ns proc: Add support for the ipc namespace

Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

3 files changed, 41 insertions, 0 deletions

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index b017181f1273..f18d6d58bf79 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -22,6 +22,9 @@ static const struct proc_ns_operations *ns_entries[] = {
 #ifdef CONFIG_UTS_NS
         &utsns_operations,
 #endif
+#ifdef CONFIG_IPC_NS
+        &ipcns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 52aa89df8a6d..a23f0b72a023 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -267,6 +267,7 @@ struct proc_ns_operations {
 };
 extern const struct proc_ns_operations netns_operations;
 extern const struct proc_ns_operations utsns_operations;
+extern const struct proc_ns_operations ipcns_operations;
 
 union proc_op {
         int (*proc_get_link)(struct inode *, struct path *);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 8054c8e5faf1..ce0a647869b1 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/mount.h>
 #include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 #include "util.h"
 
@@ -140,3 +141,39 @@ void put_ipc_ns(struct ipc_namespace *ns)
                 free_ipc_ns(ns);
         }
 }
+
+static void *ipcns_get(struct task_struct *task)
+{
+        struct ipc_namespace *ns = NULL;
+        struct nsproxy *nsproxy;
+
+        rcu_read_lock();
+        nsproxy = task_nsproxy(task);
+        if (nsproxy)
+                ns = get_ipc_ns(nsproxy->ipc_ns);
+        rcu_read_unlock();
+
+        return ns;
+}
+
+static void ipcns_put(void *ns)
+{
+        return put_ipc_ns(ns);
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, void *ns)
+{
+        /* Ditch state from the old ipc namespace */
+        exit_sem(current);
+        put_ipc_ns(nsproxy->ipc_ns);
+        nsproxy->ipc_ns = get_ipc_ns(ns);
+        return 0;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+        .name           = "ipc",
+        .type           = CLONE_NEWIPC,
+        .get            = ipcns_get,
+        .put            = ipcns_put,
+        .install        = ipcns_install,
+};