[PATCH] uml: umid cleanup

This patch cleans up the umid code:

- The only_if_set argument to get_umid is gone.

- get_umid returns an empty string rather than NULL if there is no umid.

- umid_is_random is gone since its users went away.

- Some printfs were turned into printks because the code runs late enough
  that printk is working.

- Error paths were cleaned up.

- Some functions now return an error and let the caller print the error
  message rather than printing it themselves.  This eliminates the practice of
  passing a pointer to printf or printk in, depending on where in the boot
  process we are.

- Major tidying of not_dead_yet - mostly error path cleanup, plus a comment
  explaining why it doesn't react to errors the way you might expect.

- Calls to os_* interfaces that were moved under os are changed back to
  their native libc forms.

- snprintf, strlcpy, and their bounds-checking friends are used more often,
  replacing by-hand bounds checking in some places.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/um_arch.c

@@ -146,8 +146,8 @@ void set_cmdline(char *cmd)
 
 	if(CHOOSE_MODE(honeypot, 0)) return;
 
-	umid = get_umid(1);
-	if(umid != NULL){
+	umid = get_umid();
+	if(*umid != '\0'){
 		snprintf(argv1_begin, 
 			 (argv1_end - argv1_begin) * sizeof(*ptr), 
 			 "(%s) ", umid);

arch/um/kernel/umid.c

@@ -3,15 +3,13 @@
  * Licensed under the GPL
  */
 
-#include "linux/stddef.h"
-#include "linux/kernel.h"
 #include "asm/errno.h"
 #include "init.h"
 #include "os.h"
 #include "kern.h"
+#include "linux/kernel.h"
 
-/* Changed by set_umid_arg and umid_file_name */
-int umid_is_random = 0;
+/* Changed by set_umid_arg */
 static int umid_inited = 0;
 
 static int __init set_umid_arg(char *name, int *add)
@@ -22,11 +20,9 @@ static int __init set_umid_arg(char *name, int *add)
 		return 0;
 
 	*add = 0;
-	err = set_umid(name, printf);
-	if(err == -EEXIST){
+	err = set_umid(name);
+	if(err == -EEXIST)
 		printf("umid '%s' already in use\n", name);
-		umid_is_random = 1;
-	}
 	else if(!err)
 		umid_inited = 1;