Merge remote-tracking branch 'driver-core/driver-core-next'

8 files changed, 217 insertions, 36 deletions

diff --git a/Documentation/ABI/testing/sysfs-uevent b/Documentation/ABI/testing/sysfs-uevent
new file mode 100644
index 000000000000..aa39f8d7bcdf
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-uevent
@@ -0,0 +1,47 @@
+What:           /sys/.../uevent
+Date:           May 2017
+KernelVersion:  4.13
+Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:
+                Enable passing additional variables for synthetic uevents that
+                are generated by writing /sys/.../uevent file.
+
+                Recognized extended format is ACTION [UUID [KEY=VALUE ...].
+
+                The ACTION is compulsory - it is the name of the uevent action
+                ("add", "change", "remove"). There is no change compared to
+                previous functionality here. The rest of the extended format
+                is optional.
+
+                You need to pass UUID first before any KEY=VALUE pairs.
+                The UUID must be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+                format where 'x' is a hex digit. The UUID is considered to be
+                a transaction identifier so it's possible to use the same UUID
+                value for one or more synthetic uevents in which case we
+                logically group these uevents together for any userspace
+                listeners. The UUID value appears in uevent as
+                "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment
+                variable.
+
+                If UUID is not passed in, the generated synthetic uevent gains
+                "SYNTH_UUID=0" environment variable automatically.
+
+                The KEY=VALUE pairs can contain alphanumeric characters only.
+                It's possible to define zero or more pairs - each pair is then
+                delimited by a space character ' '. Each pair appears in
+                synthetic uevent as "SYNTH_ARG_KEY=VALUE". That means the KEY
+                name gains "SYNTH_ARG_" prefix to avoid possible collisions
+                with existing variables.
+
+                Example of valid sequence written to the uevent file:
+
+                    add fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed A=1 B=abc
+
+                This generates synthetic uevent including these variables:
+
+                    ACTION=add
+                    SYNTH_ARG_A=1
+                    SYNTH_ARG_B=abc
+                    SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed
+Users:
+                udev, userspace tools generating synthetic uevents
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 6470eb8088f4..f945f2f0ee06 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -648,10 +648,7 @@ static void remove_probe_files(struct bus_type *bus)
 static ssize_t uevent_store(struct device_driver *drv, const char *buf,
 			    size_t count)
 {
-	enum kobject_action action;
-
-	if (kobject_action_type(buf, count, &action) == 0)
-		kobject_uevent(&drv->p->kobj, action);
+	kobject_synth_uevent(&drv->p->kobj, buf, count);
 	return count;
 }
 static DRIVER_ATTR_WO(uevent);
@@ -868,10 +865,7 @@ static void klist_devices_put(struct klist_node *n)
 static ssize_t bus_uevent_store(struct bus_type *bus,
 				const char *buf, size_t count)
 {
-	enum kobject_action action;
-
-	if (kobject_action_type(buf, count, &action) == 0)
-		kobject_uevent(&bus->p->subsys.kobj, action);
+	kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);
 	return count;
 }
 static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index bbecaf9293be..6564339d7f59 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -981,12 +981,9 @@ out:
 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
-	enum kobject_action action;
+	if (kobject_synth_uevent(&dev->kobj, buf, count))
+		dev_err(dev, "uevent: failed to send synthetic uevent\n");
 
-	if (kobject_action_type(buf, count, &action) == 0)
-		kobject_uevent(&dev->kobj, action);
-	else
-		dev_err(dev, "uevent: unknown action-string\n");
 	return count;
 }
 static DEVICE_ATTR_RW(uevent);
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index a102152301c8..97332d094fe2 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -866,7 +866,7 @@ static ssize_t driver_override_store(struct device *dev,
 				     const char *buf, size_t count)
 {
 	struct platform_device *pdev = to_platform_device(dev);
-	char *driver_override, *old = pdev->driver_override, *cp;
+	char *driver_override, *old, *cp;
 
 	if (count > PATH_MAX)
 		return -EINVAL;
@@ -879,12 +879,15 @@ static ssize_t driver_override_store(struct device *dev,
 	if (cp)
 		*cp = '\0';
 
+	device_lock(dev);
+	old = pdev->driver_override;
 	if (strlen(driver_override)) {
 		pdev->driver_override = driver_override;
 	} else {
 		kfree(driver_override);
 		pdev->driver_override = NULL;
 	}
+	device_unlock(dev);
 
 	kfree(old);
 
@@ -895,8 +898,12 @@ static ssize_t driver_override_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
 	struct platform_device *pdev = to_platform_device(dev);
+	ssize_t len;
 
-	return sprintf(buf, "%s\n", pdev->driver_override);
+	device_lock(dev);
+	len = sprintf(buf, "%s\n", pdev->driver_override);
+	device_unlock(dev);
+	return len;
 }
 static DEVICE_ATTR_RW(driver_override);
 
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index ca85cb80e99a..eeab34b0f589 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -217,11 +217,9 @@ extern struct kobject *firmware_kobj;
 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 			char *envp[]);
+int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 
 __printf(2, 3)
 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 
-int kobject_action_type(const char *buf, size_t count,
-			enum kobject_action *type);
-
 #endif /* _KOBJECT_H_ */
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index c6f0f0d0e17e..aa02c328dff5 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -512,7 +512,7 @@ static inline void sysfs_notify_dirent(struct kernfs_node *kn)
 }
 
 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
-						   const unsigned char *name)
+						   const char *name)
 {
 	return kernfs_find_and_get(parent, name);
 }
diff --git a/kernel/module.c b/kernel/module.c
index 3803449ca219..e3e9dbba6a5b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1203,10 +1203,7 @@ static ssize_t store_uevent(struct module_attribute *mattr,
 			    struct module_kobject *mk,
 			    const char *buffer, size_t count)
 {
-	enum kobject_action action;
-
-	if (kobject_action_type(buffer, count, &action) == 0)
-		kobject_uevent(&mk->kobj, action);
+	kobject_synth_uevent(&mk->kobj, buffer, count);
 	return count;
 }
 
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 9a2b811966eb..719c155fce20 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -23,6 +23,8 @@
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
+#include <linux/uuid.h>
+#include <linux/ctype.h>
 #include <net/sock.h>
 #include <net/net_namespace.h>
 
@@ -52,19 +54,13 @@ static const char *kobject_actions[] = {
 	[KOBJ_OFFLINE] =	"offline",
 };
 
-/**
- * kobject_action_type - translate action string to numeric type
- *
- * @buf: buffer containing the action string, newline is ignored
- * @count: length of buffer
- * @type: pointer to the location to store the action type
- *
- * Returns 0 if the action string was recognized.
- */
-int kobject_action_type(const char *buf, size_t count,
-			enum kobject_action *type)
+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'))
@@ -73,11 +69,20 @@ int kobject_action_type(const char *buf, size_t 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) != 0)
+		if (strncmp(kobject_actions[action], buf, count_first) != 0)
 			continue;
-		if (kobject_actions[action][count] != '\0')
+		if (kobject_actions[action][count_first] != '\0')
 			continue;
+		if (args)
+			*args = args_start;
 		*type = action;
 		ret = 0;
 		break;
@@ -86,6 +91,142 @@ 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\n";
+		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\n";
+		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);
+		printk(KERN_WARNING "synth uevent: %s: %s",
+		       devpath ?: "unknown device",
+		       msg ?: "failed to send uevent");
+		kfree(devpath);
+	}
+	return r;
+}
+
 #ifdef CONFIG_NET
 static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
 {