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, 9 insertions, 6 deletions

diff --git a/daemon/command.c b/daemon/command.c
index 7c67d830..58390333 100644
--- a/daemon/command.c
+++ b/daemon/command.c
@@ -28,10 +28,13 @@
 
 #include "ignore-value.h"
 
+GUESTFSD_EXT_CMD(str_mount, mount);
+GUESTFSD_EXT_CMD(str_umount, umount);
+
 static inline void
 umount_ignore_fail (const char *path)
 {
-  ignore_value (command (NULL, NULL, "umount", path, NULL));
+  ignore_value (command (NULL, NULL, str_umount, path, NULL));
 }
 
 char *
@@ -81,15 +84,15 @@ do_command (char *const *argv)
     return NULL;
   }
 
-  r = command (NULL, NULL, "mount", "--bind", "/dev", sysroot_dev, NULL);
+  r = command (NULL, NULL, str_mount, "--bind", "/dev", sysroot_dev, NULL);
   dev_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/dev/pts", sysroot_dev_pts, NULL);
+  r = command (NULL, NULL, str_mount, "--bind", "/dev/pts", sysroot_dev_pts, NULL);
   dev_pts_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/proc", sysroot_proc, NULL);
+  r = command (NULL, NULL, str_mount, "--bind", "/proc", sysroot_proc, NULL);
   proc_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/selinux", sysroot_selinux, NULL);
+  r = command (NULL, NULL, str_mount, "--bind", "/selinux", sysroot_selinux, NULL);
   selinux_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/sys", sysroot_sys, NULL);
+  r = command (NULL, NULL, str_mount, "--bind", "/sys", sysroot_sys, NULL);
   sys_ok = r != -1;
 
   CHROOT_IN;