Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/efi changes from Peter Anvin:
 "The bulk of these changes are cleaning up the efivars handling and
  breaking it up into a tree of files.  There are a number of fixes as
  well.

  The entire changeset is pretty big, but most of it is code movement.

  Several of these commits are quite new; the history got very messed up
  due to a mismerge with the urgent changes for rc8 which completely
  broke IA64, and so Ingo requested that we rebase it to straighten it
  out."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: remove "kfree(NULL)"
  efi: locking fix in efivar_entry_set_safe()
  efi, pstore: Read data from variable store before memcpy()
  efi, pstore: Remove entry from list when erasing
  efi, pstore: Initialise 'entry' before iterating
  efi: split efisubsystem from efivars
  efivarfs: Move to fs/efivarfs
  efivars: Move pstore code into the new EFI directory
  efivars: efivar_entry API
  efivars: Keep a private global pointer to efivars
  efi: move utf16 string functions to efi.h
  x86, efi: Make efi_memblock_x86_reserve_range more readable
  efivarfs: convert to use simple_open()

MAINTAINERS

@@ -3025,9 +3025,18 @@ F:	arch/ia64/kernel/efi.c
 F:	arch/x86/boot/compressed/eboot.[ch]
 F:	arch/x86/include/asm/efi.h
 F:	arch/x86/platform/efi/*
-F:	drivers/firmware/efivars.c
+F:	drivers/firmware/efi/*
 F:	include/linux/efi*.h
 
+EFI VARIABLE FILESYSTEM
+M:	Matthew Garrett <matthew.garrett@nebula.com>
+M:	Jeremy Kerr <jk@ozlabs.org>
+M:	Matt Fleming <matt.fleming@intel.com>
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git
+L:	linux-efi@vger.kernel.org
+S:	Maintained
+F:	fs/efivarfs/
+
 EFIFB FRAMEBUFFER DRIVER
 L:	linux-fbdev@vger.kernel.org
 M:	Peter Jones <pjones@redhat.com>
@@ -6391,7 +6400,7 @@ S:	Maintained
 T:	git git://git.infradead.org/users/cbou/linux-pstore.git
 F:	fs/pstore/
 F:	include/linux/pstore*
-F:	drivers/firmware/efivars.c
+F:	drivers/firmware/efi/efi-pstore.c
 F:	drivers/acpi/apei/erst.c
 
 PTP HARDWARE CLOCK SUPPORT

arch/ia64/Kconfig

@@ -110,6 +110,7 @@ config DMI
 
 config EFI
 	bool
+	select UCS2_STRING
 	default y
 
 config SCHED_OMIT_FRAME_POINTER

arch/x86/platform/efi/efi.c

@@ -453,24 +453,25 @@ static void __init do_add_efi_memmap(void)
 
 int __init efi_memblock_x86_reserve_range(void)
 {
+	struct efi_info *e = &boot_params.efi_info;
 	unsigned long pmap;
 
 #ifdef CONFIG_X86_32
 	/* Can't handle data above 4GB at this time */
-	if (boot_params.efi_info.efi_memmap_hi) {
+	if (e->efi_memmap_hi) {
 		pr_err("Memory map is above 4GB, disabling EFI.\n");
 		return -EINVAL;
 	}
-	pmap = boot_params.efi_info.efi_memmap;
+	pmap =  e->efi_memmap;
 #else
-	pmap = (boot_params.efi_info.efi_memmap |
-		((__u64)boot_params.efi_info.efi_memmap_hi<<32));
+	pmap = (e->efi_memmap |	((__u64)e->efi_memmap_hi << 32));
 #endif
 	memmap.phys_map		= (void *)pmap;
-	memmap.nr_map = boot_params.efi_info.efi_memmap_size /
-		boot_params.efi_info.efi_memdesc_size;
-	memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
-	memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
+	memmap.nr_map		= e->efi_memmap_size /
+				  e->efi_memdesc_size;
+	memmap.desc_size	= e->efi_memdesc_size;
+	memmap.desc_version	= e->efi_memdesc_version;
+
 	memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
 
 	return 0;

drivers/firmware/Kconfig

@@ -36,42 +36,6 @@ config FIRMWARE_MEMMAP
 
       See also Documentation/ABI/testing/sysfs-firmware-memmap.
 
-config EFI_VARS
-	tristate "EFI Variable Support via sysfs"
-	depends on EFI
-	select UCS2_STRING
-	default n
-	help
-	  If you say Y here, you are able to get EFI (Extensible Firmware
-	  Interface) variable information via sysfs.  You may read,
-	  write, create, and destroy EFI variables through this interface.
-
-	  Note that using this driver in concert with efibootmgr requires
-	  at least test release version 0.5.0-test3 or later, which is
-	  available from Matt Domsch's website located at:
-	  <http://linux.dell.com/efibootmgr/testing/efibootmgr-0.5.0-test3.tar.gz>
-
-	  Subsequent efibootmgr releases may be found at:
-	  <http://linux.dell.com/efibootmgr>
-
-config EFI_VARS_PSTORE
-	bool "Register efivars backend for pstore"
-	depends on EFI_VARS && PSTORE
-	default y
-	help
-	  Say Y here to enable use efivars as a backend to pstore. This
-	  will allow writing console messages, crash dumps, or anything
-	  else supported by pstore to EFI variables.
-
-config EFI_VARS_PSTORE_DEFAULT_DISABLE
-	bool "Disable using efivars as a pstore backend by default"
-	depends on EFI_VARS_PSTORE
-	default n
-	help
-	  Saying Y here will disable the use of efivars as a storage
-	  backend for pstore by default. This setting can be overridden
-	  using the efivars module's pstore_disable parameter.
-
 config EFI_PCDP
 	bool "Console device selection via EFI PCDP or HCDP table"
 	depends on ACPI && EFI && IA64
@@ -165,5 +129,6 @@ config ISCSI_IBFT
 	  Otherwise, say N.
 
 source "drivers/firmware/google/Kconfig"
+source "drivers/firmware/efi/Kconfig"
 
 endmenu

drivers/firmware/Makefile

@@ -4,7 +4,6 @@
 obj-$(CONFIG_DMI)		+= dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
 obj-$(CONFIG_EDD)		+= edd.o
-obj-$(CONFIG_EFI_VARS)		+= efivars.o
 obj-$(CONFIG_EFI_PCDP)		+= pcdp.o
 obj-$(CONFIG_DELL_RBU)          += dell_rbu.o
 obj-$(CONFIG_DCDBAS)		+= dcdbas.o
@@ -14,3 +13,4 @@ obj-$(CONFIG_ISCSI_IBFT)	+= iscsi_ibft.o
 obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
 
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
+obj-$(CONFIG_EFI)		+= efi/

drivers/firmware/efi/Kconfig

+menu "EFI (Extensible Firmware Interface) Support"
+	depends on EFI
+
+config EFI_VARS
+	tristate "EFI Variable Support via sysfs"
+	depends on EFI
+	default n
+	help
+	  If you say Y here, you are able to get EFI (Extensible Firmware
+	  Interface) variable information via sysfs.  You may read,
+	  write, create, and destroy EFI variables through this interface.
+
+	  Note that using this driver in concert with efibootmgr requires
+	  at least test release version 0.5.0-test3 or later, which is
+	  available from Matt Domsch's website located at:
+	  <http://linux.dell.com/efibootmgr/testing/efibootmgr-0.5.0-test3.tar.gz>
+
+	  Subsequent efibootmgr releases may be found at:
+	  <http://linux.dell.com/efibootmgr>
+
+config EFI_VARS_PSTORE
+	tristate "Register efivars backend for pstore"
+	depends on EFI_VARS && PSTORE
+	default y
+	help
+	  Say Y here to enable use efivars as a backend to pstore. This
+	  will allow writing console messages, crash dumps, or anything
+	  else supported by pstore to EFI variables.
+
+config EFI_VARS_PSTORE_DEFAULT_DISABLE
+	bool "Disable using efivars as a pstore backend by default"
+	depends on EFI_VARS_PSTORE
+	default n
+	help
+	  Saying Y here will disable the use of efivars as a storage
+	  backend for pstore by default. This setting can be overridden
+	  using the efivars module's pstore_disable parameter.
+
+endmenu

drivers/firmware/efi/Makefile

+#
+# Makefile for linux kernel
+#
+obj-y					+= efi.o vars.o
+obj-$(CONFIG_EFI_VARS)			+= efivars.o
+obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o

drivers/firmware/efi/efi-pstore.c

+#include <linux/efi.h>
+#include <linux/module.h>
+#include <linux/pstore.h>
+#include <linux/ucs2_string.h>
+
+#define DUMP_NAME_LEN 52
+
+static bool efivars_pstore_disable =
+	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
+
+module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
+
+#define PSTORE_EFI_ATTRIBUTES \
+	(EFI_VARIABLE_NON_VOLATILE | \
+	 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
+	 EFI_VARIABLE_RUNTIME_ACCESS)
+
+static int efi_pstore_open(struct pstore_info *psi)
+{
+	efivar_entry_iter_begin();
+	psi->data = NULL;
+	return 0;
+}
+
+static int efi_pstore_close(struct pstore_info *psi)
+{
+	efivar_entry_iter_end();
+	psi->data = NULL;
+	return 0;
+}
+
+struct pstore_read_data {
+	u64 *id;
+	enum pstore_type_id *type;
+	int *count;
+	struct timespec *timespec;
+	char **buf;
+};
+
+static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
+{
+	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+	struct pstore_read_data *cb_data = data;
+	char name[DUMP_NAME_LEN];
+	int i;
+	int cnt;
+	unsigned int part;
+	unsigned long time, size;
+
+	if (efi_guidcmp(entry->var.VendorGuid, vendor))
+		return 0;
+
+	for (i = 0; i < DUMP_NAME_LEN; i++)
+		name[i] = entry->var.VariableName[i];
+
+	if (sscanf(name, "dump-type%u-%u-%d-%lu",
+		   cb_data->type, &part, &cnt, &time) == 4) {
+		*cb_data->id = part;
+		*cb_data->count = cnt;
+		cb_data->timespec->tv_sec = time;
+		cb_data->timespec->tv_nsec = 0;
+	} else if (sscanf(name, "dump-type%u-%u-%lu",
+			  cb_data->type, &part, &time) == 3) {
+		/*
+		 * Check if an old format,
+		 * which doesn't support holding
+		 * multiple logs, remains.
+		 */
+		*cb_data->id = part;
+		*cb_data->count = 0;
+		cb_data->timespec->tv_sec = time;
+		cb_data->timespec->tv_nsec = 0;
+	} else
+		return 0;
+
+	entry->var.DataSize = 1024;
+	__efivar_entry_get(entry, &entry->var.Attributes,
+			   &entry->var.DataSize, entry->var.Data);
+	size = entry->var.DataSize;
+
+	*cb_data->buf = kmalloc(size, GFP_KERNEL);
+	if (*cb_data->buf == NULL)
+		return -ENOMEM;
+	memcpy(*cb_data->buf, entry->var.Data, size);
+	return size;
+}
+
+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+			       int *count, struct timespec *timespec,
+			       char **buf, struct pstore_info *psi)
+{
+	struct pstore_read_data data;
+
+	data.id = id;
+	data.type = type;
+	data.count = count;
+	data.timespec = timespec;
+	data.buf = buf;
+
+	return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
+				   (struct efivar_entry **)&psi->data);
+}
+
+static int efi_pstore_write(enum pstore_type_id type,
+		enum kmsg_dump_reason reason, u64 *id,
+		unsigned int part, int count, size_t size,
+		struct pstore_info *psi)
+{
+	char name[DUMP_NAME_LEN];
+	efi_char16_t efi_name[DUMP_NAME_LEN];
+	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+	int i, ret = 0;
+
+	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
+		get_seconds());
+
+	for (i = 0; i < DUMP_NAME_LEN; i++)
+		efi_name[i] = name[i];
+
+	efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
+			      !pstore_cannot_block_path(reason),
+			      size, psi->buf);
+
+	if (reason == KMSG_DUMP_OOPS)
+		efivar_run_worker();
+
+	*id = part;
+	return ret;
+};
+
+struct pstore_erase_data {
+	u64 id;
+	enum pstore_type_id type;
+	int count;
+	struct timespec time;
+	efi_char16_t *name;
+};
+
+/*
+ * Clean up an entry with the same name
+ */
+static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
+{
+	struct pstore_erase_data *ed = data;
+	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+	efi_char16_t efi_name_old[DUMP_NAME_LEN];
+	efi_char16_t *efi_name = ed->name;
+	unsigned long ucs2_len = ucs2_strlen(ed->name);
+	char name_old[DUMP_NAME_LEN];
+	int i;
+
+	if (efi_guidcmp(entry->var.VendorGuid, vendor))
+		return 0;
+
+	if (ucs2_strncmp(entry->var.VariableName,
+			  efi_name, (size_t)ucs2_len)) {
+		/*
+		 * Check if an old format, which doesn't support
+		 * holding multiple logs, remains.
+		 */
+		sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
+			(unsigned int)ed->id, ed->time.tv_sec);
+
+		for (i = 0; i < DUMP_NAME_LEN; i++)
+			efi_name_old[i] = name_old[i];
+
+		if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
+				  ucs2_strlen(efi_name_old)))
+			return 0;
+	}
+
+	/* found */
+	__efivar_entry_delete(entry);
+	list_del(&entry->list);
+
+	return 1;
+}
+
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
+			    struct timespec time, struct pstore_info *psi)
+{
+	struct pstore_erase_data edata;
+	struct efivar_entry *entry = NULL;
+	char name[DUMP_NAME_LEN];
+	efi_char16_t efi_name[DUMP_NAME_LEN];
+	int found, i;
+
+	sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
+		time.tv_sec);
+
+	for (i = 0; i < DUMP_NAME_LEN; i++)
+		efi_name[i] = name[i];
+
+	edata.id = id;
+	edata.type = type;
+	edata.count = count;
+	edata.time = time;
+	edata.name = efi_name;
+
+	efivar_entry_iter_begin();
+	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
+	efivar_entry_iter_end();
+
+	if (found)
+		efivar_unregister(entry);
+
+	return 0;
+}
+
+static struct pstore_info efi_pstore_info = {
+	.owner		= THIS_MODULE,
+	.name		= "efi",
+	.open		= efi_pstore_open,
+	.close		= efi_pstore_close,
+	.read		= efi_pstore_read,
+	.write		= efi_pstore_write,
+	.erase		= efi_pstore_erase,
+};
+
+static __init int efivars_pstore_init(void)
+{
+	if (!efi_enabled(EFI_RUNTIME_SERVICES))
+		return 0;
+
+	if (!efivars_kobject())
+		return 0;
+
+	if (efivars_pstore_disable)
+		return 0;
+
+	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
+	if (!efi_pstore_info.buf)
+		return -ENOMEM;
+
+	efi_pstore_info.bufsize = 1024;
+	spin_lock_init(&efi_pstore_info.buf_lock);
+
+	pstore_register(&efi_pstore_info);
+
+	return 0;
+}
+
+static __exit void efivars_pstore_exit(void)
+{
+}
+
+module_init(efivars_pstore_init);
+module_exit(efivars_pstore_exit);
+
+MODULE_DESCRIPTION("EFI variable backend for pstore");
+MODULE_LICENSE("GPL");

drivers/firmware/efi/efi.c

+/*
+ * efi.c - EFI subsystem
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
+ *
+ * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
+ * allowing the efivarfs to be mounted or the efivars module to be loaded.
+ * The existance of /sys/firmware/efi may also be used by userspace to
+ * determine that the system supports EFI.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/efi.h>
+
+static struct kobject *efi_kobj;
+static struct kobject *efivars_kobj;
+
+/*
+ * Let's not leave out systab information that snuck into
+ * the efivars driver
+ */
+static ssize_t systab_show(struct kobject *kobj,
+			   struct kobj_attribute *attr, char *buf)
+{
+	char *str = buf;
+
+	if (!kobj || !buf)
+		return -EINVAL;
+
+	if (efi.mps != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "MPS=0x%lx\n", efi.mps);
+	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
+	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
+	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
+	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
+	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
+	if (efi.uga != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "UGA=0x%lx\n", efi.uga);
+
+	return str - buf;
+}
+
+static struct kobj_attribute efi_attr_systab =
+			__ATTR(systab, 0400, systab_show, NULL);
+
+static struct attribute *efi_subsys_attrs[] = {
+	&efi_attr_systab.attr,
+	NULL,	/* maybe more in the future? */
+};
+
+static struct attribute_group efi_subsys_attr_group = {
+	.attrs = efi_subsys_attrs,
+};
+
+static struct efivars generic_efivars;
+static struct efivar_operations generic_ops;
+
+static int generic_ops_register(void)
+{
+	generic_ops.get_variable = efi.get_variable;
+	generic_ops.set_variable = efi.set_variable;
+	generic_ops.get_next_variable = efi.get_next_variable;
+	generic_ops.query_variable_store = efi_query_variable_store;
+
+	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
+}
+
+static void generic_ops_unregister(void)
+{
+	efivars_unregister(&generic_efivars);
+}
+
+/*
+ * We register the efi subsystem with the firmware subsystem and the
+ * efivars subsystem with the efi subsystem, if the system was booted with
+ * EFI.
+ */
+static int __init efisubsys_init(void)
+{
+	int error;
+
+	if (!efi_enabled(EFI_BOOT))
+		return 0;
+
+	/* We register the efi directory at /sys/firmware/efi */
+	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+	if (!efi_kobj) {
+		pr_err("efi: Firmware registration failed.\n");
+		return -ENOMEM;
+	}
+
+	error = generic_ops_register();
+	if (error)
+		goto err_put;
+
+	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
+	if (error) {
+		pr_err("efi: Sysfs attribute export failed with error %d.\n",
+		       error);
+		goto err_unregister;
+	}
+
+	/* and the standard mountpoint for efivarfs */
+	efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
+	if (!efivars_kobj) {
+		pr_err("efivars: Subsystem registration failed.\n");
+		error = -ENOMEM;
+		goto err_remove_group;
+	}
+
+	return 0;
+
+err_remove_group:
+	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
+err_unregister:
+	generic_ops_unregister();
+err_put:
+	kobject_put(efi_kobj);
+	return error;
+}
+
+subsys_initcall(efisubsys_init);

drivers/firmware/google/gsmi.c

@@ -28,6 +28,7 @@
 #include <linux/reboot.h>
 #include <linux/efi.h>
 #include <linux/module.h>
+#include <linux/ucs2_string.h>
 
 #define GSMI_SHUTDOWN_CLEAN	0	/* Clean Shutdown */
 /* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */
@@ -288,17 +289,6 @@ static int gsmi_exec(u8 func, u8 sub)
 	return rc;
 }
 
-/* Return the number of unicode characters in data */
-static size_t
-utf16_strlen(efi_char16_t *data, unsigned long maxlength)
-{
-	unsigned long length = 0;
-
-	while (*data++ != 0 && length < maxlength)
-		length++;
-	return length;
-}
-
 static efi_status_t gsmi_get_variable(efi_char16_t *name,
 				      efi_guid_t *vendor, u32 *attr,
 				      unsigned long *data_size,
@@ -311,7 +301,7 @@ static efi_status_t gsmi_get_variable(efi_char16_t *name,
 	};
 	efi_status_t ret = EFI_SUCCESS;
 	unsigned long flags;
-	size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2);
+	size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
 	int rc;
 
 	if (name_len >= GSMI_BUF_SIZE / 2)
@@ -380,7 +370,7 @@ static efi_status_t gsmi_get_next_variable(unsigned long *name_size,
 		return EFI_BAD_BUFFER_SIZE;
 
 	/* Let's make sure the thing is at least null-terminated */
-	if (utf16_strlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2)
+	if (ucs2_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2)
 		return EFI_INVALID_PARAMETER;
 
 	spin_lock_irqsave(&gsmi_dev.lock, flags);
@@ -408,7 +398,7 @@ static efi_status_t gsmi_get_next_variable(unsigned long *name_size,
 
 		/* Copy the name back */
 		memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE);
-		*name_size = utf16_strlen(name, GSMI_BUF_SIZE / 2) * 2;
+		*name_size = ucs2_strnlen(name, GSMI_BUF_SIZE / 2) * 2;
 
 		/* copy guid to return buffer */
 		memcpy(vendor, &param.guid, sizeof(param.guid));
@@ -434,7 +424,7 @@ static efi_status_t gsmi_set_variable(efi_char16_t *name,
 			      EFI_VARIABLE_BOOTSERVICE_ACCESS |
 			      EFI_VARIABLE_RUNTIME_ACCESS,
 	};
-	size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2);
+	size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
 	efi_status_t ret = EFI_SUCCESS;
 	int rc;
 	unsigned long flags;
@@ -893,12 +883,19 @@ static __init int gsmi_init(void)
 		goto out_remove_bin_file;
 	}
 
-	ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj);
+	ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj);
 	if (ret) {
 		printk(KERN_INFO "gsmi: Failed to register efivars\n");
 		goto out_remove_sysfs_files;
 	}
 
+	ret = efivars_sysfs_init();
+	if (ret) {
+		printk(KERN_INFO "gsmi: Failed to create efivars files\n");
+		efivars_unregister(&efivars);
+		goto out_remove_sysfs_files;
+	}
+
 	register_reboot_notifier(&gsmi_reboot_notifier);
 	register_die_notifier(&gsmi_die_notifier);
 	atomic_notifier_chain_register(&panic_notifier_list,
@@ -930,7 +927,7 @@ static void __exit gsmi_exit(void)
 	unregister_die_notifier(&gsmi_die_notifier);
 	atomic_notifier_chain_unregister(&panic_notifier_list,
 					 &gsmi_panic_notifier);
-	unregister_efivars(&efivars);
+	efivars_unregister(&efivars);
 
 	sysfs_remove_files(gsmi_kobj, gsmi_attrs);
 	sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);

fs/Kconfig

@@ -211,6 +211,7 @@ source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
 source "fs/exofs/Kconfig"
 source "fs/f2fs/Kconfig"
+source "fs/efivarfs/Kconfig"
 
 endif # MISC_FILESYSTEMS
 

fs/Makefile

@@ -125,3 +125,4 @@ obj-$(CONFIG_F2FS_FS)		+= f2fs/
 obj-y				+= exofs/ # Multiple modules
 obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
+obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/

fs/efivarfs/Kconfig

+config EFIVAR_FS
+	tristate "EFI Variable filesystem"
+	depends on EFI
+	help
+	  efivarfs is a replacement filesystem for the old EFI
+	  variable support via sysfs, as it doesn't suffer from the
+	  same 1024-byte variable size limit.
+
+	  To compile this file system support as a module, choose M
+	  here. The module will be called efivarfs.
+
+	  If unsure, say N.

fs/efivarfs/Makefile

+#
+# Makefile for the efivarfs filesystem
+#
+
+obj-$(CONFIG_EFIVAR_FS)		+= efivarfs.o
+
+efivarfs-objs			:= inode.o file.o super.o

fs/efivarfs/file.c

+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/fs.h>
+
+#include "internal.h"
+
+static ssize_t efivarfs_file_write(struct file *file,
+		const char __user *userbuf, size_t count, loff_t *ppos)
+{
+	struct efivar_entry *var = file->private_data;
+	void *data;
+	u32 attributes;
+	struct inode *inode = file->f_mapping->host;
+	unsigned long datasize = count - sizeof(attributes);
+	ssize_t bytes = 0;
+	bool set = false;
+
+	if (count < sizeof(attributes))
+		return -EINVAL;
+
+	if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
+		return -EFAULT;
+
+	if (attributes & ~(EFI_VARIABLE_MASK))
+		return -EINVAL;
+
+	data = kmalloc(datasize, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
+		bytes = -EFAULT;
+		goto out;
+	}
+
+	bytes = efivar_entry_set_get_size(var, attributes, &datasize,
+					  data, &set);
+	if (!set && bytes)
+		goto out;
+
+	if (bytes == -ENOENT) {
+		drop_nlink(inode);
+		d_delete(file->f_dentry);
+		dput(file->f_dentry);
+	} else {
+		mutex_lock(&inode->i_mutex);
+		i_size_write(inode, datasize + sizeof(attributes));
+		mutex_unlock(&inode->i_mutex);
+	}
+
+	bytes = count;
+
+out:
+	kfree(data);
+
+	return bytes;
+}
+
+static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
+		size_t count, loff_t *ppos)
+{
+	struct efivar_entry *var = file->private_data;
+	unsigned long datasize = 0;
+	u32 attributes;
+	void *data;
+	ssize_t size = 0;
+	int err;
+
+	err = efivar_entry_size(var, &datasize);
+	if (err)
+		return err;
+
+	data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
+
+	if (!data)
+		return -ENOMEM;
+
+	size = efivar_entry_get(var, &attributes, &datasize,
+				data + sizeof(attributes));
+	if (size)
+		goto out_free;
+
+	memcpy(data, &attributes, sizeof(attributes));
+	size = simple_read_from_buffer(userbuf, count, ppos,
+				       data, datasize + sizeof(attributes));
+out_free:
+	kfree(data);
+
+	return size;
+}
+
+const struct file_operations efivarfs_file_operations = {
+	.open	= simple_open,
+	.read	= efivarfs_file_read,
+	.write	= efivarfs_file_write,
+	.llseek	= no_llseek,
+};

fs/efivarfs/inode.c

+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/fs.h>
+#include <linux/ctype.h>
+
+#include "internal.h"
+
+struct inode *efivarfs_get_inode(struct super_block *sb,
+				const struct inode *dir, int mode, dev_t dev)
+{
+	struct inode *inode = new_inode(sb);
+
+	if (inode) {
+		inode->i_ino = get_next_ino();
+		inode->i_mode = mode;
+		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		switch (mode & S_IFMT) {
+		case S_IFREG:
+			inode->i_fop = &efivarfs_file_operations;
+			break;
+		case S_IFDIR:
+			inode->i_op = &efivarfs_dir_inode_operations;
+			inode->i_fop = &simple_dir_operations;
+			inc_nlink(inode);
+			break;
+		}
+	}
+	return inode;
+}
+
+/*
+ * Return true if 'str' is a valid efivarfs filename of the form,
+ *
+ *	VariableName-12345678-1234-1234-1234-1234567891bc
+ */
+bool efivarfs_valid_name(const char *str, int len)
+{
+	static const char dashes[EFI_VARIABLE_GUID_LEN] = {
+		[8] = 1, [13] = 1, [18] = 1, [23] = 1
+	};
+	const char *s = str + len - EFI_VARIABLE_GUID_LEN;
+	int i;
+
+	/*
+	 * We need a GUID, plus at least one letter for the variable name,
+	 * plus the '-' separator
+	 */
+	if (len < EFI_VARIABLE_GUID_LEN + 2)
+		return false;
+
+	/* GUID must be preceded by a '-' */
+	if (*(s - 1) != '-')
+		return false;
+
+	/*
+	 * Validate that 's' is of the correct format, e.g.
+	 *
+	 *	12345678-1234-1234-1234-123456789abc
+	 */
+	for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
+		if (dashes[i]) {
+			if (*s++ != '-')
+				return false;
+		} else {
+			if (!isxdigit(*s++))
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
+{
+	guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
+	guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
+	guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
+	guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
+	guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
+	guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
+	guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
+	guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
+	guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
+	guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
+	guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
+	guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
+	guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
+	guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
+	guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
+	guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
+}
+
+static int efivarfs_create(struct inode *dir, struct dentry *dentry,
+			  umode_t mode, bool excl)
+{
+	struct inode *inode;
+	struct efivar_entry *var;
+	int namelen, i = 0, err = 0;
+
+	if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
+		return -EINVAL;
+
+	inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
+	if (!inode)
+		return -ENOMEM;
+
+	var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
+	if (!var) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* length of the variable name itself: remove GUID and separator */
+	namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
+
+	efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
+			&var->var.VendorGuid);
+
+	for (i = 0; i < namelen; i++)
+		var->var.VariableName[i] = dentry->d_name.name[i];
+
+	var->var.VariableName[i] = '\0';
+
+	inode->i_private = var;
+
+	efivar_entry_add(var, &efivarfs_list);
+	d_instantiate(dentry, inode);
+	dget(dentry);
+out:
+	if (err) {
+		kfree(var);
+		iput(inode);
+	}
+	return err;
+}
+
+static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct efivar_entry *var = dentry->d_inode->i_private;
+
+	if (efivar_entry_delete(var))
+		return -EINVAL;
+
+	drop_nlink(dentry->d_inode);
+	dput(dentry);
+	return 0;
+};
+
+/*
+ * Handle negative dentry.
+ */
+static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
+				      unsigned int flags)
+{
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+	d_add(dentry, NULL);
+	return NULL;
+}
+
+const struct inode_operations efivarfs_dir_inode_operations = {
+	.lookup = efivarfs_lookup,
+	.unlink = efivarfs_unlink,
+	.create = efivarfs_create,
+};

fs/efivarfs/internal.h

+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef EFIVAR_FS_INTERNAL_H
+#define EFIVAR_FS_INTERNAL_H
+
+#include <linux/list.h>
+
+extern const struct file_operations efivarfs_file_operations;
+extern const struct inode_operations efivarfs_dir_inode_operations;
+extern bool efivarfs_valid_name(const char *str, int len);
+extern struct inode *efivarfs_get_inode(struct super_block *sb,
+			const struct inode *dir, int mode, dev_t dev);
+
+extern struct list_head efivarfs_list;
+
+#endif /* EFIVAR_FS_INTERNAL_H */

include/linux/efi.h

@@ -669,6 +669,12 @@ static inline int efi_enabled(int facility)
 				EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | \
 				EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS | \
 				EFI_VARIABLE_APPEND_WRITE)
+/*
+ * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
+ * not including trailing NUL
+ */
+#define EFI_VARIABLE_GUID_LEN 36
+
 /*
  * The type of search to perform when calling boottime->locate_handle
  */
@@ -726,7 +732,6 @@ static inline void memrange_efi_to_native(u64 *addr, u64 *npages)
 	*addr &= PAGE_MASK;
 }
 
-#if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE)
 /*
  * EFI Variable support.
  *
@@ -752,19 +757,88 @@ struct efivars {
 	 * which is protected by the BKL, so that path is safe.
 	 */
 	spinlock_t lock;
-	struct list_head list;
 	struct kset *kset;
 	struct kobject *kobject;
-	struct bin_attribute *new_var, *del_var;
 	const struct efivar_operations *ops;
-	struct efivar_entry *walk_entry;
-	struct pstore_info efi_pstore_info;
 };
 
-int register_efivars(struct efivars *efivars,
+/*
+ * The maximum size of VariableName + Data = 1024
+ * Therefore, it's reasonable to save that much
+ * space in each part of the structure,
+ * and we use a page for reading/writing.
+ */
+
+struct efi_variable {
+	efi_char16_t  VariableName[1024/sizeof(efi_char16_t)];
+	efi_guid_t    VendorGuid;
+	unsigned long DataSize;
+	__u8          Data[1024];
+	efi_status_t  Status;
+	__u32         Attributes;
+} __attribute__((packed));
+
+struct efivar_entry {
+	struct efi_variable var;
+	struct list_head list;
+	struct kobject kobj;
+};
+
+extern struct list_head efivar_sysfs_list;
+
+static inline void
+efivar_unregister(struct efivar_entry *var)
+{
+	kobject_put(&var->kobj);
+}
+
+int efivars_register(struct efivars *efivars,
 		     const struct efivar_operations *ops,
-		     struct kobject *parent_kobj);
-void unregister_efivars(struct efivars *efivars);
+		     struct kobject *kobject);
+int efivars_unregister(struct efivars *efivars);
+struct kobject *efivars_kobject(void);
+
+int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
+		void *data, bool atomic, bool duplicates,
+		struct list_head *head);
+
+void efivar_entry_add(struct efivar_entry *entry, struct list_head *head);
+void efivar_entry_remove(struct efivar_entry *entry);
+
+int __efivar_entry_delete(struct efivar_entry *entry);
+int efivar_entry_delete(struct efivar_entry *entry);
+
+int efivar_entry_size(struct efivar_entry *entry, unsigned long *size);
+int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		       unsigned long *size, void *data);
+int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		     unsigned long *size, void *data);
+int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
+		     unsigned long size, void *data, struct list_head *head);
+int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
+			      unsigned long *size, void *data, bool *set);
+int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
+			  bool block, unsigned long size, void *data);
+
+void efivar_entry_iter_begin(void);
+void efivar_entry_iter_end(void);
+
+int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+			struct list_head *head, void *data,
+			struct efivar_entry **prev);
+int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+		      struct list_head *head, void *data);
+
+struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
+				       struct list_head *head, bool remove);
+
+bool efivar_validate(struct efi_variable *var, u8 *data, unsigned long len);
+
+extern struct work_struct efivar_work;
+void efivar_run_worker(void);
+
+#if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE)
+int efivars_sysfs_init(void);
 
 #endif /* CONFIG_EFI_VARS */