Driver core: accept all valid action-strings in uevent-trigger

This allows the uevent file to handle any type of uevent action to be
triggered by userspace instead of just the "add" uevent.


Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 47 insertions, 31 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 0455aa78fa13..91a0367d583e 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -24,6 +24,8 @@
 #include "base.h"
 #include "power/power.h"
 
+extern const char *kobject_actions[];
+
 int (*platform_notify)(struct device * dev) = NULL;
 int (*platform_notify_remove)(struct device * dev) = NULL;
 
@@ -303,10 +305,25 @@ out:
 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
                             const char *buf, size_t count)
 {
-        if (memcmp(buf, "add", 3) != 0)
-                dev_err(dev, "uevent: unsupported action-string; this will "
-                        "be ignored in a future kernel version");
+        size_t len = count;
+        enum kobject_action action;
+
+        if (len && buf[len-1] == '\n')
+                len--;
+
+        for (action = 0; action < KOBJ_MAX; action++) {
+                if (strncmp(kobject_actions[action], buf, len) != 0)
+                        continue;
+                if (kobject_actions[action][len] != '\0')
+                        continue;
+                kobject_uevent(&dev->kobj, action);
+                goto out;
+        }
+
+        dev_err(dev, "uevent: unsupported action-string; this will "
+                     "be ignored in a future kernel version\n");
         kobject_uevent(&dev->kobj, KOBJ_ADD);
+out:
         return count;
 }
 
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 06cbf41d32d2..aa2fe22b1baa 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -36,15 +36,24 @@ extern char uevent_helper[];
 /* counter to tag the uevent, read only except for the kobject core */
 extern u64 uevent_seqnum;
 
-/* the actions here must match the proper string in lib/kobject_uevent.c */
-typedef int __bitwise kobject_action_t;
+/*
+ * The actions here must match the index to the string array
+ * in lib/kobject_uevent.c
+ *
+ * Do not add new actions here without checking with the driver-core
+ * maintainers. Action strings are not meant to express subsystem
+ * or device specific properties. In most cases you want to send a
+ * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
+ * specific variables added to the event environment.
+ */
 enum kobject_action {
-        KOBJ_ADD        = (__force kobject_action_t) 0x01,      /* exclusive to core */
-        KOBJ_REMOVE     = (__force kobject_action_t) 0x02,      /* exclusive to core */
-        KOBJ_CHANGE     = (__force kobject_action_t) 0x03,      /* device state change */
-        KOBJ_OFFLINE    = (__force kobject_action_t) 0x04,      /* device offline */
-        KOBJ_ONLINE     = (__force kobject_action_t) 0x05,      /* device online */
-        KOBJ_MOVE       = (__force kobject_action_t) 0x06,      /* device move */
+        KOBJ_ADD,
+        KOBJ_REMOVE,
+        KOBJ_CHANGE,
+        KOBJ_MOVE,
+        KOBJ_ONLINE,
+        KOBJ_OFFLINE,
+        KOBJ_MAX
 };
 
 struct kobject {
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index bd5ecbbafab1..6a80c784a8fb 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -33,25 +33,15 @@ static DEFINE_SPINLOCK(sequence_lock);
 static struct sock *uevent_sock;
 #endif
 
-static char *action_to_string(enum kobject_action action)
-{
-        switch (action) {
-        case KOBJ_ADD:
-                return "add";
-        case KOBJ_REMOVE:
-                return "remove";
-        case KOBJ_CHANGE:
-                return "change";
-        case KOBJ_OFFLINE:
-                return "offline";
-        case KOBJ_ONLINE:
-                return "online";
-        case KOBJ_MOVE:
-                return "move";
-        default:
-                return NULL;
-        }
-}
+/* the strings here must match the enum in include/linux/kobject.h */
+const char *kobject_actions[] = {
+        "add",
+        "remove",
+        "change",
+        "move",
+        "online",
+        "offline",
+};
 
 /**
  * kobject_uevent_env - send an uevent with environmental data
@@ -83,7 +73,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 
         pr_debug("%s\n", __FUNCTION__);
 
-        action_string = action_to_string(action);
+        action_string = kobject_actions[action];
         if (!action_string) {
                 pr_debug("kobject attempted to send uevent without action_string!\n");
                 return -EINVAL;