[PATCH] efivars: check that it's enabled

From: "Randy.Dunlap" <rddunlap@osdl.org>

EFI-enabled kernels crash on non-EFI machines.  efivars_init() and
efivars_exit() need to check efi_enabled instead of assuming that the
system is using EFI.

arch/i386/kernel/setup.c

@@ -65,6 +65,7 @@ static inline char * __init machine_specific_memory_setup(void);
 
 #ifdef CONFIG_EFI
 int efi_enabled = 0;
+EXPORT_SYMBOL(efi_enabled);
 #endif
 
 /* cpu data as detected by the assembly code in head.S */

drivers/firmware/efivars.c

@@ -664,6 +664,9 @@ efivars_init(void)
 	unsigned long variable_name_size = 1024;
 	int i, rc = 0, error = 0;
 
+	if (!efi_enabled)
+		return -ENODEV;
+
 	printk(KERN_INFO "EFI Variables Facility v%s\n", EFIVARS_VERSION);
 
 	/*
@@ -733,6 +736,9 @@ efivars_exit(void)
 {
 	struct list_head *pos, *n;
 
+	if (!efi_enabled)
+		return;
+
 	list_for_each_safe(pos, n, &efivar_list)
 		efivar_unregister(get_efivar_entry(pos));