20 files changed, 209 insertions, 67 deletions

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 394db40ed374..2b4c39fdfa91 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -151,6 +151,16 @@ config APPLE_PROPERTIES
 
 	  If unsure, say Y if you have a Mac.  Otherwise N.
 
+config RESET_ATTACK_MITIGATION
+	bool "Reset memory attack mitigation"
+	depends on EFI_STUB
+	help
+	  Request that the firmware clear the contents of RAM after a reboot
+	  using the TCG Platform Reset Attack Mitigation specification. This
+	  protects against an attacker forcibly rebooting the system while it
+	  still contains secrets in RAM, booting another OS and extracting the
+	  secrets.
+
 endmenu
 
 config UEFI_CPER
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 0329d319d89a..269501dfba53 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for linux kernel
 #
diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c
index c473f4c5ca34..9f6bcf173b0e 100644
--- a/drivers/firmware/efi/apple-properties.c
+++ b/drivers/firmware/efi/apple-properties.c
@@ -18,8 +18,8 @@
 #define pr_fmt(fmt) "apple-properties: " fmt
 
 #include <linux/bootmem.h>
-#include <linux/dmi.h>
 #include <linux/efi.h>
+#include <linux/platform_data/x86/apple.h>
 #include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/ucs2_string.h>
@@ -191,8 +191,7 @@ static int __init map_properties(void)
 	u64 pa_data;
 	int ret;
 
-	if (!dmi_match(DMI_SYS_VENDOR, "Apple Inc.") &&
-	    !dmi_match(DMI_SYS_VENDOR, "Apple Computer, Inc."))
+	if (!x86_apple_machine)
 		return 0;
 
 	pa_data = boot_params.hdr.setup_data;
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index 1027d7b44358..80d1a885def5 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -145,6 +145,9 @@ static int __init uefi_init(void)
 					 sizeof(efi_config_table_t),
 					 arch_tables);
 
+	if (!retval)
+		efi.config_table = (unsigned long)efi.systab->tables;
+
 	early_memunmap(config_tables, table_size);
 out:
 	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
@@ -159,6 +162,7 @@ static __init int is_usable_memory(efi_memory_desc_t *md)
 	switch (md->type) {
 	case EFI_LOADER_CODE:
 	case EFI_LOADER_DATA:
+	case EFI_ACPI_RECLAIM_MEMORY:
 	case EFI_BOOT_SERVICES_CODE:
 	case EFI_BOOT_SERVICES_DATA:
 	case EFI_CONVENTIONAL_MEMORY:
@@ -211,6 +215,10 @@ static __init void reserve_regions(void)
 
 			if (!is_usable_memory(md))
 				memblock_mark_nomap(paddr, size);
+
+			/* keep ACPI reclaim memory intact for kexec etc. */
+			if (md->type == EFI_ACPI_RECLAIM_MEMORY)
+				memblock_reserve(paddr, size);
 		}
 	}
 }
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 48a8f69da42a..d2fcafcea07e 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -534,7 +534,7 @@ static void
 cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata,
 			   int sec_no)
 {
-	uuid_le *sec_type = (uuid_le *)gdata->section_type;
+	guid_t *sec_type = (guid_t *)gdata->section_type;
 	__u16 severity;
 	char newpfx[64];
 
@@ -545,12 +545,12 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
 	printk("%s""Error %d, type: %s\n", pfx, sec_no,
 	       cper_severity_str(severity));
 	if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
-		printk("%s""fru_id: %pUl\n", pfx, (uuid_le *)gdata->fru_id);
+		printk("%s""fru_id: %pUl\n", pfx, gdata->fru_id);
 	if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
 		printk("%s""fru_text: %.20s\n", pfx, gdata->fru_text);
 
 	snprintf(newpfx, sizeof(newpfx), "%s%s", pfx, INDENT_SP);
-	if (!uuid_le_cmp(*sec_type, CPER_SEC_PROC_GENERIC)) {
+	if (guid_equal(sec_type, &CPER_SEC_PROC_GENERIC)) {
 		struct cper_sec_proc_generic *proc_err = acpi_hest_get_payload(gdata);
 
 		printk("%s""section_type: general processor error\n", newpfx);
@@ -558,7 +558,7 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
 			cper_print_proc_generic(newpfx, proc_err);
 		else
 			goto err_section_too_small;
-	} else if (!uuid_le_cmp(*sec_type, CPER_SEC_PLATFORM_MEM)) {
+	} else if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
 		struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
 
 		printk("%s""section_type: memory error\n", newpfx);
@@ -568,7 +568,7 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
 				       gdata->error_data_length);
 		else
 			goto err_section_too_small;
-	} else if (!uuid_le_cmp(*sec_type, CPER_SEC_PCIE)) {
+	} else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
 		struct cper_sec_pcie *pcie = acpi_hest_get_payload(gdata);
 
 		printk("%s""section_type: PCIe error\n", newpfx);
@@ -606,7 +606,6 @@ void cper_estatus_print(const char *pfx,
 			const struct acpi_hest_generic_status *estatus)
 {
 	struct acpi_hest_generic_data *gdata;
-	unsigned int data_len;
 	int sec_no = 0;
 	char newpfx[64];
 	__u16 severity;
@@ -617,14 +616,10 @@ void cper_estatus_print(const char *pfx,
 		       "It has been corrected by h/w "
 		       "and requires no further action");
 	printk("%s""event severity: %s\n", pfx, cper_severity_str(severity));
-	data_len = estatus->data_length;
-	gdata = (struct acpi_hest_generic_data *)(estatus + 1);
 	snprintf(newpfx, sizeof(newpfx), "%s%s", pfx, INDENT_SP);
 
-	while (data_len >= acpi_hest_get_size(gdata)) {
+	apei_estatus_for_each_section(estatus, gdata) {
 		cper_estatus_print_section(newpfx, gdata, sec_no);
-		data_len -= acpi_hest_get_record_size(gdata);
-		gdata = acpi_hest_get_next(gdata);
 		sec_no++;
 	}
 }
@@ -653,15 +648,12 @@ int cper_estatus_check(const struct acpi_hest_generic_status *estatus)
 	if (rc)
 		return rc;
 	data_len = estatus->data_length;
-	gdata = (struct acpi_hest_generic_data *)(estatus + 1);
 
-	while (data_len >= acpi_hest_get_size(gdata)) {
+	apei_estatus_for_each_section(estatus, gdata) {
 		gedata_len = acpi_hest_get_error_length(gdata);
 		if (gedata_len > data_len - acpi_hest_get_size(gdata))
 			return -EINVAL;
-
 		data_len -= acpi_hest_get_record_size(gdata);
-		gdata = acpi_hest_get_next(gdata);
 	}
 	if (data_len)
 		return -EINVAL;
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c
index b58233e4ed71..50793fda7819 100644
--- a/drivers/firmware/efi/efi-bgrt.c
+++ b/drivers/firmware/efi/efi-bgrt.c
@@ -27,26 +27,6 @@ struct bmp_header {
 	u32 size;
 } __packed;
 
-static bool efi_bgrt_addr_valid(u64 addr)
-{
-	efi_memory_desc_t *md;
-
-	for_each_efi_memory_desc(md) {
-		u64 size;
-		u64 end;
-
-		if (md->type != EFI_BOOT_SERVICES_DATA)
-			continue;
-
-		size = md->num_pages << EFI_PAGE_SHIFT;
-		end = md->phys_addr + size;
-		if (addr >= md->phys_addr && addr < end)
-			return true;
-	}
-
-	return false;
-}
-
 void __init efi_bgrt_init(struct acpi_table_header *table)
 {
 	void *image;
@@ -85,7 +65,7 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
 		goto out;
 	}
 
-	if (!efi_bgrt_addr_valid(bgrt->image_address)) {
+	if (efi_mem_type(bgrt->image_address) != EFI_BOOT_SERVICES_DATA) {
 		pr_notice("Ignoring BGRT: invalid image address\n");
 		goto out;
 	}
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 045d6d311bde..f70febf680c3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -55,6 +55,25 @@ struct efi __read_mostly efi = {
 };
 EXPORT_SYMBOL(efi);
 
+static unsigned long *efi_tables[] = {
+	&efi.mps,
+	&efi.acpi,
+	&efi.acpi20,
+	&efi.smbios,
+	&efi.smbios3,
+	&efi.sal_systab,
+	&efi.boot_info,
+	&efi.hcdp,
+	&efi.uga,
+	&efi.uv_systab,
+	&efi.fw_vendor,
+	&efi.runtime,
+	&efi.config_table,
+	&efi.esrt,
+	&efi.properties_table,
+	&efi.mem_attr_table,
+};
+
 static bool disable_runtime;
 static int __init setup_noefi(char *arg)
 {
@@ -179,7 +198,7 @@ static umode_t efi_attr_is_visible(struct kobject *kobj,
 	return attr->mode;
 }
 
-static struct attribute_group efi_subsys_attr_group = {
+static const struct attribute_group efi_subsys_attr_group = {
 	.attrs = efi_subsys_attrs,
 	.is_visible = efi_attr_is_visible,
 };
@@ -522,6 +541,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 			if (seed != NULL) {
 				add_device_randomness(seed->bits, seed->size);
 				early_memunmap(seed, sizeof(*seed) + size);
+				pr_notice("seeding entropy pool\n");
 			} else {
 				pr_err("Could not map UEFI random seed!\n");
 			}
@@ -791,19 +811,19 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 }
 
 /*
+ * IA64 has a funky EFI memory map that doesn't work the same way as
+ * other architectures.
+ */
+#ifndef CONFIG_IA64
+/*
  * efi_mem_attributes - lookup memmap attributes for physical address
  * @phys_addr: the physical address to lookup
  *
  * Search in the EFI memory map for the region covering
  * @phys_addr. Returns the EFI memory attributes if the region
  * was found in the memory map, 0 otherwise.
- *
- * Despite being marked __weak, most architectures should *not*
- * override this function. It is __weak solely for the benefit
- * of ia64 which has a funky EFI memory map that doesn't work
- * the same way as other architectures.
  */
-u64 __weak efi_mem_attributes(unsigned long phys_addr)
+u64 efi_mem_attributes(unsigned long phys_addr)
 {
 	efi_memory_desc_t *md;
 
@@ -819,6 +839,31 @@ u64 __weak efi_mem_attributes(unsigned long phys_addr)
 	return 0;
 }
 
+/*
+ * efi_mem_type - lookup memmap type for physical address
+ * @phys_addr: the physical address to lookup
+ *
+ * Search in the EFI memory map for the region covering @phys_addr.
+ * Returns the EFI memory type if the region was found in the memory
+ * map, EFI_RESERVED_TYPE (zero) otherwise.
+ */
+int efi_mem_type(unsigned long phys_addr)
+{
+	const efi_memory_desc_t *md;
+
+	if (!efi_enabled(EFI_MEMMAP))
+		return -ENOTSUPP;
+
+	for_each_efi_memory_desc(md) {
+		if ((md->phys_addr <= phys_addr) &&
+		    (phys_addr < (md->phys_addr +
+				  (md->num_pages << EFI_PAGE_SHIFT))))
+			return md->type;
+	}
+	return -EINVAL;
+}
+#endif
+
 int efi_status_to_err(efi_status_t status)
 {
 	int err;
@@ -855,6 +900,20 @@ int efi_status_to_err(efi_status_t status)
 	return err;
 }
 
+bool efi_is_table_address(unsigned long phys_addr)
+{
+	unsigned int i;
+
+	if (phys_addr == EFI_INVALID_TABLE_ADDR)
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
+		if (*(efi_tables[i]) == phys_addr)
+			return true;
+
+	return false;
+}
+
 #ifdef CONFIG_KEXEC
 static int update_efi_random_seed(struct notifier_block *nb,
 				  unsigned long code, void *unused)
@@ -867,7 +926,7 @@ static int update_efi_random_seed(struct notifier_block *nb,
 
 	seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB);
 	if (seed != NULL) {
-		size = min(seed->size, 32U);
+		size = min(seed->size, EFI_RANDOM_SEED_SIZE);
 		memunmap(seed);
 	} else {
 		pr_err("Could not map UEFI random seed!\n");
diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
index 8554d7aec31c..bd7ed3c1148a 100644
--- a/drivers/firmware/efi/esrt.c
+++ b/drivers/firmware/efi/esrt.c
@@ -230,7 +230,7 @@ static umode_t esrt_attr_is_visible(struct kobject *kobj,
 	return attr->mode;
 }
 
-static struct attribute_group esrt_attr_group = {
+static const struct attribute_group esrt_attr_group = {
 	.attrs = esrt_attrs,
 	.is_visible = esrt_attr_is_visible,
 };
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 37e24f525162..adaa4a964f0c 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # The stub may be linked into the kernel proper or into a separate boot binary,
 # but in either case, it executes before the kernel does (with MMU disabled) so
@@ -10,7 +11,7 @@ cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ -O2 \
 				   -fPIC -fno-strict-aliasing -mno-red-zone \
 				   -mno-mmx -mno-sse
 
-cflags-$(CONFIG_ARM64)		:= $(subst -pg,,$(KBUILD_CFLAGS))
+cflags-$(CONFIG_ARM64)		:= $(subst -pg,,$(KBUILD_CFLAGS)) -fpie
 cflags-$(CONFIG_ARM)		:= $(subst -pg,,$(KBUILD_CFLAGS)) \
 				   -fno-builtin -fpic -mno-single-pic-base
 
@@ -30,15 +31,17 @@ OBJECT_FILES_NON_STANDARD	:= y
 KCOV_INSTRUMENT			:= n
 
 lib-y				:= efi-stub-helper.o gop.o secureboot.o
+lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o
 
 # include the stub's generic dependencies from lib/ when building for ARM/arm64
-arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
+arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
+arm-deps-$(CONFIG_ARM64) += sort.c
 
 $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
 lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o string.o random.o \
-				   $(patsubst %.c,lib-%.o,$(arm-deps))
+				   $(patsubst %.c,lib-%.o,$(arm-deps-y))
 
 lib-$(CONFIG_ARM)		+= arm32-stub.o
 lib-$(CONFIG_ARM64)		+= arm64-stub.o
@@ -89,5 +92,4 @@ quiet_cmd_stubcopy = STUBCPY $@
 # explicitly by the decompressor linker script.
 #
 STUBCOPY_FLAGS-$(CONFIG_ARM)	+= --rename-section .data=.data.efistub
-STUBCOPY_RM-$(CONFIG_ARM)	+= -R ___ksymtab+sort -R ___kcrctab+sort
 STUBCOPY_RELOC-$(CONFIG_ARM)	:= R_ARM_ABS
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 8181ac179d14..01a9d78ee415 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -192,6 +192,9 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 		goto fail_free_cmdline;
 	}
 
+	/* Ask the firmware to clear memory on unclean shutdown */
+	efi_enable_reset_attack_mitigation(sys_table);
+
 	secure_boot = efi_get_secureboot(sys_table);
 
 	/*
@@ -235,7 +238,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 
 	efi_random_get_seed(sys_table);
 
-	if (!nokaslr()) {
+	/* hibernation expects the runtime regions to stay in the same place */
+	if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) {
 		/*
 		 * Randomize the base of the UEFI runtime services region.
 		 * Preserve the 2 MB alignment of the region by taking a
@@ -346,7 +350,9 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 	 * The easiest way to find adjacent regions is to sort the memory map
 	 * before traversing it.
 	 */
-	sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, NULL);
+	if (IS_ENABLED(CONFIG_ARM64))
+		sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc,
+		     NULL);
 
 	for (l = 0; l < map_size; l += desc_size, prev = in) {
 		u64 paddr, size;
@@ -363,7 +369,8 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 		 * a 4k page size kernel to kexec a 64k page size kernel and
 		 * vice versa.
 		 */
-		if (!regions_are_adjacent(prev, in) ||
+		if ((IS_ENABLED(CONFIG_ARM64) &&
+		     !regions_are_adjacent(prev, in)) ||
 		    !regions_have_compatible_memory_type_attrs(prev, in)) {
 
 			paddr = round_down(in->phys_addr, SZ_64K);
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index b4c2589d7c91..b9bd827caa22 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -9,9 +9,18 @@
  * published by the Free Software Foundation.
  *
  */
+
+/*
+ * To prevent the compiler from emitting GOT-indirected (and thus absolute)
+ * references to the section markers, override their visibility as 'hidden'
+ */
+#pragma GCC visibility push(hidden)
+#include <asm/sections.h>
+#pragma GCC visibility pop
+
 #include <linux/efi.h>
 #include <asm/efi.h>
-#include <asm/sections.h>
+#include <asm/memory.h>
 #include <asm/sysreg.h>
 
 #include "efistub.h"
@@ -81,9 +90,10 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
 		/*
 		 * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a
 		 * displacement in the interval [0, MIN_KIMG_ALIGN) that
-		 * is a multiple of the minimal segment alignment (SZ_64K)
+		 * doesn't violate this kernel's de-facto alignment
+		 * constraints.
 		 */
-		u32 mask = (MIN_KIMG_ALIGN - 1) & ~(SZ_64K - 1);
+		u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1);
 		u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ?
 			     (phys_seed >> 32) & mask : TEXT_OFFSET;
 
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index b0184360efc6..50a9cab5a834 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -205,7 +205,7 @@ again:
 		unsigned long m = (unsigned long)map;
 		u64 start, end;
 
-		desc = (efi_memory_desc_t *)(m + (i * desc_size));
+		desc = efi_early_memdesc_ptr(m, desc_size, i);
 		if (desc->type != EFI_CONVENTIONAL_MEMORY)
 			continue;
 
@@ -298,7 +298,7 @@ efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 		unsigned long m = (unsigned long)map;
 		u64 start, end;
 
-		desc = (efi_memory_desc_t *)(m + (i * desc_size));
+		desc = efi_early_memdesc_ptr(m, desc_size, i);
 
 		if (desc->type != EFI_CONVENTIONAL_MEMORY)
 			continue;
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 83f268c05007..f59564b72ddc 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef _DRIVERS_FIRMWARE_EFI_EFISTUB_H
 #define _DRIVERS_FIRMWARE_EFI_EFISTUB_H
diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c
index 7e72954d5860..e0e603a89aa9 100644
--- a/drivers/firmware/efi/libstub/random.c
+++ b/drivers/firmware/efi/libstub/random.c
@@ -145,8 +145,6 @@ efi_status_t efi_random_alloc(efi_system_table_t *sys_table_arg,
 	return status;
 }
 
-#define RANDOM_SEED_SIZE	32
-
 efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg)
 {
 	efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
@@ -162,25 +160,25 @@ efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg)
 		return status;
 
 	status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
-				sizeof(*seed) + RANDOM_SEED_SIZE,
+				sizeof(*seed) + EFI_RANDOM_SEED_SIZE,
 				(void **)&seed);
 	if (status != EFI_SUCCESS)
 		return status;
 
-	status = rng->get_rng(rng, &rng_algo_raw, RANDOM_SEED_SIZE,
+	status = rng->get_rng(rng, &rng_algo_raw, EFI_RANDOM_SEED_SIZE,
 			      seed->bits);
 	if (status == EFI_UNSUPPORTED)
 		/*
 		 * Use whatever algorithm we have available if the raw algorithm
 		 * is not implemented.
 		 */
-		status = rng->get_rng(rng, NULL, RANDOM_SEED_SIZE,
+		status = rng->get_rng(rng, NULL, EFI_RANDOM_SEED_SIZE,
 				      seed->bits);
 
 	if (status != EFI_SUCCESS)
 		goto err_freepool;
 
-	seed->size = RANDOM_SEED_SIZE;
+	seed->size = EFI_RANDOM_SEED_SIZE;
 	status = efi_call_early(install_configuration_table, &rng_table_guid,
 				seed);
 	if (status != EFI_SUCCESS)
diff --git a/drivers/firmware/efi/libstub/string.c b/drivers/firmware/efi/libstub/string.c
index 09d5a0894343..ed10e3f602c5 100644
--- a/drivers/firmware/efi/libstub/string.c
+++ b/drivers/firmware/efi/libstub/string.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Taken from:
  *  linux/lib/string.c
diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
new file mode 100644
index 000000000000..6224cdbc9669
--- /dev/null
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -0,0 +1,58 @@
+/*
+ * TPM handling.
+ *
+ * Copyright (C) 2016 CoreOS, Inc
+ * Copyright (C) 2017 Google, Inc.
+ *     Matthew Garrett <mjg59@google.com>
+ *
+ * This file is part of the Linux kernel, and is made available under the
+ * terms of the GNU General Public License version 2.
+ */
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+static const efi_char16_t efi_MemoryOverWriteRequest_name[] = {
+	'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't',
+	'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o',
+	'l', 0
+};
+
+#define MEMORY_ONLY_RESET_CONTROL_GUID \
+	EFI_GUID(0xe20939be, 0x32d4, 0x41be, 0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29)
+
+#define get_efi_var(name, vendor, ...) \
+	efi_call_runtime(get_variable, \
+			 (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
+			 __VA_ARGS__)
+
+#define set_efi_var(name, vendor, ...) \
+	efi_call_runtime(set_variable, \
+			 (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
+			 __VA_ARGS__)
+
+/*
+ * Enable reboot attack mitigation. This requests that the firmware clear the
+ * RAM on next reboot before proceeding with boot, ensuring that any secrets
+ * are cleared. If userland has ensured that all secrets have been removed
+ * from RAM before reboot it can simply reset this variable.
+ */
+void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg)
+{
+	u8 val = 1;
+	efi_guid_t var_guid = MEMORY_ONLY_RESET_CONTROL_GUID;
+	efi_status_t status;
+	unsigned long datasize = 0;
+
+	status = get_efi_var(efi_MemoryOverWriteRequest_name, &var_guid,
+			     NULL, &datasize, NULL);
+
+	if (status == EFI_NOT_FOUND)
+		return;
+
+	set_efi_var(efi_MemoryOverWriteRequest_name, &var_guid,
+		    EFI_VARIABLE_NON_VOLATILE |
+		    EFI_VARIABLE_BOOTSERVICE_ACCESS |
+		    EFI_VARIABLE_RUNTIME_ACCESS, sizeof(val), &val);
+}
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 78686443cb37..5fc70520e04c 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common EFI memory map functions.
  */
diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c
index 62ead9b9d871..7effff969eb9 100644
--- a/drivers/firmware/efi/reboot.c
+++ b/drivers/firmware/efi/reboot.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2014 Intel Corporation; author Matt Fleming
  * Copyright (c) 2014 Red Hat, Inc., Mark Salter <msalter@redhat.com>
@@ -5,6 +6,8 @@
 #include <linux/efi.h>
 #include <linux/reboot.h>
 
+static void (*orig_pm_power_off)(void);
+
 int efi_reboot_quirk_mode = -1;
 
 void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
@@ -51,6 +54,12 @@ bool __weak efi_poweroff_required(void)
 static void efi_power_off(void)
 {
 	efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
+	/*
+	 * The above call should not return, if it does fall back to
+	 * the original power off method (typically ACPI poweroff).
+	 */
+	if (orig_pm_power_off)
+		orig_pm_power_off();
 }
 
 static int __init efi_shutdown_init(void)
@@ -58,8 +67,10 @@ static int __init efi_shutdown_init(void)
 	if (!efi_enabled(EFI_RUNTIME_SERVICES))
 		return -ENODEV;
 
-	if (efi_poweroff_required())
+	if (efi_poweroff_required()) {
+		orig_pm_power_off = pm_power_off;
 		pm_power_off = efi_power_off;
+	}
 
 	return 0;
 }
diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c
index 08129b7b80ab..41c48a1e8baa 100644
--- a/drivers/firmware/efi/test/efi_test.c
+++ b/drivers/firmware/efi/test/efi_test.c
@@ -593,6 +593,9 @@ static long efi_runtime_query_capsulecaps(unsigned long arg)
 	if (copy_from_user(&qcaps, qcaps_user, sizeof(qcaps)))
 		return -EFAULT;
 
+	if (qcaps.capsule_count == ULONG_MAX)
+		return -EINVAL;
+
 	capsules = kcalloc(qcaps.capsule_count + 1,
 			   sizeof(efi_capsule_header_t), GFP_KERNEL);
 	if (!capsules)
diff --git a/drivers/firmware/efi/test/efi_test.h b/drivers/firmware/efi/test/efi_test.h
index a33a6c633852..9812c6a02b40 100644
--- a/drivers/firmware/efi/test/efi_test.h
+++ b/drivers/firmware/efi/test/efi_test.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * EFI Test driver Header
  *