kdb: Remove the ll command

Recently some code inspection was done after fixing a problem with
kmalloc used while in the kernel debugger context (which is not
legal), and it turned up the fact that kdb ll command will oops the
kernel.

Given that there have been zero bug reports on the command combined
with the fact it will oops the kernel it is clearly not being used.
Instead of fixing it, it will be removed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

kernel/debug/kdb/kdb_main.c

@@ -2362,69 +2362,6 @@ static int kdb_pid(int argc, const char **argv)
 	return 0;
 }
 
-/*
- * kdb_ll - This function implements the 'll' command which follows a
- *	linked list and executes an arbitrary command for each
- *	element.
- */
-static int kdb_ll(int argc, const char **argv)
-{
-	int diag = 0;
-	unsigned long addr;
-	long offset = 0;
-	unsigned long va;
-	unsigned long linkoffset;
-	int nextarg;
-	const char *command;
-
-	if (argc != 3)
-		return KDB_ARGCOUNT;
-
-	nextarg = 1;
-	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
-	if (diag)
-		return diag;
-
-	diag = kdbgetularg(argv[2], &linkoffset);
-	if (diag)
-		return diag;
-
-	/*
-	 * Using the starting address as
-	 * the first element in the list, and assuming that
-	 * the list ends with a null pointer.
-	 */
-
-	va = addr;
-	command = kdb_strdup(argv[3], GFP_KDB);
-	if (!command) {
-		kdb_printf("%s: cannot duplicate command\n", __func__);
-		return 0;
-	}
-	/* Recursive use of kdb_parse, do not use argv after this point */
-	argv = NULL;
-
-	while (va) {
-		char buf[80];
-
-		if (KDB_FLAG(CMD_INTERRUPT))
-			goto out;
-
-		sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va);
-		diag = kdb_parse(buf);
-		if (diag)
-			goto out;
-
-		addr = va + linkoffset;
-		if (kdb_getword(&va, addr, sizeof(va)))
-			goto out;
-	}
-
-out:
-	kfree(command);
-	return diag;
-}
-
 static int kdb_kgdb(int argc, const char **argv)
 {
 	return KDB_CMD_KGDB;
@@ -2866,8 +2803,6 @@ static void __init kdb_inittab(void)
 	kdb_register_repeat("btt", kdb_bt, "<vaddr>",
 	  "Backtrace process given its struct task address", 0,
 			    KDB_REPEAT_NONE);
-	kdb_register_repeat("ll", kdb_ll, "<first-element> <linkoffset> <cmd>",
-	  "Execute cmd for each element in linked list", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("env", kdb_env, "",
 	  "Show environment variables", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("set", kdb_set, "",