Merge tag 'efi-urgent-for-v5.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent

Pull EFI fixes from Ard Biesheuvel:

 - Fix the layering violation in the use of the EFI runtime services
   availability mask in users of the 'efivars' abstraction
 - Revert build fix for GCC v4.8 which is no longer supported
 - Some fixes for build issues found by Atish while working on RISC-V support
 - Avoid --whole-archive when linking the stub on arm64
 - Some x86 EFI stub cleanups from Arvind
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 76359cf..4621fb6 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -143,7 +143,7 @@
 
 core-y		+= arch/arm64/
 libs-y		:= arch/arm64/lib/ $(libs-y)
-core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 
 # Default target when executing plain make
 boot		:= arch/arm64/boot
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index c2f1d4e..feb7fe6 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -356,10 +356,7 @@
 
 static __init int efivars_pstore_init(void)
 {
-	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
-		return 0;
-
-	if (!efivars_kobject())
+	if (!efivars_kobject() || !efivar_supports_writes())
 		return 0;
 
 	if (efivars_pstore_disable)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5114cae..fdd1db0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -176,11 +176,13 @@
 static int generic_ops_register(void)
 {
 	generic_ops.get_variable = efi.get_variable;
-	generic_ops.set_variable = efi.set_variable;
-	generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
 	generic_ops.get_next_variable = efi.get_next_variable;
 	generic_ops.query_variable_store = efi_query_variable_store;
 
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
+		generic_ops.set_variable = efi.set_variable;
+		generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
+	}
 	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
 }
 
@@ -382,7 +384,8 @@
 		return -ENOMEM;
 	}
 
-	if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES)) {
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
+				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
 		efivar_ssdt_load();
 		error = generic_ops_register();
 		if (error)
@@ -416,7 +419,8 @@
 err_remove_group:
 	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
 err_unregister:
-	if (efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
+				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
 		generic_ops_unregister();
 err_put:
 	kobject_put(efi_kobj);
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 26528a4..dcea137 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -680,11 +680,8 @@
 	struct kobject *parent_kobj = efivars_kobject();
 	int error = 0;
 
-	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
-		return -ENODEV;
-
 	/* No efivars has been registered yet */
-	if (!parent_kobj)
+	if (!parent_kobj || !efivar_supports_writes())
 		return 0;
 
 	printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 4cce372e..75daaf2 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -6,8 +6,7 @@
 # enabled, even if doing so doesn't break the build.
 #
 cflags-$(CONFIG_X86_32)		:= -march=i386
-cflags-$(CONFIG_X86_64)		:= -mcmodel=small \
-				   $(call cc-option,-maccumulate-outgoing-args)
+cflags-$(CONFIG_X86_64)		:= -mcmodel=small
 cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ \
 				   -fPIC -fno-strict-aliasing -mno-red-zone \
 				   -mno-mmx -mno-sse -fshort-wchar \
diff --git a/drivers/firmware/efi/libstub/alignedmem.c b/drivers/firmware/efi/libstub/alignedmem.c
index cc89c4d..1de9878 100644
--- a/drivers/firmware/efi/libstub/alignedmem.c
+++ b/drivers/firmware/efi/libstub/alignedmem.c
@@ -44,7 +44,7 @@
 	*addr = ALIGN((unsigned long)alloc_addr, align);
 
 	if (slack > 0) {
-		int l = (alloc_addr % align) / EFI_PAGE_SIZE;
+		int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;
 
 		if (l) {
 			efi_bs_call(free_pages, alloc_addr, slack - l + 1);
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 3318ec3..a5a405d 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -122,23 +122,6 @@
 }
 
 /*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(unsigned long *image_addr,
-				 unsigned long *image_size,
-				 unsigned long *reserve_addr,
-				 unsigned long *reserve_size,
-				 unsigned long dram_base,
-				 efi_loaded_image_t *image);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
-
-/*
  * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
  * that is described in the PE/COFF header.  Most of the code is the same
  * for both archictectures, with the arch-specific code provided in the
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 2c9d422..85050f5 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -776,6 +776,22 @@
 			     unsigned long *load_size,
 			     unsigned long soft_limit,
 			     unsigned long hard_limit);
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image);
+
+asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
+					    unsigned long fdt_addr,
+					    unsigned long fdt_size);
 
 void efi_handle_post_ebs_state(void);
 
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 5a48d99..3672539 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -8,6 +8,7 @@
 
 #include <linux/efi.h>
 #include <linux/pci.h>
+#include <linux/stddef.h>
 
 #include <asm/efi.h>
 #include <asm/e820/types.h>
@@ -361,8 +362,6 @@
 	int options_size = 0;
 	efi_status_t status;
 	char *cmdline_ptr;
-	unsigned long ramdisk_addr;
-	unsigned long ramdisk_size;
 
 	efi_system_table = sys_table_arg;
 
@@ -390,8 +389,9 @@
 
 	hdr = &boot_params->hdr;
 
-	/* Copy the second sector to boot_params */
-	memcpy(&hdr->jump, image_base + 512, 512);
+	/* Copy the setup header from the second sector to boot_params */
+	memcpy(&hdr->jump, image_base + 512,
+	       sizeof(struct setup_header) - offsetof(struct setup_header, jump));
 
 	/*
 	 * Fill out some of the header fields ourselves because the
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 5f2a4d1..973eef2 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -1229,3 +1229,9 @@
 	return rv;
 }
 EXPORT_SYMBOL_GPL(efivars_unregister);
+
+int efivar_supports_writes(void)
+{
+	return __efivars && __efivars->ops->set_variable;
+}
+EXPORT_SYMBOL_GPL(efivar_supports_writes);
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 12c66f5..28bb568 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -201,6 +201,9 @@
 	sb->s_d_op		= &efivarfs_d_ops;
 	sb->s_time_gran         = 1;
 
+	if (!efivar_supports_writes())
+		sb->s_flags |= SB_RDONLY;
+
 	inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0, true);
 	if (!inode)
 		return -ENOMEM;
@@ -252,9 +255,6 @@
 
 static __init int efivarfs_init(void)
 {
-	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_VARIABLE_SERVICES))
-		return -ENODEV;
-
 	if (!efivars_kobject())
 		return -ENODEV;
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index bb35f33..05c47f8 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -994,6 +994,7 @@
 int efivars_unregister(struct efivars *efivars);
 struct kobject *efivars_kobject(void);
 
+int efivar_supports_writes(void);
 int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
 		void *data, bool duplicates, struct list_head *head);