shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-05 10:31:46 +09:00
Code Issues Packages Projects Releases Wiki Activity

PCI: Release resource invalidated by coalescing

Browse Source 
commit e54223275b upstream.

When contiguous windows are coalesced by pci_register_host_bridge(), the
second resource is expanded to include the first, and the first is
invalidated and consequently not added to the bus. However, it remains in
the resource hierarchy.  For example, these windows:

  fec00000-fec7ffff : PCI Bus 0000:00
  fec80000-fecbffff : PCI Bus 0000:00

are coalesced into this, where the first resource remains in the tree with
start/end zeroed out:

  00000000-00000000 : PCI Bus 0000:00
  fec00000-fecbffff : PCI Bus 0000:00

In some cases (e.g. the Xen scratch region), this causes future calls to
allocate_resource() to choose an inappropriate location which the caller
cannot handle.

Fix by releasing the zeroed-out resource and removing it from the resource
hierarchy.

[bhelgaas: commit log]
Fixes: 7c3855c423 ("PCI: Coalesce host bridge contiguous apertures")
Link: https://lore.kernel.org/r/20230525153248.712779-1-ross.lagerwall@citrix.com
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org	# v5.16+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ross Lagerwall
2023-05-25 16:32:48 +01:00
committed by Greg Kroah-Hartman
parent 3367d4be9b
commit 465c195e86
1 changed files with 3 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/pci/probe.c
View File

@@ -994,8 +994,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
resource_list_for_each_entry_safe(window, n, &resources) {
offset = window->offset;
res = window->res;
if (!res->flags && !res->start && !res->end)
if (!res->flags && !res->start && !res->end) {
release_resource(res);
continue;
}
list_move_tail(&window->node, &bridge->windows);