[PATCH v3 02/11] syslog_ns: add syslog_ns into user_namespace

[Rui Xiang <rui.xiang@huawei.com>]

Add a syslog_ns pointer to user_namespace, and make
syslog_ns per user_namespace, not global.

Since syslog_ns is assigned to user_ns, we can have
full capabilities in new user_ns to create a new syslog_ns.

Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
---
 include/linux/syslog.h         | 5 +++++
 include/linux/user_namespace.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/include/linux/syslog.h b/include/linux/syslog.h
index 425fafe..62ce47f 100644
--- a/include/linux/syslog.h
+++ b/include/linux/syslog.h
@@ -90,6 +90,11 @@ struct syslog_namespace {
 	size_t syslog_partial;
 
 	int dmesg_restrict;
+
+	/*
+	 * user namespace which owns this syslog ns.
+	 */
+	struct user_namespace *owner;
 };
 
 static inline struct syslog_namespace *get_syslog_ns(
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index b6b215f..ce2de5b 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -28,6 +28,7 @@ struct user_namespace {
 	unsigned int		proc_inum;
 	bool			may_mount_sysfs;
 	bool			may_mount_proc;
+	struct syslog_namespace *syslog_ns;
 };
 
 extern struct user_namespace init_user_ns;
-- 
1.8.2.2