1c56c0994a
In some situations we may end up calling down_read while already
holding the semaphore for write, thus hanging. This has been seen
when setting the MAC address for the interface. The hung task log
in this situation includes this stack:
down_read
efx_ef10_filter_insert
efx_ef10_filter_insert_addr_list
efx_ef10_filter_vlan_sync_rx_mode
efx_ef10_filter_add_vlan
efx_ef10_filter_table_probe
efx_ef10_set_mac_address
efx_set_mac_address
dev_set_mac_address
In addition, lockdep rightly points out that nested calling of
down_read is incorrect.
Fixes: c2bebe37c6b6 ("sfc: give ef10 its own rwsem in the filter table instead of filter_lock")
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.