Should I resubmit this rebased on 4.19-rc*, or just leave this patch as is? Alex On 07/30/2018 04:21 PM, Alexandru Gagniuc wrote:
When a PCI device is gone, we don't want to send IO to it if we can avoid it. We expose functionality via the irq_chip structure. As users of that structure may not know about the underlying PCI device, it's our responsibility to guard against removed devices. irq_write_msi_msg is already guarded. pci_msi_(un)mask_irq are not. Guard them for completeness. For example, surprise removal of a PCIe device triggers teardown. This touches the irq_chips ops some point to disable the interrupts. I/O generated here can crash the system on machines with buggy firmware. Not triggering the IO in the first place eliminates the problem. Signed-off-by: Alexandru Gagniuc <mr.nuke.me@xxxxxxxxx> --- There's another patch by Lukas Wunner that is needed (not yet published) in order to fully block IO on SURPRISE!!! removal. The existing code only sets the PCI_DEV_DISCONNECTED bit in an unreasonably narrow set of circumstances. Lukas' patch fixes that. However, this change is otherwise fully independent, and enjoy! drivers/pci/msi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 4d88afdfc843..5f47b5cb0401 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -227,6 +227,9 @@ static void msi_set_mask_bit(struct irq_data *data, u32 flag) { struct msi_desc *desc = irq_data_get_msi_desc(data);+ if (pci_dev_is_disconnected(msi_desc_to_pci_dev(desc)))+ return; + if (desc->msi_attrib.is_msix) { msix_mask_irq(desc, flag); readl(desc->mask_base); /* Flush write to device */
