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-rw-r--r--lib/kobject_uevent.c815
1 files changed, 815 insertions, 0 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
new file mode 100644
index 000000000..c87d5b6a8
--- /dev/null
+++ b/lib/kobject_uevent.c
@@ -0,0 +1,815 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kernel userspace event delivery
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004 Novell, Inc. All rights reserved.
+ * Copyright (C) 2004 IBM, Inc. All rights reserved.
+ *
+ * Authors:
+ * Robert Love <rml@novell.com>
+ * Kay Sievers <kay.sievers@vrfy.org>
+ * Arjan van de Ven <arjanv@redhat.com>
+ * Greg Kroah-Hartman <greg@kroah.com>
+ */
+
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/kobject.h>
+#include <linux/export.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/uidgid.h>
+#include <linux/uuid.h>
+#include <linux/ctype.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/net_namespace.h>
+
+
+u64 uevent_seqnum;
+#ifdef CONFIG_UEVENT_HELPER
+char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
+#endif
+
+struct uevent_sock {
+ struct list_head list;
+ struct sock *sk;
+};
+
+#ifdef CONFIG_NET
+static LIST_HEAD(uevent_sock_list);
+#endif
+
+/* This lock protects uevent_seqnum and uevent_sock_list */
+static DEFINE_MUTEX(uevent_sock_mutex);
+
+/* the strings here must match the enum in include/linux/kobject.h */
+static const char *kobject_actions[] = {
+ [KOBJ_ADD] = "add",
+ [KOBJ_REMOVE] = "remove",
+ [KOBJ_CHANGE] = "change",
+ [KOBJ_MOVE] = "move",
+ [KOBJ_ONLINE] = "online",
+ [KOBJ_OFFLINE] = "offline",
+ [KOBJ_BIND] = "bind",
+ [KOBJ_UNBIND] = "unbind",
+};
+
+static int kobject_action_type(const char *buf, size_t count,
+ enum kobject_action *type,
+ const char **args)
+{
+ enum kobject_action action;
+ size_t count_first;
+ const char *args_start;
+ int ret = -EINVAL;
+
+ if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
+ count--;
+
+ if (!count)
+ goto out;
+
+ args_start = strnchr(buf, count, ' ');
+ if (args_start) {
+ count_first = args_start - buf;
+ args_start = args_start + 1;
+ } else
+ count_first = count;
+
+ for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
+ if (strncmp(kobject_actions[action], buf, count_first) != 0)
+ continue;
+ if (kobject_actions[action][count_first] != '\0')
+ continue;
+ if (args)
+ *args = args_start;
+ *type = action;
+ ret = 0;
+ break;
+ }
+out:
+ return ret;
+}
+
+static const char *action_arg_word_end(const char *buf, const char *buf_end,
+ char delim)
+{
+ const char *next = buf;
+
+ while (next <= buf_end && *next != delim)
+ if (!isalnum(*next++))
+ return NULL;
+
+ if (next == buf)
+ return NULL;
+
+ return next;
+}
+
+static int kobject_action_args(const char *buf, size_t count,
+ struct kobj_uevent_env **ret_env)
+{
+ struct kobj_uevent_env *env = NULL;
+ const char *next, *buf_end, *key;
+ int key_len;
+ int r = -EINVAL;
+
+ if (count && (buf[count - 1] == '\n' || buf[count - 1] == '\0'))
+ count--;
+
+ if (!count)
+ return -EINVAL;
+
+ env = kzalloc(sizeof(*env), GFP_KERNEL);
+ if (!env)
+ return -ENOMEM;
+
+ /* first arg is UUID */
+ if (count < UUID_STRING_LEN || !uuid_is_valid(buf) ||
+ add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf))
+ goto out;
+
+ /*
+ * the rest are custom environment variables in KEY=VALUE
+ * format with ' ' delimiter between each KEY=VALUE pair
+ */
+ next = buf + UUID_STRING_LEN;
+ buf_end = buf + count - 1;
+
+ while (next <= buf_end) {
+ if (*next != ' ')
+ goto out;
+
+ /* skip the ' ', key must follow */
+ key = ++next;
+ if (key > buf_end)
+ goto out;
+
+ buf = next;
+ next = action_arg_word_end(buf, buf_end, '=');
+ if (!next || next > buf_end || *next != '=')
+ goto out;
+ key_len = next - buf;
+
+ /* skip the '=', value must follow */
+ if (++next > buf_end)
+ goto out;
+
+ buf = next;
+ next = action_arg_word_end(buf, buf_end, ' ');
+ if (!next)
+ goto out;
+
+ if (add_uevent_var(env, "SYNTH_ARG_%.*s=%.*s",
+ key_len, key, (int) (next - buf), buf))
+ goto out;
+ }
+
+ r = 0;
+out:
+ if (r)
+ kfree(env);
+ else
+ *ret_env = env;
+ return r;
+}
+
+/**
+ * kobject_synth_uevent - send synthetic uevent with arguments
+ *
+ * @kobj: struct kobject for which synthetic uevent is to be generated
+ * @buf: buffer containing action type and action args, newline is ignored
+ * @count: length of buffer
+ *
+ * Returns 0 if kobject_synthetic_uevent() is completed with success or the
+ * corresponding error when it fails.
+ */
+int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count)
+{
+ char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL };
+ enum kobject_action action;
+ const char *action_args;
+ struct kobj_uevent_env *env;
+ const char *msg = NULL, *devpath;
+ int r;
+
+ r = kobject_action_type(buf, count, &action, &action_args);
+ if (r) {
+ msg = "unknown uevent action string";
+ goto out;
+ }
+
+ if (!action_args) {
+ r = kobject_uevent_env(kobj, action, no_uuid_envp);
+ goto out;
+ }
+
+ r = kobject_action_args(action_args,
+ count - (action_args - buf), &env);
+ if (r == -EINVAL) {
+ msg = "incorrect uevent action arguments";
+ goto out;
+ }
+
+ if (r)
+ goto out;
+
+ r = kobject_uevent_env(kobj, action, env->envp);
+ kfree(env);
+out:
+ if (r) {
+ devpath = kobject_get_path(kobj, GFP_KERNEL);
+ pr_warn("synth uevent: %s: %s\n",
+ devpath ?: "unknown device",
+ msg ?: "failed to send uevent");
+ kfree(devpath);
+ }
+ return r;
+}
+
+#ifdef CONFIG_UEVENT_HELPER
+static int kobj_usermode_filter(struct kobject *kobj)
+{
+ const struct kobj_ns_type_operations *ops;
+
+ ops = kobj_ns_ops(kobj);
+ if (ops) {
+ const void *init_ns, *ns;
+
+ ns = kobj->ktype->namespace(kobj);
+ init_ns = ops->initial_ns();
+ return ns != init_ns;
+ }
+
+ return 0;
+}
+
+static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem)
+{
+ int buffer_size = sizeof(env->buf) - env->buflen;
+ int len;
+
+ len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size);
+ if (len >= buffer_size) {
+ pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n",
+ buffer_size, len);
+ return -ENOMEM;
+ }
+
+ env->argv[0] = uevent_helper;
+ env->argv[1] = &env->buf[env->buflen];
+ env->argv[2] = NULL;
+
+ env->buflen += len + 1;
+ return 0;
+}
+
+static void cleanup_uevent_env(struct subprocess_info *info)
+{
+ kfree(info->data);
+}
+#endif
+
+#ifdef CONFIG_NET
+static struct sk_buff *alloc_uevent_skb(struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ struct netlink_skb_parms *parms;
+ struct sk_buff *skb = NULL;
+ char *scratch;
+ size_t len;
+
+ /* allocate message with maximum possible size */
+ len = strlen(action_string) + strlen(devpath) + 2;
+ skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+ if (!skb)
+ return NULL;
+
+ /* add header */
+ scratch = skb_put(skb, len);
+ sprintf(scratch, "%s@%s", action_string, devpath);
+
+ skb_put_data(skb, env->buf, env->buflen);
+
+ parms = &NETLINK_CB(skb);
+ parms->creds.uid = GLOBAL_ROOT_UID;
+ parms->creds.gid = GLOBAL_ROOT_GID;
+ parms->dst_group = 1;
+ parms->portid = 0;
+
+ return skb;
+}
+
+static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ struct sk_buff *skb = NULL;
+ struct uevent_sock *ue_sk;
+ int retval = 0;
+
+ /* send netlink message */
+ list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+ struct sock *uevent_sock = ue_sk->sk;
+
+ if (!netlink_has_listeners(uevent_sock, 1))
+ continue;
+
+ if (!skb) {
+ retval = -ENOMEM;
+ skb = alloc_uevent_skb(env, action_string, devpath);
+ if (!skb)
+ continue;
+ }
+
+ retval = netlink_broadcast(uevent_sock, skb_get(skb), 0, 1,
+ GFP_KERNEL);
+ /* ENOBUFS should be handled in userspace */
+ if (retval == -ENOBUFS || retval == -ESRCH)
+ retval = 0;
+ }
+ consume_skb(skb);
+
+ return retval;
+}
+
+static int uevent_net_broadcast_tagged(struct sock *usk,
+ struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ struct user_namespace *owning_user_ns = sock_net(usk)->user_ns;
+ struct sk_buff *skb = NULL;
+ int ret = 0;
+
+ skb = alloc_uevent_skb(env, action_string, devpath);
+ if (!skb)
+ return -ENOMEM;
+
+ /* fix credentials */
+ if (owning_user_ns != &init_user_ns) {
+ struct netlink_skb_parms *parms = &NETLINK_CB(skb);
+ kuid_t root_uid;
+ kgid_t root_gid;
+
+ /* fix uid */
+ root_uid = make_kuid(owning_user_ns, 0);
+ if (uid_valid(root_uid))
+ parms->creds.uid = root_uid;
+
+ /* fix gid */
+ root_gid = make_kgid(owning_user_ns, 0);
+ if (gid_valid(root_gid))
+ parms->creds.gid = root_gid;
+ }
+
+ ret = netlink_broadcast(usk, skb, 0, 1, GFP_KERNEL);
+ /* ENOBUFS should be handled in userspace */
+ if (ret == -ENOBUFS || ret == -ESRCH)
+ ret = 0;
+
+ return ret;
+}
+#endif
+
+static int kobject_uevent_net_broadcast(struct kobject *kobj,
+ struct kobj_uevent_env *env,
+ const char *action_string,
+ const char *devpath)
+{
+ int ret = 0;
+
+#ifdef CONFIG_NET
+ const struct kobj_ns_type_operations *ops;
+ const struct net *net = NULL;
+
+ ops = kobj_ns_ops(kobj);
+ if (!ops && kobj->kset) {
+ struct kobject *ksobj = &kobj->kset->kobj;
+
+ if (ksobj->parent != NULL)
+ ops = kobj_ns_ops(ksobj->parent);
+ }
+
+ /* kobjects currently only carry network namespace tags and they
+ * are the only tag relevant here since we want to decide which
+ * network namespaces to broadcast the uevent into.
+ */
+ if (ops && ops->netlink_ns && kobj->ktype->namespace)
+ if (ops->type == KOBJ_NS_TYPE_NET)
+ net = kobj->ktype->namespace(kobj);
+
+ if (!net)
+ ret = uevent_net_broadcast_untagged(env, action_string,
+ devpath);
+ else
+ ret = uevent_net_broadcast_tagged(net->uevent_sock->sk, env,
+ action_string, devpath);
+#endif
+
+ return ret;
+}
+
+static void zap_modalias_env(struct kobj_uevent_env *env)
+{
+ static const char modalias_prefix[] = "MODALIAS=";
+ size_t len;
+ int i, j;
+
+ for (i = 0; i < env->envp_idx;) {
+ if (strncmp(env->envp[i], modalias_prefix,
+ sizeof(modalias_prefix) - 1)) {
+ i++;
+ continue;
+ }
+
+ len = strlen(env->envp[i]) + 1;
+
+ if (i != env->envp_idx - 1) {
+ memmove(env->envp[i], env->envp[i + 1],
+ env->buflen - len);
+
+ for (j = i; j < env->envp_idx - 1; j++)
+ env->envp[j] = env->envp[j + 1] - len;
+ }
+
+ env->envp_idx--;
+ env->buflen -= len;
+ }
+}
+
+/**
+ * kobject_uevent_env - send an uevent with environmental data
+ *
+ * @kobj: struct kobject that the action is happening to
+ * @action: action that is happening
+ * @envp_ext: pointer to environmental data
+ *
+ * Returns 0 if kobject_uevent_env() is completed with success or the
+ * corresponding error when it fails.
+ */
+int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
+ char *envp_ext[])
+{
+ struct kobj_uevent_env *env;
+ const char *action_string = kobject_actions[action];
+ const char *devpath = NULL;
+ const char *subsystem;
+ struct kobject *top_kobj;
+ struct kset *kset;
+ const struct kset_uevent_ops *uevent_ops;
+ int i = 0;
+ int retval = 0;
+
+ /*
+ * Mark "remove" event done regardless of result, for some subsystems
+ * do not want to re-trigger "remove" event via automatic cleanup.
+ */
+ if (action == KOBJ_REMOVE)
+ kobj->state_remove_uevent_sent = 1;
+
+ pr_debug("kobject: '%s' (%p): %s\n",
+ kobject_name(kobj), kobj, __func__);
+
+ /* search the kset we belong to */
+ top_kobj = kobj;
+ while (!top_kobj->kset && top_kobj->parent)
+ top_kobj = top_kobj->parent;
+
+ if (!top_kobj->kset) {
+ pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
+ "without kset!\n", kobject_name(kobj), kobj,
+ __func__);
+ return -EINVAL;
+ }
+
+ kset = top_kobj->kset;
+ uevent_ops = kset->uevent_ops;
+
+ /* skip the event, if uevent_suppress is set*/
+ if (kobj->uevent_suppress) {
+ pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
+ "caused the event to drop!\n",
+ kobject_name(kobj), kobj, __func__);
+ return 0;
+ }
+ /* skip the event, if the filter returns zero. */
+ if (uevent_ops && uevent_ops->filter)
+ if (!uevent_ops->filter(kset, kobj)) {
+ pr_debug("kobject: '%s' (%p): %s: filter function "
+ "caused the event to drop!\n",
+ kobject_name(kobj), kobj, __func__);
+ return 0;
+ }
+
+ /* originating subsystem */
+ if (uevent_ops && uevent_ops->name)
+ subsystem = uevent_ops->name(kset, kobj);
+ else
+ subsystem = kobject_name(&kset->kobj);
+ if (!subsystem) {
+ pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
+ "event to drop!\n", kobject_name(kobj), kobj,
+ __func__);
+ return 0;
+ }
+
+ /* environment buffer */
+ env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
+ if (!env)
+ return -ENOMEM;
+
+ /* complete object path */
+ devpath = kobject_get_path(kobj, GFP_KERNEL);
+ if (!devpath) {
+ retval = -ENOENT;
+ goto exit;
+ }
+
+ /* default keys */
+ retval = add_uevent_var(env, "ACTION=%s", action_string);
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env, "DEVPATH=%s", devpath);
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
+ if (retval)
+ goto exit;
+
+ /* keys passed in from the caller */
+ if (envp_ext) {
+ for (i = 0; envp_ext[i]; i++) {
+ retval = add_uevent_var(env, "%s", envp_ext[i]);
+ if (retval)
+ goto exit;
+ }
+ }
+
+ /* let the kset specific function add its stuff */
+ if (uevent_ops && uevent_ops->uevent) {
+ retval = uevent_ops->uevent(kset, kobj, env);
+ if (retval) {
+ pr_debug("kobject: '%s' (%p): %s: uevent() returned "
+ "%d\n", kobject_name(kobj), kobj,
+ __func__, retval);
+ goto exit;
+ }
+ }
+
+ switch (action) {
+ case KOBJ_ADD:
+ /*
+ * Mark "add" event so we can make sure we deliver "remove"
+ * event to userspace during automatic cleanup. If
+ * the object did send an "add" event, "remove" will
+ * automatically generated by the core, if not already done
+ * by the caller.
+ */
+ kobj->state_add_uevent_sent = 1;
+ break;
+
+ case KOBJ_UNBIND:
+ zap_modalias_env(env);
+ break;
+
+ default:
+ break;
+ }
+
+ mutex_lock(&uevent_sock_mutex);
+ /* we will send an event, so request a new sequence number */
+ retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum);
+ if (retval) {
+ mutex_unlock(&uevent_sock_mutex);
+ goto exit;
+ }
+ retval = kobject_uevent_net_broadcast(kobj, env, action_string,
+ devpath);
+ mutex_unlock(&uevent_sock_mutex);
+
+#ifdef CONFIG_UEVENT_HELPER
+ /* call uevent_helper, usually only enabled during early boot */
+ if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
+ struct subprocess_info *info;
+
+ retval = add_uevent_var(env, "HOME=/");
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env,
+ "PATH=/sbin:/bin:/usr/sbin:/usr/bin");
+ if (retval)
+ goto exit;
+ retval = init_uevent_argv(env, subsystem);
+ if (retval)
+ goto exit;
+
+ retval = -ENOMEM;
+ info = call_usermodehelper_setup(env->argv[0], env->argv,
+ env->envp, GFP_KERNEL,
+ NULL, cleanup_uevent_env, env);
+ if (info) {
+ retval = call_usermodehelper_exec(info, UMH_NO_WAIT);
+ env = NULL; /* freed by cleanup_uevent_env */
+ }
+ }
+#endif
+
+exit:
+ kfree(devpath);
+ kfree(env);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(kobject_uevent_env);
+
+/**
+ * kobject_uevent - notify userspace by sending an uevent
+ *
+ * @kobj: struct kobject that the action is happening to
+ * @action: action that is happening
+ *
+ * Returns 0 if kobject_uevent() is completed with success or the
+ * corresponding error when it fails.
+ */
+int kobject_uevent(struct kobject *kobj, enum kobject_action action)
+{
+ return kobject_uevent_env(kobj, action, NULL);
+}
+EXPORT_SYMBOL_GPL(kobject_uevent);
+
+/**
+ * add_uevent_var - add key value string to the environment buffer
+ * @env: environment buffer structure
+ * @format: printf format for the key=value pair
+ *
+ * Returns 0 if environment variable was added successfully or -ENOMEM
+ * if no space was available.
+ */
+int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
+{
+ va_list args;
+ int len;
+
+ if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
+ WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
+ return -ENOMEM;
+ }
+
+ va_start(args, format);
+ len = vsnprintf(&env->buf[env->buflen],
+ sizeof(env->buf) - env->buflen,
+ format, args);
+ va_end(args);
+
+ if (len >= (sizeof(env->buf) - env->buflen)) {
+ WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
+ return -ENOMEM;
+ }
+
+ env->envp[env->envp_idx++] = &env->buf[env->buflen];
+ env->buflen += len + 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(add_uevent_var);
+
+#if defined(CONFIG_NET)
+static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb,
+ struct netlink_ext_ack *extack)
+{
+ /* u64 to chars: 2^64 - 1 = 21 chars */
+ char buf[sizeof("SEQNUM=") + 21];
+ struct sk_buff *skbc;
+ int ret;
+
+ /* bump and prepare sequence number */
+ ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum);
+ if (ret < 0 || (size_t)ret >= sizeof(buf))
+ return -ENOMEM;
+ ret++;
+
+ /* verify message does not overflow */
+ if ((skb->len + ret) > UEVENT_BUFFER_SIZE) {
+ NL_SET_ERR_MSG(extack, "uevent message too big");
+ return -EINVAL;
+ }
+
+ /* copy skb and extend to accommodate sequence number */
+ skbc = skb_copy_expand(skb, 0, ret, GFP_KERNEL);
+ if (!skbc)
+ return -ENOMEM;
+
+ /* append sequence number */
+ skb_put_data(skbc, buf, ret);
+
+ /* remove msg header */
+ skb_pull(skbc, NLMSG_HDRLEN);
+
+ /* set portid 0 to inform userspace message comes from kernel */
+ NETLINK_CB(skbc).portid = 0;
+ NETLINK_CB(skbc).dst_group = 1;
+
+ ret = netlink_broadcast(usk, skbc, 0, 1, GFP_KERNEL);
+ /* ENOBUFS should be handled in userspace */
+ if (ret == -ENOBUFS || ret == -ESRCH)
+ ret = 0;
+
+ return ret;
+}
+
+static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net;
+ int ret;
+
+ if (!nlmsg_data(nlh))
+ return -EINVAL;
+
+ /*
+ * Verify that we are allowed to send messages to the target
+ * network namespace. The caller must have CAP_SYS_ADMIN in the
+ * owning user namespace of the target network namespace.
+ */
+ net = sock_net(NETLINK_CB(skb).sk);
+ if (!netlink_ns_capable(skb, net->user_ns, CAP_SYS_ADMIN)) {
+ NL_SET_ERR_MSG(extack, "missing CAP_SYS_ADMIN capability");
+ return -EPERM;
+ }
+
+ mutex_lock(&uevent_sock_mutex);
+ ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack);
+ mutex_unlock(&uevent_sock_mutex);
+
+ return ret;
+}
+
+static void uevent_net_rcv(struct sk_buff *skb)
+{
+ netlink_rcv_skb(skb, &uevent_net_rcv_skb);
+}
+
+static int uevent_net_init(struct net *net)
+{
+ struct uevent_sock *ue_sk;
+ struct netlink_kernel_cfg cfg = {
+ .groups = 1,
+ .input = uevent_net_rcv,
+ .flags = NL_CFG_F_NONROOT_RECV
+ };
+
+ ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
+ if (!ue_sk)
+ return -ENOMEM;
+
+ ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
+ if (!ue_sk->sk) {
+ pr_err("kobject_uevent: unable to create netlink socket!\n");
+ kfree(ue_sk);
+ return -ENODEV;
+ }
+
+ net->uevent_sock = ue_sk;
+
+ /* Restrict uevents to initial user namespace. */
+ if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) {
+ mutex_lock(&uevent_sock_mutex);
+ list_add_tail(&ue_sk->list, &uevent_sock_list);
+ mutex_unlock(&uevent_sock_mutex);
+ }
+
+ return 0;
+}
+
+static void uevent_net_exit(struct net *net)
+{
+ struct uevent_sock *ue_sk = net->uevent_sock;
+
+ if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) {
+ mutex_lock(&uevent_sock_mutex);
+ list_del(&ue_sk->list);
+ mutex_unlock(&uevent_sock_mutex);
+ }
+
+ netlink_kernel_release(ue_sk->sk);
+ kfree(ue_sk);
+}
+
+static struct pernet_operations uevent_net_ops = {
+ .init = uevent_net_init,
+ .exit = uevent_net_exit,
+};
+
+static int __init kobject_uevent_init(void)
+{
+ return register_pernet_subsys(&uevent_net_ops);
+}
+
+
+postcore_initcall(kobject_uevent_init);
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-17 08:58:56 +0000