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Diffstat (limited to 'lib/kobject_uevent.c')
-rw-r--r--lib/kobject_uevent.c96
1 files changed, 66 insertions, 30 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 27c6118afd1c..78e16b95d210 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -30,7 +30,7 @@
#include <net/net_namespace.h>
-u64 uevent_seqnum;
+atomic64_t uevent_seqnum;
#ifdef CONFIG_UEVENT_HELPER
char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
#endif
@@ -42,10 +42,9 @@ struct uevent_sock {
#ifdef CONFIG_NET
static LIST_HEAD(uevent_sock_list);
-#endif
-
-/* This lock protects uevent_seqnum and uevent_sock_list */
+/* This lock protects uevent_sock_list */
static DEFINE_MUTEX(uevent_sock_mutex);
+#endif
/* the strings here must match the enum in include/linux/kobject.h */
static const char *kobject_actions[] = {
@@ -200,7 +199,7 @@ int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count)
r = kobject_action_type(buf, count, &action, &action_args);
if (r) {
- msg = "unknown uevent action string\n";
+ msg = "unknown uevent action string";
goto out;
}
@@ -212,7 +211,7 @@ int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count)
r = kobject_action_args(action_args,
count - (action_args - buf), &env);
if (r == -EINVAL) {
- msg = "incorrect uevent action arguments\n";
+ msg = "incorrect uevent action arguments";
goto out;
}
@@ -224,7 +223,7 @@ int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count)
out:
if (r) {
devpath = kobject_get_path(kobj, GFP_KERNEL);
- printk(KERN_WARNING "synth uevent: %s: %s",
+ pr_warn("synth uevent: %s: %s\n",
devpath ?: "unknown device",
msg ?: "failed to send uevent");
kfree(devpath);
@@ -251,12 +250,13 @@ static int kobj_usermode_filter(struct kobject *kobj)
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,
- sizeof(env->buf) - env->buflen);
- if (len >= (sizeof(env->buf) - env->buflen)) {
- WARN(1, KERN_ERR "init_uevent_argv: buffer size too small\n");
+ len = strscpy(&env->buf[env->buflen], subsystem, buffer_size);
+ if (len < 0) {
+ pr_warn("%s: insufficient buffer space (%u left) for %s\n",
+ __func__, buffer_size, subsystem);
return -ENOMEM;
}
@@ -314,6 +314,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
int retval = 0;
/* send netlink message */
+ mutex_lock(&uevent_sock_mutex);
list_for_each_entry(ue_sk, &uevent_sock_list, list) {
struct sock *uevent_sock = ue_sk->sk;
@@ -333,6 +334,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
if (retval == -ENOBUFS || retval == -ESRCH)
retval = 0;
}
+ mutex_unlock(&uevent_sock_mutex);
consume_skb(skb);
return retval;
@@ -431,8 +433,23 @@ static void zap_modalias_env(struct kobj_uevent_env *env)
len = strlen(env->envp[i]) + 1;
if (i != env->envp_idx - 1) {
+ /* @env->envp[] contains pointers to @env->buf[]
+ * with @env->buflen chars, and we are removing
+ * variable MODALIAS here pointed by @env->envp[i]
+ * with length @len as shown below:
+ *
+ * 0 @env->buf[] @env->buflen
+ * ---------------------------------------------
+ * ^ ^ ^ ^
+ * | |-> @len <-| target block |
+ * @env->envp[0] @env->envp[i] @env->envp[i + 1]
+ *
+ * so the "target block" indicated above is moved
+ * backward by @len, and its right size is
+ * @env->buflen - (@env->envp[i + 1] - @env->envp[0]).
+ */
memmove(env->envp[i], env->envp[i + 1],
- env->buflen - len);
+ env->buflen - (env->envp[i + 1] - env->envp[0]));
for (j = i; j < env->envp_idx - 1; j++)
env->envp[j] = env->envp[j + 1] - len;
@@ -466,6 +483,13 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
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__);
@@ -493,7 +517,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
}
/* skip the event, if the filter returns zero. */
if (uevent_ops && uevent_ops->filter)
- if (!uevent_ops->filter(kset, kobj)) {
+ if (!uevent_ops->filter(kobj)) {
pr_debug("kobject: '%s' (%p): %s: filter function "
"caused the event to drop!\n",
kobject_name(kobj), kobj, __func__);
@@ -502,7 +526,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
/* originating subsystem */
if (uevent_ops && uevent_ops->name)
- subsystem = uevent_ops->name(kset, kobj);
+ subsystem = uevent_ops->name(kobj);
else
subsystem = kobject_name(&kset->kobj);
if (!subsystem) {
@@ -546,7 +570,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
/* let the kset specific function add its stuff */
if (uevent_ops && uevent_ops->uevent) {
- retval = uevent_ops->uevent(kset, kobj, env);
+ retval = uevent_ops->uevent(kobj, env);
if (retval) {
pr_debug("kobject: '%s' (%p): %s: uevent() returned "
"%d\n", kobject_name(kobj), kobj,
@@ -567,10 +591,6 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
kobj->state_add_uevent_sent = 1;
break;
- case KOBJ_REMOVE:
- kobj->state_remove_uevent_sent = 1;
- break;
-
case KOBJ_UNBIND:
zap_modalias_env(env);
break;
@@ -579,16 +599,14 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
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);
+ retval = add_uevent_var(env, "SEQNUM=%llu",
+ atomic64_inc_return(&uevent_seqnum));
+ if (retval)
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 */
@@ -684,7 +702,8 @@ static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb,
int ret;
/* bump and prepare sequence number */
- ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum);
+ ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu",
+ atomic64_inc_return(&uevent_seqnum));
if (ret < 0 || (size_t)ret >= sizeof(buf))
return -ENOMEM;
ret++;
@@ -738,9 +757,7 @@ static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh,
return -EPERM;
}
- mutex_lock(&uevent_sock_mutex);
ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack);
- mutex_unlock(&uevent_sock_mutex);
return ret;
}
@@ -765,8 +782,7 @@ static int uevent_net_init(struct net *net)
ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
if (!ue_sk->sk) {
- printk(KERN_ERR
- "kobject_uevent: unable to create netlink socket!\n");
+ pr_err("kobject_uevent: unable to create netlink socket!\n");
kfree(ue_sk);
return -ENODEV;
}
@@ -810,3 +826,23 @@ static int __init kobject_uevent_init(void)
postcore_initcall(kobject_uevent_init);
#endif
+
+#ifdef CONFIG_UEVENT_HELPER
+static const struct ctl_table uevent_helper_sysctl_table[] = {
+ {
+ .procname = "hotplug",
+ .data = &uevent_helper,
+ .maxlen = UEVENT_HELPER_PATH_LEN,
+ .mode = 0644,
+ .proc_handler = proc_dostring,
+ },
+};
+
+static int __init init_uevent_helper_sysctl(void)
+{
+ register_sysctl_init("kernel", uevent_helper_sysctl_table);
+ return 0;
+}
+
+postcore_initcall(init_uevent_helper_sysctl);
+#endif
generated by cgit (git 2.34.1) at 2025-12-24 19:43:45 +0000