net: rmnet: no longer rely on RTNL in rmnet_fill_info()

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rmnet_fill_info() used rmnet_get_port_rtnl(), and thus required
RTNL.

Now that priv->mux_id and port->data_format are properly
annotated, rmnet_fill_info() can simply fetch the port under
rcu_read_lock().

rmnet_get_port_rcu() was only used from the data path and thus
used rcu_dereference_bh(). Relax its lockdep condition so that it
can also be called from process context under a plain
rcu_read_lock(), and use it from rmnet_fill_info().

Note that rmnet_get_port_rcu() checks real_dev->rx_handler before
returning rx_handler_data: this is what makes the lockless lookup
safe against rmnet_unregister_real_device(), which clears
rx_handler, waits for a grace period in
netdev_rx_handler_unregister(), and only then frees the port.

While at it, add missing const qualifiers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sean Tranchetti <sean.tranchetti@oss.qualcomm.com>
Reviewed-by: Subash Abhinov Kasiviswanathan <subash.a.kasiviswanathan@oss.qualcomm.com>
Link: https://patch.msgid.link/20260916132231.1780091-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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This commit is contained in:

Eric Dumazet 2026-09-16 13:22:31 +00:00 • committed by Jakub Kicinski

parent 0067187dbe

commit d7c9ba103b

2 changed files with 18 additions and 22 deletions

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38

drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c

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2

drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h

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