linux-toradex.git/drivers/net/netdevsim/netdev.c, branch v6.11-rc5 Linux kernel for Apalis and Colibri modules netdevsim: fix backwards compatibility in nsim_get_iflink() 2024-06-10T10:51:04+00:00 David Wei dw@davidwei.uk 2024-06-06T14:59:08+00:00 5add2f7288468f35a374620dabf126c13baaea9c 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 <watanabe.yu@gmail.com> Suggested-by: Yu Watanabe <watanabe.yu@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Signed-off-by: David S. Miller <davem@davemloft.net> 
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 <watanabe.yu@gmail.com>
Suggested-by: Yu Watanabe <watanabe.yu@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdevsim: add NAPI support 2024-05-09T01:59:47+00:00 David Wei dw@davidwei.uk 2024-05-07T16:32:27+00:00 3762ec05a9fbda16aaaa2568df679ab8ad13f38d 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 <dw@davidwei.uk> Link: https://lore.kernel.org/r/20240507163228.2066817-2-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
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 <dw@davidwei.uk>
Link: https://lore.kernel.org/r/20240507163228.2066817-2-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07T23:19:14+00:00 Eric Dumazet edumazet@google.com 2024-05-06T10:28:12+00:00 1eb2cded45b35816085c1f962933c187d970f9dc 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 <edumazet@google.com> Reported-by: Simon Horman <horms@kernel.org> Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Shannon Nelson <shannon.nelson@amd.com> Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
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 <edumazet@google.com>
Reported-by: Simon Horman <horms@kernel.org>
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: netdevsim: add some fake page pool use 2024-04-15T18:21:11+00:00 Jakub Kicinski kuba@kernel.org 2024-04-12T14:14:31+00:00 1580cbcbfe770b0a7fb76735c1a601483335c1c2 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 <kuba@kernel.org> 
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 <kuba@kernel.org>
netdevsim: report stats by default, like a real device 2024-04-08T10:40:41+00:00 Jakub Kicinski kuba@kernel.org 2024-04-05T02:45:24+00:00 f216306bfb602b449cb2c49cf03870fb8761d146 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 <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
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 <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdevsim: add ndo_get_iflink() implementation 2024-03-01T10:43:10+00:00 David Wei dw@davidwei.uk 2024-02-28T23:22:51+00:00 8debcf5832c3e8a6baaea27c75ad8a6ba5077beb Add an implementation for ndo_get_iflink() in netdevsim that shows the ifindex of the linked peer, if any. Signed-off-by: David Wei <dw@davidwei.uk> Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add an implementation for ndo_get_iflink() in netdevsim that shows the
ifindex of the linked peer, if any.

Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdevsim: forward skbs from one connected port to another 2024-03-01T10:43:10+00:00 David Wei dw@davidwei.uk 2024-02-28T23:22:50+00:00 9eb95228a74163e26d338913a5d61e571ea45307 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 <dw@davidwei.uk> Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
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 <dw@davidwei.uk>
Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdevsim: allow two netdevsim ports to be connected 2024-03-01T10:43:10+00:00 David Wei dw@davidwei.uk 2024-02-28T23:22:49+00:00 f532957d76de89b8ee2545cb6ad5265e1701d0ba Add two netdevsim bus attribute to sysfs: /sys/bus/netdevsim/link_device /sys/bus/netdevsim/unlink_device Writing "A M B N" to link_device will link netdevsim M in netnsid A with netdevsim N in netnsid B. Writing "A M" to unlink_device will unlink netdevsim M in netnsid A from its peer, if any. rtnl_lock is taken to ensure nothing changes during the linking. Signed-off-by: David Wei <dw@davidwei.uk> Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add two netdevsim bus attribute to sysfs:
/sys/bus/netdevsim/link_device
/sys/bus/netdevsim/unlink_device

Writing "A M B N" to link_device will link netdevsim M in netnsid A with
netdevsim N in netnsid B.

Writing "A M" to unlink_device will unlink netdevsim M in netnsid A from
its peer, if any.

rtnl_lock is taken to ensure nothing changes during the linking.

Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: netdevsim: don't try to destroy PHC on VFs 2024-01-17T10:56:44+00:00 Jakub Kicinski kuba@kernel.org 2024-01-16T19:14:00+00:00 ea937f77208323d35ffe2f8d8fc81b00118bfcda PHC gets initialized in nsim_init_netdevsim(), which is only called if (nsim_dev_port_is_pf()). Create a counterpart of nsim_init_netdevsim() and move the mock_phc_destroy() there. This fixes a crash trying to destroy netdevsim with VFs instantiated, as caught by running the devlink.sh test: BUG: kernel NULL pointer dereference, address: 00000000000000b8 RIP: 0010:mock_phc_destroy+0xd/0x30 Call Trace: <TASK> nsim_destroy+0x4a/0x70 [netdevsim] __nsim_dev_port_del+0x47/0x70 [netdevsim] nsim_dev_reload_destroy+0x105/0x120 [netdevsim] nsim_drv_remove+0x2f/0xb0 [netdevsim] device_release_driver_internal+0x1a1/0x210 bus_remove_device+0xd5/0x120 device_del+0x159/0x490 device_unregister+0x12/0x30 del_device_store+0x11a/0x1a0 [netdevsim] kernfs_fop_write_iter+0x130/0x1d0 vfs_write+0x30b/0x4b0 ksys_write+0x69/0xf0 do_syscall_64+0xcc/0x1e0 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Fixes: b63e78fca889 ("net: netdevsim: use mock PHC driver") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
PHC gets initialized in nsim_init_netdevsim(), which
is only called if (nsim_dev_port_is_pf()).

Create a counterpart of nsim_init_netdevsim() and
move the mock_phc_destroy() there.

This fixes a crash trying to destroy netdevsim with
VFs instantiated, as caught by running the devlink.sh test:

    BUG: kernel NULL pointer dereference, address: 00000000000000b8
    RIP: 0010:mock_phc_destroy+0xd/0x30
    Call Trace:
     <TASK>
     nsim_destroy+0x4a/0x70 [netdevsim]
     __nsim_dev_port_del+0x47/0x70 [netdevsim]
     nsim_dev_reload_destroy+0x105/0x120 [netdevsim]
     nsim_drv_remove+0x2f/0xb0 [netdevsim]
     device_release_driver_internal+0x1a1/0x210
     bus_remove_device+0xd5/0x120
     device_del+0x159/0x490
     device_unregister+0x12/0x30
     del_device_store+0x11a/0x1a0 [netdevsim]
     kernfs_fop_write_iter+0x130/0x1d0
     vfs_write+0x30b/0x4b0
     ksys_write+0x69/0xf0
     do_syscall_64+0xcc/0x1e0
     entry_SYSCALL_64_after_hwframe+0x6f/0x77

Fixes: b63e78fca889 ("net: netdevsim: use mock PHC driver")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fill in MODULE_DESCRIPTION()s in kuba@'s modules 2023-10-28T10:29:27+00:00 Jakub Kicinski kuba@kernel.org 2023-10-27T21:13:08+00:00 1fff1f799038a99cd1f2ae3999661ad9d506bb8c W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Fill it in for the modules I maintain. Acked-by: Kalle Valo <kvalo@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Fill it in for the modules I maintain.

Acked-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>