new helper: readlink_copy()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 10 deletions

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 9ae46b87470d..89026095f2b5 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -146,7 +146,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
         struct task_struct *task;
         void *ns;
         char name[50];
-        int len = -EACCES;
+        int res = -EACCES;
 
         task = get_proc_task(inode);
         if (!task)
@@ -155,24 +155,18 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
         if (!ptrace_may_access(task, PTRACE_MODE_READ))
                 goto out_put_task;
 
-        len = -ENOENT;
+        res = -ENOENT;
         ns = ns_ops->get(task);
         if (!ns)
                 goto out_put_task;
 
         snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
-        len = strlen(name);
-
-        if (len > buflen)
-                len = buflen;
-        if (copy_to_user(buffer, name, len))
-                len = -EFAULT;
-
+        res = readlink_copy(buffer, buflen, name);
         ns_ops->put(ns);
 out_put_task:
         put_task_struct(task);
 out:
-        return len;
+        return res;
 }
 
 static const struct inode_operations proc_ns_link_inode_operations = {