tree b9a2afb38a4c2ac8ad31f49ec0d71fe9e5b1994c
parent 030305d69fc6963c16003f50d7e8d74b02d0a143
author Christoph Hellwig <hch@lst.de> 1485778541 +0100
committer Bjorn Helgaas <bhelgaas@google.com> 1486053346 -0600

PCI/MSI: Don't apply affinity if there aren't enough vectors left

Bart reported a problem wіth an out of bounds access in the low-level IRQ
affinity code, which we root caused to the qla2xxx driver assigning all its
MSI-X vectors to the pre and post vectors, and not having any left for the
actually spread IRQs.

Fix this issue by not asking for affinity assignment when there are no
vectors to assign left.

Fixes: 402723ad5c62 ("PCI/MSI: Provide pci_alloc_irq_vectors_affinity()")
Link: https://lkml.kernel.org/r/1485359225.3093.3.camel@sandisk.com
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>