linux/drivers/pnp/core.c
Rafael J. Wysocki 71150d2265 PNP: Avoid leaving unregistered device objects in lists
pnp_register_protocol() and __pnp_add_device() both have a problem
that if device_register() fails, the objects they create will be left
in the lists they have been put one beforehand.  Unfortunately, that
is not handled by the callers of those routines either, so in case
of a device registration errors the PNP bus type's data structures
will end up in an inconsistent state.

Make pnp_register_protocol() and __pnp_add_device() remove the
objects from the lists if device registration fails.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-18 22:40:04 +01:00

253 lines
5.1 KiB
C

/*
* core.c - contains all core device and protocol registration functions
*
* Copyright 2002 Adam Belay <ambx1@neo.rr.com>
*/
#include <linux/pnp.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/dma-mapping.h>
#include "base.h"
static LIST_HEAD(pnp_protocols);
LIST_HEAD(pnp_global);
DEFINE_MUTEX(pnp_lock);
/*
* ACPI or PNPBIOS should tell us about all platform devices, so we can
* skip some blind probes. ISAPNP typically enumerates only plug-in ISA
* devices, not built-in things like COM ports.
*/
int pnp_platform_devices;
EXPORT_SYMBOL(pnp_platform_devices);
void *pnp_alloc(long size)
{
void *result;
result = kzalloc(size, GFP_KERNEL);
if (!result) {
printk(KERN_ERR "pnp: Out of Memory\n");
return NULL;
}
return result;
}
static void pnp_remove_protocol(struct pnp_protocol *protocol)
{
mutex_lock(&pnp_lock);
list_del(&protocol->protocol_list);
mutex_unlock(&pnp_lock);
}
/**
* pnp_protocol_register - adds a pnp protocol to the pnp layer
* @protocol: pointer to the corresponding pnp_protocol structure
*
* Ex protocols: ISAPNP, PNPBIOS, etc
*/
int pnp_register_protocol(struct pnp_protocol *protocol)
{
struct list_head *pos;
int nodenum, ret;
INIT_LIST_HEAD(&protocol->devices);
INIT_LIST_HEAD(&protocol->cards);
nodenum = 0;
mutex_lock(&pnp_lock);
/* assign the lowest unused number */
list_for_each(pos, &pnp_protocols) {
struct pnp_protocol *cur = to_pnp_protocol(pos);
if (cur->number == nodenum) {
pos = &pnp_protocols;
nodenum++;
}
}
protocol->number = nodenum;
dev_set_name(&protocol->dev, "pnp%d", nodenum);
list_add_tail(&protocol->protocol_list, &pnp_protocols);
mutex_unlock(&pnp_lock);
ret = device_register(&protocol->dev);
if (ret)
pnp_remove_protocol(protocol);
return ret;
}
/**
* pnp_protocol_unregister - removes a pnp protocol from the pnp layer
* @protocol: pointer to the corresponding pnp_protocol structure
*/
void pnp_unregister_protocol(struct pnp_protocol *protocol)
{
pnp_remove_protocol(protocol);
device_unregister(&protocol->dev);
}
static void pnp_free_ids(struct pnp_dev *dev)
{
struct pnp_id *id;
struct pnp_id *next;
id = dev->id;
while (id) {
next = id->next;
kfree(id);
id = next;
}
}
void pnp_free_resource(struct pnp_resource *pnp_res)
{
list_del(&pnp_res->list);
kfree(pnp_res);
}
void pnp_free_resources(struct pnp_dev *dev)
{
struct pnp_resource *pnp_res, *tmp;
list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
pnp_free_resource(pnp_res);
}
}
static void pnp_release_device(struct device *dmdev)
{
struct pnp_dev *dev = to_pnp_dev(dmdev);
pnp_free_ids(dev);
pnp_free_resources(dev);
pnp_free_options(dev);
kfree(dev);
}
struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id,
const char *pnpid)
{
struct pnp_dev *dev;
struct pnp_id *dev_id;
dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
if (!dev)
return NULL;
INIT_LIST_HEAD(&dev->resources);
INIT_LIST_HEAD(&dev->options);
dev->protocol = protocol;
dev->number = id;
dev->dma_mask = DMA_BIT_MASK(24);
dev->dev.parent = &dev->protocol->dev;
dev->dev.bus = &pnp_bus_type;
dev->dev.dma_mask = &dev->dma_mask;
dev->dev.coherent_dma_mask = dev->dma_mask;
dev->dev.release = &pnp_release_device;
dev_set_name(&dev->dev, "%02x:%02x", dev->protocol->number, dev->number);
dev_id = pnp_add_id(dev, pnpid);
if (!dev_id) {
kfree(dev);
return NULL;
}
return dev;
}
static void pnp_delist_device(struct pnp_dev *dev)
{
mutex_lock(&pnp_lock);
list_del(&dev->global_list);
list_del(&dev->protocol_list);
mutex_unlock(&pnp_lock);
}
int __pnp_add_device(struct pnp_dev *dev)
{
int ret;
pnp_fixup_device(dev);
dev->status = PNP_READY;
mutex_lock(&pnp_lock);
list_add_tail(&dev->global_list, &pnp_global);
list_add_tail(&dev->protocol_list, &dev->protocol->devices);
mutex_unlock(&pnp_lock);
ret = device_register(&dev->dev);
if (ret)
pnp_delist_device(dev);
else if (dev->protocol->can_wakeup)
device_set_wakeup_capable(&dev->dev,
dev->protocol->can_wakeup(dev));
return ret;
}
/*
* pnp_add_device - adds a pnp device to the pnp layer
* @dev: pointer to dev to add
*
* adds to driver model, name database, fixups, interface, etc.
*/
int pnp_add_device(struct pnp_dev *dev)
{
int ret;
char buf[128];
int len = 0;
struct pnp_id *id;
if (dev->card)
return -EINVAL;
ret = __pnp_add_device(dev);
if (ret)
return ret;
buf[0] = '\0';
for (id = dev->id; id; id = id->next)
len += scnprintf(buf + len, sizeof(buf) - len, " %s", id->id);
dev_printk(KERN_DEBUG, &dev->dev, "%s device, IDs%s (%s)\n",
dev->protocol->name, buf,
dev->active ? "active" : "disabled");
return 0;
}
void __pnp_remove_device(struct pnp_dev *dev)
{
pnp_delist_device(dev);
device_unregister(&dev->dev);
}
static int __init pnp_init(void)
{
return bus_register(&pnp_bus_type);
}
subsys_initcall(pnp_init);
int pnp_debug;
#if defined(CONFIG_PNP_DEBUG_MESSAGES)
module_param_named(debug, pnp_debug, int, 0644);
#endif