![Mike Waychison](/assets/img/avatar_default.png)
Signed-off-by: Mike Waychison <mikew@google.com> Cc: Matt Domsch <Matt_Domsch@dell.com>, Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
830 lines
21 KiB
C
830 lines
21 KiB
C
/*
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* EFI Variables - efivars.c
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*
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* Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
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* Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
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*
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* This code takes all variables accessible from EFI runtime and
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* exports them via sysfs
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Changelog:
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*
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* 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
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* remove check for efi_enabled in exit
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* add MODULE_VERSION
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*
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* 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
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* minor bug fixes
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*
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* 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
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* converted driver to export variable information via sysfs
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* and moved to drivers/firmware directory
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* bumped revision number to v0.07 to reflect conversion & move
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*
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* 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
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* fix locking per Peter Chubb's findings
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*
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* 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
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* move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
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*
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* 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
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* use list_for_each_safe when deleting vars.
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* remove ifdef CONFIG_SMP around include <linux/smp.h>
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* v0.04 release to linux-ia64@linuxia64.org
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*
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* 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
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* Moved vars from /proc/efi to /proc/efi/vars, and made
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* efi.c own the /proc/efi directory.
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* v0.03 release to linux-ia64@linuxia64.org
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*
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* 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
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* At the request of Stephane, moved ownership of /proc/efi
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* to efi.c, and now efivars lives under /proc/efi/vars.
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*
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* 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
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* Feedback received from Stephane Eranian incorporated.
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* efivar_write() checks copy_from_user() return value.
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* efivar_read/write() returns proper errno.
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* v0.02 release to linux-ia64@linuxia64.org
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*
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* 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
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* v0.01 release to linux-ia64@linuxia64.org
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*/
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#include <linux/capability.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/smp.h>
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#include <linux/efi.h>
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#include <linux/sysfs.h>
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#include <linux/kobject.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <asm/uaccess.h>
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#define EFIVARS_VERSION "0.08"
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#define EFIVARS_DATE "2004-May-17"
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MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
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MODULE_DESCRIPTION("sysfs interface to EFI Variables");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(EFIVARS_VERSION);
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/*
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* The maximum size of VariableName + Data = 1024
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* Therefore, it's reasonable to save that much
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* space in each part of the structure,
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* and we use a page for reading/writing.
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*/
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struct efi_variable {
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efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
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efi_guid_t VendorGuid;
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unsigned long DataSize;
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__u8 Data[1024];
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efi_status_t Status;
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__u32 Attributes;
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} __attribute__((packed));
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struct efivar_entry {
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struct efivars *efivars;
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struct efi_variable var;
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struct list_head list;
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struct kobject kobj;
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};
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struct efivar_attribute {
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struct attribute attr;
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ssize_t (*show) (struct efivar_entry *entry, char *buf);
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ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
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};
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#define EFIVAR_ATTR(_name, _mode, _show, _store) \
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struct efivar_attribute efivar_attr_##_name = { \
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.attr = {.name = __stringify(_name), .mode = _mode}, \
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.show = _show, \
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.store = _store, \
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};
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#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
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#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
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/*
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* Prototype for sysfs creation function
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*/
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static int
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efivar_create_sysfs_entry(struct efivars *efivars,
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unsigned long variable_name_size,
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efi_char16_t *variable_name,
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efi_guid_t *vendor_guid);
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/* Return the number of unicode characters in data */
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static unsigned long
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utf8_strlen(efi_char16_t *data, unsigned long maxlength)
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{
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unsigned long length = 0;
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while (*data++ != 0 && length < maxlength)
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length++;
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return length;
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}
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/*
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* Return the number of bytes is the length of this string
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* Note: this is NOT the same as the number of unicode characters
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*/
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static inline unsigned long
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utf8_strsize(efi_char16_t *data, unsigned long maxlength)
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{
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return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
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}
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static efi_status_t
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get_var_data(struct efivars *efivars, struct efi_variable *var)
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{
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efi_status_t status;
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spin_lock(&efivars->lock);
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var->DataSize = 1024;
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status = efivars->ops->get_variable(var->VariableName,
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&var->VendorGuid,
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&var->Attributes,
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&var->DataSize,
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var->Data);
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spin_unlock(&efivars->lock);
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if (status != EFI_SUCCESS) {
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printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
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status);
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}
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return status;
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}
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static ssize_t
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efivar_guid_read(struct efivar_entry *entry, char *buf)
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{
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struct efi_variable *var = &entry->var;
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char *str = buf;
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if (!entry || !buf)
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return 0;
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efi_guid_unparse(&var->VendorGuid, str);
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str += strlen(str);
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str += sprintf(str, "\n");
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return str - buf;
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}
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static ssize_t
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efivar_attr_read(struct efivar_entry *entry, char *buf)
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{
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struct efi_variable *var = &entry->var;
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char *str = buf;
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efi_status_t status;
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if (!entry || !buf)
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return -EINVAL;
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status = get_var_data(entry->efivars, var);
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if (status != EFI_SUCCESS)
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return -EIO;
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if (var->Attributes & 0x1)
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str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
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if (var->Attributes & 0x2)
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str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
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if (var->Attributes & 0x4)
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str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
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return str - buf;
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}
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static ssize_t
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efivar_size_read(struct efivar_entry *entry, char *buf)
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{
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struct efi_variable *var = &entry->var;
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char *str = buf;
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efi_status_t status;
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if (!entry || !buf)
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return -EINVAL;
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status = get_var_data(entry->efivars, var);
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if (status != EFI_SUCCESS)
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return -EIO;
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str += sprintf(str, "0x%lx\n", var->DataSize);
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return str - buf;
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}
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static ssize_t
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efivar_data_read(struct efivar_entry *entry, char *buf)
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{
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struct efi_variable *var = &entry->var;
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efi_status_t status;
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if (!entry || !buf)
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return -EINVAL;
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status = get_var_data(entry->efivars, var);
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if (status != EFI_SUCCESS)
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return -EIO;
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memcpy(buf, var->Data, var->DataSize);
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return var->DataSize;
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}
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/*
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* We allow each variable to be edited via rewriting the
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* entire efi variable structure.
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*/
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static ssize_t
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efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
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{
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struct efi_variable *new_var, *var = &entry->var;
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struct efivars *efivars = entry->efivars;
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efi_status_t status = EFI_NOT_FOUND;
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if (count != sizeof(struct efi_variable))
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return -EINVAL;
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new_var = (struct efi_variable *)buf;
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/*
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* If only updating the variable data, then the name
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* and guid should remain the same
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*/
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if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
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efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
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printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
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return -EINVAL;
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}
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if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
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printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
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return -EINVAL;
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}
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spin_lock(&efivars->lock);
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status = efivars->ops->set_variable(new_var->VariableName,
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&new_var->VendorGuid,
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new_var->Attributes,
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new_var->DataSize,
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new_var->Data);
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spin_unlock(&efivars->lock);
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if (status != EFI_SUCCESS) {
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printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
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status);
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return -EIO;
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}
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memcpy(&entry->var, new_var, count);
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return count;
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}
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static ssize_t
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efivar_show_raw(struct efivar_entry *entry, char *buf)
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{
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struct efi_variable *var = &entry->var;
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efi_status_t status;
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if (!entry || !buf)
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return 0;
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status = get_var_data(entry->efivars, var);
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if (status != EFI_SUCCESS)
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return -EIO;
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memcpy(buf, var, sizeof(*var));
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return sizeof(*var);
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}
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/*
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* Generic read/write functions that call the specific functions of
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* the atttributes...
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*/
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static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
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char *buf)
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{
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struct efivar_entry *var = to_efivar_entry(kobj);
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struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
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ssize_t ret = -EIO;
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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if (efivar_attr->show) {
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ret = efivar_attr->show(var, buf);
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}
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return ret;
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}
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static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
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const char *buf, size_t count)
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{
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struct efivar_entry *var = to_efivar_entry(kobj);
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struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
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ssize_t ret = -EIO;
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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if (efivar_attr->store)
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ret = efivar_attr->store(var, buf, count);
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return ret;
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}
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static const struct sysfs_ops efivar_attr_ops = {
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.show = efivar_attr_show,
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.store = efivar_attr_store,
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};
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static void efivar_release(struct kobject *kobj)
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{
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struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
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kfree(var);
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}
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static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
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static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
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static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
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static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
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static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
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static struct attribute *def_attrs[] = {
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&efivar_attr_guid.attr,
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&efivar_attr_size.attr,
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&efivar_attr_attributes.attr,
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&efivar_attr_data.attr,
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&efivar_attr_raw_var.attr,
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NULL,
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};
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static struct kobj_type efivar_ktype = {
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.release = efivar_release,
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.sysfs_ops = &efivar_attr_ops,
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.default_attrs = def_attrs,
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};
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static inline void
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efivar_unregister(struct efivar_entry *var)
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{
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kobject_put(&var->kobj);
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}
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static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t pos, size_t count)
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{
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struct efi_variable *new_var = (struct efi_variable *)buf;
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struct efivars *efivars = bin_attr->private;
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struct efivar_entry *search_efivar, *n;
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unsigned long strsize1, strsize2;
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efi_status_t status = EFI_NOT_FOUND;
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int found = 0;
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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spin_lock(&efivars->lock);
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/*
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* Does this variable already exist?
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*/
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list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
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strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
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strsize2 = utf8_strsize(new_var->VariableName, 1024);
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if (strsize1 == strsize2 &&
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!memcmp(&(search_efivar->var.VariableName),
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new_var->VariableName, strsize1) &&
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!efi_guidcmp(search_efivar->var.VendorGuid,
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new_var->VendorGuid)) {
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found = 1;
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break;
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}
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}
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if (found) {
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spin_unlock(&efivars->lock);
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return -EINVAL;
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}
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/* now *really* create the variable via EFI */
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status = efivars->ops->set_variable(new_var->VariableName,
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&new_var->VendorGuid,
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new_var->Attributes,
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new_var->DataSize,
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new_var->Data);
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if (status != EFI_SUCCESS) {
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printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
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status);
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spin_unlock(&efivars->lock);
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return -EIO;
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}
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spin_unlock(&efivars->lock);
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/* Create the entry in sysfs. Locking is not required here */
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status = efivar_create_sysfs_entry(efivars,
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utf8_strsize(new_var->VariableName,
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1024),
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new_var->VariableName,
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&new_var->VendorGuid);
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if (status) {
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printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
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}
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return count;
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}
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static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t pos, size_t count)
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{
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struct efi_variable *del_var = (struct efi_variable *)buf;
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struct efivars *efivars = bin_attr->private;
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struct efivar_entry *search_efivar, *n;
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unsigned long strsize1, strsize2;
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efi_status_t status = EFI_NOT_FOUND;
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int found = 0;
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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spin_lock(&efivars->lock);
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/*
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* Does this variable already exist?
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*/
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list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
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strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
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strsize2 = utf8_strsize(del_var->VariableName, 1024);
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if (strsize1 == strsize2 &&
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!memcmp(&(search_efivar->var.VariableName),
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del_var->VariableName, strsize1) &&
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!efi_guidcmp(search_efivar->var.VendorGuid,
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del_var->VendorGuid)) {
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found = 1;
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break;
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}
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}
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if (!found) {
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spin_unlock(&efivars->lock);
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return -EINVAL;
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}
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/* force the Attributes/DataSize to 0 to ensure deletion */
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del_var->Attributes = 0;
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del_var->DataSize = 0;
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status = efivars->ops->set_variable(del_var->VariableName,
|
|
&del_var->VendorGuid,
|
|
del_var->Attributes,
|
|
del_var->DataSize,
|
|
del_var->Data);
|
|
|
|
if (status != EFI_SUCCESS) {
|
|
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
|
|
status);
|
|
spin_unlock(&efivars->lock);
|
|
return -EIO;
|
|
}
|
|
list_del(&search_efivar->list);
|
|
/* We need to release this lock before unregistering. */
|
|
spin_unlock(&efivars->lock);
|
|
efivar_unregister(search_efivar);
|
|
|
|
/* It's dead Jim.... */
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* 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 kobject *efi_kobj;
|
|
|
|
/*
|
|
* efivar_create_sysfs_entry()
|
|
* Requires:
|
|
* variable_name_size = number of bytes required to hold
|
|
* variable_name (not counting the NULL
|
|
* character at the end.
|
|
* efivars->lock is not held on entry or exit.
|
|
* Returns 1 on failure, 0 on success
|
|
*/
|
|
static int
|
|
efivar_create_sysfs_entry(struct efivars *efivars,
|
|
unsigned long variable_name_size,
|
|
efi_char16_t *variable_name,
|
|
efi_guid_t *vendor_guid)
|
|
{
|
|
int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
|
|
char *short_name;
|
|
struct efivar_entry *new_efivar;
|
|
|
|
short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
|
|
new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
|
|
|
|
if (!short_name || !new_efivar) {
|
|
kfree(short_name);
|
|
kfree(new_efivar);
|
|
return 1;
|
|
}
|
|
|
|
new_efivar->efivars = efivars;
|
|
memcpy(new_efivar->var.VariableName, variable_name,
|
|
variable_name_size);
|
|
memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
|
|
|
|
/* Convert Unicode to normal chars (assume top bits are 0),
|
|
ala UTF-8 */
|
|
for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
|
|
short_name[i] = variable_name[i] & 0xFF;
|
|
}
|
|
/* This is ugly, but necessary to separate one vendor's
|
|
private variables from another's. */
|
|
|
|
*(short_name + strlen(short_name)) = '-';
|
|
efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
|
|
|
|
new_efivar->kobj.kset = efivars->kset;
|
|
i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
|
|
"%s", short_name);
|
|
if (i) {
|
|
kfree(short_name);
|
|
kfree(new_efivar);
|
|
return 1;
|
|
}
|
|
|
|
kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
|
|
kfree(short_name);
|
|
short_name = NULL;
|
|
|
|
spin_lock(&efivars->lock);
|
|
list_add(&new_efivar->list, &efivars->list);
|
|
spin_unlock(&efivars->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
create_efivars_bin_attributes(struct efivars *efivars)
|
|
{
|
|
struct bin_attribute *attr;
|
|
int error;
|
|
|
|
/* new_var */
|
|
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
|
|
if (!attr)
|
|
return -ENOMEM;
|
|
|
|
attr->attr.name = "new_var";
|
|
attr->attr.mode = 0200;
|
|
attr->write = efivar_create;
|
|
attr->private = efivars;
|
|
efivars->new_var = attr;
|
|
|
|
/* del_var */
|
|
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
|
|
if (!attr) {
|
|
error = -ENOMEM;
|
|
goto out_free;
|
|
}
|
|
attr->attr.name = "del_var";
|
|
attr->attr.mode = 0200;
|
|
attr->write = efivar_delete;
|
|
attr->private = efivars;
|
|
efivars->del_var = attr;
|
|
|
|
sysfs_bin_attr_init(efivars->new_var);
|
|
sysfs_bin_attr_init(efivars->del_var);
|
|
|
|
/* Register */
|
|
error = sysfs_create_bin_file(&efivars->kset->kobj,
|
|
efivars->new_var);
|
|
if (error) {
|
|
printk(KERN_ERR "efivars: unable to create new_var sysfs file"
|
|
" due to error %d\n", error);
|
|
goto out_free;
|
|
}
|
|
error = sysfs_create_bin_file(&efivars->kset->kobj,
|
|
efivars->del_var);
|
|
if (error) {
|
|
printk(KERN_ERR "efivars: unable to create del_var sysfs file"
|
|
" due to error %d\n", error);
|
|
sysfs_remove_bin_file(&efivars->kset->kobj,
|
|
efivars->new_var);
|
|
goto out_free;
|
|
}
|
|
|
|
return 0;
|
|
out_free:
|
|
kfree(efivars->new_var);
|
|
efivars->new_var = NULL;
|
|
kfree(efivars->new_var);
|
|
efivars->new_var = NULL;
|
|
return error;
|
|
}
|
|
|
|
void unregister_efivars(struct efivars *efivars)
|
|
{
|
|
struct efivar_entry *entry, *n;
|
|
|
|
list_for_each_entry_safe(entry, n, &efivars->list, list) {
|
|
spin_lock(&efivars->lock);
|
|
list_del(&entry->list);
|
|
spin_unlock(&efivars->lock);
|
|
efivar_unregister(entry);
|
|
}
|
|
if (efivars->new_var)
|
|
sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
|
|
if (efivars->del_var)
|
|
sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
|
|
kfree(efivars->new_var);
|
|
kfree(efivars->del_var);
|
|
kset_unregister(efivars->kset);
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_efivars);
|
|
|
|
int register_efivars(struct efivars *efivars,
|
|
const struct efivar_operations *ops,
|
|
struct kobject *parent_kobj)
|
|
{
|
|
efi_status_t status = EFI_NOT_FOUND;
|
|
efi_guid_t vendor_guid;
|
|
efi_char16_t *variable_name;
|
|
unsigned long variable_name_size = 1024;
|
|
int error = 0;
|
|
|
|
variable_name = kzalloc(variable_name_size, GFP_KERNEL);
|
|
if (!variable_name) {
|
|
printk(KERN_ERR "efivars: Memory allocation failed.\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock_init(&efivars->lock);
|
|
INIT_LIST_HEAD(&efivars->list);
|
|
efivars->ops = ops;
|
|
|
|
efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
|
|
if (!efivars->kset) {
|
|
printk(KERN_ERR "efivars: Subsystem registration failed.\n");
|
|
error = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Per EFI spec, the maximum storage allocated for both
|
|
* the variable name and variable data is 1024 bytes.
|
|
*/
|
|
|
|
do {
|
|
variable_name_size = 1024;
|
|
|
|
status = ops->get_next_variable(&variable_name_size,
|
|
variable_name,
|
|
&vendor_guid);
|
|
switch (status) {
|
|
case EFI_SUCCESS:
|
|
efivar_create_sysfs_entry(efivars,
|
|
variable_name_size,
|
|
variable_name,
|
|
&vendor_guid);
|
|
break;
|
|
case EFI_NOT_FOUND:
|
|
break;
|
|
default:
|
|
printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
|
|
status);
|
|
status = EFI_NOT_FOUND;
|
|
break;
|
|
}
|
|
} while (status != EFI_NOT_FOUND);
|
|
|
|
error = create_efivars_bin_attributes(efivars);
|
|
if (error)
|
|
unregister_efivars(efivars);
|
|
|
|
out:
|
|
kfree(variable_name);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_efivars);
|
|
|
|
static struct efivars __efivars;
|
|
static struct efivar_operations ops;
|
|
|
|
/*
|
|
* For now we register the efi subsystem with the firmware subsystem
|
|
* and the vars subsystem with the efi subsystem. In the future, it
|
|
* might make sense to split off the efi subsystem into its own
|
|
* driver, but for now only efivars will register with it, so just
|
|
* include it here.
|
|
*/
|
|
|
|
static int __init
|
|
efivars_init(void)
|
|
{
|
|
int error = 0;
|
|
|
|
printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
|
|
EFIVARS_DATE);
|
|
|
|
if (!efi_enabled)
|
|
return 0;
|
|
|
|
/* For now we'll register the efi directory at /sys/firmware/efi */
|
|
efi_kobj = kobject_create_and_add("efi", firmware_kobj);
|
|
if (!efi_kobj) {
|
|
printk(KERN_ERR "efivars: Firmware registration failed.\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ops.get_variable = efi.get_variable;
|
|
ops.set_variable = efi.set_variable;
|
|
ops.get_next_variable = efi.get_next_variable;
|
|
error = register_efivars(&__efivars, &ops, efi_kobj);
|
|
|
|
/* Don't forget the systab entry */
|
|
error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
|
|
if (error) {
|
|
printk(KERN_ERR
|
|
"efivars: Sysfs attribute export failed with error %d.\n",
|
|
error);
|
|
unregister_efivars(&__efivars);
|
|
kobject_put(efi_kobj);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static void __exit
|
|
efivars_exit(void)
|
|
{
|
|
unregister_efivars(&__efivars);
|
|
kobject_put(efi_kobj);
|
|
}
|
|
|
|
module_init(efivars_init);
|
|
module_exit(efivars_exit);
|
|
|