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-rw-r--r--lib/kobject_uevent.c279
1 files changed, 95 insertions, 184 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 845bf67..dd061da 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -29,6 +29,7 @@
char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
u64 hotplug_seqnum;
static DEFINE_SPINLOCK(sequence_lock);
+static struct sock *uevent_sock;
static char *action_to_string(enum kobject_action action)
{
@@ -48,123 +49,6 @@ static char *action_to_string(enum kobject_action action)
}
}
-static struct sock *uevent_sock;
-
-/**
- * send_uevent - notify userspace by sending event through netlink socket
- *
- * @signal: signal name
- * @obj: object path (kobject)
- * @envp: possible hotplug environment to pass with the message
- * @gfp_mask:
- */
-static int send_uevent(const char *signal, const char *obj,
- char **envp, gfp_t gfp_mask)
-{
- struct sk_buff *skb;
- char *pos;
- int len;
-
- if (!uevent_sock)
- return -EIO;
-
- len = strlen(signal) + 1;
- len += strlen(obj) + 1;
-
- /* allocate buffer with the maximum possible message size */
- skb = alloc_skb(len + BUFFER_SIZE, gfp_mask);
- if (!skb)
- return -ENOMEM;
-
- pos = skb_put(skb, len);
- sprintf(pos, "%s@%s", signal, obj);
-
- /* copy the environment key by key to our continuous buffer */
- if (envp) {
- int i;
-
- for (i = 2; envp[i]; i++) {
- len = strlen(envp[i]) + 1;
- pos = skb_put(skb, len);
- strcpy(pos, envp[i]);
- }
- }
-
- NETLINK_CB(skb).dst_group = 1;
- return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
-}
-
-static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr, gfp_t gfp_mask)
-{
- char *path;
- char *attrpath;
- char *signal;
- int len;
- int rc = -ENOMEM;
-
- path = kobject_get_path(kobj, gfp_mask);
- if (!path)
- return -ENOMEM;
-
- signal = action_to_string(action);
- if (!signal)
- return -EINVAL;
-
- if (attr) {
- len = strlen(path);
- len += strlen(attr->name) + 2;
- attrpath = kmalloc(len, gfp_mask);
- if (!attrpath)
- goto exit;
- sprintf(attrpath, "%s/%s", path, attr->name);
- rc = send_uevent(signal, attrpath, NULL, gfp_mask);
- kfree(attrpath);
- } else
- rc = send_uevent(signal, path, NULL, gfp_mask);
-
-exit:
- kfree(path);
- return rc;
-}
-
-/**
- * kobject_uevent - notify userspace by sending event through netlink socket
- *
- * @signal: signal name
- * @kobj: struct kobject that the event is happening to
- * @attr: optional struct attribute the event belongs to
- */
-int kobject_uevent(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr)
-{
- return do_kobject_uevent(kobj, action, attr, GFP_KERNEL);
-}
-EXPORT_SYMBOL_GPL(kobject_uevent);
-
-int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr)
-{
- return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
-}
-EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
-
-static int __init kobject_uevent_init(void)
-{
- uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
- THIS_MODULE);
-
- if (!uevent_sock) {
- printk(KERN_ERR
- "kobject_uevent: unable to create netlink socket!\n");
- return -ENODEV;
- }
-
- return 0;
-}
-
-postcore_initcall(kobject_uevent_init);
-
/**
* kobject_hotplug - notify userspace by executing /sbin/hotplug
*
@@ -173,95 +57,84 @@ postcore_initcall(kobject_uevent_init);
*/
void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
{
- char *argv [3];
- char **envp = NULL;
- char *buffer = NULL;
- char *seq_buff;
+ char **envp;
+ char *buffer;
char *scratch;
+ const char *action_string;
+ const char *devpath = NULL;
+ const char *subsystem;
+ struct kobject *top_kobj;
+ struct kset *kset;
+ struct kset_hotplug_ops *hotplug_ops;
+ u64 seq;
+ char *seq_buff;
int i = 0;
int retval;
- char *kobj_path = NULL;
- const char *name = NULL;
- char *action_string;
- u64 seq;
- struct kobject *top_kobj = kobj;
- struct kset *kset;
- static struct kset_hotplug_ops null_hotplug_ops;
- struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops;
- /* If this kobj does not belong to a kset,
- try to find a parent that does. */
+ pr_debug("%s\n", __FUNCTION__);
+
+ action_string = action_to_string(action);
+ if (!action_string)
+ return;
+
+ /* search the kset we belong to */
+ top_kobj = kobj;
if (!top_kobj->kset && top_kobj->parent) {
do {
top_kobj = top_kobj->parent;
} while (!top_kobj->kset && top_kobj->parent);
}
-
- if (top_kobj->kset)
- kset = top_kobj->kset;
- else
+ if (!top_kobj->kset)
return;
- if (kset->hotplug_ops)
- hotplug_ops = kset->hotplug_ops;
+ kset = top_kobj->kset;
+ hotplug_ops = kset->hotplug_ops;
- /* If the kset has a filter operation, call it.
- Skip the event, if the filter returns zero. */
- if (hotplug_ops->filter) {
+ /* skip the event, if the filter returns zero. */
+ if (hotplug_ops && hotplug_ops->filter)
if (!hotplug_ops->filter(kset, kobj))
return;
- }
-
- pr_debug ("%s\n", __FUNCTION__);
-
- action_string = action_to_string(action);
- if (!action_string)
- return;
- envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
+ /* environment index */
+ envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
if (!envp)
return;
- memset (envp, 0x00, NUM_ENVP * sizeof (char *));
+ /* environment values */
buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
if (!buffer)
goto exit;
- if (hotplug_ops->name)
- name = hotplug_ops->name(kset, kobj);
- if (name == NULL)
- name = kobject_name(&kset->kobj);
+ /* complete object path */
+ devpath = kobject_get_path(kobj, GFP_KERNEL);
+ if (!devpath)
+ goto exit;
- argv [0] = hotplug_path;
- argv [1] = (char *)name; /* won't be changed but 'const' has to go */
- argv [2] = NULL;
+ /* originating subsystem */
+ if (hotplug_ops && hotplug_ops->name)
+ subsystem = hotplug_ops->name(kset, kobj);
+ else
+ subsystem = kobject_name(&kset->kobj);
- /* minimal command environment */
- envp [i++] = "HOME=/";
- envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ /* event environemnt for helper process only */
+ envp[i++] = "HOME=/";
+ envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ /* default keys */
scratch = buffer;
-
envp [i++] = scratch;
scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
-
- kobj_path = kobject_get_path(kobj, GFP_KERNEL);
- if (!kobj_path)
- goto exit;
-
envp [i++] = scratch;
- scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
-
+ scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
envp [i++] = scratch;
- scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1;
+ scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
- /* reserve space for the sequence,
- * put the real one in after the hotplug call */
+ /* just reserve the space, overwrite it after kset call has returned */
envp[i++] = seq_buff = scratch;
scratch += strlen("SEQNUM=18446744073709551616") + 1;
- if (hotplug_ops->hotplug) {
- /* have the kset specific function add its stuff */
+ /* let the kset specific function add its stuff */
+ if (hotplug_ops && hotplug_ops->hotplug) {
retval = hotplug_ops->hotplug (kset, kobj,
&envp[i], NUM_ENVP - i, scratch,
BUFFER_SIZE - (scratch - buffer));
@@ -272,27 +145,49 @@ void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
}
}
+ /* we will send an event, request a new sequence number */
spin_lock(&sequence_lock);
seq = ++hotplug_seqnum;
spin_unlock(&sequence_lock);
sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
- pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n",
- __FUNCTION__, argv[0], argv[1], (unsigned long long)seq,
- envp[0], envp[1], envp[2], envp[3], envp[4]);
-
- send_uevent(action_string, kobj_path, envp, GFP_KERNEL);
+ /* send netlink message */
+ if (uevent_sock) {
+ struct sk_buff *skb;
+ size_t len;
+
+ /* allocate message with the maximum possible size */
+ len = strlen(action_string) + strlen(devpath) + 2;
+ skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
+ if (skb) {
+ /* add header */
+ scratch = skb_put(skb, len);
+ sprintf(scratch, "%s@%s", action_string, devpath);
+
+ /* copy keys to our continuous event payload buffer */
+ for (i = 2; envp[i]; i++) {
+ len = strlen(envp[i]) + 1;
+ scratch = skb_put(skb, len);
+ strcpy(scratch, envp[i]);
+ }
+
+ NETLINK_CB(skb).dst_group = 1;
+ netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
+ }
+ }
- if (!hotplug_path[0])
- goto exit;
+ /* call uevent_helper, usually only enabled during early boot */
+ if (hotplug_path[0]) {
+ char *argv [3];
- retval = call_usermodehelper (argv[0], argv, envp, 0);
- if (retval)
- pr_debug ("%s - call_usermodehelper returned %d\n",
- __FUNCTION__, retval);
+ argv [0] = hotplug_path;
+ argv [1] = (char *)subsystem;
+ argv [2] = NULL;
+ call_usermodehelper (argv[0], argv, envp, 0);
+ }
exit:
- kfree(kobj_path);
+ kfree(devpath);
kfree(buffer);
kfree(envp);
return;
@@ -350,4 +245,20 @@ int add_hotplug_env_var(char **envp, int num_envp, int *cur_index,
}
EXPORT_SYMBOL(add_hotplug_env_var);
+static int __init kobject_uevent_init(void)
+{
+ uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
+ THIS_MODULE);
+
+ if (!uevent_sock) {
+ printk(KERN_ERR
+ "kobject_uevent: unable to create netlink socket!\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+postcore_initcall(kobject_uevent_init);
+
#endif /* CONFIG_HOTPLUG */
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