daemon: collect list of called external commands

guestfsd calls many different tools. Keeping track of all of them is
error prone. This patch introduces a new helper macro to put the command
string into its own ELF section:

GUESTFSD_EXT_CMD(C_variable, command_name);

This syntax makes it still possible to grep for used command names.

The actual usage of the collected list could be like this:

  objcopy -j .guestfsd_ext_cmds -O binary daemon/guestfsd /dev/stdout |
  tr '\0' '\n' | sort -u

The resulting output will be used to tell mkinitrd which programs to
copy into the initrd.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

RWMJ:
 - Move str_vgchange at request of author.
 - Fix snprintf call in daemon/debug.c

1 files changed, 2 insertions, 1 deletions

diff --git a/daemon/9p.c b/daemon/9p.c
index 8c0eeb68..49efafc1 100644
--- a/daemon/9p.c
+++ b/daemon/9p.c
@@ -33,6 +33,7 @@
 #include "actions.h"
 
 #define BUS_PATH "/sys/bus/virtio/drivers/9pnet_virtio"
+GUESTFSD_EXT_CMD(str_mount, mount);
 
 static char *read_whole_file (const char *filename);
 
@@ -211,7 +212,7 @@ do_mount_9p (const char *mount_tag, const char *mountpoint, const char *options)
   }
 
   r = command (NULL, &err,
-               "mount", "-o", opts, "-t", "9p", mount_tag, mp, NULL);
+               str_mount, "-o", opts, "-t", "9p", mount_tag, mp, NULL);
   if (r == -1) {
     reply_with_error ("%s on %s: %s", mount_tag, mountpoint, err);
     goto out;