Merge tag 'efi-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:

 - another missing RT_PROP table related fix, to ensure that the
   efivarfs pseudo filesystem fails gracefully if variable services
   are unsupported

 - use the correct alignment for literal EFI GUIDs

 - fix a use after unmap issue in the memreserve code

* tag 'efi-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: use 32-bit alignment for efi_guid_t literals
  firmware/efi: Fix a use after bug in efi_mem_reserve_persistent
  efivars: respect EFI_UNSUPPORTED return from firmware

Author: torvalds

drivers/firmware/efi/efi.c

@@ -927,7 +927,7 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 	}
 
 	/* first try to find a slot in an existing linked list entry */
-	for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
+	for (prsv = efi_memreserve_root->next; prsv; ) {
 		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 		if (index < rsv->size) {
@@ -937,6 +937,7 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 			memunmap(rsv);
 			return efi_mem_reserve_iomem(addr, size);
 		}
+		prsv = rsv->next;
 		memunmap(rsv);
 	}
 

drivers/firmware/efi/vars.c

@@ -484,6 +484,10 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
 				}
 			}
 
+			break;
+		case EFI_UNSUPPORTED:
+			err = -EOPNOTSUPP;
+			status = EFI_NOT_FOUND;
 			break;
 		case EFI_NOT_FOUND:
 			break;

include/linux/efi.h

@@ -72,8 +72,10 @@ typedef void *efi_handle_t;
  */
 typedef guid_t efi_guid_t __aligned(__alignof__(u32));
 
-#define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \
-	GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
+#define EFI_GUID(a, b, c, d...) (efi_guid_t){ {					\
+	(a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff,	\
+	(b) & 0xff, ((b) >> 8) & 0xff,						\
+	(c) & 0xff, ((c) >> 8) & 0xff, d } }
 
 /*
  * Generic EFI table header