mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-24 10:49:54 +02:00
Alex Williamson
45d7cf5174
[ Upstream commit98693e0897] Thanks to a device generating an ACS violation during bus reset, lockdep reported the following circular locking issue: CPU0: SET_IRQS (MSI/X): holds igate, acquires memory_lock CPU1: HOT_RESET: holds memory_lock, acquires pci_bus_sem CPU2: AER: holds pci_bus_sem, acquires igate This results in a potential 3-way deadlock. Remove the pci_bus_sem->igate leg of the triangle by using RCU to peek at the eventfd rather than locking it with igate. Fixes:3be3a074cf("vfio-pci: Don't use device_lock around AER interrupt setup") Signed-off-by: Alex Williamson <alex.williamson@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20251124223623.2770706-1-alex@shazbot.org Signed-off-by: Alex Williamson <alex@shazbot.org> Signed-off-by: Sasha Levin <sashal@kernel.org>