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From: Igor Druzhinin <igor.druzhinin@citrix.com>
To: <xen-devel@lists.xenproject.org>
Cc: <jbeulich@suse.com>, <paul@xen.org>,
	Igor Druzhinin <igor.druzhinin@citrix.com>
Subject: [PATCH] pci: fix handling of PCI bridges with subordinate bus number 0xff
Date: Fri, 24 Sep 2021 02:06:59 +0100	[thread overview]
Message-ID: <1632445619-9211-1-git-send-email-igor.druzhinin@citrix.com> (raw)

Bus number 0xff is valid according to the PCI spec. Using u8 typed sub_bus
and assigning 0xff to it will result in the following loop getting stuck.

    for ( ; sec_bus <= sub_bus; sec_bus++ ) {...}

Just change its type to u16 the same way that is already handled in
dmar_scope_add_buses().

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
---
 xen/drivers/passthrough/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index fc4fa2e..48b415c 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -364,7 +364,7 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 bus, u8 devfn)
     switch ( pdev->type = pdev_type(pseg->nr, bus, devfn) )
     {
         u16 cap;
-        u8 sec_bus, sub_bus;
+        u16 sec_bus, sub_bus;
 
         case DEV_TYPE_PCIe2PCI_BRIDGE:
         case DEV_TYPE_LEGACY_PCI_BRIDGE:
-- 
2.7.4



             reply	other threads:[~2021-09-24  1:07 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24  1:06 Igor Druzhinin [this message]
2021-09-24  6:38 ` [PATCH] pci: fix handling of PCI bridges with subordinate bus number 0xff Jan Beulich

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