685390] ? __pfx_xen_pin_page+0x10/0x10 [ 3680.685394] __xen_pgd_walk+0x233/0x2c0 [ 3680.685401] ? stop_one_cpu+0x91/0x100 [ 3680.685405] __xen_pgd_pin+0x5d/0x250 [ 3680.685410] xen_mm_pin_all+0x70/0xa0 [ 3680.685415] xen_pv_pre_suspend+0xf/0x280 [ 3680.685420] xen_suspend+0x57/0x1a0 [ 3680.685428] multi_cpu_stop+0x6b/0x120 [ 3680.685432] ? update_cpumasks_hier+0x7c/0xa60 [ 3680.685439] ? __pfx_multi_cpu_stop+0x10/0x10 [ 3680.685443] cpu_stopper_thread+0x8c/0x140 [ 3680.685448] ? smpboot_thread_fn+0x20/0x1f0 [ 3680.685454] ? __pfx_smpboot_thread_fn+0x10/0x10 [ 3680.685458] smpboot_thread_fn+0xed/0x1f0 [ 3680.685462] kthread+0xde/0x110 [ 3680.685467] ? __pfx_kthread+0x10/0x10 [ 3680.685471] ret_from_fork+0x2f/0x50 [ 3680.685478] ? __pfx_kthread+0x10/0x10 [ 3680.685482] ret_from_fork_asm+0x1a/0x30 [ 3680.685489] </TASK> [ 3680.685491] [ 3680.685491] other info that might help us debug this: [ 3680.685497] 1 lock held by migration/0/19: [ 3680.685500] #0: ffffffff8284df38 (pgd_lock){+.+.}-{3:3}, at: xen_mm_pin_all+0x14/0xa0 [ 3680.685512] [ 3680.685512] stack backtrace: [ 3680.685518] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Tainted: G W 6.12.0+ #16 [ 3680.685528] Tainted: [W]=WARN [ 3680.685531] Stopper: multi_cpu_stop+0x0/0x120 <- __stop_cpus.constprop.0+0x8c/0xd0 [ 3680.685538] Call Trace: [ 3680.685541] <TASK> [ 3680.685544] dump_stack_lvl+0x77/0xb0 [ 3680.685549] __lock_acquire+0x93c/0x2310 [ 3680.685554] lock_acquire+0xce/0x2c0 [ 3680.685558] ? xen_pin_page+0x175/0x1d0 [ 3680.685562] _raw_spin_lock_nest_lock+0x2f/0x70 [ 3680.685568] ? xen_pin_page+0x175/0x1d0 [ 3680.685572] xen_pin_page+0x175/0x1d0 [ 3680.685578] ? __pfx_xen_pin_page+0x10/0x10 [ 3680.685582] __xen_pgd_walk+0x233/0x2c0 [ 3680.685588] ? stop_one_cpu+0x91/0x100 [ 3680.685592] __xen_pgd_pin+0x5d/0x250 [ 3680.685596] xen_mm_pin_all+0x70/0xa0 [ 3680.685600] xen_pv_pre_suspend+0xf/0x280 [ 3680.685607] xen_suspend+0x57/0x1a0 [ 3680.685611] multi_cpu_stop+0x6b/0x120 [ 3680.685615] ? update_cpumasks_hier+0x7c/0xa60 [ 3680.685620] ? __pfx_multi_cpu_stop+0x10/0x10 [ 3680.685625] cpu_stopper_thread+0x8c/0x140 [ 3680.685629] ? smpboot_thread_fn+0x20/0x1f0 [ 3680.685634] ? __pfx_smpboot_thread_fn+0x10/0x10 [ 3680.685638] smpboot_thread_fn+0xed/0x1f0 [ 3680.685642] kthread+0xde/0x110 [ 3680.685645] ? __pfx_kthread+0x10/0x10 [ 3680.685649] ret_from_fork+0x2f/0x50 [ 3680.685654] ? __pfx_kthread+0x10/0x10 [ 3680.685657] ret_from_fork_asm+0x1a/0x30 [ 3680.685662] </TASK> [ 3680.685267] xen:grant_table: Grant tables using version 1 layout [ 3680.685921] OOM killer enabled. [ 3680.685934] Restarting tasks ... done. Signed-off-by: Maksym Planeta <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Message-ID: <[email protected]> Signed-off-by: Juergen Gross <[email protected]>

During the update procedure, when overwrite element in a pre-allocated htab, the freeing of old_element is protected by the bucket lock. The reason why the bucket lock is necessary is that the old_element has already been stashed in htab->extra_elems after alloc_htab_elem() returns. If freeing the old_element after the bucket lock is unlocked, the stashed element may be reused by concurrent update procedure and the freeing of old_element will run concurrently with the reuse of the old_element. However, the invocation of check_and_free_fields() may acquire a spin-lock which violates the lockdep rule because its caller has already held a raw-spin-lock (bucket lock). The following warning will be reported when such race happens: BUG: scheduling while atomic: test_progs/676/0x00000003 3 locks held by test_progs/676: #0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830 #1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500 #2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0 Modules linked in: bpf_testmod(O) Preemption disabled at: [<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500 CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11 Tainted: [W]=WARN, [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)... Call Trace: <TASK> dump_stack_lvl+0x57/0x70 dump_stack+0x10/0x20 __schedule_bug+0x120/0x170 __schedule+0x300c/0x4800 schedule_rtlock+0x37/0x60 rtlock_slowlock_locked+0x6d9/0x54c0 rt_spin_lock+0x168/0x230 hrtimer_cancel_wait_running+0xe9/0x1b0 hrtimer_cancel+0x24/0x30 bpf_timer_delete_work+0x1d/0x40 bpf_timer_cancel_and_free+0x5e/0x80 bpf_obj_free_fields+0x262/0x4a0 check_and_free_fields+0x1d0/0x280 htab_map_update_elem+0x7fc/0x1500 bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43 bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e bpf_prog_test_run_syscall+0x322/0x830 __sys_bpf+0x135d/0x3ca0 __x64_sys_bpf+0x75/0xb0 x64_sys_call+0x1b5/0xa10 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... </TASK> It seems feasible to break the reuse and refill of per-cpu extra_elems into two independent parts: reuse the per-cpu extra_elems with bucket lock being held and refill the old_element as per-cpu extra_elems after the bucket lock is unlocked. However, it will make the concurrent overwrite procedures on the same CPU return unexpected -E2BIG error when the map is full. Therefore, the patch fixes the lock problem by breaking the cancelling of bpf_timer into two steps for PREEMPT_RT: 1) use hrtimer_try_to_cancel() and check its return value 2) if the timer is running, use hrtimer_cancel() through a kworker to cancel it again Considering that the current implementation of hrtimer_cancel() will try to acquire a being held softirq_expiry_lock when the current timer is running, these steps above are reasonable. However, it also has downside. When the timer is running, the cancelling of the timer is delayed when releasing the last map uref. The delay is also fixable (e.g., break the cancelling of bpf timer into two parts: one part in locked scope, another one in unlocked scope), it can be revised later if necessary. It is a bit hard to decide the right fix tag. One reason is that the problem depends on PREEMPT_RT which is enabled in v6.12. Considering the softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced in v5.15, the bpf_timer commit is used in the fixes tag and an extra depends-on tag is added to state the dependency on PREEMPT_RT. Fixes: b00628b ("bpf: Introduce bpf timers.") Depends-on: v6.12+ with PREEMPT_RT enabled Reported-by: Sebastian Andrzej Siewior <[email protected]> Closes: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Hou Tao <[email protected]> Reviewed-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>

Hou Tao says: ==================== The patch set continues the previous work [1] to move all the freeings of htab elements out of bucket lock. One motivation for the patch set is the locking problem reported by Sebastian [2]: the freeing of bpf_timer under PREEMPT_RT may acquire a spin-lock (namely softirq_expiry_lock). However the freeing procedure for htab element has already held a raw-spin-lock (namely bucket lock), and it will trigger the warning: "BUG: scheduling while atomic" as demonstrated by the selftests patch. Another motivation is to reduce the locked scope of bucket lock. However, the patch set doesn't move all freeing of htab element out of bucket lock, it still keep the free of special fields in pre-allocated hash map under the protect of bucket lock in htab_map_update_elem(). The patch set is structured as follows: * Patch #1 moves the element freeing out of bucket lock for htab_lru_map_delete_node(). However the freeing is still in the locked scope of LRU raw spin lock. * Patch #2~#3 move the element freeing out of bucket lock for __htab_map_lookup_and_delete_elem() * Patch #4 cancels the bpf_timer in two steps to fix the locking problem in htab_map_update_elem() for PREEMPT_PRT. * Patch #5 adds a selftest for the locking problem Please see individual patches for more details. Comments are always welcome. --- v3: * patch #1: update the commit message to state that the freeing of special field is still in the locked scope of LRU raw spin lock * patch #4: cancel the bpf_timer in two steps only for PREEMPT_RT (suggested by Alexei) v2: https://lore.kernel.org/bpf/[email protected] * cancels the bpf timer in two steps instead of breaking the reuse the refill of per-cpu ->extra_elems into two steps v1: https://lore.kernel.org/bpf/[email protected] [1]: https://lore.kernel.org/bpf/[email protected] [2]: https://lore.kernel.org/bpf/[email protected] ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>

The 32-bit Debian kernel 6.12 fails to boot and crashes like this: init (pid 65): Protection id trap (code 7) CPU: 0 UID: 0 PID: 65 Comm: init Not tainted 6.12.9 #2 Hardware name: 9000/778/B160L YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI PSW: 00000000000001000000000000001111 Not tainted r00-03 0004000f 110d39d0 109a6558 12974400 r04-07 12a810e0 12a810e0 00000000 12a81144 r08-11 12a81174 00000007 00000000 00000002 r12-15 f8c55c08 0000006c 00000001 f8c55c08 r16-19 00000002 f8c58620 002da3a8 0000004e r20-23 00001a46 0000000f 10754f84 00000000 r24-27 00000000 00000003 12ae6980 1127b9d0 r28-31 00000000 00000000 12974440 109a6558 sr00-03 00000000 00000000 00000000 00000010 sr04-07 00000000 00000000 00000000 00000000 IASQ: 00000000 00000000 IAOQ: 110d39d0 110d39d4 IIR: baadf00d ISR: 00000000 IOR: 110d39d0 CPU: 0 CR30: 128740c0 CR31: 00000000 ORIG_R28: 000003f3 IAOQ[0]: 0x110d39d0 IAOQ[1]: 0x110d39d4 RP(r2): security_sk_free+0x70/0x1a4 Backtrace: [<10d8c844>] __sk_destruct+0x2bc/0x378 [<10d8e33c>] sk_destruct+0x68/0x8c [<10d8e3dc>] __sk_free+0x7c/0x148 [<10d8e560>] sk_free+0xb8/0xf0 [<10f6420c>] unix_release_sock+0x3ac/0x50c [<10f643b8>] unix_release+0x4c/0x7c [<10d832f8>] __sock_release+0x5c/0xf8 [<10d833b4>] sock_close+0x20/0x44 [<107ba52c>] __fput+0xf8/0x468 [<107baa08>] __fput_sync+0xb4/0xd4 [<107b471c>] sys_close+0x44/0x94 [<10405334>] syscall_exit+0x0/0x10 Bisecting points to this commit which triggers the issue: commit 417c564 Author: KP Singh <[email protected]> Date: Fri Aug 16 17:43:07 2024 +0200 lsm: replace indirect LSM hook calls with static calls After more analysis it seems that we don't fully implement the static calls and jump tables yet. Additionally the functions which mark kernel memory read-only or read-write-executable needs to be further enhanced to be able to fully support static calls. Enabling CONFIG_SECURITY_YAMA=y was one possibility to trigger the issue, although YAMA isn't the reason for the fault. As a temporary solution disable JUMP_LABEL functionality to avoid the crashes. Signed-off-by: Helge Deller <[email protected]> Cc: Guenter Roeck <[email protected]> Reviewed-by: Guenter Roeck <[email protected]> Cc: <[email protected]> # v6.12+

A regression was caused by commit e4b5ccd ("drm/v3d: Ensure job pointer is set to NULL after job completion"), but this commit is not yet in next-fixes, fast-forward it. Try #2, first one didn't have v6.13 in it. Signed-off-by: Maarten Lankhorst <[email protected]>

Ido Schimmel says: ==================== vxlan: Age FDB entries based on Rx traffic tl;dr - This patchset prevents VXLAN FDB entries from lingering if traffic is only forwarded to a silent host. The VXLAN driver maintains two timestamps for each FDB entry: 'used' and 'updated'. The first is refreshed by both the Rx and Tx paths and the second is refreshed upon migration. The driver ages out entries according to their 'used' time which means that an entry can linger when traffic is only forwarded to a silent host that might have migrated to a different remote. This patchset solves the problem by adjusting the above semantics and aligning them to those of the bridge driver. That is, 'used' time is refreshed by the Tx path, 'updated' time is refresh by Rx path or user space updates and entries are aged out according to their 'updated' time. Patches #1-#2 perform small changes in how the 'used' and 'updated' fields are accessed. Patches #3-#5 refresh the 'updated' time where needed. Patch #6 flips the driver to age out FDB entries according to their 'updated' time. Patch #7 removes unnecessary updates to the 'used' time. Patch #8 extends a test case to cover aging of FDB entries in the presence of Tx traffic. ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>

When COWing a relocation tree path, at relocation.c:replace_path(), we can trigger a lockdep splat while we are in the btrfs_search_slot() call against the relocation root. This happens in that callchain at ctree.c:read_block_for_search() when we happen to find a child extent buffer already loaded through the fs tree with a lockdep class set to the fs tree. So when we attempt to lock that extent buffer through a relocation tree we have to reset the lockdep class to the class for a relocation tree, since a relocation tree has extent buffers that used to belong to a fs tree and may currently be already loaded (we swap extent buffers between the two trees at the end of replace_path()). However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset the lockdep class at ctree.c:read_block_for_search() before we read lock an extent buffer, just like we did for btrfs_search_slot() in commit b40130b ("btrfs: fix lockdep splat with reloc root extent buffers"). So add the missing btrfs_maybe_reset_lockdep_class() calls before the attempts to read lock an extent buffer at ctree.c:read_block_for_search(). The lockdep splat was reported by syzbot and it looks like this: ====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted ------------------------------------------------------ syz.0.0/5335 is trying to acquire lock: ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 but task is already holding lock: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}: reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374 __lock_release kernel/locking/lockdep.c:5563 [inline] lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870 up_write+0x79/0x590 kernel/locking/rwsem.c:1629 btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660 btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755 btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153 replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224 merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692 merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942 relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (btrfs-tree-01/1){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693 btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189 btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline] btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132 btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573 btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755 btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153 btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351 btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline] btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330 btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline] btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374 vfs_rename+0xbdb/0xf00 fs/namei.c:5067 do_renameat2+0xd94/0x13f0 fs/namei.c:5224 __do_sys_renameat2 fs/namei.c:5258 [inline] __se_sys_renameat2 fs/namei.c:5255 [inline] __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (btrfs-tree-01){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline] read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610 btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237 replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224 merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692 merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942 relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-treloc-02/1); lock(btrfs-tree-01/1); lock(btrfs-treloc-02/1); rlock(btrfs-tree-01); *** DEADLOCK *** 8 locks held by syz.0.0/5335: #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559 #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183 #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086 #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659 #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288 #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288 #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189 #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189 stack backtrace: CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline] read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610 btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237 replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224 merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692 merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942 relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1ac6985d29 Code: ff ff c3 (...) RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29 RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007 RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88 </TASK> Reported-by: [email protected] Link: https://lore.kernel.org/linux-btrfs/[email protected]/ Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search") Signed-off-by: Filipe Manana <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>

In "one-shot" mode, turbostat 1. takes a counter snapshot 2. forks and waits for a child 3. takes the end counter snapshot and prints the result. But turbostat counter snapshots currently use affinity to travel around the system so that counter reads are "local", and this affinity must be cleared between #1 and #2 above. The offending commit removed that reset that allowed the child to run on cpu_present_set. Fix that issue, and improve upon the original by using cpu_possible_set for the child. This allows the child to also run on CPUs that hotplug online during its runtime. Reported-by: Zhang Rui <[email protected]> Fixes: 7bb3fe2 ("tools/power/turbostat: Obey allowed CPUs during startup") Signed-off-by: Len Brown <[email protected]>

libtraceevent parses and returns an array of argument fields, sometimes larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr", idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6 elements max, creating an out-of-bounds access. This runtime error is found by UBsan. The error message: $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1 builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]' #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966 #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110 #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436 #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897 #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335 #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502 #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351 #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404 #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448 #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556 #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360 #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6) 0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1) = 1 Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint") Signed-off-by: Howard Chu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]>

This fixes the following hard lockup in isolate_lru_folios() during memory reclaim. If the LRU mostly contains ineligible folios this may trigger watchdog. watchdog: Watchdog detected hard LOCKUP on cpu 173 RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0 Call Trace: _raw_spin_lock_irqsave+0x31/0x40 folio_lruvec_lock_irqsave+0x5f/0x90 folio_batch_move_lru+0x91/0x150 lru_add_drain_per_cpu+0x1c/0x40 process_one_work+0x17d/0x350 worker_thread+0x27b/0x3a0 kthread+0xe8/0x120 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1b/0x30 lruvec->lru_lock owner： PID: 2865 TASK: ffff888139214d40 CPU: 40 COMMAND: "kswapd0" #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde [exception RIP: isolate_lru_folios+403] RIP: ffffffffa597df53 RSP: ffffc90006fb7c28 RFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffc90006fb7c60 RCX: ffffea04a2196f88 RDX: ffffc90006fb7c60 RSI: ffffc90006fb7c60 RDI: ffffea04a2197048 RBP: ffff88812cbd3010 R8: ffffea04a2197008 R9: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffffea04a2197008 R13: ffffea04a2197048 R14: ffffc90006fb7de8 R15: 0000000003e3e937 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <NMI exception stack> #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788 #7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0 #8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354 #9 [ffffc90006fb7ef8] kthread at ffffffffa5748238 crash> Scenario: User processe are requesting a large amount of memory and keep page active. Then a module continuously requests memory from ZONE_DMA32 area. Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached. However pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area. Reproduce: Terminal 1: Construct to continuously increase pages active(anon). mkdir /tmp/memory mount -t tmpfs -o size=1024000M tmpfs /tmp/memory dd if=/dev/zero of=/tmp/memory/block bs=4M tail /tmp/memory/block Terminal 2: vmstat -a 1 active will increase. procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ... r b swpd free inact active si so bi bo 1 0 0 1445623076 45898836 83646008 0 0 0 1 0 0 1445623076 43450228 86094616 0 0 0 1 0 0 1445623076 41003480 88541364 0 0 0 1 0 0 1445623076 38557088 90987756 0 0 0 1 0 0 1445623076 36109688 93435156 0 0 0 1 0 0 1445619552 33663256 95881632 0 0 0 1 0 0 1445619804 31217140 98327792 0 0 0 1 0 0 1445619804 28769988 100774944 0 0 0 1 0 0 1445619804 26322348 103222584 0 0 0 1 0 0 1445619804 23875592 105669340 0 0 0 cat /proc/meminfo | head Active(anon) increase. MemTotal: 1579941036 kB MemFree: 1445618500 kB MemAvailable: 1453013224 kB Buffers: 6516 kB Cached: 128653956 kB SwapCached: 0 kB Active: 118110812 kB Inactive: 11436620 kB Active(anon): 115345744 kB Inactive(anon): 945292 kB When the Active(anon) is 115345744 kB, insmod module triggers the ZONE_DMA32 watermark. perf record -e vmscan:mm_vmscan_lru_isolate -aR perf script isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2 nr_skipped=2 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0 nr_skipped=0 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844 nr_skipped=28835844 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844 nr_skipped=28835844 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29 nr_skipped=29 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0 nr_skipped=0 nr_taken=0 lru=active_anon See nr_scanned=28835844. 28835844 * 4k = 115343376KB approximately equal to 115345744 kB. If increase Active(anon) to 1000G then insmod module triggers the ZONE_DMA32 watermark. hard lockup will occur. In my device nr_scanned = 0000000003e3e937 when hard lockup. Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB. [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53 ffffc90006fb7c30: 0000000000000020 0000000000000000 ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000 ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8 ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48 ffffc90006fb7c70: 0000000000000000 0000000000000000 ffffc90006fb7c80: 0000000000000000 0000000000000000 ffffc90006fb7c90: 0000000000000000 0000000000000000 ffffc90006fb7ca0: 0000000000000000 0000000003e3e937 ffffc90006fb7cb0: 0000000000000000 0000000000000000 ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000 About the Fixes: Why did it take eight years to be discovered? The problem requires the following conditions to occur: 1. The device memory should be large enough. 2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area. 3. The memory in ZONE_DMA32 needs to reach the watermark. If the memory is not large enough, or if the usage design of ZONE_DMA32 area memory is reasonable, this problem is difficult to detect. notes: The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL, but other suitable scenarios may also trigger the problem. Link: https://lkml.kernel.org/r/[email protected] Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis") Signed-off-by: liuye <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

Suman Ghosh says: ==================== Add af_xdp support for cn10k This patchset includes changes to support AF_XDP for cn10k chipsets. Both non-zero copy and zero copy will be supported after these changes. Also, the RSS will be reconfigured once a particular receive queue is added/removed to/from AF_XDP support. Patch #1: octeontx2-pf: use xdp_return_frame() to free xdp buffers Patch #2: octeontx2-pf: Add AF_XDP non-zero copy support Patch #3: octeontx2-pf: AF_XDP zero copy receive support Patch #4: octeontx2-pf: Reconfigure RSS table after enabling AF_XDP zerocopy on rx queue Patch #5: octeontx2-pf: Prepare for AF_XDP transmit Patch #6: octeontx2-pf: AF_XDP zero copy transmit support ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Paolo Abeni <[email protected]>

…ea as VM_ALLOC Erhard reported the following KASAN hit while booting his PowerMac G4 with a KASAN-enabled kernel 6.13-rc6: BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8 Write of size 8 at addr f1000000 by task chronyd/1293 CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2 Tainted: [W]=WARN Hardware name: PowerMac3,6 7455 0x80010303 PowerMac Call Trace: [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable) [c24375b0] [c0504998] print_report+0xdc/0x504 [c2437610] [c050475c] kasan_report+0xf8/0x108 [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8 [c24376c0] [c004c014] patch_instructions+0x15c/0x16c [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478 [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14 [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4 [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890 [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420 [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c --- interrupt: c00 at 0x5a1274 NIP: 005a1274 LR: 006a3b3c CTR: 005296c8 REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4) MSR: 0200f932 <VEC,EE,PR,FP,ME,IR,DR,RI> CR: 24004422 XER: 00000000 GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932 GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57 GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002 GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001 NIP [005a1274] 0x5a1274 LR [006a3b3c] 0x6a3b3c --- interrupt: c00 The buggy address belongs to the virtual mapping at [f1000000, f1002000) created by: text_area_cpu_up+0x20/0x190 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30 flags: 0x80000000(zone=2) raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001 raw: 00000000 page dumped because: kasan: bad access detected Memory state around the buggy address: f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not initialised hence not supposed to be used yet. Powerpc text patching infrastructure allocates a virtual memory area using get_vm_area() and flags it as VM_ALLOC. But that flag is meant to be used for vmalloc() and vmalloc() allocated memory is not supposed to be used before a call to __vmalloc_node_range() which is never called for that area. That went undetected until commit e4137f0 ("mm, kasan, kmsan: instrument copy_from/to_kernel_nofault") The area allocated by text_area_cpu_up() is not vmalloc memory, it is mapped directly on demand when needed by map_kernel_page(). There is no VM flag corresponding to such usage, so just pass no flag. That way the area will be unpoisonned and usable immediately. Reported-by: Erhard Furtner <[email protected]> Closes: https://lore.kernel.org/all/20250112135832.57c92322@yea/ Fixes: 37bc3e5 ("powerpc/lib/code-patching: Use alternate map for patch_instruction()") Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Madhavan Srinivasan <[email protected]> Link: https://patch.msgid.link/06621423da339b374f48c0886e3a5db18e896be8.1739342693.git.christophe.leroy@csgroup.eu

We have several places across the kernel where we want to access another task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making a call to syscall_get_arguments(). This works for register arguments right away by accessing the task's `regs' member of `struct pt_regs', however for stack arguments seen with 32-bit/o32 kernels things are more complicated. Technically they ought to be obtained from the user stack with calls to an access_remote_vm(), but we have an easier way available already. So as to be able to access syscall stack arguments as regular function arguments following the MIPS calling convention we copy them over from the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in handle_sys(), to the current stack frame's outgoing argument space at the top of the stack, which is where the handler called expects to see its incoming arguments. This area is also pointed at by the `pt_regs' pointer obtained by task_pt_regs(). Make the o32 stack argument space a proper member of `struct pt_regs' then, by renaming the existing member from `pad0' to `args' and using generated offsets to access the space. No functional change though. With the change in place the o32 kernel stack frame layout at the entry to a syscall handler invoked by handle_sys() is therefore as follows: $sp + 68 -> | ... | <- pt_regs.regs[9] +---------------------+ $sp + 64 -> | $t0 | <- pt_regs.regs[8] +---------------------+ $sp + 60 -> | $a3/argument #4 | <- pt_regs.regs[7] +---------------------+ $sp + 56 -> | $a2/argument #3 | <- pt_regs.regs[6] +---------------------+ $sp + 52 -> | $a1/argument #2 | <- pt_regs.regs[5] +---------------------+ $sp + 48 -> | $a0/argument #1 | <- pt_regs.regs[4] +---------------------+ $sp + 44 -> | $v1 | <- pt_regs.regs[3] +---------------------+ $sp + 40 -> | $v0 | <- pt_regs.regs[2] +---------------------+ $sp + 36 -> | $at | <- pt_regs.regs[1] +---------------------+ $sp + 32 -> | $zero | <- pt_regs.regs[0] +---------------------+ $sp + 28 -> | stack argument #8 | <- pt_regs.args[7] +---------------------+ $sp + 24 -> | stack argument #7 | <- pt_regs.args[6] +---------------------+ $sp + 20 -> | stack argument #6 | <- pt_regs.args[5] +---------------------+ $sp + 16 -> | stack argument #5 | <- pt_regs.args[4] +---------------------+ $sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3] +---------------------+ $sp + 8 -> | psABI space for $a2 | <- pt_regs.args[2] +---------------------+ $sp + 4 -> | psABI space for $a1 | <- pt_regs.args[1] +---------------------+ $sp + 0 -> | psABI space for $a0 | <- pt_regs.args[0] +---------------------+ holding user data received and with the first 4 frame slots reserved by the psABI for the compiler to spill the incoming arguments from $a0-$a3 registers (which it sometimes does according to its needs) and the next 4 frame slots designated by the psABI for any stack function arguments that follow. This data is also available for other tasks to peek/poke at as reqired and where permitted. Signed-off-by: Maciej W. Rozycki <[email protected]> Signed-off-by: Thomas Bogendoerfer <[email protected]>

…/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.14, take #2 - Large set of fixes for vector handling, specially in the interactions between host and guest state. This fixes a number of bugs affecting actual deployments, and greatly simplifies the FP/SIMD/SVE handling. Thanks to Mark Rutland for dealing with this thankless task. - Fix an ugly race between vcpu and vgic creation/init, resulting in unexpected behaviours. - Fix use of kernel VAs at EL2 when emulating timers with nVHE. - Small set of pKVM improvements and cleanups.

Since commit 6037802 ("power: supply: core: implement extension API") there is the following ABBA deadlock (simplified) between the LED trigger code and the power-supply code: 1) When registering a power-supply class device, power_supply_register() calls led_trigger_register() from power_supply_create_triggers() in a scoped_guard(rwsem_read, &psy->extensions_sem) context. led_trigger_register() then in turn takes a LED subsystem lock. So here we have the following locking order: * Read-lock extensions_sem * Lock LED subsystem lock(s) 2) When registering a LED class device, with its default trigger set to a power-supply LED trigger (which has already been registered) The LED class code calls power_supply_led_trigger_activate() when setting up the default trigger. power_supply_led_trigger_activate() calls power_supply_get_property() to determine the initial value of to assign to the LED and that read-locks extensions_sem. So now we have the following locking order: * Lock LED subsystem lock(s) * Read-lock extensions_sem Fixing this is easy, there is no need to hold the extensions_sem when calling power_supply_create_triggers() since all triggers are always created rather then checking for the presence of certain attributes as power_supply_add_hwmon_sysfs() does. Move power_supply_create_triggers() out of the guard block to fix this. Here is the lockdep report fixed by this change: [ 31.249343] ====================================================== [ 31.249378] WARNING: possible circular locking dependency detected [ 31.249413] 6.13.0-rc6+ #251 Tainted: G C E [ 31.249440] ------------------------------------------------------ [ 31.249471] (udev-worker)/553 is trying to acquire lock: [ 31.249501] ffff892adbcaf660 (&psy->extensions_sem){.+.+}-{4:4}, at: power_supply_get_property.part.0+0x22/0x150 [ 31.249574] but task is already holding lock: [ 31.249603] ffff892adbc0bad0 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x34/0xe0 [ 31.249657] which lock already depends on the new lock. [ 31.249696] the existing dependency chain (in reverse order) is: [ 31.249735] -> #2 (&led_cdev->trigger_lock){+.+.}-{4:4}: [ 31.249778] down_write+0x3b/0xd0 [ 31.249803] led_trigger_set_default+0x34/0xe0 [ 31.249833] led_classdev_register_ext+0x311/0x3a0 [ 31.249863] input_leds_connect+0x1dc/0x2a0 [ 31.249889] input_attach_handler.isra.0+0x75/0x90 [ 31.249921] input_register_device.cold+0xa1/0x150 [ 31.249955] hidinput_connect+0x8a2/0xb80 [ 31.249982] hid_connect+0x582/0x5c0 [ 31.250007] hid_hw_start+0x3f/0x60 [ 31.250030] hid_device_probe+0x122/0x1f0 [ 31.250053] really_probe+0xde/0x340 [ 31.250080] __driver_probe_device+0x78/0x110 [ 31.250105] driver_probe_device+0x1f/0xa0 [ 31.250132] __device_attach_driver+0x85/0x110 [ 31.250160] bus_for_each_drv+0x78/0xc0 [ 31.250184] __device_attach+0xb0/0x1b0 [ 31.250207] bus_probe_device+0x94/0xb0 [ 31.250230] device_add+0x64a/0x860 [ 31.250252] hid_add_device+0xe5/0x240 [ 31.250279] usbhid_probe+0x4dc/0x620 [ 31.250303] usb_probe_interface+0xe4/0x2a0 [ 31.250329] really_probe+0xde/0x340 [ 31.250353] __driver_probe_device+0x78/0x110 [ 31.250377] driver_probe_device+0x1f/0xa0 [ 31.250404] __device_attach_driver+0x85/0x110 [ 31.250431] bus_for_each_drv+0x78/0xc0 [ 31.250455] __device_attach+0xb0/0x1b0 [ 31.250478] bus_probe_device+0x94/0xb0 [ 31.250501] device_add+0x64a/0x860 [ 31.250523] usb_set_configuration+0x606/0x8a0 [ 31.250552] usb_generic_driver_probe+0x3e/0x60 [ 31.250579] usb_probe_device+0x3d/0x120 [ 31.250605] really_probe+0xde/0x340 [ 31.250629] __driver_probe_device+0x78/0x110 [ 31.250653] driver_probe_device+0x1f/0xa0 [ 31.250680] __device_attach_driver+0x85/0x110 [ 31.250707] bus_for_each_drv+0x78/0xc0 [ 31.250731] __device_attach+0xb0/0x1b0 [ 31.250753] bus_probe_device+0x94/0xb0 [ 31.250776] device_add+0x64a/0x860 [ 31.250798] usb_new_device.cold+0x141/0x38f [ 31.250828] hub_event+0x1166/0x1980 [ 31.250854] process_one_work+0x20f/0x580 [ 31.250879] worker_thread+0x1d1/0x3b0 [ 31.250904] kthread+0xee/0x120 [ 31.250926] ret_from_fork+0x30/0x50 [ 31.250954] ret_from_fork_asm+0x1a/0x30 [ 31.250982] -> #1 (triggers_list_lock){++++}-{4:4}: [ 31.251022] down_write+0x3b/0xd0 [ 31.251045] led_trigger_register+0x40/0x1b0 [ 31.251074] power_supply_register_led_trigger+0x88/0x150 [ 31.251107] power_supply_create_triggers+0x55/0xe0 [ 31.251135] __power_supply_register.part.0+0x34e/0x4a0 [ 31.251164] devm_power_supply_register+0x70/0xc0 [ 31.251190] bq27xxx_battery_setup+0x1a1/0x6d0 [bq27xxx_battery] [ 31.251235] bq27xxx_battery_i2c_probe+0xe5/0x17f [bq27xxx_battery_i2c] [ 31.251272] i2c_device_probe+0x125/0x2b0 [ 31.251299] really_probe+0xde/0x340 [ 31.251324] __driver_probe_device+0x78/0x110 [ 31.251348] driver_probe_device+0x1f/0xa0 [ 31.251375] __driver_attach+0xba/0x1c0 [ 31.251398] bus_for_each_dev+0x6b/0xb0 [ 31.251421] bus_add_driver+0x111/0x1f0 [ 31.251445] driver_register+0x6e/0xc0 [ 31.251470] i2c_register_driver+0x41/0xb0 [ 31.251498] do_one_initcall+0x5e/0x3a0 [ 31.251522] do_init_module+0x60/0x220 [ 31.251550] __do_sys_init_module+0x15f/0x190 [ 31.251575] do_syscall_64+0x93/0x180 [ 31.251598] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 31.251629] -> #0 (&psy->extensions_sem){.+.+}-{4:4}: [ 31.251668] __lock_acquire+0x13ce/0x21c0 [ 31.251694] lock_acquire+0xcf/0x2e0 [ 31.251719] down_read+0x3e/0x170 [ 31.251741] power_supply_get_property.part.0+0x22/0x150 [ 31.251774] power_supply_update_leds+0x8d/0x230 [ 31.251804] power_supply_led_trigger_activate+0x18/0x20 [ 31.251837] led_trigger_set+0x1fc/0x300 [ 31.251863] led_trigger_set_default+0x90/0xe0 [ 31.251892] led_classdev_register_ext+0x311/0x3a0 [ 31.251921] devm_led_classdev_multicolor_register_ext+0x6e/0xb80 [led_class_multicolor] [ 31.251969] ktd202x_probe+0x464/0x5c0 [leds_ktd202x] [ 31.252002] i2c_device_probe+0x125/0x2b0 [ 31.252027] really_probe+0xde/0x340 [ 31.252052] __driver_probe_device+0x78/0x110 [ 31.252076] driver_probe_device+0x1f/0xa0 [ 31.252103] __driver_attach+0xba/0x1c0 [ 31.252125] bus_for_each_dev+0x6b/0xb0 [ 31.252148] bus_add_driver+0x111/0x1f0 [ 31.252172] driver_register+0x6e/0xc0 [ 31.252197] i2c_register_driver+0x41/0xb0 [ 31.252225] do_one_initcall+0x5e/0x3a0 [ 31.252248] do_init_module+0x60/0x220 [ 31.252274] __do_sys_init_module+0x15f/0x190 [ 31.253986] do_syscall_64+0x93/0x180 [ 31.255826] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 31.257614] other info that might help us debug this: [ 31.257619] Chain exists of: &psy->extensions_sem --> triggers_list_lock --> &led_cdev->trigger_lock [ 31.257630] Possible unsafe locking scenario: [ 31.257632] CPU0 CPU1 [ 31.257633] ---- ---- [ 31.257634] lock(&led_cdev->trigger_lock); [ 31.257637] lock(triggers_list_lock); [ 31.257640] lock(&led_cdev->trigger_lock); [ 31.257643] rlock(&psy->extensions_sem); [ 31.257646] *** DEADLOCK *** [ 31.289433] 4 locks held by (udev-worker)/553: [ 31.289443] #0: ffff892ad9658108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xaf/0x1c0 [ 31.289463] #1: ffff892adbc0bbc8 (&led_cdev->led_access){+.+.}-{4:4}, at: led_classdev_register_ext+0x1c7/0x3a0 [ 31.289476] #2: ffffffffad0e30b0 (triggers_list_lock){++++}-{4:4}, at: led_trigger_set_default+0x2c/0xe0 [ 31.289487] #3: ffff892adbc0bad0 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x34/0xe0 Fixes: 6037802 ("power: supply: core: implement extension API") Cc: Thomas Weißschuh <[email protected]> Cc: Armin Wolf <[email protected]> Signed-off-by: Hans de Goede <[email protected]> Reviewed-by: Thomas Weißschuh <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sebastian Reichel <[email protected]>

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reduce hooking in TCP code #2

reduce hooking in TCP code #2

pabeni commented Mar 19, 2020