s390/pci: Serialize device addition and removal

Browse source

commit 774a1fa880 upstream.

Prior changes ensured that when zpci_release_device() is called and it
removed the zdev from the zpci_list this instance can not be found via
the zpci_list anymore even while allowing re-add of reserved devices.
This only accounts for the overall lifetime and zpci_list addition and
removal, it does not yet prevent concurrent add of a new instance for
the same underlying device. Such concurrent add would subsequently cause
issues such as attempted re-use of the same IOMMU sysfs directory and is
generally undesired.

Introduce a new zpci_add_remove_lock mutex to serialize adding a new
device with removal. Together this ensures that if a struct zpci_dev is
not found in the zpci_list it was either already removed and torn down,
or its removal and tear down is in progress with the
zpci_add_remove_lock held.

Cc: stable@vger.kernel.org
Fixes: a46044a92a ("s390/pci: fix zpci_zdev_put() on reserve")
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Tested-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Niklas Schnelle 2025-05-22 14:13:15 +02:00 • committed by Greg Kroah-Hartman

parent 31a7dc5a24

commit f2e8a863fd

1 changed files with 7 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

7

arch/s390/pci/pci.c

View file