Stable backport request for "xen/events: don't use chip_data for legacy IRQs"

Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> · Fri, 30 Oct 2020 13:29:28 +0000

Hi,

Please backport [1] to 4.4, 4.9, 4.14, 4.19.

It fixes a commit that has been backported to all the current stable releases but for some reason the fixup was only backported to 5.4 & 5.8.

Debian 9 no longer boots as a Xen HVM guest because it is missing the fixup patch.

Thanks,
Ross

[1]:

commit 0891fb39ba67bd7ae023ea0d367297ffff010781
Author: Juergen Gross <jgross@xxxxxxxx>
Date:   Wed Sep 30 11:16:14 2020 +0200

    xen/events: don't use chip_data for legacy IRQs

    Since commit c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
    Xen is using the chip_data pointer for storing IRQ specific data. When
    running as a HVM domain this can result in problems for legacy IRQs, as
    those might use chip_data for their own purposes.

    Use a local array for this purpose in case of legacy IRQs, avoiding the
    double use.

    Cc: stable@xxxxxxxxxxxxxxx
    Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
    Tested-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx>
    Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@xxxxxxxx
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>