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reduce hooking in TCP code #2

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pabeni opened this issue Mar 19, 2020 · 3 comments
Closed

reduce hooking in TCP code #2

pabeni opened this issue Mar 19, 2020 · 3 comments

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@pabeni
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pabeni commented Mar 19, 2020

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

pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <jslaby@suse.cz>
Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com
Fixes: 07e6124 ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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/20200227112708.93023-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <davem@davemloft.net>
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <lyude@redhat.com>
Fixes: cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
Cc: Sean Paul <seanpaul@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Mikita Lipski <mikita.lipski@amd.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200309210131.1497545-1-lyude@redhat.com
pkrystad pushed a commit to pkrystad/mptcp_net-next that referenced this issue Mar 19, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 21, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 25, 2020
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 <andre.przywara@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 26, 2020
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 <ast@kernel.org>
jenkins-tessares pushed a commit that referenced this issue Mar 26, 2020
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 <jakub@cloudflare.com>
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/158385850787.30597.8346421465837046618.stgit@john-Precision-5820-Tower
jenkins-tessares pushed a commit that referenced this issue Mar 26, 2020
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 <peterx@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>                                                                                                                                                                       
Link: https://lkml.kernel.org/r/20200312205830.81796-1-peterx@redhat.com
jenkins-tessares pushed a commit that referenced this issue Mar 26, 2020
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 <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Link: http://lkml.kernel.org/r/20200317175640.2047-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jenkins-tessares pushed a commit that referenced this issue Mar 27, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 27, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 28, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Mar 31, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Apr 1, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Apr 1, 2020
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 <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
[ add patchset cover letter with background and numbers ]
Signed-off-by: David Sterba <dsterba@suse.com>
jenkins-tessares pushed a commit that referenced this issue Apr 1, 2020
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: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
jenkins-tessares pushed a commit that referenced this issue Apr 1, 2020
…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 <tomi.valkeinen@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200320125200.6772-1-peter.ujfalusi@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jenkins-tessares pushed a commit that referenced this issue Apr 1, 2020
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: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
jenkins-tessares pushed a commit that referenced this issue Apr 8, 2020
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 <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
jenkins-tessares pushed a commit that referenced this issue Apr 8, 2020
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/20200319021623.5426-1-mikel@mikelr.com
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
jenkins-tessares pushed a commit that referenced this issue Apr 8, 2020
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 <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Link: http://lkml.kernel.org/r/20200227195606.46212-2-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jenkins-tessares pushed a commit that referenced this issue Apr 8, 2020
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 <cai@lca.pw>
Tested-by: Borislav Petkov <bp@suse.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
jenkins-tessares pushed a commit that referenced this issue Apr 9, 2020
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 <lixinhai.lxh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/1581150928-3214-2-git-send-email-lixinhai.lxh@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jenkins-tessares pushed a commit that referenced this issue Apr 21, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Apr 24, 2020
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 <davem@davemloft.net>
jenkins-tessares pushed a commit that referenced this issue Apr 25, 2020
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 <davem@davemloft.net>
matttbe pushed a commit that referenced this issue Nov 12, 2024
Ley Foon Tan says:

====================
net: stmmac: dwmac4: Fixes issues in dwmac4

This patch series fixes issues in the dwmac4 driver. These three patches
don't cause any user-visible issues, so they are targeted for net-next.

Patch #1:
Corrects the masking logic in the MTL Operation Mode RTC mask and shift
macros. The current code lacks the use of the ~ operator, which is
necessary to clear the bits properly.

Patch #2:
Addresses inaccuracies in the MTL_OP_MODE_*_MASK macros. The RTC fields
are located in bits [1:0], and this patch ensures the mask and shift
macros use the appropriate values to reflect this.

Patch #3:
Moves the handling of the Receive Watchdog Timeout (RWT) out of the
Abnormal Interrupt Summary (AIS) condition. According to the databook,
the RWT interrupt is not included in the AIS.

v1: https://lore.kernel.org/20241023112005.GN402847@kernel.org
v2: https://lore.kernel.org/20241101082336.1552084-3-leyfoon.tan@starfivetech.com
====================

Link: https://patch.msgid.link/20241107063637.2122726-1-leyfoon.tan@starfivetech.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MPTCPimporter pushed a commit that referenced this issue Nov 13, 2024
Inet-diag has two modes: (1) dumping information for a specific socket,
for which kernel creates one netlink message with the information and
(2) dumping information for multiple sockets (possibly with a filter),
where for the reply kernel sends many messages, one for each matched
socket.

Currently those two modes work differently as the information about
a specific socket is never split between multiple messages. For (2),
multi-socket dump for the reply kernel allocates up to 32Kb skb and
fills that with as many socket dumps as possible. For (1), one-socket
dump kernel pre-calculates the required space for the reply, allocates
a new skb and nlmsg and only then starts filling the socket's details.

Preallocating the needed size quite makes sense as most of the details
are fix-sized and provided for each socket, see inet_sk_attr_size().
But there's an exception: .idiag_get_aux_size() which is optional for
a socket. This is provided only for TCP sockets by tcp_diag.

For TCP-MD5 it calculates the memory needed to fill an array of
(struct tcp_diag_md5sig). The issue here is that the amount of keys may
change in inet_diag_dump_one_icsk() between inet_sk_attr_size() and
sk_diag_fill() calls. As the code expects fix-sized information on any
socket, it considers sk_diag_fill() failures by -EMSGSIZE reason as
a bug, resulting in such WARN_ON():

[] ------------[ cut here ]------------
[] WARNING: CPU: 7 PID: 17420 at net/ipv4/inet_diag.c:586 inet_diag_dump_one_icsk+0x3c8/0x420
[] CPU: 7 UID: 0 PID: 17420 Comm: diag_ipv4 Tainted: G        W          6.11.0-rc6-00022-gc9fd7a9f9aca-dirty #2
[] pc : inet_diag_dump_one_icsk+0x3c8/0x420
[] lr : inet_diag_dump_one_icsk+0x1d4/0x420
[] sp : ffff8000aef87460
...
[] Call trace:
[]  inet_diag_dump_one_icsk+0x3c8/0x420
[]  tcp_diag_dump_one+0xa0/0xf0
[]  inet_diag_cmd_exact+0x234/0x278
[]  inet_diag_handler_cmd+0x16c/0x288
[]  sock_diag_rcv_msg+0x1a8/0x550
[]  netlink_rcv_skb+0x198/0x378
[]  sock_diag_rcv+0x20/0x48
[]  netlink_unicast+0x400/0x6a8
[]  netlink_sendmsg+0x654/0xa58
[]  __sys_sendto+0x1ec/0x330
[]  __arm64_sys_sendto+0xc8/0x168
...
[] ---[ end trace 0000000000000000 ]---

One way to solve it would be to grab lock_sock() in
inet_diag_dump_one_icsk(), but that may be costly and bring new lock
dependencies. The alternative is to call tcp_diag_put_md5sig() as
the last attribute of the netlink message and calculate how much space
left after all previous attributes filled and translate it into
(struct tcp_diag_md5sig)-sized units. If it turns out that there's not
enough space for all TCP-MD5 keys, mark the dump as inconsistent by
setting NLM_F_DUMP_INTR flag. Userspace may figure out that dumping
raced with the socket properties change and retry again.

Currently it may be unexpected by userspace that netlink message for one
socket may be inconsistent, but I believe we're on a safe side from
breaking userspace as previously dump would fail and an ugly WARN was
produced in dmesg. IOW, it is a clear improvement.

This is not a theoretical issue: I've written a test and that reproduces
the issue I suspected (the backtrace above).

Fixes: c03fa9b ("tcp_diag: report TCP MD5 signing keys and addresses")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Message-Id: <20241113-tcp-md5-diag-prep-v2-1-00a2a7feb1fa@gmail.com>
matttbe pushed a commit that referenced this issue Nov 14, 2024
When I try to manually set bitrates:

iw wlan0 set bitrates legacy-2.4 1

I get sleeping from invalid context error, see below. Fix that by switching to
use recently introduced ieee80211_iterate_stations_mtx().

Do note that WCN6855 firmware is still crashing, I'm not sure if that firmware
even supports bitrate WMI commands and should we consider disabling
ath12k_mac_op_set_bitrate_mask() for WCN6855? But that's for another patch.

BUG: sleeping function called from invalid context at drivers/net/wireless/ath/ath12k/wmi.c:420
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 2236, name: iw
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
3 locks held by iw/2236:
 #0: ffffffffabc6f1d8 (cb_lock){++++}-{3:3}, at: genl_rcv+0x14/0x40
 #1: ffff888138410810 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: nl80211_pre_doit+0x54d/0x800 [cfg80211]
 #2: ffffffffab2cfaa0 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_stations_atomic+0x2f/0x200 [mac80211]
CPU: 3 UID: 0 PID: 2236 Comm: iw Not tainted 6.11.0-rc7-wt-ath+ #1772
Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0xa4/0xe0
 dump_stack+0x10/0x20
 __might_resched+0x363/0x5a0
 ? __alloc_skb+0x165/0x340
 __might_sleep+0xad/0x160
 ath12k_wmi_cmd_send+0xb1/0x3d0 [ath12k]
 ? ath12k_wmi_init_wcn7850+0xa40/0xa40 [ath12k]
 ? __netdev_alloc_skb+0x45/0x7b0
 ? __asan_memset+0x39/0x40
 ? ath12k_wmi_alloc_skb+0xf0/0x150 [ath12k]
 ? reacquire_held_locks+0x4d0/0x4d0
 ath12k_wmi_set_peer_param+0x340/0x5b0 [ath12k]
 ath12k_mac_disable_peer_fixed_rate+0xa3/0x110 [ath12k]
 ? ath12k_mac_vdev_stop+0x4f0/0x4f0 [ath12k]
 ieee80211_iterate_stations_atomic+0xd4/0x200 [mac80211]
 ath12k_mac_op_set_bitrate_mask+0x5d2/0x1080 [ath12k]
 ? ath12k_mac_vif_chan+0x320/0x320 [ath12k]
 drv_set_bitrate_mask+0x267/0x470 [mac80211]
 ieee80211_set_bitrate_mask+0x4cc/0x8a0 [mac80211]
 ? __this_cpu_preempt_check+0x13/0x20
 nl80211_set_tx_bitrate_mask+0x2bc/0x530 [cfg80211]
 ? nl80211_parse_tx_bitrate_mask+0x2320/0x2320 [cfg80211]
 ? trace_contention_end+0xef/0x140
 ? rtnl_unlock+0x9/0x10
 ? nl80211_pre_doit+0x557/0x800 [cfg80211]
 genl_family_rcv_msg_doit+0x1f0/0x2e0
 ? genl_family_rcv_msg_attrs_parse.isra.0+0x250/0x250
 ? ns_capable+0x57/0xd0
 genl_family_rcv_msg+0x34c/0x600
 ? genl_family_rcv_msg_dumpit+0x310/0x310
 ? __lock_acquire+0xc62/0x1de0
 ? he_set_mcs_mask.isra.0+0x8d0/0x8d0 [cfg80211]
 ? nl80211_parse_tx_bitrate_mask+0x2320/0x2320 [cfg80211]
 ? cfg80211_external_auth_request+0x690/0x690 [cfg80211]
 genl_rcv_msg+0xa0/0x130
 netlink_rcv_skb+0x14c/0x400
 ? genl_family_rcv_msg+0x600/0x600
 ? netlink_ack+0xd70/0xd70
 ? rwsem_optimistic_spin+0x4f0/0x4f0
 ? genl_rcv+0x14/0x40
 ? down_read_killable+0x580/0x580
 ? netlink_deliver_tap+0x13e/0x350
 ? __this_cpu_preempt_check+0x13/0x20
 genl_rcv+0x23/0x40
 netlink_unicast+0x45e/0x790
 ? netlink_attachskb+0x7f0/0x7f0
 netlink_sendmsg+0x7eb/0xdb0
 ? netlink_unicast+0x790/0x790
 ? __this_cpu_preempt_check+0x13/0x20
 ? selinux_socket_sendmsg+0x31/0x40
 ? netlink_unicast+0x790/0x790
 __sock_sendmsg+0xc9/0x160
 ____sys_sendmsg+0x620/0x990
 ? kernel_sendmsg+0x30/0x30
 ? __copy_msghdr+0x410/0x410
 ? __kasan_check_read+0x11/0x20
 ? mark_lock+0xe6/0x1470
 ___sys_sendmsg+0xe9/0x170
 ? copy_msghdr_from_user+0x120/0x120
 ? __lock_acquire+0xc62/0x1de0
 ? do_fault_around+0x2c6/0x4e0
 ? do_user_addr_fault+0x8c1/0xde0
 ? reacquire_held_locks+0x220/0x4d0
 ? do_user_addr_fault+0x8c1/0xde0
 ? __kasan_check_read+0x11/0x20
 ? __fdget+0x4e/0x1d0
 ? sockfd_lookup_light+0x1a/0x170
 __sys_sendmsg+0xd2/0x180
 ? __sys_sendmsg_sock+0x20/0x20
 ? reacquire_held_locks+0x4d0/0x4d0
 ? debug_smp_processor_id+0x17/0x20
 __x64_sys_sendmsg+0x72/0xb0
 ? lockdep_hardirqs_on+0x7d/0x100
 x64_sys_call+0x894/0x9f0
 do_syscall_64+0x64/0x130
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f230fe04807
Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
RSP: 002b:00007ffe996a7ea8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000556f9f9c3390 RCX: 00007f230fe04807
RDX: 0000000000000000 RSI: 00007ffe996a7ee0 RDI: 0000000000000003
RBP: 0000556f9f9c88c0 R08: 0000000000000002 R09: 0000000000000000
R10: 0000556f965ca190 R11: 0000000000000246 R12: 0000556f9f9c8780
R13: 00007ffe996a7ee0 R14: 0000556f9f9c87d0 R15: 0000556f9f9c88c0
 </TASK>

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://patch.msgid.link/20241007165932.78081-2-kvalo@kernel.org
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
matttbe pushed a commit that referenced this issue Nov 18, 2024
…tified'

Petr Machata says:

====================
net: ndo_fdb_add/del: Have drivers report whether they notified

Currently when FDB entries are added to or deleted from a VXLAN netdevice,
the VXLAN driver emits one notification, including the VXLAN-specific
attributes. The core however always sends a notification as well, a generic
one. Thus two notifications are unnecessarily sent for these operations. A
similar situation comes up with bridge driver, which also emits
notifications on its own.

 # ip link add name vx type vxlan id 1000 dstport 4789
 # bridge monitor fdb &
 [1] 1981693
 # bridge fdb add de:ad:be:ef:13:37 dev vx self dst 192.0.2.1
 de:ad:be:ef:13:37 dev vx dst 192.0.2.1 self permanent
 de:ad:be:ef:13:37 dev vx self permanent

In order to prevent this duplicity, add a parameter, bool *notified, to
ndo_fdb_add and ndo_fdb_del. The flag is primed to false, and if the callee
sends a notification on its own, it sets the flag to true, thus informing
the core that it should not generate another notification.

Patches #1 to #2 are concerned with the above.

In the remaining patches, #3 to #7, add a selftest. This takes place across
several patches. Many of the helpers we would like to use for the test are
in forwarding/lib.sh, whereas net/ is a more suitable place for the test,
so the libraries need to be massaged a bit first.
====================

Link: https://patch.msgid.link/cover.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Nov 22, 2024
…dfl()

When getting an LLC CPU mask in the default CPU selection policy,
scx_select_cpu_dfl(), a pointer to the sched_domain is dereferenced
using rcu_read_lock() without holding rcu_read_lock(). Such an unprotected
dereference often causes the following warning and can cause an invalid
memory access in the worst case.

Therefore, protect dereference of a sched_domain pointer using a pair
of rcu_read_lock() and unlock().

[   20.996135] =============================
[   20.996345] WARNING: suspicious RCU usage
[   20.996563] 6.11.0-virtme #17 Tainted: G        W
[   20.996576] -----------------------------
[   20.996576] kernel/sched/ext.c:3323 suspicious rcu_dereference_check() usage!
[   20.996576]
[   20.996576] other info that might help us debug this:
[   20.996576]
[   20.996576]
[   20.996576] rcu_scheduler_active = 2, debug_locks = 1
[   20.996576] 4 locks held by kworker/8:1/140:
[   20.996576]  #0: ffff8b18c00dd348 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x4a0/0x590
[   20.996576]  #1: ffffb3da01f67e58 ((work_completion)(&dev->power.work)){+.+.}-{0:0}, at: process_one_work+0x1ba/0x590
[   20.996576]  #2: ffffffffa316f9f0 (&rcu_state.gp_wq){..-.}-{2:2}, at: swake_up_one+0x15/0x60
[   20.996576]  #3: ffff8b1880398a60 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x59/0x7d0
[   20.996576]
[   20.996576] stack backtrace:
[   20.996576] CPU: 8 UID: 0 PID: 140 Comm: kworker/8:1 Tainted: G        W          6.11.0-virtme #17
[   20.996576] Tainted: [W]=WARN
[   20.996576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[   20.996576] Workqueue: pm pm_runtime_work
[   20.996576] Sched_ext: simple (disabling+all), task: runnable_at=-6ms
[   20.996576] Call Trace:
[   20.996576]  <IRQ>
[   20.996576]  dump_stack_lvl+0x6f/0xb0
[   20.996576]  lockdep_rcu_suspicious.cold+0x4e/0x96
[   20.996576]  scx_select_cpu_dfl+0x234/0x260
[   20.996576]  select_task_rq_scx+0xfb/0x190
[   20.996576]  select_task_rq+0x47/0x110
[   20.996576]  try_to_wake_up+0x110/0x7d0
[   20.996576]  swake_up_one+0x39/0x60
[   20.996576]  rcu_core+0xb08/0xe50
[   20.996576]  ? srso_alias_return_thunk+0x5/0xfbef5
[   20.996576]  ? mark_held_locks+0x40/0x70
[   20.996576]  handle_softirqs+0xd3/0x410
[   20.996576]  irq_exit_rcu+0x78/0xa0
[   20.996576]  sysvec_apic_timer_interrupt+0x73/0x80
[   20.996576]  </IRQ>
[   20.996576]  <TASK>
[   20.996576]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[   20.996576] RIP: 0010:_raw_spin_unlock_irqrestore+0x36/0x70
[   20.996576] Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 11 b4 36 ff 48 89 df e8 99 0d 37 ff f7 c5 00 02 00 00 75 17 9c 58 f6 c4 02 75 2b <65> ff 0d 5b 55 3c 5e 74 16 5b 5d e9 95 8e 28 00 e8 a5 ee 44 ff 9c
[   20.996576] RSP: 0018:ffffb3da01f67d20 EFLAGS: 00000246
[   20.996576] RAX: 0000000000000002 RBX: ffffffffa4640220 RCX: 0000000000000040
[   20.996576] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa1c7b27b
[   20.996576] RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
[   20.996576] R10: 0000000000000001 R11: 000000000000021c R12: 0000000000000246
[   20.996576] R13: ffff8b1881363958 R14: 0000000000000000 R15: ffff8b1881363800
[   20.996576]  ? _raw_spin_unlock_irqrestore+0x4b/0x70
[   20.996576]  serial_port_runtime_resume+0xd4/0x1a0
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  __rpm_callback+0x44/0x170
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_callback+0x55/0x60
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_resume+0x582/0x7b0
[   20.996576]  pm_runtime_work+0x7c/0xb0
[   20.996576]  process_one_work+0x1fb/0x590
[   20.996576]  worker_thread+0x18e/0x350
[   20.996576]  ? __pfx_worker_thread+0x10/0x10
[   20.996576]  kthread+0xe2/0x110
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork+0x34/0x50
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork_asm+0x1a/0x30
[   20.996576]  </TASK>
[   21.056592] sched_ext: BPF scheduler "simple" disabled (unregistered from user space)

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
matttbe pushed a commit that referenced this issue Nov 29, 2024
Commit bab1c29 ("LoongArch: Fix sleeping in atomic context in
setup_tlb_handler()") changes the gfp flag from GFP_KERNEL to GFP_ATOMIC
for alloc_pages_node(). However, for PREEMPT_RT kernels we can still get
a "sleeping in atomic context" error:

[    0.372259] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[    0.372266] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
[    0.372268] preempt_count: 1, expected: 0
[    0.372270] RCU nest depth: 1, expected: 1
[    0.372272] 3 locks held by swapper/1/0:
[    0.372274]  #0: 900000000c9f5e60 (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x524/0x1c60
[    0.372294]  #1: 90000000087013b8 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x50/0x140
[    0.372305]  #2: 900000047fffd388 (&zone->lock){+.+.}-{3:3}, at: __rmqueue_pcplist+0x30c/0xea0
[    0.372314] irq event stamp: 0
[    0.372316] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[    0.372322] hardirqs last disabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0
[    0.372329] softirqs last  enabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0
[    0.372335] softirqs last disabled at (0): [<0000000000000000>] 0x0
[    0.372341] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-rc7+ #1891
[    0.372346] Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022
[    0.372349] Stack : 0000000000000089 9000000005a0db9c 90000000071519c8 9000000100388000
[    0.372486]         900000010038b890 0000000000000000 900000010038b898 9000000007e53788
[    0.372492]         900000000815bcc8 900000000815bcc0 900000010038b700 0000000000000001
[    0.372498]         0000000000000001 4b031894b9d6b725 00000000055ec000 9000000100338fc0
[    0.372503]         00000000000000c4 0000000000000001 000000000000002d 0000000000000003
[    0.372509]         0000000000000030 0000000000000003 00000000055ec000 0000000000000003
[    0.372515]         900000000806d000 9000000007e53788 00000000000000b0 0000000000000004
[    0.372521]         0000000000000000 0000000000000000 900000000c9f5f10 0000000000000000
[    0.372526]         90000000076f12d8 9000000007e53788 9000000005924778 0000000000000000
[    0.372532]         00000000000000b0 0000000000000004 0000000000000000 0000000000070000
[    0.372537]         ...
[    0.372540] Call Trace:
[    0.372542] [<9000000005924778>] show_stack+0x38/0x180
[    0.372548] [<90000000071519c4>] dump_stack_lvl+0x94/0xe4
[    0.372555] [<900000000599b880>] __might_resched+0x1a0/0x260
[    0.372561] [<90000000071675cc>] rt_spin_lock+0x4c/0x140
[    0.372565] [<9000000005cbb768>] __rmqueue_pcplist+0x308/0xea0
[    0.372570] [<9000000005cbed84>] get_page_from_freelist+0x564/0x1c60
[    0.372575] [<9000000005cc0d98>] __alloc_pages_noprof+0x218/0x1820
[    0.372580] [<900000000593b36c>] tlb_init+0x1ac/0x298
[    0.372585] [<9000000005924b74>] per_cpu_trap_init+0x114/0x140
[    0.372589] [<9000000005921964>] cpu_probe+0x4e4/0xa60
[    0.372592] [<9000000005934874>] start_secondary+0x34/0xc0
[    0.372599] [<900000000715615c>] smpboot_entry+0x64/0x6c

This is because in PREEMPT_RT kernels normal spinlocks are replaced by
rt spinlocks and rt_spin_lock() will cause sleeping. Fix it by disabling
NUMA optimization completely for PREEMPT_RT kernels.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
matttbe pushed a commit that referenced this issue Dec 6, 2024
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.13, part #2

 - Constrain invalidations from GICR_INVLPIR to only affect the LPI
   INTID space

 - Set of robustness improvements to the management of vgic irqs and GIC
   ITS table entries

 - Fix compilation issue w/ CONFIG_CC_OPTIMIZE_FOR_SIZE=y where
   set_sysreg_masks() wasn't getting inlined, breaking check for a
   constant sysreg index

 - Correct KVM's vPMU overflow condition to match the architecture for
   hyp and non-hyp counters
matttbe pushed a commit that referenced this issue Dec 6, 2024
…ndex

Intel SoundWire machine driver always uses Pin number 2 and above.
Currently, the pin number is used as the FW DAI index directly. As a
result, FW DAI 0 and 1 are never used. That worked fine because we use
up to 2 DAIs in a SDW link. Convert the topology pin index to ALH dai
index, the mapping is using 2-off indexing, iow, pin #2 is ALH dai #0.

The issue exists since beginning. And the Fixes tag is the first commit
that this commit can be applied.

Fixes: b66bfc3 ("ASoC: SOF: sof-audio: Fix broken early bclk feature for SSP")
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://patch.msgid.link/20241127092955.20026-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
matttbe pushed a commit that referenced this issue Dec 6, 2024
…to HEAD

KVM/riscv changes for 6.13 part #2

- Svade and Svadu extension support for Host and Guest/VM
matttbe pushed a commit that referenced this issue Dec 6, 2024
Konstantin Shkolnyy says:

====================
vsock/test: fix wrong setsockopt() parameters

Parameters were created using wrong C types, which caused them to be of
wrong size on some architectures, causing problems.

The problem with SO_RCVLOWAT was found on s390 (big endian), while x86-64
didn't show it. After the fix, all tests pass on s390.
Then Stefano Garzarella pointed out that SO_VM_SOCKETS_* calls might have
a similar problem, which turned out to be true, hence, the second patch.

Changes for v8:
- Fix whitespace warnings from "checkpatch.pl --strict"
- Add maintainers to Cc:
Changes for v7:
- Rebase on top of https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
- Add the "net" tags to the subjects
Changes for v6:
- rework the patch #3 to avoid creating a new file for new functions,
and exclude vsock_perf from calling the new functions.
- add "Reviewed-by:" to the patch #2.
Changes for v5:
- in the patch #2 replace the introduced uint64_t with unsigned long long
to match documentation
- add a patch #3 that verifies every setsockopt() call.
Changes for v4:
- add "Reviewed-by:" to the first patch, and add a second patch fixing
SO_VM_SOCKETS_* calls, which depends on the first one (hence, it's now
a patch series.)
Changes for v3:
- fix the same problem in vsock_perf and update commit message
Changes for v2:
- add "Fixes:" lines to the commit message
====================

Link: https://patch.msgid.link/20241203150656.287028-1-kshk@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Dec 11, 2024
Since the netlink attribute range validation provides inclusive
checking, the *max* of attribute NL80211_ATTR_MLO_LINK_ID should be
IEEE80211_MLD_MAX_NUM_LINKS - 1 otherwise causing an off-by-one.

One crash stack for demonstration:
==================================================================
BUG: KASAN: wild-memory-access in ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
Read of size 6 at addr 001102080000000c by task fuzzer.386/9508

CPU: 1 PID: 9508 Comm: syz.1.386 Not tainted 6.1.70 #2
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x177/0x231 lib/dump_stack.c:106
 print_report+0xe0/0x750 mm/kasan/report.c:398
 kasan_report+0x139/0x170 mm/kasan/report.c:495
 kasan_check_range+0x287/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
 rdev_tx_control_port net/wireless/rdev-ops.h:761 [inline]
 nl80211_tx_control_port+0x7b3/0xc40 net/wireless/nl80211.c:15453
 genl_family_rcv_msg_doit+0x22e/0x320 net/netlink/genetlink.c:756
 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
 genl_rcv_msg+0x539/0x740 net/netlink/genetlink.c:850
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2508
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x74b/0x8c0 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0x882/0xb90 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5cc/0x8f0 net/socket.c:2499
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2553
 __sys_sendmsg net/socket.c:2582 [inline]
 __do_sys_sendmsg net/socket.c:2591 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2589
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x90 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Update the policy to ensure correct validation.

Fixes: 7b0a0e3 ("wifi: cfg80211: do some rework towards MLO link APIs")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Suggested-by: Cengiz Can <cengiz.can@canonical.com>
Link: https://patch.msgid.link/20241130170526.96698-1-linma@zju.edu.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
matttbe pushed a commit that referenced this issue Dec 11, 2024
When virtnet_close is followed by virtnet_open, some TX completions can
possibly remain unconsumed, until they are finally processed during the
first NAPI poll after the netdev_tx_reset_queue(), resulting in a crash
[1]. Commit b96ed2c ("virtio_net: move netdev_tx_reset_queue() call
before RX napi enable") was not sufficient to eliminate all BQL crash
cases for virtio-net.

This issue can be reproduced with the latest net-next master by running:
`while :; do ip l set DEV down; ip l set DEV up; done` under heavy network
TX load from inside the machine.

netdev_tx_reset_queue() can actually be dropped from virtnet_open path;
the device is not stopped in any case. For BQL core part, it's just like
traffic nearly ceases to exist for some period. For stall detector added
to BQL, even if virtnet_close could somehow lead to some TX completions
delayed for long, followed by virtnet_open, we can just take it as stall
as mentioned in commit 6025b91 ("net: dqs: add NIC stall detector
based on BQL"). Note also that users can still reset stall_max via sysfs.

So, drop netdev_tx_reset_queue() from virtnet_enable_queue_pair(). This
eliminates the BQL crashes. As a result, netdev_tx_reset_queue() is now
explicitly required in freeze/restore path. This patch adds it to
immediately after free_unused_bufs(), following the rule of thumb:
netdev_tx_reset_queue() should follow any SKB freeing not followed by
netdev_tx_completed_queue(). This seems the most consistent and
streamlined approach, and now netdev_tx_reset_queue() runs whenever
free_unused_bufs() is done.

[1]:
------------[ cut here ]------------
kernel BUG at lib/dynamic_queue_limits.c:99!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 7 UID: 0 PID: 1598 Comm: ip Tainted: G    N 6.12.0net-next_main+ #2
Tainted: [N]=TEST
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), \
BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:dql_completed+0x26b/0x290
Code: b7 c2 49 89 e9 44 89 da 89 c6 4c 89 d7 e8 ed 17 47 00 58 65 ff 0d
4d 27 90 7e 0f 85 fd fe ff ff e8 ea 53 8d ff e9 f3 fe ff ff <0f> 0b 01
d2 44 89 d1 29 d1 ba 00 00 00 00 0f 48 ca e9 28 ff ff ff
RSP: 0018:ffffc900002b0d08 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff888102398c80 RCX: 0000000080190009
RDX: 0000000000000000 RSI: 000000000000006a RDI: 0000000000000000
RBP: ffff888102398c00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000000ca R11: 0000000000015681 R12: 0000000000000001
R13: ffffc900002b0d68 R14: ffff88811115e000 R15: ffff8881107aca40
FS:  00007f41ded69500(0000) GS:ffff888667dc0000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ccc2dc1a0 CR3: 0000000104fd8003 CR4: 0000000000772ef0
PKRU: 55555554
Call Trace:
 <IRQ>
 ? die+0x32/0x80
 ? do_trap+0xd9/0x100
 ? dql_completed+0x26b/0x290
 ? dql_completed+0x26b/0x290
 ? do_error_trap+0x6d/0xb0
 ? dql_completed+0x26b/0x290
 ? exc_invalid_op+0x4c/0x60
 ? dql_completed+0x26b/0x290
 ? asm_exc_invalid_op+0x16/0x20
 ? dql_completed+0x26b/0x290
 __free_old_xmit+0xff/0x170 [virtio_net]
 free_old_xmit+0x54/0xc0 [virtio_net]
 virtnet_poll+0xf4/0xe30 [virtio_net]
 ? __update_load_avg_cfs_rq+0x264/0x2d0
 ? update_curr+0x35/0x260
 ? reweight_entity+0x1be/0x260
 __napi_poll.constprop.0+0x28/0x1c0
 net_rx_action+0x329/0x420
 ? enqueue_hrtimer+0x35/0x90
 ? trace_hardirqs_on+0x1d/0x80
 ? kvm_sched_clock_read+0xd/0x20
 ? sched_clock+0xc/0x30
 ? kvm_sched_clock_read+0xd/0x20
 ? sched_clock+0xc/0x30
 ? sched_clock_cpu+0xd/0x1a0
 handle_softirqs+0x138/0x3e0
 do_softirq.part.0+0x89/0xc0
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xa7/0xb0
 virtnet_open+0xc8/0x310 [virtio_net]
 __dev_open+0xfa/0x1b0
 __dev_change_flags+0x1de/0x250
 dev_change_flags+0x22/0x60
 do_setlink.isra.0+0x2df/0x10b0
 ? rtnetlink_rcv_msg+0x34f/0x3f0
 ? netlink_rcv_skb+0x54/0x100
 ? netlink_unicast+0x23e/0x390
 ? netlink_sendmsg+0x21e/0x490
 ? ____sys_sendmsg+0x31b/0x350
 ? avc_has_perm_noaudit+0x67/0xf0
 ? cred_has_capability.isra.0+0x75/0x110
 ? __nla_validate_parse+0x5f/0xee0
 ? __pfx___probestub_irq_enable+0x3/0x10
 ? __create_object+0x5e/0x90
 ? security_capable+0x3b/0x70
 rtnl_newlink+0x784/0xaf0
 ? avc_has_perm_noaudit+0x67/0xf0
 ? cred_has_capability.isra.0+0x75/0x110
 ? stack_depot_save_flags+0x24/0x6d0
 ? __pfx_rtnl_newlink+0x10/0x10
 rtnetlink_rcv_msg+0x34f/0x3f0
 ? do_syscall_64+0x6c/0x180
 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
 ? __pfx_rtnetlink_rcv_msg+0x10/0x10
 netlink_rcv_skb+0x54/0x100
 netlink_unicast+0x23e/0x390
 netlink_sendmsg+0x21e/0x490
 ____sys_sendmsg+0x31b/0x350
 ? copy_msghdr_from_user+0x6d/0xa0
 ___sys_sendmsg+0x86/0xd0
 ? __pte_offset_map+0x17/0x160
 ? preempt_count_add+0x69/0xa0
 ? __call_rcu_common.constprop.0+0x147/0x610
 ? preempt_count_add+0x69/0xa0
 ? preempt_count_add+0x69/0xa0
 ? _raw_spin_trylock+0x13/0x60
 ? trace_hardirqs_on+0x1d/0x80
 __sys_sendmsg+0x66/0xc0
 do_syscall_64+0x6c/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f41defe5b34
Code: 15 e1 12 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00
f3 0f 1e fa 80 3d 35 95 0f 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55
RSP: 002b:00007ffe5336ecc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f41defe5b34
RDX: 0000000000000000 RSI: 00007ffe5336ed30 RDI: 0000000000000003
RBP: 00007ffe5336eda0 R08: 0000000000000010 R09: 0000000000000001
R10: 00007ffe5336f6f9 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000067452259 R14: 0000556ccc28b040 R15: 0000000000000000
 </TASK>
[...]

Fixes: c8bd1f7 ("virtio_net: add support for Byte Queue Limits")
Cc: <stable@vger.kernel.org> # v6.11+
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
[ pabeni: trimmed possibly troublesome separator ]
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Dec 11, 2024
…nts'

Koichiro Den says:

====================
virtio_net: correct netdev_tx_reset_queue() invocation points

When virtnet_close is followed by virtnet_open, some TX completions can
possibly remain unconsumed, until they are finally processed during the
first NAPI poll after the netdev_tx_reset_queue(), resulting in a crash
[1]. Commit b96ed2c ("virtio_net: move netdev_tx_reset_queue() call
before RX napi enable") was not sufficient to eliminate all BQL crash
scenarios for virtio-net.

This issue can be reproduced with the latest net-next master by running:
`while :; do ip l set DEV down; ip l set DEV up; done` under heavy network
TX load from inside the machine.

This patch series resolves the issue and also addresses similar existing
problems:

(a). Drop netdev_tx_reset_queue() from open/close path. This eliminates the
     BQL crashes due to the problematic open/close path.

(b). As a result of (a), netdev_tx_reset_queue() is now explicitly required
     in freeze/restore path. Add netdev_tx_reset_queue() immediately after
     free_unused_bufs() invocation.

(c). Fix missing resetting in virtnet_tx_resize().
     virtnet_tx_resize() has lacked proper resetting since commit
     c8bd1f7 ("virtio_net: add support for Byte Queue Limits").

(d). Fix missing resetting in the XDP_SETUP_XSK_POOL path.
     Similar to (c), this path lacked proper resetting. Call
     netdev_tx_reset_queue() when virtqueue_reset() has actually recycled
     unused buffers.

This patch series consists of six commits:
  [1/6]: Resolves (a) and (b).                      # also -stable 6.11.y
  [2/6]: Minor fix to make [4/6] streamlined.
  [3/6]: Prerequisite for (c).                      # also -stable 6.11.y
  [4/6]: Resolves (c) (incl. Prerequisite for (d))  # also -stable 6.11.y
  [5/6]: Preresuisite for (d).
  [6/6]: Resolves (d).

Changes for v4:
  - move netdev_tx_reset_queue() out of free_unused_bufs()
  - submit to net, not net-next
Changes for v3:
  - replace 'flushed' argument with 'recycle_done'
Changes for v2:
  - add tx queue resetting for (b) to (d) above

v3: https://lore.kernel.org/all/20241204050724.307544-1-koichiro.den@canonical.com/
v2: https://lore.kernel.org/all/20241203073025.67065-1-koichiro.den@canonical.com/
v1: https://lore.kernel.org/all/20241130181744.3772632-1-koichiro.den@canonical.com/

[1]:
------------[ cut here ]------------
kernel BUG at lib/dynamic_queue_limits.c:99!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 7 UID: 0 PID: 1598 Comm: ip Tainted: G    N 6.12.0net-next_main+ #2
Tainted: [N]=TEST
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), \
BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:dql_completed+0x26b/0x290
Code: b7 c2 49 89 e9 44 89 da 89 c6 4c 89 d7 e8 ed 17 47 00 58 65 ff 0d
4d 27 90 7e 0f 85 fd fe ff ff e8 ea 53 8d ff e9 f3 fe ff ff <0f> 0b 01
d2 44 89 d1 29 d1 ba 00 00 00 00 0f 48 ca e9 28 ff ff ff
RSP: 0018:ffffc900002b0d08 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff888102398c80 RCX: 0000000080190009
RDX: 0000000000000000 RSI: 000000000000006a RDI: 0000000000000000
RBP: ffff888102398c00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000000ca R11: 0000000000015681 R12: 0000000000000001
R13: ffffc900002b0d68 R14: ffff88811115e000 R15: ffff8881107aca40
FS:  00007f41ded69500(0000) GS:ffff888667dc0000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ccc2dc1a0 CR3: 0000000104fd8003 CR4: 0000000000772ef0
PKRU: 55555554
Call Trace:
 <IRQ>
 ? die+0x32/0x80
 ? do_trap+0xd9/0x100
 ? dql_completed+0x26b/0x290
 ? dql_completed+0x26b/0x290
 ? do_error_trap+0x6d/0xb0
 ? dql_completed+0x26b/0x290
 ? exc_invalid_op+0x4c/0x60
 ? dql_completed+0x26b/0x290
 ? asm_exc_invalid_op+0x16/0x20
 ? dql_completed+0x26b/0x290
 __free_old_xmit+0xff/0x170 [virtio_net]
 free_old_xmit+0x54/0xc0 [virtio_net]
 virtnet_poll+0xf4/0xe30 [virtio_net]
 ? __update_load_avg_cfs_rq+0x264/0x2d0
 ? update_curr+0x35/0x260
 ? reweight_entity+0x1be/0x260
 __napi_poll.constprop.0+0x28/0x1c0
 net_rx_action+0x329/0x420
 ? enqueue_hrtimer+0x35/0x90
 ? trace_hardirqs_on+0x1d/0x80
 ? kvm_sched_clock_read+0xd/0x20
 ? sched_clock+0xc/0x30
 ? kvm_sched_clock_read+0xd/0x20
 ? sched_clock+0xc/0x30
 ? sched_clock_cpu+0xd/0x1a0
 handle_softirqs+0x138/0x3e0
 do_softirq.part.0+0x89/0xc0
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xa7/0xb0
 virtnet_open+0xc8/0x310 [virtio_net]
 __dev_open+0xfa/0x1b0
 __dev_change_flags+0x1de/0x250
 dev_change_flags+0x22/0x60
 do_setlink.isra.0+0x2df/0x10b0
 ? rtnetlink_rcv_msg+0x34f/0x3f0
 ? netlink_rcv_skb+0x54/0x100
 ? netlink_unicast+0x23e/0x390
 ? netlink_sendmsg+0x21e/0x490
 ? ____sys_sendmsg+0x31b/0x350
 ? avc_has_perm_noaudit+0x67/0xf0
 ? cred_has_capability.isra.0+0x75/0x110
 ? __nla_validate_parse+0x5f/0xee0
 ? __pfx___probestub_irq_enable+0x3/0x10
 ? __create_object+0x5e/0x90
 ? security_capable+0x3b/0x7�[I0
 rtnl_newlink+0x784/0xaf0
 ? avc_has_perm_noaudit+0x67/0xf0
 ? cred_has_capability.isra.0+0x75/0x110
 ? stack_depot_save_flags+0x24/0x6d0
 ? __pfx_rtnl_newlink+0x10/0x10
 rtnetlink_rcv_msg+0x34f/0x3f0
 ? do_syscall_64+0x6c/0x180
 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
 ? __pfx_rtnetlink_rcv_msg+0x10/0x10
 netlink_rcv_skb+0x54/0x100
 netlink_unicast+0x23e/0x390
 netlink_sendmsg+0x21e/0x490
 ____sys_sendmsg+0x31b/0x350
 ? copy_msghdr_from_user+0x6d/0xa0
 ___sys_sendmsg+0x86/0xd0
 ? __pte_offset_map+0x17/0x160
 ? preempt_count_add+0x69/0xa0
 ? __call_rcu_common.constprop.0+0x147/0x610
 ? preempt_count_add+0x69/0xa0
 ? preempt_count_add+0x69/0xa0
 ? _raw_spin_trylock+0x13/0x60
 ? trace_hardirqs_on+0x1d/0x80
 __sys_sendmsg+0x66/0xc0
 do_syscall_64+0x6c/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f41defe5b34
Code: 15 e1 12 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00
f3 0f 1e fa 80 3d 35 95 0f 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55
RSP: 002b:00007ffe5336ecc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f41defe5b34
RDX: 0000000000000000 RSI: 00007ffe5336ed30 RDI: 0000000000000003
RBP: 00007ffe5336eda0 R08: 0000000000000010 R09: 0000000000000001
R10: 00007ffe5336f6f9 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000067452259 R14: 0000556ccc28b040 R15: 0000000000000000
 </TASK>
[...]
====================

Link: https://patch.msgid.link/20241206011047.923923-1-koichiro.den@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Dec 13, 2024
Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 #6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 #7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 #8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 #9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <yingfu.zhou@shopee.com>
Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Signed-off-by: Yue.zhao <yue.zhao@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
matttbe pushed a commit that referenced this issue Dec 13, 2024
Add more test cases for LPM trie in test_maps:

1) test_lpm_trie_update_flags
It constructs various use cases for BPF_EXIST and BPF_NOEXIST and check
whether the return value of update operation is expected.

2) test_lpm_trie_update_full_maps
It tests the update operations on a full LPM trie map. Adding new node
will fail and overwriting the value of existed node will succeed.

3) test_lpm_trie_iterate_strs and test_lpm_trie_iterate_ints
There two test cases test whether the iteration through get_next_key is
sorted and expected. These two test cases delete the minimal key after
each iteration and check whether next iteration returns the second
minimal key. The only difference between these two test cases is the
former one saves strings in the LPM trie and the latter saves integers.
Without the fix of get_next_key, these two cases will fail as shown
below:
  test_lpm_trie_iterate_strs(1091):FAIL:iterate #2 got abc exp abS
  test_lpm_trie_iterate_ints(1142):FAIL:iterate #1 got 0x2 exp 0x1

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241206110622.1161752-10-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
matttbe pushed a commit that referenced this issue Dec 13, 2024
Hou Tao says:

====================
This patch set fixes several issues for LPM trie. These issues were
found during adding new test cases or were reported by syzbot.

The patch set is structured as follows:

Patch #1~#2 are clean-ups for lpm_trie_update_elem().
Patch #3 handles BPF_EXIST and BPF_NOEXIST correctly for LPM trie.
Patch #4 fixes the accounting of n_entries when doing in-place update.
Patch #5 fixes the exact match condition in trie_get_next_key() and it
may skip keys when the passed key is not found in the map.
Patch #6~#7 switch from kmalloc() to bpf memory allocator for LPM trie
to fix several lock order warnings reported by syzbot. It also enables
raw_spinlock_t for LPM trie again. After these changes, the LPM trie will
be closer to being usable in any context (though the reentrance check of
trie->lock is still missing, but it is on my todo list).
Patch #8: move test_lpm_map to map_tests to make it run regularly.
Patch #9: add test cases for the issues fixed by patch #3~#5.

Please see individual patches for more details. Comments are always
welcome.

Change Log:
v3:
  * patch #2: remove the unnecessary NULL-init for im_node
  * patch #6: alloc the leaf node before disabling IRQ to low
    the possibility of -ENOMEM when leaf_size is large; Free
    these nodes outside the trie lock (Suggested by Alexei)
  * collect review and ack tags (Thanks for Toke & Daniel)

v2: https://lore.kernel.org/bpf/20241127004641.1118269-1-houtao@huaweicloud.com/
  * collect review tags (Thanks for Toke)
  * drop "Add bpf_mem_cache_is_mergeable() helper" patch
  * patch #3~#4: add fix tag
  * patch #4: rename the helper to trie_check_add_elem() and increase
    n_entries in it.
  * patch #6: use one bpf mem allocator and update commit message to
    clarify that using bpf mem allocator is more appropriate.
  * patch #7: update commit message to add the possible max running time
    for update operation.
  * patch #9: update commit message to specify the purpose of these test
    cases.

v1: https://lore.kernel.org/bpf/20241118010808.2243555-1-houtao@huaweicloud.com/
====================

Link: https://lore.kernel.org/all/20241206110622.1161752-1-houtao@huaweicloud.com/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
matttbe pushed a commit that referenced this issue Dec 13, 2024
This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Tested-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
matttbe pushed a commit that referenced this issue Dec 13, 2024
This fixes the circular locking dependency warning below, by
releasing the socket lock before enterning iso_listen_bis, to
avoid any potential deadlock with hdev lock.

[   75.307983] ======================================================
[   75.307984] WARNING: possible circular locking dependency detected
[   75.307985] 6.12.0-rc6+ #22 Not tainted
[   75.307987] ------------------------------------------------------
[   75.307987] kworker/u81:2/2623 is trying to acquire lock:
[   75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO)
               at: iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308021]
               but task is already holding lock:
[   75.308022] ffff8fdd61a10078 (&hdev->lock)
               at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308053]
               which lock already depends on the new lock.

[   75.308054]
               the existing dependency chain (in reverse order) is:
[   75.308055]
               -> #1 (&hdev->lock){+.+.}-{3:3}:
[   75.308057]        __mutex_lock+0xad/0xc50
[   75.308061]        mutex_lock_nested+0x1b/0x30
[   75.308063]        iso_sock_listen+0x143/0x5c0 [bluetooth]
[   75.308085]        __sys_listen_socket+0x49/0x60
[   75.308088]        __x64_sys_listen+0x4c/0x90
[   75.308090]        x64_sys_call+0x2517/0x25f0
[   75.308092]        do_syscall_64+0x87/0x150
[   75.308095]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   75.308098]
               -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[   75.308100]        __lock_acquire+0x155e/0x25f0
[   75.308103]        lock_acquire+0xc9/0x300
[   75.308105]        lock_sock_nested+0x32/0x90
[   75.308107]        iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308128]        hci_connect_cfm+0x6c/0x190 [bluetooth]
[   75.308155]        hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth]
[   75.308180]        hci_le_meta_evt+0xe7/0x200 [bluetooth]
[   75.308206]        hci_event_packet+0x21f/0x5c0 [bluetooth]
[   75.308230]        hci_rx_work+0x3ae/0xb10 [bluetooth]
[   75.308254]        process_one_work+0x212/0x740
[   75.308256]        worker_thread+0x1bd/0x3a0
[   75.308258]        kthread+0xe4/0x120
[   75.308259]        ret_from_fork+0x44/0x70
[   75.308261]        ret_from_fork_asm+0x1a/0x30
[   75.308263]
               other info that might help us debug this:

[   75.308264]  Possible unsafe locking scenario:

[   75.308264]        CPU0                CPU1
[   75.308265]        ----                ----
[   75.308265]   lock(&hdev->lock);
[   75.308267]                            lock(sk_lock-
                                                AF_BLUETOOTH-BTPROTO_ISO);
[   75.308268]                            lock(&hdev->lock);
[   75.308269]   lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
[   75.308270]
                *** DEADLOCK ***

[   75.308271] 4 locks held by kworker/u81:2/2623:
[   75.308272]  #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0},
                at: process_one_work+0x443/0x740
[   75.308276]  #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)),
                at: process_one_work+0x1ce/0x740
[   75.308280]  #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3}
                at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308304]  #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2},
                at: hci_connect_cfm+0x29/0x190 [bluetooth]

Fixes: 02171da ("Bluetooth: ISO: Add hcon for listening bis sk")
Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
matttbe pushed a commit that referenced this issue Dec 13, 2024
This fixes the circular locking dependency warning below, by reworking
iso_sock_recvmsg, to ensure that the socket lock is always released
before calling a function that locks hdev.

[  561.670344] ======================================================
[  561.670346] WARNING: possible circular locking dependency detected
[  561.670349] 6.12.0-rc6+ #26 Not tainted
[  561.670351] ------------------------------------------------------
[  561.670353] iso-tester/3289 is trying to acquire lock:
[  561.670355] ffff88811f600078 (&hdev->lock){+.+.}-{3:3},
               at: iso_conn_big_sync+0x73/0x260 [bluetooth]
[  561.670405]
               but task is already holding lock:
[  561.670407] ffff88815af58258 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0},
               at: iso_sock_recvmsg+0xbf/0x500 [bluetooth]
[  561.670450]
               which lock already depends on the new lock.

[  561.670452]
               the existing dependency chain (in reverse order) is:
[  561.670453]
               -> #2 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0}:
[  561.670458]        lock_acquire+0x7c/0xc0
[  561.670463]        lock_sock_nested+0x3b/0xf0
[  561.670467]        bt_accept_dequeue+0x1a5/0x4d0 [bluetooth]
[  561.670510]        iso_sock_accept+0x271/0x830 [bluetooth]
[  561.670547]        do_accept+0x3dd/0x610
[  561.670550]        __sys_accept4+0xd8/0x170
[  561.670553]        __x64_sys_accept+0x74/0xc0
[  561.670556]        x64_sys_call+0x17d6/0x25f0
[  561.670559]        do_syscall_64+0x87/0x150
[  561.670563]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670567]
               -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[  561.670571]        lock_acquire+0x7c/0xc0
[  561.670574]        lock_sock_nested+0x3b/0xf0
[  561.670577]        iso_sock_listen+0x2de/0xf30 [bluetooth]
[  561.670617]        __sys_listen_socket+0xef/0x130
[  561.670620]        __x64_sys_listen+0xe1/0x190
[  561.670623]        x64_sys_call+0x2517/0x25f0
[  561.670626]        do_syscall_64+0x87/0x150
[  561.670629]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670632]
               -> #0 (&hdev->lock){+.+.}-{3:3}:
[  561.670636]        __lock_acquire+0x32ad/0x6ab0
[  561.670639]        lock_acquire.part.0+0x118/0x360
[  561.670642]        lock_acquire+0x7c/0xc0
[  561.670644]        __mutex_lock+0x18d/0x12f0
[  561.670647]        mutex_lock_nested+0x1b/0x30
[  561.670651]        iso_conn_big_sync+0x73/0x260 [bluetooth]
[  561.670687]        iso_sock_recvmsg+0x3e9/0x500 [bluetooth]
[  561.670722]        sock_recvmsg+0x1d5/0x240
[  561.670725]        sock_read_iter+0x27d/0x470
[  561.670727]        vfs_read+0x9a0/0xd30
[  561.670731]        ksys_read+0x1a8/0x250
[  561.670733]        __x64_sys_read+0x72/0xc0
[  561.670736]        x64_sys_call+0x1b12/0x25f0
[  561.670738]        do_syscall_64+0x87/0x150
[  561.670741]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670744]
               other info that might help us debug this:

[  561.670745] Chain exists of:
&hdev->lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> sk_lock-AF_BLUETOOTH

[  561.670751]  Possible unsafe locking scenario:

[  561.670753]        CPU0                    CPU1
[  561.670754]        ----                    ----
[  561.670756]   lock(sk_lock-AF_BLUETOOTH);
[  561.670758]                                lock(sk_lock
                                              AF_BLUETOOTH-BTPROTO_ISO);
[  561.670761]                                lock(sk_lock-AF_BLUETOOTH);
[  561.670764]   lock(&hdev->lock);
[  561.670767]
                *** DEADLOCK ***

Fixes: 07a9342 ("Bluetooth: ISO: Send BIG Create Sync via hci_sync")
Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
matttbe pushed a commit that referenced this issue Dec 16, 2024
Guangguan Wang says:

====================
net: several fixes for smc

v1 -> v2:
rewrite patch #2 suggested by Paolo.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
matttbe pushed a commit that referenced this issue Dec 20, 2024
Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.

The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().

Before the patch:

  (gdb) run trace --errno-summary -a sleep 1
  <SNIP>
   Summary of events:

   gvfs-afc-volume (3187), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     pselect6               1      0     0.000     0.000     0.000     0.000      0.00%

   GUsbEventThread (3519), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                   1      0     0.000     0.000     0.000     0.000      0.00%
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  478		if (env->arch_strerrno == NULL)
  (gdb) bt
  #0  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  #1  0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
  #2  0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
  #3  0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
  #4  0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
  #5  0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
  #6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  #7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  #8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  #9  0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
  (gdb)

After:

  root@number:~# perf trace -a --errno-summary sleep 1
  <SNIP>
     pw-data-loop (2685), 1410 events, 16.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     epoll_wait           188      0   983.428     0.000     5.231    15.595      8.68%
     ioctl                 94      0     0.811     0.004     0.009     0.016      2.82%
     read                 188      0     0.322     0.001     0.002     0.006      5.15%
     write                141      0     0.280     0.001     0.002     0.018      8.39%
     timerfd_settime       94      0     0.138     0.001     0.001     0.007      6.47%

   gnome-control-c (179406), 1848 events, 20.9%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                 222      0   959.577     0.000     4.322    21.414     11.40%
     recvmsg              150      0     0.539     0.001     0.004     0.013      5.12%
     write                300      0     0.442     0.001     0.001     0.007      3.29%
     read                 150      0     0.183     0.001     0.001     0.009      5.53%
     getpid               102      0     0.101     0.000     0.001     0.008      7.82%

  root@number:~#

Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <vmolnaro@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Veronika Molnarova <vmolnaro@redhat.com>
Acked-by: Michael Petlan <mpetlan@redhat.com>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
matttbe pushed a commit that referenced this issue Dec 20, 2024
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.13, part #2

 - Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
   SPE/TRBE initialization

 - Align nested page table walker with the intended memory attribute
   combining rules of the architecture

 - Prevent userspace from constraining the advertised ASID width,
   avoiding horrors of guest TLBIs not matching the intended context in
   hardware

 - Don't leak references on LPIs when insertion into the translation
   cache fails
matttbe pushed a commit that referenced this issue Dec 20, 2024
The vmemmap's, which is used for RV64 with SPARSEMEM_VMEMMAP, page
tables are populated using pmd (page middle directory) hugetables.
However, the pmd allocation is not using the generic mechanism used by
the VMA code (e.g. pmd_alloc()), or the RISC-V specific
create_pgd_mapping()/alloc_pmd_late(). Instead, the vmemmap page table
code allocates a page, and calls vmemmap_set_pmd(). This results in
that the pmd ctor is *not* called, nor would it make sense to do so.

Now, when tearing down a vmemmap page table pmd, the cleanup code
would unconditionally, and incorrectly call the pmd dtor, which
results in a crash (best case).

This issue was found when running the HMM selftests:

  | tools/testing/selftests/mm# ./test_hmm.sh smoke
  | ... # when unloading the test_hmm.ko module
  | page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10915b
  | flags: 0x1000000000000000(node=0|zone=1)
  | raw: 1000000000000000 0000000000000000 dead000000000122 0000000000000000
  | raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
  | page dumped because: VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte)
  | ------------[ cut here ]------------
  | kernel BUG at include/linux/mm.h:3080!
  | Kernel BUG [#1]
  | Modules linked in: test_hmm(-) sch_fq_codel fuse drm drm_panel_orientation_quirks backlight dm_mod
  | CPU: 1 UID: 0 PID: 514 Comm: modprobe Tainted: G        W          6.12.0-00982-gf2a4f1682d07 #2
  | Tainted: [W]=WARN
  | Hardware name: riscv-virtio qemu/qemu, BIOS 2024.10 10/01/2024
  | epc : remove_pgd_mapping+0xbec/0x1070
  |  ra : remove_pgd_mapping+0xbec/0x1070
  | epc : ffffffff80010a68 ra : ffffffff80010a68 sp : ff20000000a73940
  |  gp : ffffffff827b2d88 tp : ff6000008785da40 t0 : ffffffff80fbce04
  |  t1 : 0720072007200720 t2 : 706d756420656761 s0 : ff20000000a73a50
  |  s1 : ff6000008915cff8 a0 : 0000000000000039 a1 : 0000000000000008
  |  a2 : ff600003fff0de20 a3 : 0000000000000000 a4 : 0000000000000000
  |  a5 : 0000000000000000 a6 : c0000000ffffefff a7 : ffffffff824469b8
  |  s2 : ff1c0000022456c0 s3 : ff1ffffffdbfffff s4 : ff6000008915c000
  |  s5 : ff6000008915c000 s6 : ff6000008915c000 s7 : ff1ffffffdc00000
  |  s8 : 0000000000000001 s9 : ff1ffffffdc00000 s10: ffffffff819a31f0
  |  s11: ffffffffffffffff t3 : ffffffff8000c950 t4 : ff60000080244f00
  |  t5 : ff60000080244000 t6 : ff20000000a73708
  | status: 0000000200000120 badaddr: ffffffff80010a68 cause: 0000000000000003
  | [<ffffffff80010a68>] remove_pgd_mapping+0xbec/0x1070
  | [<ffffffff80fd238e>] vmemmap_free+0x14/0x1e
  | [<ffffffff8032e698>] section_deactivate+0x220/0x452
  | [<ffffffff8032ef7e>] sparse_remove_section+0x4a/0x58
  | [<ffffffff802f8700>] __remove_pages+0x7e/0xba
  | [<ffffffff803760d8>] memunmap_pages+0x2bc/0x3fe
  | [<ffffffff02a3ca28>] dmirror_device_remove_chunks+0x2ea/0x518 [test_hmm]
  | [<ffffffff02a3e026>] hmm_dmirror_exit+0x3e/0x1018 [test_hmm]
  | [<ffffffff80102c14>] __riscv_sys_delete_module+0x15a/0x2a6
  | [<ffffffff80fd020c>] do_trap_ecall_u+0x1f2/0x266
  | [<ffffffff80fde0a2>] _new_vmalloc_restore_context_a0+0xc6/0xd2
  | Code: bf51 7597 0184 8593 76a5 854a 4097 0029 80e7 2c00 (9002) 7597
  | ---[ end trace 0000000000000000 ]---
  | Kernel panic - not syncing: Fatal exception in interrupt

Add a check to avoid calling the pmd dtor, if the calling context is
vmemmap_free().

Fixes: c75a74f ("riscv: mm: Add memory hotplugging support")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20241120131203.1859787-1-bjorn@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
matttbe pushed a commit that referenced this issue Dec 20, 2024
Aishwarya reports that warnings are sometimes seen when running the
ftrace kselftests, e.g.

| WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0
| Modules linked in:
| CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x4a0/0x4c0
| lr : arch_stack_walk+0x248/0x4c0
| sp : ffff800083643d20
| x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928
| x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80
| x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0
| x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000
| x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000
| x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001
| x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0
| x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690
| x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8
| Call trace:
|  arch_stack_walk+0x4a0/0x4c0 (P)
|  arch_stack_walk+0x248/0x4c0 (L)
|  profile_pc+0x44/0x80
|  profile_tick+0x50/0x80 (F)
|  tick_nohz_handler+0xcc/0x160 (F)
|  __hrtimer_run_queues+0x2ac/0x340 (F)
|  hrtimer_interrupt+0xf4/0x268 (F)
|  arch_timer_handler_virt+0x34/0x60 (F)
|  handle_percpu_devid_irq+0x88/0x220 (F)
|  generic_handle_domain_irq+0x34/0x60 (F)
|  gic_handle_irq+0x54/0x140 (F)
|  call_on_irq_stack+0x24/0x58 (F)
|  do_interrupt_handler+0x88/0x98
|  el1_interrupt+0x34/0x68 (F)
|  el1h_64_irq_handler+0x18/0x28
|  el1h_64_irq+0x6c/0x70
|  queued_spin_lock_slowpath+0x78/0x460 (P)

The warning in question is:

  WARN_ON_ONCE(state->common.pc == orig_pc))

... in kunwind_recover_return_address(), which is triggered when
return_to_handler() is encountered in the trace, but
ftrace_graph_ret_addr() cannot find a corresponding original return
address on the fgraph return stack.

This happens because the stacktrace code encounters an exception
boundary where the LR was not live at the time of the exception, but the
LR happens to contain return_to_handler(); either because the task
recently returned there, or due to unfortunate usage of the LR at a
scratch register. In such cases attempts to recover the return address
via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE()
above and aborting the unwind (hence the stacktrace terminating after
reporting the PC at the time of the exception).

Handling unreliable LR values in these cases is likely to require some
larger rework, so for the moment avoid this problem by restoring the old
behaviour of skipping the LR at exception boundaries, which the
stacktrace code did prior to commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

This commit is effectively a partial revert, keeping the structures and
logic to explicitly identify exception boundaries while still skipping
reporting of the LR. The logic to explicitly identify exception
boundaries is still useful for general robustness and as a building
block for future support for RELIABLE_STACKTRACE.

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
matttbe pushed a commit that referenced this issue Dec 20, 2024
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.

To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.

Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:

  42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")

... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:

  f8a00ce ("proc: restrict kernel stack dumps to root")

... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):

| for n in $(seq 1 10); do
|     while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
|  arch_stack_walk+0x1c8/0x370 (P)
|  stack_trace_save_tsk+0x8c/0x108
|  proc_pid_stack+0xb0/0x134
|  proc_single_show+0x60/0x120
|  seq_read_iter+0x104/0x438
|  seq_read+0xf8/0x140
|  vfs_read+0xc4/0x31c
|  ksys_read+0x70/0x108
|  __arm64_sys_read+0x1c/0x28
|  invoke_syscall+0x48/0x104
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x30/0xcc
|  el0t_64_sync_handler+0x10c/0x138
|  el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---

Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.

The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:

  9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
matttbe pushed a commit that referenced this issue Dec 20, 2024
The current implementation removes cache tags after disabling ATS,
leading to potential memory leaks and kernel crashes. Specifically,
CACHE_TAG_DEVTLB type cache tags may still remain in the list even
after the domain is freed, causing a use-after-free condition.

This issue really shows up when multiple VFs from different PFs
passed through to a single user-space process via vfio-pci. In such
cases, the kernel may crash with kernel messages like:

 BUG: kernel NULL pointer dereference, address: 0000000000000014
 PGD 19036a067 P4D 1940a3067 PUD 136c9b067 PMD 0
 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 74 UID: 0 PID: 3183 Comm: testCli Not tainted 6.11.9 #2
 RIP: 0010:cache_tag_flush_range+0x9b/0x250
 Call Trace:
  <TASK>
  ? __die+0x1f/0x60
  ? page_fault_oops+0x163/0x590
  ? exc_page_fault+0x72/0x190
  ? asm_exc_page_fault+0x22/0x30
  ? cache_tag_flush_range+0x9b/0x250
  ? cache_tag_flush_range+0x5d/0x250
  intel_iommu_tlb_sync+0x29/0x40
  intel_iommu_unmap_pages+0xfe/0x160
  __iommu_unmap+0xd8/0x1a0
  vfio_unmap_unpin+0x182/0x340 [vfio_iommu_type1]
  vfio_remove_dma+0x2a/0xb0 [vfio_iommu_type1]
  vfio_iommu_type1_ioctl+0xafa/0x18e0 [vfio_iommu_type1]

Move cache_tag_unassign_domain() before iommu_disable_pci_caps() to fix
it.

Fixes: 3b1d9e2 ("iommu/vt-d: Add cache tag assignment interface")
Cc: stable@vger.kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20241129020506.576413-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
matttbe pushed a commit that referenced this issue Dec 20, 2024
…s_lock

For storing a value to a queue attribute, the queue_attr_store function
first freezes the queue (->q_usage_counter(io)) and then acquire
->sysfs_lock. This seems not correct as the usual ordering should be to
acquire ->sysfs_lock before freezing the queue. This incorrect ordering
causes the following lockdep splat which we are able to reproduce always
simply by accessing /sys/kernel/debug file using ls command:

[   57.597146] WARNING: possible circular locking dependency detected
[   57.597154] 6.12.0-10553-gb86545e02e8c #20 Tainted: G        W
[   57.597162] ------------------------------------------------------
[   57.597168] ls/4605 is trying to acquire lock:
[   57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0
[   57.597200]
               but task is already holding lock:
[   57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4
[   57.597226]
               which lock already depends on the new lock.

[   57.597233]
               the existing dependency chain (in reverse order) is:
[   57.597241]
               -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}:
[   57.597255]        down_write+0x6c/0x18c
[   57.597264]        start_creating+0xb4/0x24c
[   57.597274]        debugfs_create_dir+0x2c/0x1e8
[   57.597283]        blk_register_queue+0xec/0x294
[   57.597292]        add_disk_fwnode+0x2e4/0x548
[   57.597302]        brd_alloc+0x2c8/0x338
[   57.597309]        brd_init+0x100/0x178
[   57.597317]        do_one_initcall+0x88/0x3e4
[   57.597326]        kernel_init_freeable+0x3cc/0x6e0
[   57.597334]        kernel_init+0x34/0x1cc
[   57.597342]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597350]
               -> #4 (&q->debugfs_mutex){+.+.}-{4:4}:
[   57.597362]        __mutex_lock+0xfc/0x12a0
[   57.597370]        blk_register_queue+0xd4/0x294
[   57.597379]        add_disk_fwnode+0x2e4/0x548
[   57.597388]        brd_alloc+0x2c8/0x338
[   57.597395]        brd_init+0x100/0x178
[   57.597402]        do_one_initcall+0x88/0x3e4
[   57.597410]        kernel_init_freeable+0x3cc/0x6e0
[   57.597418]        kernel_init+0x34/0x1cc
[   57.597426]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597434]
               -> #3 (&q->sysfs_lock){+.+.}-{4:4}:
[   57.597446]        __mutex_lock+0xfc/0x12a0
[   57.597454]        queue_attr_store+0x9c/0x110
[   57.597462]        sysfs_kf_write+0x70/0xb0
[   57.597471]        kernfs_fop_write_iter+0x1b0/0x2ac
[   57.597480]        vfs_write+0x3dc/0x6e8
[   57.597488]        ksys_write+0x84/0x140
[   57.597495]        system_call_exception+0x130/0x360
[   57.597504]        system_call_common+0x160/0x2c4
[   57.597516]
               -> #2 (&q->q_usage_counter(io)#21){++++}-{0:0}:
[   57.597530]        __submit_bio+0x5ec/0x828
[   57.597538]        submit_bio_noacct_nocheck+0x1e4/0x4f0
[   57.597547]        iomap_readahead+0x2a0/0x448
[   57.597556]        xfs_vm_readahead+0x28/0x3c
[   57.597564]        read_pages+0x88/0x41c
[   57.597571]        page_cache_ra_unbounded+0x1ac/0x2d8
[   57.597580]        filemap_get_pages+0x188/0x984
[   57.597588]        filemap_read+0x13c/0x4bc
[   57.597596]        xfs_file_buffered_read+0x88/0x17c
[   57.597605]        xfs_file_read_iter+0xac/0x158
[   57.597614]        vfs_read+0x2d4/0x3b4
[   57.597622]        ksys_read+0x84/0x144
[   57.597629]        system_call_exception+0x130/0x360
[   57.597637]        system_call_common+0x160/0x2c4
[   57.597647]
               -> #1 (mapping.invalidate_lock#2){++++}-{4:4}:
[   57.597661]        down_read+0x6c/0x220
[   57.597669]        filemap_fault+0x870/0x100c
[   57.597677]        xfs_filemap_fault+0xc4/0x18c
[   57.597684]        __do_fault+0x64/0x164
[   57.597693]        __handle_mm_fault+0x1274/0x1dac
[   57.597702]        handle_mm_fault+0x248/0x484
[   57.597711]        ___do_page_fault+0x428/0xc0c
[   57.597719]        hash__do_page_fault+0x30/0x68
[   57.597727]        do_hash_fault+0x90/0x35c
[   57.597736]        data_access_common_virt+0x210/0x220
[   57.597745]        _copy_from_user+0xf8/0x19c
[   57.597754]        sel_write_load+0x178/0xd54
[   57.597762]        vfs_write+0x108/0x6e8
[   57.597769]        ksys_write+0x84/0x140
[   57.597777]        system_call_exception+0x130/0x360
[   57.597785]        system_call_common+0x160/0x2c4
[   57.597794]
               -> #0 (&mm->mmap_lock){++++}-{4:4}:
[   57.597806]        __lock_acquire+0x17cc/0x2330
[   57.597814]        lock_acquire+0x138/0x400
[   57.597822]        __might_fault+0x7c/0xc0
[   57.597830]        filldir64+0xe8/0x390
[   57.597839]        dcache_readdir+0x80/0x2d4
[   57.597846]        iterate_dir+0xd8/0x1d4
[   57.597855]        sys_getdents64+0x88/0x2d4
[   57.597864]        system_call_exception+0x130/0x360
[   57.597872]        system_call_common+0x160/0x2c4
[   57.597881]
               other info that might help us debug this:

[   57.597888] Chain exists of:
                 &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3

[   57.597905]  Possible unsafe locking scenario:

[   57.597911]        CPU0                    CPU1
[   57.597917]        ----                    ----
[   57.597922]   rlock(&sb->s_type->i_mutex_key#3);
[   57.597932]                                lock(&q->debugfs_mutex);
[   57.597940]                                lock(&sb->s_type->i_mutex_key#3);
[   57.597950]   rlock(&mm->mmap_lock);
[   57.597958]
                *** DEADLOCK ***

[   57.597965] 2 locks held by ls/4605:
[   57.597971]  #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154
[   57.597989]  #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4

Prevent the above lockdep warning by acquiring ->sysfs_lock before
freezing the queue while storing a queue attribute in queue_attr_store
function. Later, we also found[1] another function __blk_mq_update_nr_
hw_queues where we first freeze queue and then acquire the ->sysfs_lock.
So we've also updated lock ordering in __blk_mq_update_nr_hw_queues
function and ensured that in all code paths we follow the correct lock
ordering i.e. acquire ->sysfs_lock before freezing the queue.

[1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/

Reported-by: kjain@linux.ibm.com
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: kjain@linux.ibm.com
Cc: hch@lst.de
Cc: axboe@kernel.dk
Cc: ritesh.list@gmail.com
Cc: ming.lei@redhat.com
Cc: gjoyce@linux.ibm.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241210144222.1066229-1-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
matttbe pushed a commit that referenced this issue Dec 23, 2024
Petr Machata says:

====================
bridge: Handle changes in VLAN_FLAG_BRIDGE_BINDING

When bridge binding is enabled on a VLAN netdevice, its link state should
track bridge ports that are members of the corresponding VLAN. This works
for a newly-added netdevices. However toggling the option does not have the
effect of enabling or disabling the behavior as appropriate.

In this patchset, have bridge react to bridge_binding toggles on VLAN
uppers.

There has been another attempt at supporting this behavior in 2022 by
Sevinj Aghayeva [0]. A discussion ensued that informed how this new
patchset is constructed, namely that the logic is in the bridge as opposed
to the 8021q driver, and the bridge reacts to NETDEV_CHANGE events on the
8021q upper.

Patches #1 and #2 contain the implementation, patches #3 and #4 a
selftest.

[0] https://lore.kernel.org/netdev/cover.1660100506.git.sevinj.aghayeva@gmail.com/
====================

Link: https://patch.msgid.link/cover.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Dec 24, 2024
Daniel Machon says:

====================
net: lan969x: add RGMII support

== Description:

This series is the fourth of a multi-part series, that prepares and adds
support for the new lan969x switch driver.

The upstreaming efforts is split into multiple series (might change a
bit as we go along):

        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.

        5) Add FDMA support.

== RGMII support:

The lan969x switch device includes two RGMII port interfaces (port 28
and 29) supporting data speeds of 1 Gbps, 100 Mbps and 10 Mbps.

== Patch breakdown:

Patch #1 does some preparation work.

Patch #2 adds new function: is_port_rgmii() to the match data ops.

Patch #3 uses the is_port_rgmii() in a number of places.

Patch #4 makes sure that we do not configure an RGMII device as a
         low-speed device, when doing a port config.

Patch #5 makes sure we only return the PCS if the port mode requires
         it.

Patch #6 adds checks for RGMII PHY modes in sparx5_verify_speeds().

Patch #7 adds registers required to configure RGMII.

Patch #8 adds RGMII implementation.

Patch #9 documents RGMII delays in the dt-bindings.

Details are in the commit description of the individual patches

v4: https://lore.kernel.org/20241213-sparx5-lan969x-switch-driver-4-v4-0-d1a72c9c4714@microchip.com
v3: https://lore.kernel.org/20241118-sparx5-lan969x-switch-driver-4-v3-0-3cefee5e7e3a@microchip.com
v2: https://lore.kernel.org/20241113-sparx5-lan969x-switch-driver-4-v2-0-0db98ac096d1@microchip.com
v1: https://lore.kernel.org/20241106-sparx5-lan969x-switch-driver-4-v1-0-f7f7316436bd@microchip.com
====================

Link: https://patch.msgid.link/20241220-sparx5-lan969x-switch-driver-4-v5-0-fa8ba5dff732@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Dec 28, 2024
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 <pablo@netfilter.org>
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