2 files changed, 20 insertions, 0 deletions

diff --git a/ipc/util.c b/ipc/util.c
index 4ed5a17dd06f..3783b7991cc7 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -747,9 +747,16 @@ int ipc_parse_version(int *cmd)
 #ifdef CONFIG_PROC_FS
 struct ipc_proc_iter {
         struct ipc_namespace *ns;
+        struct pid_namespace *pid_ns;
         struct ipc_proc_iface *iface;
 };
 
+struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s)
+{
+        struct ipc_proc_iter *iter = s->private;
+        return iter->pid_ns;
+}
+
 /*
  * This routine locks the ipc structure found at least at position pos.
  */
@@ -872,6 +879,7 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
 
         iter->iface = PDE_DATA(inode);
         iter->ns    = get_ipc_ns(current->nsproxy->ipc_ns);
+        iter->pid_ns = get_pid_ns(task_active_pid_ns(current));
 
         return 0;
 }
@@ -881,6 +889,7 @@ static int sysvipc_proc_release(struct inode *inode, struct file *file)
         struct seq_file *seq = file->private_data;
         struct ipc_proc_iter *iter = seq->private;
         put_ipc_ns(iter->ns);
+        put_pid_ns(iter->pid_ns);
         return seq_release_private(inode, file);
 }
 
diff --git a/ipc/util.h b/ipc/util.h
index 959c10eb9cc1..e39ed9705f99 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -23,6 +23,7 @@ int msg_init(void);
 void shm_init(void);
 
 struct ipc_namespace;
+struct pid_namespace;
 
 #ifdef CONFIG_POSIX_MQUEUE
 extern void mq_clear_sbinfo(struct ipc_namespace *ns);
@@ -86,6 +87,7 @@ int ipc_init_ids(struct ipc_ids *);
 #ifdef CONFIG_PROC_FS
 void __init ipc_init_proc_interface(const char *path, const char *header,
                 int ids, int (*show)(struct seq_file *, void *));
+struct pid_namespace *ipc_seq_pid_ns(struct seq_file *);
 #else
 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
 #endif
@@ -150,6 +152,15 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
                                              struct ipc_ids *ids, int id, int cmd,
                                              struct ipc64_perm *perm, int extra_perm);
 
+static inline void ipc_update_pid(struct pid **pos, struct pid *pid)
+{
+        struct pid *old = *pos;
+        if (old != pid) {
+                *pos = get_pid(pid);
+                put_pid(old);
+        }
+}
+
 #ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
 /* On IA-64, we always use the "64-bit version" of the IPC structures.  */
 # define ipc_parse_version(cmd) IPC_64