1 files changed, 90 insertions, 25 deletions

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 4f4f79532c6c..87f18aedd3bd 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -36,6 +36,7 @@
 #include <linux/inet.h>
 #include <linux/configfs.h>
 #include <linux/etherdevice.h>
+#include <linux/utsname.h>
 
 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
 MODULE_DESCRIPTION("Console driver for network interfaces");
@@ -84,6 +85,8 @@ static struct console netconsole_ext;
  *		Also, other parameters of a target may be modified at
  *		runtime only when it is disabled (enabled == 0).
  * @extended:	Denotes whether console is extended or not.
+ * @release:	Denotes whether kernel release version should be prepended
+ *		to the message. Depends on extended console.
  * @np:		The netpoll structure for this target.
  *		Contains the other userspace visible parameters:
  *		dev_name	(read-write)
@@ -101,6 +104,7 @@ struct netconsole_target {
 #endif
 	bool			enabled;
 	bool			extended;
+	bool			release;
 	struct netpoll		np;
 };
 
@@ -188,6 +192,15 @@ static struct netconsole_target *alloc_param_target(char *target_config)
 		target_config++;
 	}
 
+	if (*target_config == 'r') {
+		if (!nt->extended) {
+			pr_err("Netconsole configuration error. Release feature requires extended log message");
+			goto fail;
+		}
+		nt->release = true;
+		target_config++;
+	}
+
 	/* Parse parameters and setup netpoll */
 	err = netpoll_parse_options(&nt->np, target_config);
 	if (err)
@@ -222,6 +235,7 @@ static void free_param_target(struct netconsole_target *nt)
  *				|
  *				<target>/
  *				|	enabled
+ *				|	release
  *				|	dev_name
  *				|	local_port
  *				|	remote_port
@@ -246,27 +260,32 @@ static struct netconsole_target *to_target(struct config_item *item)
 
 static ssize_t enabled_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->enabled);
+	return sysfs_emit(buf, "%d\n", to_target(item)->enabled);
 }
 
 static ssize_t extended_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->extended);
+	return sysfs_emit(buf, "%d\n", to_target(item)->extended);
+}
+
+static ssize_t release_show(struct config_item *item, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", to_target(item)->release);
 }
 
 static ssize_t dev_name_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%s\n", to_target(item)->np.dev_name);
+	return sysfs_emit(buf, "%s\n", to_target(item)->np.dev_name);
 }
 
 static ssize_t local_port_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.local_port);
+	return sysfs_emit(buf, "%d\n", to_target(item)->np.local_port);
 }
 
 static ssize_t remote_port_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.remote_port);
+	return sysfs_emit(buf, "%d\n", to_target(item)->np.remote_port);
 }
 
 static ssize_t local_ip_show(struct config_item *item, char *buf)
@@ -274,9 +293,9 @@ static ssize_t local_ip_show(struct config_item *item, char *buf)
 	struct netconsole_target *nt = to_target(item);
 
 	if (nt->np.ipv6)
-		return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.local_ip.in6);
+		return sysfs_emit(buf, "%pI6c\n", &nt->np.local_ip.in6);
 	else
-		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
+		return sysfs_emit(buf, "%pI4\n", &nt->np.local_ip);
 }
 
 static ssize_t remote_ip_show(struct config_item *item, char *buf)
@@ -284,9 +303,9 @@ static ssize_t remote_ip_show(struct config_item *item, char *buf)
 	struct netconsole_target *nt = to_target(item);
 
 	if (nt->np.ipv6)
-		return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.remote_ip.in6);
+		return sysfs_emit(buf, "%pI6c\n", &nt->np.remote_ip.in6);
 	else
-		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
+		return sysfs_emit(buf, "%pI4\n", &nt->np.remote_ip);
 }
 
 static ssize_t local_mac_show(struct config_item *item, char *buf)
@@ -294,12 +313,12 @@ static ssize_t local_mac_show(struct config_item *item, char *buf)
 	struct net_device *dev = to_target(item)->np.dev;
 	static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
-	return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
+	return sysfs_emit(buf, "%pM\n", dev ? dev->dev_addr : bcast);
 }
 
 static ssize_t remote_mac_show(struct config_item *item, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%pM\n", to_target(item)->np.remote_mac);
+	return sysfs_emit(buf, "%pM\n", to_target(item)->np.remote_mac);
 }
 
 /*
@@ -314,17 +333,15 @@ static ssize_t enabled_store(struct config_item *item,
 {
 	struct netconsole_target *nt = to_target(item);
 	unsigned long flags;
-	int enabled;
+	bool enabled;
 	int err;
 
 	mutex_lock(&dynamic_netconsole_mutex);
-	err = kstrtoint(buf, 10, &enabled);
-	if (err < 0)
+	err = kstrtobool(buf, &enabled);
+	if (err)
 		goto out_unlock;
 
 	err = -EINVAL;
-	if (enabled < 0 || enabled > 1)
-		goto out_unlock;
 	if ((bool)enabled == nt->enabled) {
 		pr_info("network logging has already %s\n",
 			nt->enabled ? "started" : "stopped");
@@ -332,6 +349,11 @@ static ssize_t enabled_store(struct config_item *item,
 	}
 
 	if (enabled) {	/* true */
+		if (nt->release && !nt->extended) {
+			pr_err("Not enabling netconsole. Release feature requires extended log message");
+			goto out_unlock;
+		}
+
 		if (nt->extended && !console_is_registered(&netconsole_ext))
 			register_console(&netconsole_ext);
 
@@ -366,11 +388,11 @@ out_unlock:
 	return err;
 }
 
-static ssize_t extended_store(struct config_item *item, const char *buf,
-		size_t count)
+static ssize_t release_store(struct config_item *item, const char *buf,
+			     size_t count)
 {
 	struct netconsole_target *nt = to_target(item);
-	int extended;
+	bool release;
 	int err;
 
 	mutex_lock(&dynamic_netconsole_mutex);
@@ -381,14 +403,38 @@ static ssize_t extended_store(struct config_item *item, const char *buf,
 		goto out_unlock;
 	}
 
-	err = kstrtoint(buf, 10, &extended);
-	if (err < 0)
+	err = kstrtobool(buf, &release);
+	if (err)
 		goto out_unlock;
-	if (extended < 0 || extended > 1) {
+
+	nt->release = release;
+
+	mutex_unlock(&dynamic_netconsole_mutex);
+	return strnlen(buf, count);
+out_unlock:
+	mutex_unlock(&dynamic_netconsole_mutex);
+	return err;
+}
+
+static ssize_t extended_store(struct config_item *item, const char *buf,
+		size_t count)
+{
+	struct netconsole_target *nt = to_target(item);
+	bool extended;
+	int err;
+
+	mutex_lock(&dynamic_netconsole_mutex);
+	if (nt->enabled) {
+		pr_err("target (%s) is enabled, disable to update parameters\n",
+		       config_item_name(&nt->item));
 		err = -EINVAL;
 		goto out_unlock;
 	}
 
+	err = kstrtobool(buf, &extended);
+	if (err)
+		goto out_unlock;
+
 	nt->extended = extended;
 
 	mutex_unlock(&dynamic_netconsole_mutex);
@@ -576,10 +622,12 @@ CONFIGFS_ATTR(, local_ip);
 CONFIGFS_ATTR(, remote_ip);
 CONFIGFS_ATTR_RO(, local_mac);
 CONFIGFS_ATTR(, remote_mac);
+CONFIGFS_ATTR(, release);
 
 static struct configfs_attribute *netconsole_target_attrs[] = {
 	&attr_enabled,
 	&attr_extended,
+	&attr_release,
 	&attr_dev_name,
 	&attr_local_port,
 	&attr_remote_port,
@@ -772,9 +820,23 @@ static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
 	const char *header, *body;
 	int offset = 0;
 	int header_len, body_len;
+	const char *msg_ready = msg;
+	const char *release;
+	int release_len = 0;
 
-	if (msg_len <= MAX_PRINT_CHUNK) {
-		netpoll_send_udp(&nt->np, msg, msg_len);
+	if (nt->release) {
+		release = init_utsname()->release;
+		release_len = strlen(release) + 1;
+	}
+
+	if (msg_len + release_len <= MAX_PRINT_CHUNK) {
+		/* No fragmentation needed */
+		if (nt->release) {
+			scnprintf(buf, MAX_PRINT_CHUNK, "%s,%s", release, msg);
+			msg_len += release_len;
+			msg_ready = buf;
+		}
+		netpoll_send_udp(&nt->np, msg_ready, msg_len);
 		return;
 	}
 
@@ -792,7 +854,10 @@ static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
 	 * Transfer multiple chunks with the following extra header.
 	 * "ncfrag=<byte-offset>/<total-bytes>"
 	 */
-	memcpy(buf, header, header_len);
+	if (nt->release)
+		scnprintf(buf, MAX_PRINT_CHUNK, "%s,", release);
+	memcpy(buf + release_len, header, header_len);
+	header_len += release_len;
 
 	while (offset < body_len) {
 		int this_header = header_len;