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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 Aug 2, 2024
In z_erofs_get_gbuf(), the current task may be migrated to another
CPU between `z_erofs_gbuf_id()` and `spin_lock(&gbuf->lock)`.

Therefore, z_erofs_put_gbuf() will trigger the following issue
which was found by stress test:

<2>[772156.434168] kernel BUG at fs/erofs/zutil.c:58!
..
<4>[772156.435007]
<4>[772156.439237] CPU: 0 PID: 3078 Comm: stress Kdump: loaded Tainted: G            E      6.10.0-rc7+ #2
<4>[772156.439239] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 1.0.0 01/01/2017
<4>[772156.439241] pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
<4>[772156.439243] pc : z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.439252] lr : z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
..
<6>[772156.445958] stress (3127): drop_caches: 1
<4>[772156.446120] Call trace:
<4>[772156.446121]  z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.446761]  z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
<4>[772156.446897]  z_erofs_decompress_queue+0x740/0xa10 [erofs]
<4>[772156.447036]  z_erofs_runqueue+0x428/0x8c0 [erofs]
<4>[772156.447160]  z_erofs_readahead+0x224/0x390 [erofs]
..

Fixes: f36f301 ("erofs: rename per-CPU buffers to global buffer pool and make it configurable")
Cc: <stable@vger.kernel.org> # 6.10+
Reviewed-by: Chunhai Guo <guochunhai@vivo.com>
Reviewed-by: Sandeep Dhavale <dhavale@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240722035110.3456740-1-hsiangkao@linux.alibaba.com
matttbe pushed a commit that referenced this issue Aug 2, 2024
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
matttbe pushed a commit that referenced this issue Aug 2, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Fix a possible null-ptr-deref sometimes triggered by iptables-restore at
boot time. Register iptables {ipv4,ipv6} nat table pernet in first place
to fix this issue. Patch #1 and #2 from Kuniyuki Iwashima.

netfilter pull request 24-07-31

* tag 'nf-24-07-31' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init().
  netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init().
====================

Link: https://patch.msgid.link/20240731213046.6194-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Aug 7, 2024
linkwatch_event() grabs possibly very contended RTNL mutex.

system_wq is not suitable for such work.

Inspired by many noisy syzbot reports.

3 locks held by kworker/0:7/5266:
 #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90003f6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 , at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fa6f208 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240805085821.1616528-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 9, 2024
…pinlock_t'

This lock is acquired under irq_desc::lock with interrupts disabled.

When PREEMPT_RT is enabled, 'spinlock_t' becomes preemptible, which results
in invalid lock acquire context;

  [ BUG: Invalid wait context ]
  swapper/0/1 is trying to lock:
  ffff0000008fed30 (&ctl->lock){....}-{3:3}, at: meson_gpio_irq_update_bits0
  other info that might help us debug this:
  context-{5:5}
  3 locks held by swapper/0/1:
   #0: ffff0000003cd0f8 (&dev->mutex){....}-{4:4}, at: __driver_attach+0x90c
   #1: ffff000004714650 (&desc->request_mutex){+.+.}-{4:4}, at: __setup_irq0
   #2: ffff0000047144c8 (&irq_desc_lock_class){-.-.}-{2:2}, at: __setup_irq0
  stack backtrace:
  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.9.9-sdkernel #1
  Call trace:
   _raw_spin_lock_irqsave+0x60/0x88
   meson_gpio_irq_update_bits+0x34/0x70
   meson8_gpio_irq_set_type+0x78/0xc4
   meson_gpio_irq_set_type+0x30/0x60
   __irq_set_trigger+0x60/0x180
   __setup_irq+0x30c/0x6e0
   request_threaded_irq+0xec/0x1a4

Fixes: 215f4cc ("irqchip/meson: Add support for gpio interrupt controller")
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240729131850.3015508-1-avkrasnov@salutedevices.com
matttbe pushed a commit that referenced this issue Aug 9, 2024
When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: gnault@redhat.com
CC: cong.wang@bytedance.com
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 12, 2024
Tariq Toukan says:

====================
mlx5 misc patches 2024-08-08

This patchset contains multiple enhancements from the team to the mlx5
core and Eth drivers.

Patch #1 by Chris bumps a defined value to permit more devices doing TC
offloads.

Patch #2 by Jianbo adds an IPsec fast-path optimization to replace the
slow async handling.

Patches #3 and #4 by Jianbo add TC offload support for complicated rules
to overcome firmware limitation.

Patch #5 by Gal unifies the access macro to advertised/supported link
modes.

Patches #6 to #9 by Gal adds extack messages in ethtool ops to replace
prints to the kernel log.

Patch #10 by Cosmin switches to using 'update' verb instead of 'replace'
to better reflect the operation.

Patch #11 by Cosmin exposes an update connection tracking operation to
replace the assumed delete+add implementaiton.
====================

Link: https://patch.msgid.link/20240808055927.2059700-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 13, 2024
Petr Machata says:

====================
net: nexthop: Increase weight to u16

In CLOS networks, as link failures occur at various points in the network,
ECMP weights of the involved nodes are adjusted to compensate. With high
fan-out of the involved nodes, and overall high number of nodes,
a (non-)ECMP weight ratio that we would like to configure does not fit into
8 bits. Instead of, say, 255:254, we might like to configure something like
1000:999. For these deployments, the 8-bit weight may not be enough.

To that end, in this patchset increase the next hop weight from u8 to u16.

Patch #1 adds a flag that indicates whether the reserved fields are zeroed.
This is a follow-up to a new fix merged in commit 6d745cd ("net:
nexthop: Initialize all fields in dumped nexthops"). The theory behind this
patch is that there is a strict ordering between the fields actually being
zeroed, the kernel declaring that they are, and the kernel repurposing the
fields. Thus clients can use the flag to tell if it is safe to interpret
the reserved fields in any way.

Patch #2 contains the substantial code and the commit message covers the
details of the changes.

Patches #3 to #6 add selftests.
====================

Link: https://patch.msgid.link/cover.1723036486.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 16, 2024
Currently the dma debugging code can end up indirectly calling printk
under the radix_lock. This happens when a radix tree node allocation
fails.

This is a problem because the printk code, when used together with
netconsole, can end up inside the dma debugging code while trying to
transmit a message over netcons.

This creates the possibility of either a circular deadlock on the same
CPU, with that CPU trying to grab the radix_lock twice, or an ABBA
deadlock between different CPUs, where one CPU grabs the console lock
first and then waits for the radix_lock, while the other CPU is holding
the radix_lock and is waiting for the console lock.

The trace captured by lockdep is of the ABBA variant.

-> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}:
                  _raw_spin_lock_irqsave+0x5a/0x90
                  debug_dma_map_page+0x79/0x180
                  dma_map_page_attrs+0x1d2/0x2f0
                  bnxt_start_xmit+0x8c6/0x1540
                  netpoll_start_xmit+0x13f/0x180
                  netpoll_send_skb+0x20d/0x320
                  netpoll_send_udp+0x453/0x4a0
                  write_ext_msg+0x1b9/0x460
                  console_flush_all+0x2ff/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  devkmsg_emit+0x5a/0x80
                  devkmsg_write+0xfd/0x180
                  do_iter_readv_writev+0x164/0x1b0
                  vfs_writev+0xf9/0x2b0
                  do_writev+0x6d/0x110
                  do_syscall_64+0x80/0x150
                  entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #0 (console_owner){-.-.}-{0:0}:
                  __lock_acquire+0x15d1/0x31a0
                  lock_acquire+0xe8/0x290
                  console_flush_all+0x2ea/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  _printk+0x59/0x80
                  warn_alloc+0x122/0x1b0
                  __alloc_pages_slowpath+0x1101/0x1120
                  __alloc_pages+0x1eb/0x2c0
                  alloc_slab_page+0x5f/0x150
                  new_slab+0x2dc/0x4e0
                  ___slab_alloc+0xdcb/0x1390
                  kmem_cache_alloc+0x23d/0x360
                  radix_tree_node_alloc+0x3c/0xf0
                  radix_tree_insert+0xf5/0x230
                  add_dma_entry+0xe9/0x360
                  dma_map_page_attrs+0x1d2/0x2f0
                  __bnxt_alloc_rx_frag+0x147/0x180
                  bnxt_alloc_rx_data+0x79/0x160
                  bnxt_rx_skb+0x29/0xc0
                  bnxt_rx_pkt+0xe22/0x1570
                  __bnxt_poll_work+0x101/0x390
                  bnxt_poll+0x7e/0x320
                  __napi_poll+0x29/0x160
                  net_rx_action+0x1e0/0x3e0
                  handle_softirqs+0x190/0x510
                  run_ksoftirqd+0x4e/0x90
                  smpboot_thread_fn+0x1a8/0x270
                  kthread+0x102/0x120
                  ret_from_fork+0x2f/0x40
                  ret_from_fork_asm+0x11/0x20

This bug is more likely than it seems, because when one CPU has run out
of memory, chances are the other has too.

The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so
not many users are likely to trigger it.

Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Konstantin Ovsepian <ovs@meta.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
matttbe pushed a commit that referenced this issue Aug 19, 2024
Add support for offloading cls U32 filters. Only "skbedit queue_mapping"
and "drop" actions are supported. Also, only "ip" and "802_3" tc
protocols are allowed. The PF must advertise the VIRTCHNL_VF_OFFLOAD_TC_U32
capability flag.

Since the filters will be enabled via the FD stage at the PF, a new type
of FDIR filters is added and the existing list and state machine are used.

The new filters can be used to configure flow directors based on raw
(binary) pattern in the rx packet.

Examples:

0. # tc qdisc add dev enp175s0v0  ingress

1. Redirect UDP from src IP 192.168.2.1 to queue 12:

    # tc filter add dev <dev> protocol ip ingress u32 \
	match u32 0x45000000 0xff000000 at 0  \
	match u32 0x00110000 0x00ff0000 at 8  \
	match u32 0xC0A80201 0xffffffff at 12 \
	match u32 0x00000000 0x00000000 at 24 \
	action skbedit queue_mapping 12 skip_sw

2. Drop all ICMP:

    # tc filter add dev <dev> protocol ip ingress u32 \
	match u32 0x45000000 0xff000000 at 0  \
	match u32 0x00010000 0x00ff0000 at 8  \
	match u32 0x00000000 0x00000000 at 24 \
	action drop skip_sw

3. Redirect ICMP traffic from MAC 3c:fd:fe:a5:47:e0 to queue 7
   (note proto: 802_3):

   # tc filter add dev <dev> protocol 802_3 ingress u32 \
	match u32 0x00003CFD 0x0000ffff at 4   \
	match u32 0xFEA547E0 0xffffffff at 8   \
	match u32 0x08004500 0xffffff00 at 12  \
	match u32 0x00000001 0x000000ff at 20  \
	match u32 0x0000 0x0000 at 40          \
	action skbedit queue_mapping 7 skip_sw

Notes on matches:
1 - All intermediate fields that are needed to parse the correct PTYPE
    must be provided (in e.g. 3: Ethernet Type 0x0800 in MAC, IP version
    and IP length: 0x45 and protocol: 0x01 (ICMP)).
2 - The last match must provide an offset that guarantees all required
    headers are accounted for, even if the last header is not matched.
    For example, in #2, the last match is 4 bytes at offset 24 starting
    from IP header, so the total is 14 (MAC) + 24 + 4 = 42, which is the
    sum of MAC+IP+ICMP headers.

Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
matttbe pushed a commit that referenced this issue Aug 19, 2024
Prevent the call trace below from happening, by not allowing IPsec
creation over a slave, if master device doesn't support IPsec.

WARNING: CPU: 44 PID: 16136 at kernel/locking/rwsem.c:240 down_read+0x75/0x94
Modules linked in: esp4_offload esp4 act_mirred act_vlan cls_flower sch_ingress mlx5_vdpa vringh vhost_iotlb vdpa mst_pciconf(OE) nfsv3 nfs_acl nfs lockd grace fscache netfs xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill cuse fuse rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi rdma_cm ib_ipoib iw_cm ib_cm ipmi_ssif intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd kvm_amd kvm irqbypass crct10dif_pclmul crc32_pclmul mlx5_ib ghash_clmulni_intel sha1_ssse3 dell_smbios ib_uverbs aesni_intel crypto_simd dcdbas wmi_bmof dell_wmi_descriptor cryptd pcspkr ib_core acpi_ipmi sp5100_tco ccp i2c_piix4 ipmi_si ptdma k10temp ipmi_devintf ipmi_msghandler acpi_power_meter acpi_cpufreq ext4 mbcache jbd2 sd_mod t10_pi sg mgag200 drm_kms_helper syscopyarea sysfillrect mlx5_core sysimgblt fb_sys_fops cec
 ahci libahci mlxfw drm pci_hyperv_intf libata tg3 sha256_ssse3 tls megaraid_sas i2c_algo_bit psample wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: mst_pci]
CPU: 44 PID: 16136 Comm: kworker/44:3 Kdump: loaded Tainted: GOE 5.15.0-20240509.el8uek.uek7_u3_update_v6.6_ipsec_bf.x86_64 #2
Hardware name: Dell Inc. PowerEdge R7525/074H08, BIOS 2.0.3 01/15/2021
Workqueue: events xfrm_state_gc_task
RIP: 0010:down_read+0x75/0x94
Code: 00 48 8b 45 08 65 48 8b 14 25 80 fc 01 00 83 e0 02 48 09 d0 48 83 c8 01 48 89 45 08 5d 31 c0 89 c2 89 c6 89 c7 e9 cb 88 3b 00 <0f> 0b 48 8b 45 08 a8 01 74 b2 a8 02 75 ae 48 89 c2 48 83 ca 02 f0
RSP: 0018:ffffb26387773da8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffa08b658af900 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ff886bc5e1366f2f RDI: 0000000000000000
RBP: ffffa08b658af940 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffa0a9bfb31540
R13: ffffa0a9bfb37900 R14: 0000000000000000 R15: ffffa0a9bfb37905
FS:  0000000000000000(0000) GS:ffffa0a9bfb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a45ed814e8 CR3: 000000109038a000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 ? show_trace_log_lvl+0x1d6/0x2f9
 ? show_trace_log_lvl+0x1d6/0x2f9
 ? mlx5_devcom_for_each_peer_begin+0x29/0x60 [mlx5_core]
 ? down_read+0x75/0x94
 ? __warn+0x80/0x113
 ? down_read+0x75/0x94
 ? report_bug+0xa4/0x11d
 ? handle_bug+0x35/0x8b
 ? exc_invalid_op+0x14/0x75
 ? asm_exc_invalid_op+0x16/0x1b
 ? down_read+0x75/0x94
 ? down_read+0xe/0x94
 mlx5_devcom_for_each_peer_begin+0x29/0x60 [mlx5_core]
 mlx5_ipsec_fs_roce_tx_destroy+0xb1/0x130 [mlx5_core]
 tx_destroy+0x1b/0xc0 [mlx5_core]
 tx_ft_put+0x53/0xc0 [mlx5_core]
 mlx5e_xfrm_free_state+0x45/0x90 [mlx5_core]
 ___xfrm_state_destroy+0x10f/0x1a2
 xfrm_state_gc_task+0x81/0xa9
 process_one_work+0x1f1/0x3c6
 worker_thread+0x53/0x3e4
 ? process_one_work.cold+0x46/0x3c
 kthread+0x127/0x144
 ? set_kthread_struct+0x60/0x52
 ret_from_fork+0x22/0x2d
 </TASK>
---[ end trace 5ef7896144d398e1 ]---

Fixes: dfbd229 ("net/mlx5: Configure IPsec steering for egress RoCEv2 MPV traffic")
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20240815071611.2211873-5-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 21, 2024
Ido Schimmel says:

====================
Preparations for FIB rule DSCP selector

This patchset moves the masking of the upper DSCP bits in 'flowi4_tos'
to the core instead of relying on callers of the FIB lookup API to do
it.

This will allow us to start changing users of the API to initialize the
'flowi4_tos' field with all six bits of the DSCP field. In turn, this
will allow us to extend FIB rules with a new DSCP selector.

By masking the upper DSCP bits in the core we are able to maintain the
behavior of the TOS selector in FIB rules and routes to only match on
the lower DSCP bits.

While working on this I found two users of the API that do not mask the
upper DSCP bits before performing the lookup. The first is an ancient
netlink family that is unlikely to be used. It is adjusted in patch #1
to mask both the upper DSCP bits and the ECN bits before calling the
API.

The second user is a nftables module that differs in this regard from
its equivalent iptables module. It is adjusted in patch #2 to invoke the
API with the upper DSCP bits masked, like all other callers. The
relevant selftest passed, but in the unlikely case that regressions are
reported because of this change, we can restore the existing behavior
using a new flow information flag as discussed here [1].

The last patch moves the masking of the upper DSCP bits to the core,
making the first two patches redundant, but I wanted to post them
separately to call attention to the behavior change for these two users
of the FIB lookup API.

Future patchsets (around 3) will start unmasking the upper DSCP bits
throughout the networking stack before adding support for the new FIB
rule DSCP selector.

Changes from v1 [2]:

Patch #3: Include <linux/ip.h> in <linux/in_route.h> instead of
including it in net/ip_fib.h

[1] https://lore.kernel.org/netdev/ZpqpB8vJU%2FQ6LSqa@debian/
[2] https://lore.kernel.org/netdev/20240725131729.1729103-1-idosch@nvidia.com/
====================

Link: https://patch.msgid.link/20240814125224.972815-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Aug 23, 2024
…on array

The out-of-bounds access is reported by UBSAN:

[    0.000000] UBSAN: array-index-out-of-bounds in ../arch/riscv/kernel/vendor_extensions.c:41:66
[    0.000000] index -1 is out of range for type 'riscv_isavendorinfo [32]'
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.11.0-rc2ubuntu-defconfig #2
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] Call Trace:
[    0.000000] [<ffffffff94e078ba>] dump_backtrace+0x32/0x40
[    0.000000] [<ffffffff95c83c1a>] show_stack+0x38/0x44
[    0.000000] [<ffffffff95c94614>] dump_stack_lvl+0x70/0x9c
[    0.000000] [<ffffffff95c94658>] dump_stack+0x18/0x20
[    0.000000] [<ffffffff95c8bbb2>] ubsan_epilogue+0x10/0x46
[    0.000000] [<ffffffff95485a82>] __ubsan_handle_out_of_bounds+0x94/0x9c
[    0.000000] [<ffffffff94e09442>] __riscv_isa_vendor_extension_available+0x90/0x92
[    0.000000] [<ffffffff94e043b6>] riscv_cpufeature_patch_func+0xc4/0x148
[    0.000000] [<ffffffff94e035f8>] _apply_alternatives+0x42/0x50
[    0.000000] [<ffffffff95e04196>] apply_boot_alternatives+0x3c/0x100
[    0.000000] [<ffffffff95e05b52>] setup_arch+0x85a/0x8bc
[    0.000000] [<ffffffff95e00ca0>] start_kernel+0xa4/0xfb6

The dereferencing using cpu should actually not happen, so remove it.

Fixes: 23c996f ("riscv: Extend cpufeature.c to detect vendor extensions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240814192619.276794-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
matttbe pushed a commit that referenced this issue Aug 23, 2024
Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240815024736.2040971-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
matttbe pushed a commit that referenced this issue Aug 23, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 disable BH when collecting stats via hardware offload to ensure
         concurrent updates from packet path do not result in losing stats.
         From Sebastian Andrzej Siewior.

Patch #2 uses write seqcount to reset counters serialize against reader.
         Also from Sebastian Andrzej Siewior.

Patch #3 ensures vlan header is in place before accessing its fields,
         according to KMSAN splat triggered by syzbot.

* tag 'nf-24-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: flowtable: validate vlan header
  netfilter: nft_counter: Synchronize nft_counter_reset() against reader.
  netfilter: nft_counter: Disable BH in nft_counter_offload_stats().
====================

Link: https://patch.msgid.link/20240822101842.4234-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 27, 2024
…rnel/git/netfilter/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following batch contains Netfilter updates for net-next:

Patch #1 fix checksum calculation in nfnetlink_queue with SCTP,
	 segment GSO packet since skb_zerocopy() does not support
	 GSO_BY_FRAGS, from Antonio Ojea.

Patch #2 extend nfnetlink_queue coverage to handle SCTP packets,
	 from Antonio Ojea.

Patch #3 uses consume_skb() instead of kfree_skb() in nfnetlink,
         from Donald Hunter.

Patch #4 adds a dedicate commit list for sets to speed up
	 intra-transaction lookups, from Florian Westphal.

Patch #5 skips removal of element from abort path for the pipapo
         backend, ditching the shadow copy of this datastructure
	 is sufficient.

Patch #6 moves nf_ct_netns_get() out of nf_conncount_init() to
	 let users of conncoiunt decide when to enable conntrack,
	 this is needed by openvswitch, from Xin Long.

Patch #7 pass context to all nft_parse_register_load() in
	 preparation for the next patch.

Patches #8 and #9 reject loads from uninitialized registers from
	 control plane to remove register initialization from
	 datapath. From Florian Westphal.

* tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: don't initialize registers in nft_do_chain()
  netfilter: nf_tables: allow loads only when register is initialized
  netfilter: nf_tables: pass context structure to nft_parse_register_load
  netfilter: move nf_ct_netns_get out of nf_conncount_init
  netfilter: nf_tables: do not remove elements if set backend implements .abort
  netfilter: nf_tables: store new sets in dedicated list
  netfilter: nfnetlink: convert kfree_skb to consume_skb
  selftests: netfilter: nft_queue.sh: sctp coverage
  netfilter: nfnetlink_queue: unbreak SCTP traffic
====================

Link: https://patch.msgid.link/20240822221939.157858-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Aug 29, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 sets on NFT_PKTINFO_L4PROTO for UDP packets less than 4 bytes
payload from netdev/egress by subtracting skb_network_offset() when
validating IPv4 packet length, otherwise 'meta l4proto udp' never
matches.

Patch #2 subtracts skb_network_offset() when validating IPv6 packet
length for netdev/egress.

netfilter pull request 24-08-28

* tag 'nf-24-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables_ipv6: consider network offset in netdev/egress validation
  netfilter: nf_tables: restore IP sanity checks for netdev/egress
====================

Link: https://patch.msgid.link/20240828214708.619261-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Aug 30, 2024
…/kernel/git/kvmarm/kvmarm into for-next/fixes

KVM/arm64 fixes for 6.11, round #2

 - Don't drop references on LPIs that weren't visited by the
   vgic-debug iterator

 - Cure lock ordering issue when unregistering vgic redistributors

 - Fix for misaligned stage-2 mappings when VMs are backed by hugetlb
   pages

 - Treat SGI registers as UNDEFINED if a VM hasn't been configured for
   GICv3

* tag 'kvmarm-fixes-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm:
  KVM: arm64: Make ICC_*SGI*_EL1 undef in the absence of a vGICv3
  KVM: arm64: Ensure canonical IPA is hugepage-aligned when handling fault
  KVM: arm64: vgic: Don't hold config_lock while unregistering redistributors
  KVM: arm64: vgic-debug: Don't put unmarked LPIs
  KVM: arm64: vgic: Hold config_lock while tearing down a CPU interface
  KVM: selftests: arm64: Correct feature test for S1PIE in get-reg-list
  KVM: arm64: Tidying up PAuth code in KVM
  KVM: arm64: vgic-debug: Exit the iterator properly w/o LPI
  KVM: arm64: Enforce dependency on an ARMv8.4-aware toolchain
  docs: KVM: Fix register ID of SPSR_FIQ
  KVM: arm64: vgic: fix unexpected unlock sparse warnings
  KVM: arm64: fix kdoc warnings in W=1 builds
  KVM: arm64: fix override-init warnings in W=1 builds
  KVM: arm64: free kvm->arch.nested_mmus with kvfree()
matttbe pushed a commit that referenced this issue Sep 4, 2024
Daniel Machon says:

====================
net: microchip: add FDMA library and use it for Sparx5

This patch series is the first of a 2-part series, that adds a new
common FDMA library for Microchip switch chips Sparx5 and lan966x. These
chips share the same FDMA engine, and as such will benefit from a
common library with a common implementation.  This also has the benefit
of removing a lot open-coded bookkeeping and duplicate code for the two
drivers.

Additionally, upstreaming efforts for a third chip, lan969x, will begin
in the near future. This chip will use the new library too.

In this first series, the FDMA library is introduced and used by the
Sparx5 switch driver.

 ###################
 # Example of use: #
 ###################

- Initialize the rx and tx fdma structs with values for: number of
  DCB's, number of DB's, channel ID, DB size (data buffer size), and
  total size of the requested memory. Also provide two callbacks:
  nextptr_cb() and dataptr_cb() for getting the nextptr and dataptr.

- Allocate memory using fdma_alloc_phys() or fdma_alloc_coherent().

- Initialize the DCB's with fdma_dcb_init().

- Add new DCB's with fdma_dcb_add().

- Free memory with fdma_free_phys() or fdma_free_coherent().

 #####################
 # Patch  breakdown: #
 #####################

Patch #1:  introduces library and selects it for Sparx5.

Patch #2:  includes the fdma_api.h header and removes old symbols.

Patch #3:  replaces old rx and tx variables with equivalent ones from the
           fdma struct. Only the variables that can be changed without
           breaking traffic is changed in this patch.

Patch #4:  uses the library for allocation of rx buffers. This requires
           quite a bit of refactoring in this single patch.

Patch #5:  uses the library for adding DCB's in the rx path.

Patch #6:  uses the library for freeing rx buffers.

Patch #7:  uses the library helpers in the rx path.

Patch #8:  uses the library for allocation of tx buffers. This requires
           quite a bit of refactoring in this single patch.

Patch #9:  uses the library for adding DCB's in the tx path.

Patch #10: uses the library helpers in the tx path.

Patch #11: ditches the existing linked list for storing buffer addresses,
           and instead uses offsets into contiguous memory.

Patch #12: modifies existing rx and tx functions to be direction
           independent.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
matttbe pushed a commit that referenced this issue Sep 5, 2024
Currently, netif_queue_set_napi() is called from ice_vsi_rebuild() that is
not rtnl-locked when called from the reset. This creates the need to take
the rtnl_lock just for a single function and complicates the
synchronization with .ndo_bpf. At the same time, there no actual need to
fill napi-to-queue information at this exact point.

Fill napi-to-queue information when opening the VSI and clear it when the
VSI is being closed. Those routines are already rtnl-locked.

Also, rewrite napi-to-queue assignment in a way that prevents inclusion of
XDP queues, as this leads to out-of-bounds writes, such as one below.

[  +0.000004] BUG: KASAN: slab-out-of-bounds in netif_queue_set_napi+0x1c2/0x1e0
[  +0.000012] Write of size 8 at addr ffff889881727c80 by task bash/7047
[  +0.000006] CPU: 24 PID: 7047 Comm: bash Not tainted 6.10.0-rc2+ #2
[  +0.000004] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0014.082620210524 08/26/2021
[  +0.000003] Call Trace:
[  +0.000003]  <TASK>
[  +0.000002]  dump_stack_lvl+0x60/0x80
[  +0.000007]  print_report+0xce/0x630
[  +0.000007]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  +0.000007]  ? __virt_addr_valid+0x1c9/0x2c0
[  +0.000005]  ? netif_queue_set_napi+0x1c2/0x1e0
[  +0.000003]  kasan_report+0xe9/0x120
[  +0.000004]  ? netif_queue_set_napi+0x1c2/0x1e0
[  +0.000004]  netif_queue_set_napi+0x1c2/0x1e0
[  +0.000005]  ice_vsi_close+0x161/0x670 [ice]
[  +0.000114]  ice_dis_vsi+0x22f/0x270 [ice]
[  +0.000095]  ice_pf_dis_all_vsi.constprop.0+0xae/0x1c0 [ice]
[  +0.000086]  ice_prepare_for_reset+0x299/0x750 [ice]
[  +0.000087]  pci_dev_save_and_disable+0x82/0xd0
[  +0.000006]  pci_reset_function+0x12d/0x230
[  +0.000004]  reset_store+0xa0/0x100
[  +0.000006]  ? __pfx_reset_store+0x10/0x10
[  +0.000002]  ? __pfx_mutex_lock+0x10/0x10
[  +0.000004]  ? __check_object_size+0x4c1/0x640
[  +0.000007]  kernfs_fop_write_iter+0x30b/0x4a0
[  +0.000006]  vfs_write+0x5d6/0xdf0
[  +0.000005]  ? fd_install+0x180/0x350
[  +0.000005]  ? __pfx_vfs_write+0x10/0xA10
[  +0.000004]  ? do_fcntl+0x52c/0xcd0
[  +0.000004]  ? kasan_save_track+0x13/0x60
[  +0.000003]  ? kasan_save_free_info+0x37/0x60
[  +0.000006]  ksys_write+0xfa/0x1d0
[  +0.000003]  ? __pfx_ksys_write+0x10/0x10
[  +0.000002]  ? __x64_sys_fcntl+0x121/0x180
[  +0.000004]  ? _raw_spin_lock+0x87/0xe0
[  +0.000005]  do_syscall_64+0x80/0x170
[  +0.000007]  ? _raw_spin_lock+0x87/0xe0
[  +0.000004]  ? __pfx__raw_spin_lock+0x10/0x10
[  +0.000003]  ? file_close_fd_locked+0x167/0x230
[  +0.000005]  ? syscall_exit_to_user_mode+0x7d/0x220
[  +0.000005]  ? do_syscall_64+0x8c/0x170
[  +0.000004]  ? do_syscall_64+0x8c/0x170
[  +0.000003]  ? do_syscall_64+0x8c/0x170
[  +0.000003]  ? fput+0x1a/0x2c0
[  +0.000004]  ? filp_close+0x19/0x30
[  +0.000004]  ? do_dup2+0x25a/0x4c0
[  +0.000004]  ? __x64_sys_dup2+0x6e/0x2e0
[  +0.000002]  ? syscall_exit_to_user_mode+0x7d/0x220
[  +0.000004]  ? do_syscall_64+0x8c/0x170
[  +0.000003]  ? __count_memcg_events+0x113/0x380
[  +0.000005]  ? handle_mm_fault+0x136/0x820
[  +0.000005]  ? do_user_addr_fault+0x444/0xa80
[  +0.000004]  ? clear_bhb_loop+0x25/0x80
[  +0.000004]  ? clear_bhb_loop+0x25/0x80
[  +0.000002]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  +0.000005] RIP: 0033:0x7f2033593154

Fixes: 080b0c8 ("ice: Fix ASSERT_RTNL() warning during certain scenarios")
Fixes: 91fdbce ("ice: Add support in the driver for associating queue with napi")
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
matttbe pushed a commit that referenced this issue Sep 6, 2024
Chi Zhiling reported:

  We found a null pointer accessing in tracefs[1], the reason is that the
  variable 'ei_child' is set to LIST_POISON1, that means the list was
  removed in eventfs_remove_rec. so when access the ei_child->is_freed, the
  panic triggered.

  by the way, the following script can reproduce this panic

  loop1 (){
      while true
      do
          echo "p:kp submit_bio" > /sys/kernel/debug/tracing/kprobe_events
          echo "" > /sys/kernel/debug/tracing/kprobe_events
      done
  }
  loop2 (){
      while true
      do
          tree /sys/kernel/debug/tracing/events/kprobes/
      done
  }
  loop1 &
  loop2

  [1]:
  [ 1147.959632][T17331] Unable to handle kernel paging request at virtual address dead000000000150
  [ 1147.968239][T17331] Mem abort info:
  [ 1147.971739][T17331]   ESR = 0x0000000096000004
  [ 1147.976172][T17331]   EC = 0x25: DABT (current EL), IL = 32 bits
  [ 1147.982171][T17331]   SET = 0, FnV = 0
  [ 1147.985906][T17331]   EA = 0, S1PTW = 0
  [ 1147.989734][T17331]   FSC = 0x04: level 0 translation fault
  [ 1147.995292][T17331] Data abort info:
  [ 1147.998858][T17331]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
  [ 1148.005023][T17331]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  [ 1148.010759][T17331]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
  [ 1148.016752][T17331] [dead000000000150] address between user and kernel address ranges
  [ 1148.024571][T17331] Internal error: Oops: 0000000096000004 [#1] SMP
  [ 1148.030825][T17331] Modules linked in: team_mode_loadbalance team nlmon act_gact cls_flower sch_ingress bonding tls macvlan dummy ib_core bridge stp llc veth amdgpu amdxcp mfd_core gpu_sched drm_exec drm_buddy radeon crct10dif_ce video drm_suballoc_helper ghash_ce drm_ttm_helper sha2_ce ttm sha256_arm64 i2c_algo_bit sha1_ce sbsa_gwdt cp210x drm_display_helper cec sr_mod cdrom drm_kms_helper binfmt_misc sg loop fuse drm dm_mod nfnetlink ip_tables autofs4 [last unloaded: tls]
  [ 1148.072808][T17331] CPU: 3 PID: 17331 Comm: ls Tainted: G        W         ------- ----  6.6.43 #2
  [ 1148.081751][T17331] Source Version: 21b3b386e948bedd29369af66f3e98ab01b1c650
  [ 1148.088783][T17331] Hardware name: Greatwall GW-001M1A-FTF/GW-001M1A-FTF, BIOS KunLun BIOS V4.0 07/16/2020
  [ 1148.098419][T17331] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  [ 1148.106060][T17331] pc : eventfs_iterate+0x2c0/0x398
  [ 1148.111017][T17331] lr : eventfs_iterate+0x2fc/0x398
  [ 1148.115969][T17331] sp : ffff80008d56bbd0
  [ 1148.119964][T17331] x29: ffff80008d56bbf0 x28: ffff001ff5be2600 x27: 0000000000000000
  [ 1148.127781][T17331] x26: ffff001ff52ca4e0 x25: 0000000000009977 x24: dead000000000100
  [ 1148.135598][T17331] x23: 0000000000000000 x22: 000000000000000b x21: ffff800082645f10
  [ 1148.143415][T17331] x20: ffff001fddf87c70 x19: ffff80008d56bc90 x18: 0000000000000000
  [ 1148.151231][T17331] x17: 0000000000000000 x16: 0000000000000000 x15: ffff001ff52ca4e0
  [ 1148.159048][T17331] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
  [ 1148.166864][T17331] x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000804391d0
  [ 1148.174680][T17331] x8 : 0000000180000000 x7 : 0000000000000018 x6 : 0000aaab04b92862
  [ 1148.182498][T17331] x5 : 0000aaab04b92862 x4 : 0000000080000000 x3 : 0000000000000068
  [ 1148.190314][T17331] x2 : 000000000000000f x1 : 0000000000007ea8 x0 : 0000000000000001
  [ 1148.198131][T17331] Call trace:
  [ 1148.201259][T17331]  eventfs_iterate+0x2c0/0x398
  [ 1148.205864][T17331]  iterate_dir+0x98/0x188
  [ 1148.210036][T17331]  __arm64_sys_getdents64+0x78/0x160
  [ 1148.215161][T17331]  invoke_syscall+0x78/0x108
  [ 1148.219593][T17331]  el0_svc_common.constprop.0+0x48/0xf0
  [ 1148.224977][T17331]  do_el0_svc+0x24/0x38
  [ 1148.228974][T17331]  el0_svc+0x40/0x168
  [ 1148.232798][T17331]  el0t_64_sync_handler+0x120/0x130
  [ 1148.237836][T17331]  el0t_64_sync+0x1a4/0x1a8
  [ 1148.242182][T17331] Code: 54ffff6c f9400676 910006d6 f9000676 (b9405300)
  [ 1148.248955][T17331] ---[ end trace 0000000000000000 ]---

The issue is that list_del() is used on an SRCU protected list variable
before the synchronization occurs. This can poison the list pointers while
there is a reader iterating the list.

This is simply fixed by using list_del_rcu() that is specifically made for
this purpose.

Link: https://lore.kernel.org/linux-trace-kernel/20240829085025.3600021-1-chizhiling@163.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240904131605.640d42b1@gandalf.local.home
Fixes: 43aa6f9 ("eventfs: Get rid of dentry pointers without refcounts")
Reported-by: Chi Zhiling <chizhiling@kylinos.cn>
Tested-by: Chi Zhiling <chizhiling@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
matttbe pushed a commit that referenced this issue Sep 9, 2024
…rnel/git/netfilter/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

Patch #1 adds ctnetlink support for kernel side filtering for
	 deletions, from Changliang Wu.

Patch #2 updates nft_counter support to Use u64_stats_t,
	 from Sebastian Andrzej Siewior.

Patch #3 uses kmemdup_array() in all xtables frontends,
	 from Yan Zhen.

Patch #4 is a oneliner to use ERR_CAST() in nf_conntrack instead
	 opencoded casting, from Shen Lichuan.

Patch #5 removes unused argument in nftables .validate interface,
	 from Florian Westphal.

Patch #6 is a oneliner to correct a typo in nftables kdoc,
	 from Simon Horman.

Patch #7 fixes missing kdoc in nftables, also from Simon.

Patch #8 updates nftables to handle timeout less than CONFIG_HZ.

Patch #9 rejects element expiration if timeout is zero,
	 otherwise it is silently ignored.

Patch #10 disallows element expiration larger than timeout.

Patch #11 removes unnecessary READ_ONCE annotation while mutex is held.

Patch #12 adds missing READ_ONCE/WRITE_ONCE annotation in dynset.

Patch #13 annotates data-races around element expiration.

Patch #14 allocates timeout and expiration in one single set element
	  extension, they are tighly couple, no reason to keep them
	  separated anymore.

Patch #15 updates nftables to interpret zero timeout element as never
	  times out. Note that it is already possible to declare sets
	  with elements that never time out but this generalizes to all
	  kind of set with timeouts.

Patch #16 supports for element timeout and expiration updates.

* tag 'nf-next-24-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: set element timeout update support
  netfilter: nf_tables: zero timeout means element never times out
  netfilter: nf_tables: consolidate timeout extension for elements
  netfilter: nf_tables: annotate data-races around element expiration
  netfilter: nft_dynset: annotate data-races around set timeout
  netfilter: nf_tables: remove annotation to access set timeout while holding lock
  netfilter: nf_tables: reject expiration higher than timeout
  netfilter: nf_tables: reject element expiration with no timeout
  netfilter: nf_tables: elements with timeout below CONFIG_HZ never expire
  netfilter: nf_tables: Add missing Kernel doc
  netfilter: nf_tables: Correct spelling in nf_tables.h
  netfilter: nf_tables: drop unused 3rd argument from validate callback ops
  netfilter: conntrack: Convert to use ERR_CAST()
  netfilter: Use kmemdup_array instead of kmemdup for multiple allocation
  netfilter: nft_counter: Use u64_stats_t for statistic.
  netfilter: ctnetlink: support CTA_FILTER for flush
====================

Link: https://patch.msgid.link/20240905232920.5481-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Sep 11, 2024
Daniel Machon says:

====================
net: lan966x: use the newly introduced FDMA library

This patch series is the second of a 2-part series [1], that adds a new
common FDMA library for Microchip switch chips Sparx5 and lan966x. These
chips share the same FDMA engine, and as such will benefit from a common
library with a common implementation.  This also has the benefit of
removing a lot of open-coded bookkeeping and duplicate code for the two
drivers.

In this second series, the FDMA library will be taken into use by the
lan966x switch driver.

 ###################
 # Example of use: #
 ###################

- Initialize the rx and tx fdma structs with values for: number of
  DCB's, number of DB's, channel ID, DB size (data buffer size), and
  total size of the requested memory. Also provide two callbacks:
  nextptr_cb() and dataptr_cb() for getting the nextptr and dataptr.

- Allocate memory using fdma_alloc_phys() or fdma_alloc_coherent().

- Initialize the DCB's with fdma_dcb_init().

- Add new DCB's with fdma_dcb_add().

- Free memory with fdma_free_phys() or fdma_free_coherent().

 #####################
 # Patch  breakdown: #
 #####################

Patch #1:  select FDMA library for lan966x.

Patch #2:  includes the fdma_api.h header and removes old symbols.

Patch #3:  replaces old rx and tx variables with equivalent ones from the
           fdma struct. Only the variables that can be changed without
           breaking traffic is changed in this patch.

Patch #4:  uses the library for allocation of rx buffers. This requires
           quite a bit of refactoring in this single patch.

Patch #5:  uses the library for adding DCB's in the rx path.

Patch #6:  uses the library for freeing rx buffers.

Patch #7:  uses the library for allocation of tx buffers. This requires
           quite a bit of refactoring in this single patch.

Patch #8:  uses the library for adding DCB's in the tx path.

Patch #9:  uses the library helpers in the tx path.

Patch #10: ditch last_in_use variable and use library instead.

Patch #11: uses library helpers throughout.

Patch #12: refactor lan966x_fdma_reload() function.

[1] https://lore.kernel.org/netdev/20240902-fdma-sparx5-v1-0-1e7d5e5a9f34@microchip.com/

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
====================

Link: https://patch.msgid.link/20240905-fdma-lan966x-v1-0-e083f8620165@microchip.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Sep 12, 2024
Mina Almasry says:

====================
Device Memory TCP

Device memory TCP (devmem TCP) is a proposal for transferring data
to and/or from device memory efficiently, without bouncing the data
to a host memory buffer.

* Problem:

A large amount of data transfers have device memory as the source
and/or destination. Accelerators drastically increased the volume
of such transfers. Some examples include:

- ML accelerators transferring large amounts of training data from storage
  into GPU/TPU memory. In some cases ML training setup time can be as long
  as 50% of TPU compute time, improving data transfer throughput &
  efficiency can help improving GPU/TPU utilization.

- Distributed training, where ML accelerators, such as GPUs on different
  hosts, exchange data among them.

- Distributed raw block storage applications transfer large amounts of
  data with remote SSDs, much of this data does not require host
  processing.

Today, the majority of the Device-to-Device data transfers the network
are implemented as the following low level operations: Device-to-Host
copy, Host-to-Host network transfer, and Host-to-Device copy.

The implementation is suboptimal, especially for bulk data transfers,
and can put significant strains on system resources, such as host memory
bandwidth, PCIe bandwidth, etc. One important reason behind the current
state is the kernel’s lack of semantics to express device to network
transfers.

* Proposal:

In this patch series we attempt to optimize this use case by implementing
socket APIs that enable the user to:

1. send device memory across the network directly, and
2. receive incoming network packets directly into device memory.

Packet _payloads_ go directly from the NIC to device memory for receive
and from device memory to NIC for transmit.
Packet _headers_ go to/from host memory and are processed by the TCP/IP
stack normally. The NIC _must_ support header split to achieve this.

Advantages:

- Alleviate host memory bandwidth pressure, compared to existing
 network-transfer + device-copy semantics.

- Alleviate PCIe BW pressure, by limiting data transfer to the lowest level
  of the PCIe tree, compared to traditional path which sends data through
  the root complex.

* Patch overview:

** Part 1: netlink API

Gives user ability to bind dma-buf to an RX queue.

** Part 2: scatterlist support

Currently the standard for device memory sharing is DMABUF, which doesn't
generate struct pages. On the other hand, networking stack (skbs, drivers,
and page pool) operate on pages. We have 2 options:

1. Generate struct pages for dmabuf device memory, or,
2. Modify the networking stack to process scatterlist.

Approach #1 was attempted in RFC v1. RFC v2 implements approach #2.

** part 3: page pool support

We piggy back on page pool memory providers proposal:
https://github.com/kuba-moo/linux/tree/pp-providers

It allows the page pool to define a memory provider that provides the
page allocation and freeing. It helps abstract most of the device memory
TCP changes from the driver.

** part 4: support for unreadable skb frags

Page pool iovs are not accessible by the host; we implement changes
throughput the networking stack to correctly handle skbs with unreadable
frags.

** Part 5: recvmsg() APIs

We define user APIs for the user to send and receive device memory.

Not included with this series is the GVE devmem TCP support, just to
simplify the review. Code available here if desired:
https://github.com/mina/linux/tree/tcpdevmem

This series is built on top of net-next with Jakub's pp-providers changes
cherry-picked.

* NIC dependencies:

1. (strict) Devmem TCP require the NIC to support header split, i.e. the
   capability to split incoming packets into a header + payload and to put
   each into a separate buffer. Devmem TCP works by using device memory
   for the packet payload, and host memory for the packet headers.

2. (optional) Devmem TCP works better with flow steering support & RSS
   support, i.e. the NIC's ability to steer flows into certain rx queues.
   This allows the sysadmin to enable devmem TCP on a subset of the rx
   queues, and steer devmem TCP traffic onto these queues and non devmem
   TCP elsewhere.

The NIC I have access to with these properties is the GVE with DQO support
running in Google Cloud, but any NIC that supports these features would
suffice. I may be able to help reviewers bring up devmem TCP on their NICs.

* Testing:

The series includes a udmabuf kselftest that show a simple use case of
devmem TCP and validates the entire data path end to end without
a dependency on a specific dmabuf provider.

** Test Setup

Kernel: net-next with this series and memory provider API cherry-picked
locally.

Hardware: Google Cloud A3 VMs.

NIC: GVE with header split & RSS & flow steering support.
====================

Link: https://patch.msgid.link/20240910171458.219195-1-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Sep 13, 2024
If smb2_compound_op() is called with a valid @CFILE and returned
-EINVAL, we need to call cifs_get_writable_path() before retrying it
as the reference of @CFILE was already dropped by previous call.

This fixes the following KASAN splat when running fstests generic/013
against Windows Server 2022:

  CIFS: Attempting to mount //w22-fs0/scratch
  run fstests generic/013 at 2024-09-02 19:48:59
  ==================================================================
  BUG: KASAN: slab-use-after-free in detach_if_pending+0xab/0x200
  Write of size 8 at addr ffff88811f1a3730 by task kworker/3:2/176

  CPU: 3 UID: 0 PID: 176 Comm: kworker/3:2 Not tainted 6.11.0-rc6 #2
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40
  04/01/2014
  Workqueue: cifsoplockd cifs_oplock_break [cifs]
  Call Trace:
   <TASK>
   dump_stack_lvl+0x5d/0x80
   ? detach_if_pending+0xab/0x200
   print_report+0x156/0x4d9
   ? detach_if_pending+0xab/0x200
   ? __virt_addr_valid+0x145/0x300
   ? __phys_addr+0x46/0x90
   ? detach_if_pending+0xab/0x200
   kasan_report+0xda/0x110
   ? detach_if_pending+0xab/0x200
   detach_if_pending+0xab/0x200
   timer_delete+0x96/0xe0
   ? __pfx_timer_delete+0x10/0x10
   ? rcu_is_watching+0x20/0x50
   try_to_grab_pending+0x46/0x3b0
   __cancel_work+0x89/0x1b0
   ? __pfx___cancel_work+0x10/0x10
   ? kasan_save_track+0x14/0x30
   cifs_close_deferred_file+0x110/0x2c0 [cifs]
   ? __pfx_cifs_close_deferred_file+0x10/0x10 [cifs]
   ? __pfx_down_read+0x10/0x10
   cifs_oplock_break+0x4c1/0xa50 [cifs]
   ? __pfx_cifs_oplock_break+0x10/0x10 [cifs]
   ? lock_is_held_type+0x85/0xf0
   ? mark_held_locks+0x1a/0x90
   process_one_work+0x4c6/0x9f0
   ? find_held_lock+0x8a/0xa0
   ? __pfx_process_one_work+0x10/0x10
   ? lock_acquired+0x220/0x550
   ? __list_add_valid_or_report+0x37/0x100
   worker_thread+0x2e4/0x570
   ? __kthread_parkme+0xd1/0xf0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x17f/0x1c0
   ? kthread+0xda/0x1c0
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x31/0x60
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

  Allocated by task 1118:
   kasan_save_stack+0x30/0x50
   kasan_save_track+0x14/0x30
   __kasan_kmalloc+0xaa/0xb0
   cifs_new_fileinfo+0xc8/0x9d0 [cifs]
   cifs_atomic_open+0x467/0x770 [cifs]
   lookup_open.isra.0+0x665/0x8b0
   path_openat+0x4c3/0x1380
   do_filp_open+0x167/0x270
   do_sys_openat2+0x129/0x160
   __x64_sys_creat+0xad/0xe0
   do_syscall_64+0xbb/0x1d0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

  Freed by task 83:
   kasan_save_stack+0x30/0x50
   kasan_save_track+0x14/0x30
   kasan_save_free_info+0x3b/0x70
   poison_slab_object+0xe9/0x160
   __kasan_slab_free+0x32/0x50
   kfree+0xf2/0x300
   process_one_work+0x4c6/0x9f0
   worker_thread+0x2e4/0x570
   kthread+0x17f/0x1c0
   ret_from_fork+0x31/0x60
   ret_from_fork_asm+0x1a/0x30

  Last potentially related work creation:
   kasan_save_stack+0x30/0x50
   __kasan_record_aux_stack+0xad/0xc0
   insert_work+0x29/0xe0
   __queue_work+0x5ea/0x760
   queue_work_on+0x6d/0x90
   _cifsFileInfo_put+0x3f6/0x770 [cifs]
   smb2_compound_op+0x911/0x3940 [cifs]
   smb2_set_path_size+0x228/0x270 [cifs]
   cifs_set_file_size+0x197/0x460 [cifs]
   cifs_setattr+0xd9c/0x14b0 [cifs]
   notify_change+0x4e3/0x740
   do_truncate+0xfa/0x180
   vfs_truncate+0x195/0x200
   __x64_sys_truncate+0x109/0x150
   do_syscall_64+0xbb/0x1d0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: 71f15c9 ("smb: client: retry compound request without reusing lease")
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
matttbe pushed a commit that referenced this issue Sep 13, 2024
…nux/kernel/git/ukleinek/linux

Pull pwm fix from Uwe Kleine-König:
 "Fix an off-by-one in the stm32 driver.

  Hardware engineers tend to start counting at 1 while the software guys
  usually start with 0. This isn't so nice because that results in
  drivers where pwm device #2 needs to use the hardware registers with
  index 3.

  This was noticed by Fabrice Gasnier.

  A small patch fixing that mismatch is the only change included here"

* tag 'pwm/for-6.11-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
  pwm: stm32: Use the right CCxNP bit in stm32_pwm_enable()
matttbe pushed a commit that referenced this issue Sep 13, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following batch contains two fixes from Florian Westphal:

Patch #1 fixes a sk refcount leak in nft_socket on mismatch.

Patch #2 fixes cgroupsv2 matching from containers due to incorrect
	 level in subtree.

netfilter pull request 24-09-12

* tag 'nf-24-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_socket: make cgroupsv2 matching work with namespaces
  netfilter: nft_socket: fix sk refcount leaks
====================

Link: https://patch.msgid.link/20240911222520.3606-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
matttbe pushed a commit that referenced this issue Sep 16, 2024
Ido Schimmel says:

====================
net: fib_rules: Add DSCP selector support

Currently, the kernel rejects IPv4 FIB rules that try to match on the
upper three DSCP bits:

 # ip -4 rule add tos 0x1c table 100
 # ip -4 rule add tos 0x3c table 100
 Error: Invalid tos.

The reason for that is that historically users of the FIB lookup API
only populated the lower three DSCP bits in the TOS field of the IPv4
flow key ('flowi4_tos'), which fits the TOS definition from the initial
IPv4 specification (RFC 791).

This is not very useful nowadays and instead some users want to be able
to match on the six bits DSCP field, which replaced the TOS and IP
precedence fields over 25 years ago (RFC 2474). In addition, the current
behavior differs between IPv4 and IPv6 which does allow users to match
on the entire DSCP field using the TOS selector.

Recent patchsets made sure that callers of the FIB lookup API now
populate the entire DSCP field in the IPv4 flow key. Therefore, it is
now possible to extend FIB rules to match on DSCP.

This is done by adding a new DSCP attribute which is implemented for
both IPv4 and IPv6 to provide user space programs a consistent behavior
between both address families.

The behavior of the old TOS selector is unchanged and IPv4 FIB rules
using it will only match on the lower three DSCP bits. The kernel will
reject rules that try to use both selectors.

Patch #1 adds the new DSCP attribute but rejects its usage.

Patches #2-#3 implement IPv4 and IPv6 support.

Patch #4 allows user space to use the new attribute.

Patches #5-#6 add selftests.
====================

Link: https://patch.msgid.link/20240911093748.3662015-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Sep 16, 2024
Nelson Escobar says:

====================
enic: Report per queue stats

Patch #1: Use a macro instead of static const variables for array sizes.  I
          didn't want to add more static const variables in the next patch
          so clean up the existing ones first.

Patch #2: Collect per queue statistics

Patch #3: Report per queue stats in netdev qstats

Patch #4: Report some per queue stats in ethtool

 # NETIF="eno6" tools/testing/selftests/drivers/net/stats.py
KTAP version 1
1..5
ok 1 stats.check_pause # XFAIL pause not supported by the device
ok 2 stats.check_fec # XFAIL FEC not supported by the device
ok 3 stats.pkt_byte_sum
ok 4 stats.qstat_by_ifindex
ok 5 stats.check_down

 # tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
     --dump qstats-get --json '{"ifindex": "34"}'
[{'ifindex': 34,
  'rx-bytes': 66762680,
  'rx-csum-unnecessary': 1009345,
  'rx-hw-drop-overruns': 0,
  'rx-hw-drops': 0,
  'rx-packets': 1009673,
  'tx-bytes': 137936674899,
  'tx-csum-none': 125,
  'tx-hw-gso-packets': 2408712,
  'tx-needs-csum': 2431531,
  'tx-packets': 15475466,
  'tx-stop': 0,
  'tx-wake': 0}]

v2: https://lore.kernel.org/20240905010900.24152-1-neescoba@cisco.com
v1: https://lore.kernel.org/20240823235401.29996-1-neescoba@cisco.com
====================

Link: https://patch.msgid.link/20240912005039.10797-1-neescoba@cisco.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
matttbe pushed a commit that referenced this issue Sep 27, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

v2: with kdoc fixes per Paolo Abeni.

The following patchset contains Netfilter fixes for net:

Patch #1 and #2 handle an esoteric scenario: Given two tasks sending UDP
packets to one another, two packets of the same flow in each direction
handled by different CPUs that result in two conntrack objects in NEW
state, where reply packet loses race. Then, patch #3 adds a testcase for
this scenario. Series from Florian Westphal.

1) NAT engine can falsely detect a port collision if it happens to pick
   up a reply packet as NEW rather than ESTABLISHED. Add extra code to
   detect this and suppress port reallocation in this case.

2) To complete the clash resolution in the reply direction, extend conntrack
   logic to detect clashing conntrack in the reply direction to existing entry.

3) Adds a test case.

Then, an assorted list of fixes follow:

4) Add a selftest for tproxy, from Antonio Ojea.

5) Guard ctnetlink_*_size() functions under
   #if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS)
   From Andy Shevchenko.

6) Use -m socket --transparent in iptables tproxy documentation.
   From XIE Zhibang.

7) Call kfree_rcu() when releasing flowtable hooks to address race with
   netlink dump path, from Phil Sutter.

8) Fix compilation warning in nf_reject with CONFIG_BRIDGE_NETFILTER=n.
   From Simon Horman.

9) Guard ctnetlink_label_size() under CONFIG_NF_CONNTRACK_EVENTS which
   is its only user, to address a compilation warning. From Simon Horman.

10) Use rcu-protected list iteration over basechain hooks from netlink
    dump path.

11) Fix memcg for nf_tables, use GFP_KERNEL_ACCOUNT is not complete.

12) Remove old nfqueue conntrack clash resolution. Instead trying to
    use same destination address consistently which requires double DNAT,
    use the existing clash resolution which allows clashing packets
    go through with different destination. Antonio Ojea originally
    reported an issue from the postrouting chain, I proposed a fix:
    https://lore.kernel.org/netfilter-devel/ZuwSwAqKgCB2a51-@calendula/T/
    which he reported it did not work for him.

13) Adds a selftest for patch 12.

14) Fixes ipvs.sh selftest.

netfilter pull request 24-09-26

* tag 'nf-24-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  selftests: netfilter: Avoid hanging ipvs.sh
  kselftest: add test for nfqueue induced conntrack race
  netfilter: nfnetlink_queue: remove old clash resolution logic
  netfilter: nf_tables: missing objects with no memcg accounting
  netfilter: nf_tables: use rcu chain hook list iterator from netlink dump path
  netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS
  netfilter: nf_reject: Fix build warning when CONFIG_BRIDGE_NETFILTER=n
  netfilter: nf_tables: Keep deleted flowtable hooks until after RCU
  docs: tproxy: ignore non-transparent sockets in iptables
  netfilter: ctnetlink: Guard possible unused functions
  selftests: netfilter: nft_tproxy.sh: add tcp tests
  selftests: netfilter: add reverse-clash resolution test case
  netfilter: conntrack: add clash resolution for reverse collisions
  netfilter: nf_nat: don't try nat source port reallocation for reverse dir clash
====================

Link: https://patch.msgid.link/20240926110717.102194-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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