From dedc9937e876cb5430bca6a1dccfcc2ff22f8b7c Mon Sep 17 00:00:00 2001
From: Jon Mason <jdmason@kudzu.us>
Date: Thu, 5 Oct 2006 18:47:21 +0200
Subject: [PATCH] [PATCH] x86-64: Calgary IOMMU: deobfuscate calgary_init
calgary_init's for loop does not correspond to the actual device being
checked, which makes its upperbound check for array overflow useless.
Changing this to a do-while loop is the correct way of doing this.
There should be no possibility of spinning forever in this loop, as
pci_get_device states that it will go through all iterations, then
return NULL (thus breaking the loop).
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
---
arch/x86_64/kernel/pci-calgary.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index f760045d6d35..1100031528dc 100644
--- a/arch/x86_64/kernel/pci-calgary.c
+++ b/arch/x86_64/kernel/pci-calgary.c
@@ -816,6 +816,8 @@ static int __init calgary_init_one(struct pci_dev *dev)
void __iomem *bbar;
int ret;
+ BUG_ON(dev->bus->number >= MAX_PHB_BUS_NUM);
+
address = locate_register_space(dev);
/* map entire 1MB of Calgary config space */
bbar = ioremap_nocache(address, 1024 * 1024);
@@ -842,10 +844,10 @@ done:
static int __init calgary_init(void)
{
- int i, ret = -ENODEV;
+ int ret = -ENODEV;
struct pci_dev *dev = NULL;
- for (i = 0; i < MAX_PHB_BUS_NUM; i++) {
+ do {
dev = pci_get_device(PCI_VENDOR_ID_IBM,
PCI_DEVICE_ID_IBM_CALGARY,
dev);
@@ -861,12 +863,12 @@ static int __init calgary_init(void)
ret = calgary_init_one(dev);
if (ret)
goto error;
- }
+ } while (1);
return ret;
error:
- for (i--; i >= 0; i--) {
+ do {
dev = pci_find_device_reverse(PCI_VENDOR_ID_IBM,
PCI_DEVICE_ID_IBM_CALGARY,
dev);
@@ -882,7 +884,7 @@ error:
calgary_disable_translation(dev);
calgary_free_bus(dev);
pci_dev_put(dev); /* Undo calgary_init_one()'s pci_dev_get() */
- }
+ } while (1);
return ret;
}
--
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