linux/drivers/pci/pci-stub.c
Tejun Heo 99a0fadf56 PCI: pci-stub: ignore zero-length id parameters
pci-stub uses strsep() to separate list of ids and generates a warning
message when it fails to parse an id.  However, not specifying the
parameter results in ids set to an empty string.  strsep() happily
returns the empty string as the first token and thus triggers the
warning message spuriously.

Make the tokner ignore zero length ids.

Reported-by: Chris Wright <chrisw@sous-sol.org>
Reported-by: Prasad Joshi <P.G.Joshi@student.reading.ac.uk>
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-23 12:53:52 -08:00

98 lines
2.4 KiB
C

/* pci-stub - simple stub driver to reserve a pci device
*
* Copyright (C) 2008 Red Hat, Inc.
* Author:
* Chris Wright
*
* This work is licensed under the terms of the GNU GPL, version 2.
*
* Usage is simple, allocate a new id to the stub driver and bind the
* device to it. For example:
*
* # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
* # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
* .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
*/
#include <linux/module.h>
#include <linux/pci.h>
static char ids[1024] __initdata;
module_param_string(ids, ids, sizeof(ids), 0);
MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
"\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
" and multiple comma separated entries can be specified");
static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
dev_printk(KERN_INFO, &dev->dev, "claimed by stub\n");
return 0;
}
static struct pci_driver stub_driver = {
.name = "pci-stub",
.id_table = NULL, /* only dynamic id's */
.probe = pci_stub_probe,
};
static int __init pci_stub_init(void)
{
char *p, *id;
int rc;
rc = pci_register_driver(&stub_driver);
if (rc)
return rc;
/* no ids passed actually */
if (ids[0] == '\0')
return 0;
/* add ids specified in the module parameter */
p = ids;
while ((id = strsep(&p, ","))) {
unsigned int vendor, device, subvendor = PCI_ANY_ID,
subdevice = PCI_ANY_ID, class=0, class_mask=0;
int fields;
if (!strlen(id))
continue;
fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
&vendor, &device, &subvendor, &subdevice,
&class, &class_mask);
if (fields < 2) {
printk(KERN_WARNING
"pci-stub: invalid id string \"%s\"\n", id);
continue;
}
printk(KERN_INFO
"pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
vendor, device, subvendor, subdevice, class, class_mask);
rc = pci_add_dynid(&stub_driver, vendor, device,
subvendor, subdevice, class, class_mask, 0);
if (rc)
printk(KERN_WARNING
"pci-stub: failed to add dynamic id (%d)\n", rc);
}
return 0;
}
static void __exit pci_stub_exit(void)
{
pci_unregister_driver(&stub_driver);
}
module_init(pci_stub_init);
module_exit(pci_stub_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");