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/*
* drivers/base/hotplug.c - hotplug call code
*
* Copyright (c) 2000-2001 David Brownell
* Copyright (c) 2002 Greg Kroah-Hartman
* Copyright (c) 2002 IBM Corp.
*
* Based off of drivers/usb/core/usb.c:call_agent(), which was
* written by David Brownell.
*
*/
#undef DEBUG
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/kmod.h>
#include <linux/interrupt.h>
#include "base.h"
#include "fs/fs.h"
/*
* hotplugging invokes what /proc/sys/kernel/hotplug says (normally
* /sbin/hotplug) when devices or classes get added or removed.
*
* This invokes a user mode policy agent, typically helping to load driver
* or other modules, configure the device, and more. Drivers can provide
* a MODULE_DEVICE_TABLE to help with module loading subtasks.
*
* See the documentation at http://linux-hotplug.sf.net for more info.
*
*/
#define BUFFER_SIZE 1024 /* should be enough memory for the env */
#define NUM_ENVP 32 /* number of env pointers */
static char prefix [] = "devices"; /* /sys/devices/... */
static int do_hotplug (struct device *dev, char *argv1, const char *action,
int (* hotplug) (struct device *, char **, int, char *, int))
{
char *argv [3], **envp, *buffer, *scratch;
char *dev_path;
int retval;
int i = 0;
int dev_length;
pr_debug ("%s\n", __FUNCTION__);
if (!hotplug_path [0])
return -ENODEV;
if (in_interrupt ()) {
pr_debug ("%s - in_interrupt, not allowed!", __FUNCTION__);
return -EIO;
}
if (!current->fs->root) {
/* don't try to do anything unless we have a root partition */
pr_debug ("%s - %s -- no FS yet\n", __FUNCTION__, action);
return -EIO;
}
envp = (char **) kmalloc (NUM_ENVP * sizeof (char *), GFP_KERNEL);
if (!envp)
return -ENOMEM;
memset (envp, 0x00, NUM_ENVP * sizeof (char *));
buffer = kmalloc (BUFFER_SIZE, GFP_KERNEL);
if (!buffer) {
kfree (envp);
return -ENOMEM;
}
dev_length = get_devpath_length (dev);
dev_length += strlen(prefix);
dev_path = kmalloc (dev_length, GFP_KERNEL);
if (!dev_path) {
kfree (buffer);
kfree (envp);
return -ENOMEM;
}
memset (dev_path, 0x00, dev_length);
strcpy (dev_path, prefix);
fill_devpath (dev, dev_path, dev_length);
argv [0] = hotplug_path;
argv [1] = argv1;
argv [2] = 0;
/* minimal command environment */
envp [i++] = "HOME=/";
envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
scratch = buffer;
envp [i++] = scratch;
scratch += sprintf (scratch, "ACTION=%s", action) + 1;
envp [i++] = scratch;
scratch += sprintf (scratch, "DEVPATH=%s", dev_path) + 1;
if (hotplug) {
/* have the bus specific function add its stuff */
retval = hotplug (dev, &envp[i], NUM_ENVP - i, scratch,
BUFFER_SIZE - (scratch - buffer));
if (retval) {
pr_debug ("%s - hotplug() returned %d\n",
__FUNCTION__, retval);
goto exit;
}
}
pr_debug ("%s: %s %s %s %s %s %s\n", __FUNCTION__, argv [0], argv[1],
envp[0], envp[1], envp[2], envp[3]);
retval = call_usermodehelper (argv [0], argv, envp);
if (retval)
pr_debug ("%s - call_usermodehelper returned %d\n",
__FUNCTION__, retval);
exit:
kfree (dev_path);
kfree (buffer);
kfree (envp);
return retval;
}
/*
* dev_hotplug - called when any device is added or removed from a bus
*/
int dev_hotplug (struct device *dev, const char *action)
{
pr_debug ("%s\n", __FUNCTION__);
if (!dev)
return -ENODEV;
if (!dev->bus)
return -ENODEV;
return do_hotplug (dev, dev->bus->name, action, dev->bus->hotplug);
}
/*
* class_hotplug - called when a class is added or removed from a device
*/
int class_hotplug (struct device *dev, const char *action)
{
struct device_class * cls;
int retval;
pr_debug ("%s\n", __FUNCTION__);
if (!dev)
return -ENODEV;
if (!dev->bus)
return -ENODEV;
cls = get_devclass(dev->driver->devclass);
if (!cls)
return -ENODEV;
retval = do_hotplug (dev, cls->name, action, cls->hotplug);
put_devclass(cls);
return retval;
}
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