[PATCH 4/4] Implement /proc/cmdline and /proc/mounts as symlinks.

[Jeremie Koenig]

* /proc/cmdline -> /proc/2/cmdline (process 2 is usually gnumach)

  This is not perfect, as the format of /proc/cmdline and /proc/*/cmdline
  are different on Linux.  Namely, the latter includes NUL bytes to
  separate subsequent arguments, while the former contains only spaces
  and a trailing newline.

* /proc/mounts -> /etc/mtab (push the problem to mount)

  Among other things, many parts of d-i want /proc/mounts. Implementing
  it the right way is non-trivial, though. In the meantime, we publish a
  symlink to /etc/mtab so that the user can fake it in whatever way they
  want. Furthermore I hope to be porting busybox mount soon, and use it
  to manage the mtab.
---
 procfs_dir.c          |    6 ++++++
 procfs_nonpid_files.c |   26 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/procfs_dir.c b/procfs_dir.c
index f76e6a4..f99f402 100644
--- a/procfs_dir.c
+++ b/procfs_dir.c
@@ -654,6 +654,12 @@ procfs_fill_root_dir(struct procfs_dir *dir, time_t 
timestamp)
   if ((err = procfs_create_loadavg (dir, &node, timestamp)) != 0)
     return err;
 
+  if ((err = procfs_create_cmdline (dir, &node, timestamp)) != 0)
+    return err;
+
+  if ((err = procfs_create_mounts (dir, &node, timestamp)) != 0)
+    return err;
+
   return 0;
 }
 
diff --git a/procfs_nonpid_files.c b/procfs_nonpid_files.c
index 2c1209e..8e88cf3 100644
--- a/procfs_nonpid_files.c
+++ b/procfs_nonpid_files.c
@@ -166,6 +166,32 @@ error_t procfs_create_loadavg (struct procfs_dir *dir,
   return err;
 }
 
+error_t procfs_create_cmdline (struct procfs_dir *dir, 
+                           struct node **node,
+                           time_t timestamp)
+{
+  struct procfs_dir_entry *dir_entry;
+  int err;
+
+  dir_entry = update_pid_entries (dir, "cmdline", timestamp, "2/cmdline");
+  err = procfs_create_node (dir_entry, "cmdline", node);
+
+  return err;
+}
+
+error_t procfs_create_mounts (struct procfs_dir *dir, 
+                           struct node **node,
+                           time_t timestamp)
+{
+  struct procfs_dir_entry *dir_entry;
+  int err;
+
+  dir_entry = update_pid_entries (dir, "mounts", timestamp, "/etc/mtab");
+  err = procfs_create_node (dir_entry, "mounts", node);
+
+  return err;
+}
+
 error_t get_uptime (struct timeval *uptime)
 {
   struct timeval boot_time, now;
-- 
1.7.1