linux-toradex.git/drivers/net/netdevsim, branch v6.12-rc4

netdevsim: use cond_resched() in nsim_dev_trap_report_work()

2024-10-15T16:58:43+00:00

I am still seeing many syzbot reports hinting that syzbot
might fool nsim_dev_trap_report_work() with hundreds of ports [1]

Lets use cond_resched(), and system_unbound_wq
instead of implicit system_wq.

[1]
INFO: task syz-executor:20633 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25856 pid:20633 tgid:20633 ppid:1      flags:0x00004006
...
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16760 Comm: kworker/1:0 Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events nsim_dev_trap_report_work
 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d 04 fb 9c 0c 48 89 de 5b e9 c3 c7 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90  0f 1e fa 48 8b 04 24 65 48 8b 0c 25 c0 d7 03 00 65 8b 15 60 f0
RSP: 0018:ffffc90000a187e8 EFLAGS: 00000246
RAX: 0000000000000100 RBX: ffffc90000a188e0 RCX: ffff888027d3bc00
RDX: ffff888027d3bc00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88804a2e6000 R08: ffffffff8a4bc495 R09: ffffffff89da3577
R10: 0000000000000004 R11: ffffffff8a4bc2b0 R12: dffffc0000000000
R13: ffff88806573b503 R14: dffffc0000000000 R15: ffff8880663cca00
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc90a747f98 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 000000000000002b DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 
 
 
  __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
  spin_unlock_bh include/linux/spinlock.h:396 [inline]
  nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
  nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850
  process_one_work kernel/workqueue.c:3229 [inline]
  process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
  kthread+0x2f0/0x390 kernel/kthread.c:389
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 

Fixes: ba5e1272142d ("netdevsim: avoid potential loop in nsim_dev_trap_report_work()")
Reported-by: syzbot+d383dc9579a76f56c251@syzkaller.appspotmail.com
Reported-by: syzbot+c596faae21a68bf7afd0@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet 
Cc: Jiri Pirko 
Link: https://patch.msgid.link/20241012094230.3893510-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

net: Add struct kernel_ethtool_ts_info

2024-07-15T15:02:26+00:00

In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.

Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.

Acked-by: Shannon Nelson 
Acked-by: Alexandra Winter 
Signed-off-by: Kory Maincent 
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski

netdevsim: fix backwards compatibility in nsim_get_iflink()

2024-06-10T10:51:04+00:00

The default ndo_get_iflink() implementation returns the current ifindex
of the netdev. But the overridden nsim_get_iflink() returns 0 if the
current nsim is not linked, breaking backwards compatibility for
userspace that depend on this behaviour.

Fix the problem by returning the current ifindex if not linked to a
peer.

Fixes: 8debcf5832c3 ("netdevsim: add ndo_get_iflink() implementation")
Reported-by: Yu Watanabe 
Suggested-by: Yu Watanabe 
Signed-off-by: David Wei 
Signed-off-by: David S. Miller

netdevsim: add NAPI support

2024-05-09T01:59:47+00:00

Add NAPI support to netdevim, similar to veth.

* Add a nsim_rq rx queue structure to hold a NAPI instance and a skb
  queue.
* During xmit, store the skb in the peer skb queue and schedule NAPI.
* During napi_poll(), drain the skb queue and pass up the stack.
* Add assoc between rxq and NAPI instance using netif_queue_set_napi().

Signed-off-by: David Wei 
Link: https://lore.kernel.org/r/20240507163228.2066817-2-dw@davidwei.uk
Signed-off-by: Jakub Kicinski

net: annotate writes on dev->mtu from ndo_change_mtu()

2024-05-07T23:19:14+00:00

Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet 
Reported-by: Simon Horman 
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller 
Reviewed-by: Sabrina Dubroca 
Reviewed-by: Simon Horman 
Acked-by: Shannon Nelson 
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: netdevsim: add some fake page pool use

2024-04-15T18:21:11+00:00

Add very basic page pool use so that we can exercise
the netlink uAPI in a selftest.

Page pool gets created on open, destroyed on close.
But we control allocating of a single page thru debugfs.
This page may survive past the page pool itself so that
we can test orphaned page pools.

Link: https://lore.kernel.org/r/20240412141436.828666-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski

netdevsim: report stats by default, like a real device

2024-04-08T10:40:41+00:00

Real devices should implement qstats. Devices which support
pause or FEC configuration should also report the relevant stats.

nsim was missing FEC stats completely, some of the qstats
and pause stats required toggling a debugfs knob.

Note that the tests which used pause always initialize the setting
so they shouldn't be affected by the different starting value.

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

netdevsim: add ndo_get_iflink() implementation

2024-03-01T10:43:10+00:00

Add an implementation for ndo_get_iflink() in netdevsim that shows the
ifindex of the linked peer, if any.

Signed-off-by: David Wei 
Reviewed-by: Maciek Machnikowski 
Signed-off-by: David S. Miller

netdevsim: forward skbs from one connected port to another

2024-03-01T10:43:10+00:00

Forward skbs sent from one netdevsim port to its connected netdevsim
port using dev_forward_skb, in a spirit similar to veth.

Add a tx_dropped variable to struct netdevsim, tracking the number of
skbs that could not be forwarded using dev_forward_skb().

The xmit() function accessing the peer ptr is protected by an RCU read
critical section. The rcu_read_lock() is functionally redundant as since
v5.0 all softirqs are implicitly RCU read critical sections; but it is
useful for human readers.

If another CPU is concurrently in nsim_destroy(), then it will first set
the peer ptr to NULL. This does not affect any existing readers that
dereferenced a non-NULL peer. Then, in unregister_netdevice(), there is
a synchronize_rcu() before the netdev is actually unregistered and
freed. This ensures that any readers i.e. xmit() that got a non-NULL
peer will complete before the netdev is freed.

Any readers after the RCU_INIT_POINTER() but before synchronize_rcu()
will dereference NULL, making it safe.

The codepath to nsim_destroy() and nsim_create() takes both the newly
added nsim_dev_list_lock and rtnl_lock. This makes it safe with
concurrent calls to linking two netdevsims together.

Signed-off-by: David Wei 
Reviewed-by: Maciek Machnikowski 
Signed-off-by: David S. Miller