Commit dedc9937 authored by Jon Mason's avatar Jon Mason Committed by Andi Kleen

[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: default avatarJon Mason <jdmason@kudzu.us>
Signed-off-by: default avatarMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 814eadce
......@@ -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 @@ static int __init calgary_init_one(struct pci_dev *dev)
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 @@ static int __init calgary_init(void)
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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