Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
 "Four fixes:
   - fix a kexec crash on arm64
   - fix a reboot crash on some Android platforms
   - future-proof the code for upcoming ACPI 6.2 changes
   - fix a build warning on x86"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efibc: Replace variable set function in notifier call
  x86/efi: fix a -Wtype-limits compilation warning
  efi/bgrt: Drop BGRT status field reserved bits check
  efi/memreserve: deal with memreserve entries in unmapped memory

arch/x86/platform/efi/quirks.c

@@ -728,7 +728,7 @@ void efi_recover_from_page_fault(unsigned long phys_addr)
 	 * Address range 0x0000 - 0x0fff is always mapped in the efi_pgd, so
 	 * page faulting on these addresses isn't expected.
 	 */
-	if (phys_addr >= 0x0000 && phys_addr <= 0x0fff)
+	if (phys_addr <= 0x0fff)
 		return;
 
 	/*

drivers/firmware/efi/efi-bgrt.c

@@ -47,11 +47,6 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
 		       bgrt->version);
 		goto out;
 	}
-	if (bgrt->status & 0xfe) {
-		pr_notice("Ignoring BGRT: reserved status bits are non-zero %u\n",
-		       bgrt->status);
-		goto out;
-	}
 	if (bgrt->image_type != 0) {
 		pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
 		       bgrt->image_type);

drivers/firmware/efi/efi.c

@@ -1009,14 +1009,16 @@ 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) {
-		rsv = __va(prsv);
+		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 		if (index < rsv->size) {
 			rsv->entry[index].base = addr;
 			rsv->entry[index].size = size;
 
+			memunmap(rsv);
 			return 0;
 		}
+		memunmap(rsv);
 	}
 
 	/* no slot found - allocate a new linked list entry */
@@ -1024,7 +1026,13 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 	if (!rsv)
 		return -ENOMEM;
 
-	rsv->size = EFI_MEMRESERVE_COUNT(PAGE_SIZE);
+	/*
+	 * The memremap() call above assumes that a linux_efi_memreserve entry
+	 * never crosses a page boundary, so let's ensure that this remains true
+	 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
+	 * using SZ_4K explicitly in the size calculation below.
+	 */
+	rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
 	atomic_set(&rsv->count, 1);
 	rsv->entry[0].base = addr;
 	rsv->entry[0].size = size;

drivers/firmware/efi/efibc.c

@@ -43,11 +43,13 @@ static int efibc_set_variable(const char *name, const char *value)
 	efibc_str_to_str16(value, (efi_char16_t *)entry->var.Data);
 	memcpy(&entry->var.VendorGuid, &guid, sizeof(guid));
 
-	ret = efivar_entry_set(entry,
+	ret = efivar_entry_set_safe(entry->var.VariableName,
+				    entry->var.VendorGuid,
 				    EFI_VARIABLE_NON_VOLATILE
 				    | EFI_VARIABLE_BOOTSERVICE_ACCESS
 				    | EFI_VARIABLE_RUNTIME_ACCESS,
-			       size, entry->var.Data, NULL);
+				    false, size, entry->var.Data);
+
 	if (ret)
 		pr_err("failed to set %s EFI variable: 0x%x\n",
 		       name, ret);