![Khalid Aziz](/assets/img/avatar_default.png)
Some of the EFI variable attributes are missing from print out from /sys/firmware/efi/vars/*/attributes. This patch adds those in. It also updates code to use pre-defined constants for masking current value of attributes. Signed-off-by: Khalid Aziz <khalid.aziz@hp.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Matthew Garrett <mjg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1274 lines
32 KiB
C
1274 lines
32 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 <linux/pstore.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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#define DUMP_NAME_LEN 52
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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 PSTORE_EFI_ATTRIBUTES \
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(EFI_VARIABLE_NON_VOLATILE | \
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EFI_VARIABLE_BOOTSERVICE_ACCESS | \
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EFI_VARIABLE_RUNTIME_ACCESS)
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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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utf16_strnlen(efi_char16_t *s, size_t maxlength)
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{
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unsigned long length = 0;
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while (*s++ != 0 && length < maxlength)
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length++;
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return length;
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}
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static inline unsigned long
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utf16_strlen(efi_char16_t *s)
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{
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return utf16_strnlen(s, ~0UL);
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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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utf16_strsize(efi_char16_t *data, unsigned long maxlength)
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{
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return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
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}
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static inline int
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utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
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{
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while (1) {
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if (len == 0)
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return 0;
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if (*a < *b)
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return -1;
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if (*a > *b)
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return 1;
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if (*a == 0) /* implies *b == 0 */
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return 0;
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a++;
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b++;
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len--;
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}
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}
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static bool
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validate_device_path(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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struct efi_generic_dev_path *node;
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int offset = 0;
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node = (struct efi_generic_dev_path *)buffer;
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if (len < sizeof(*node))
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return false;
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while (offset <= len - sizeof(*node) &&
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node->length >= sizeof(*node) &&
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node->length <= len - offset) {
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offset += node->length;
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if ((node->type == EFI_DEV_END_PATH ||
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node->type == EFI_DEV_END_PATH2) &&
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node->sub_type == EFI_DEV_END_ENTIRE)
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return true;
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node = (struct efi_generic_dev_path *)(buffer + offset);
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}
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/*
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* If we're here then either node->length pointed past the end
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* of the buffer or we reached the end of the buffer without
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* finding a device path end node.
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*/
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return false;
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}
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static bool
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validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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/* An array of 16-bit integers */
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if ((len % 2) != 0)
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return false;
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return true;
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}
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static bool
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validate_load_option(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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u16 filepathlength;
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int i, desclength = 0, namelen;
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namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
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/* Either "Boot" or "Driver" followed by four digits of hex */
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for (i = match; i < match+4; i++) {
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if (var->VariableName[i] > 127 ||
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hex_to_bin(var->VariableName[i] & 0xff) < 0)
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return true;
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}
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/* Reject it if there's 4 digits of hex and then further content */
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if (namelen > match + 4)
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return false;
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/* A valid entry must be at least 8 bytes */
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if (len < 8)
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return false;
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filepathlength = buffer[4] | buffer[5] << 8;
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/*
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* There's no stored length for the description, so it has to be
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* found by hand
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*/
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desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
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/* Each boot entry must have a descriptor */
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if (!desclength)
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return false;
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/*
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* If the sum of the length of the description, the claimed filepath
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* length and the original header are greater than the length of the
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* variable, it's malformed
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*/
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if ((desclength + filepathlength + 6) > len)
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return false;
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/*
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* And, finally, check the filepath
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*/
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return validate_device_path(var, match, buffer + desclength + 6,
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filepathlength);
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}
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static bool
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validate_uint16(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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/* A single 16-bit integer */
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if (len != 2)
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return false;
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return true;
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}
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static bool
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validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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int i;
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for (i = 0; i < len; i++) {
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if (buffer[i] > 127)
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return false;
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if (buffer[i] == 0)
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return true;
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}
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return false;
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}
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struct variable_validate {
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char *name;
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bool (*validate)(struct efi_variable *var, int match, u8 *data,
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unsigned long len);
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};
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static const struct variable_validate variable_validate[] = {
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{ "BootNext", validate_uint16 },
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{ "BootOrder", validate_boot_order },
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{ "DriverOrder", validate_boot_order },
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{ "Boot*", validate_load_option },
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{ "Driver*", validate_load_option },
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{ "ConIn", validate_device_path },
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{ "ConInDev", validate_device_path },
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{ "ConOut", validate_device_path },
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{ "ConOutDev", validate_device_path },
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{ "ErrOut", validate_device_path },
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{ "ErrOutDev", validate_device_path },
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{ "Timeout", validate_uint16 },
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{ "Lang", validate_ascii_string },
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{ "PlatformLang", validate_ascii_string },
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{ "", NULL },
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};
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static bool
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validate_var(struct efi_variable *var, u8 *data, unsigned long len)
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{
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int i;
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u16 *unicode_name = var->VariableName;
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for (i = 0; variable_validate[i].validate != NULL; i++) {
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const char *name = variable_validate[i].name;
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int match;
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for (match = 0; ; match++) {
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char c = name[match];
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u16 u = unicode_name[match];
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/* All special variables are plain ascii */
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if (u > 127)
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return true;
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/* Wildcard in the matching name means we've matched */
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if (c == '*')
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return variable_validate[i].validate(var,
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match, data, len);
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/* Case sensitive match */
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if (c != u)
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break;
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/* Reached the end of the string while matching */
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if (!c)
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return variable_validate[i].validate(var,
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match, data, len);
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}
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}
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return true;
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}
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static efi_status_t
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get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
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{
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efi_status_t status;
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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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return status;
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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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status = get_var_data_locked(efivars, var);
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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 & EFI_VARIABLE_NON_VOLATILE)
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str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
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if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
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str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
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if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
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str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
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if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
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str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
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if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
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str += sprintf(str,
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"EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
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if (var->Attributes &
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EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
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str += sprintf(str,
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"EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
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if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
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str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\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)) {
|
|
printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
|
|
printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
|
|
validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
|
|
printk(KERN_ERR "efivars: Malformed variable content\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
spin_lock(&efivars->lock);
|
|
status = efivars->ops->set_variable(new_var->VariableName,
|
|
&new_var->VendorGuid,
|
|
new_var->Attributes,
|
|
new_var->DataSize,
|
|
new_var->Data);
|
|
|
|
spin_unlock(&efivars->lock);
|
|
|
|
if (status != EFI_SUCCESS) {
|
|
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
|
|
status);
|
|
return -EIO;
|
|
}
|
|
|
|
memcpy(&entry->var, new_var, count);
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
efivar_show_raw(struct efivar_entry *entry, char *buf)
|
|
{
|
|
struct efi_variable *var = &entry->var;
|
|
efi_status_t status;
|
|
|
|
if (!entry || !buf)
|
|
return 0;
|
|
|
|
status = get_var_data(entry->efivars, var);
|
|
if (status != EFI_SUCCESS)
|
|
return -EIO;
|
|
|
|
memcpy(buf, var, sizeof(*var));
|
|
return sizeof(*var);
|
|
}
|
|
|
|
/*
|
|
* Generic read/write functions that call the specific functions of
|
|
* the attributes...
|
|
*/
|
|
static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct efivar_entry *var = to_efivar_entry(kobj);
|
|
struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
|
|
ssize_t ret = -EIO;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EACCES;
|
|
|
|
if (efivar_attr->show) {
|
|
ret = efivar_attr->show(var, buf);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct efivar_entry *var = to_efivar_entry(kobj);
|
|
struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
|
|
ssize_t ret = -EIO;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EACCES;
|
|
|
|
if (efivar_attr->store)
|
|
ret = efivar_attr->store(var, buf, count);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct sysfs_ops efivar_attr_ops = {
|
|
.show = efivar_attr_show,
|
|
.store = efivar_attr_store,
|
|
};
|
|
|
|
static void efivar_release(struct kobject *kobj)
|
|
{
|
|
struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
|
|
kfree(var);
|
|
}
|
|
|
|
static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
|
|
static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
|
|
static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
|
|
static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
|
|
static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
|
|
|
|
static struct attribute *def_attrs[] = {
|
|
&efivar_attr_guid.attr,
|
|
&efivar_attr_size.attr,
|
|
&efivar_attr_attributes.attr,
|
|
&efivar_attr_data.attr,
|
|
&efivar_attr_raw_var.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct kobj_type efivar_ktype = {
|
|
.release = efivar_release,
|
|
.sysfs_ops = &efivar_attr_ops,
|
|
.default_attrs = def_attrs,
|
|
};
|
|
|
|
static struct pstore_info efi_pstore_info;
|
|
|
|
static inline void
|
|
efivar_unregister(struct efivar_entry *var)
|
|
{
|
|
kobject_put(&var->kobj);
|
|
}
|
|
|
|
#ifdef CONFIG_PSTORE
|
|
|
|
static int efi_pstore_open(struct pstore_info *psi)
|
|
{
|
|
struct efivars *efivars = psi->data;
|
|
|
|
spin_lock(&efivars->lock);
|
|
efivars->walk_entry = list_first_entry(&efivars->list,
|
|
struct efivar_entry, list);
|
|
return 0;
|
|
}
|
|
|
|
static int efi_pstore_close(struct pstore_info *psi)
|
|
{
|
|
struct efivars *efivars = psi->data;
|
|
|
|
spin_unlock(&efivars->lock);
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
|
|
struct timespec *timespec,
|
|
char **buf, struct pstore_info *psi)
|
|
{
|
|
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
|
|
struct efivars *efivars = psi->data;
|
|
char name[DUMP_NAME_LEN];
|
|
int i;
|
|
unsigned int part, size;
|
|
unsigned long time;
|
|
|
|
while (&efivars->walk_entry->list != &efivars->list) {
|
|
if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
|
|
vendor)) {
|
|
for (i = 0; i < DUMP_NAME_LEN; i++) {
|
|
name[i] = efivars->walk_entry->var.VariableName[i];
|
|
}
|
|
if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
|
|
*id = part;
|
|
timespec->tv_sec = time;
|
|
timespec->tv_nsec = 0;
|
|
get_var_data_locked(efivars, &efivars->walk_entry->var);
|
|
size = efivars->walk_entry->var.DataSize;
|
|
*buf = kmalloc(size, GFP_KERNEL);
|
|
if (*buf == NULL)
|
|
return -ENOMEM;
|
|
memcpy(*buf, efivars->walk_entry->var.Data,
|
|
size);
|
|
efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
|
|
struct efivar_entry, list);
|
|
return size;
|
|
}
|
|
}
|
|
efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
|
|
struct efivar_entry, list);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int efi_pstore_write(enum pstore_type_id type,
|
|
enum kmsg_dump_reason reason, u64 *id,
|
|
unsigned int part, size_t size, struct pstore_info *psi)
|
|
{
|
|
char name[DUMP_NAME_LEN];
|
|
char stub_name[DUMP_NAME_LEN];
|
|
efi_char16_t efi_name[DUMP_NAME_LEN];
|
|
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
|
|
struct efivars *efivars = psi->data;
|
|
struct efivar_entry *entry, *found = NULL;
|
|
int i, ret = 0;
|
|
|
|
sprintf(stub_name, "dump-type%u-%u-", type, part);
|
|
sprintf(name, "%s%lu", stub_name, get_seconds());
|
|
|
|
spin_lock(&efivars->lock);
|
|
|
|
for (i = 0; i < DUMP_NAME_LEN; i++)
|
|
efi_name[i] = stub_name[i];
|
|
|
|
/*
|
|
* Clean up any entries with the same name
|
|
*/
|
|
|
|
list_for_each_entry(entry, &efivars->list, list) {
|
|
get_var_data_locked(efivars, &entry->var);
|
|
|
|
if (efi_guidcmp(entry->var.VendorGuid, vendor))
|
|
continue;
|
|
if (utf16_strncmp(entry->var.VariableName, efi_name,
|
|
utf16_strlen(efi_name)))
|
|
continue;
|
|
/* Needs to be a prefix */
|
|
if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
|
|
continue;
|
|
|
|
/* found */
|
|
found = entry;
|
|
efivars->ops->set_variable(entry->var.VariableName,
|
|
&entry->var.VendorGuid,
|
|
PSTORE_EFI_ATTRIBUTES,
|
|
0, NULL);
|
|
}
|
|
|
|
if (found)
|
|
list_del(&found->list);
|
|
|
|
for (i = 0; i < DUMP_NAME_LEN; i++)
|
|
efi_name[i] = name[i];
|
|
|
|
efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
|
|
size, psi->buf);
|
|
|
|
spin_unlock(&efivars->lock);
|
|
|
|
if (found)
|
|
efivar_unregister(found);
|
|
|
|
if (size)
|
|
ret = efivar_create_sysfs_entry(efivars,
|
|
utf16_strsize(efi_name,
|
|
DUMP_NAME_LEN * 2),
|
|
efi_name, &vendor);
|
|
|
|
*id = part;
|
|
return ret;
|
|
};
|
|
|
|
static int efi_pstore_erase(enum pstore_type_id type, u64 id,
|
|
struct pstore_info *psi)
|
|
{
|
|
efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi);
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
static int efi_pstore_open(struct pstore_info *psi)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int efi_pstore_close(struct pstore_info *psi)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
|
|
struct timespec *timespec,
|
|
char **buf, struct pstore_info *psi)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
static int efi_pstore_write(enum pstore_type_id type,
|
|
enum kmsg_dump_reason reason, u64 *id,
|
|
unsigned int part, size_t size, struct pstore_info *psi)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int efi_pstore_erase(enum pstore_type_id type, u64 id,
|
|
struct pstore_info *psi)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
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 ssize_t efivar_create(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *bin_attr,
|
|
char *buf, loff_t pos, size_t count)
|
|
{
|
|
struct efi_variable *new_var = (struct efi_variable *)buf;
|
|
struct efivars *efivars = bin_attr->private;
|
|
struct efivar_entry *search_efivar, *n;
|
|
unsigned long strsize1, strsize2;
|
|
efi_status_t status = EFI_NOT_FOUND;
|
|
int found = 0;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EACCES;
|
|
|
|
if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
|
|
validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
|
|
printk(KERN_ERR "efivars: Malformed variable content\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
spin_lock(&efivars->lock);
|
|
|
|
/*
|
|
* Does this variable already exist?
|
|
*/
|
|
list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
|
|
strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
|
|
strsize2 = utf16_strsize(new_var->VariableName, 1024);
|
|
if (strsize1 == strsize2 &&
|
|
!memcmp(&(search_efivar->var.VariableName),
|
|
new_var->VariableName, strsize1) &&
|
|
!efi_guidcmp(search_efivar->var.VendorGuid,
|
|
new_var->VendorGuid)) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (found) {
|
|
spin_unlock(&efivars->lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* now *really* create the variable via EFI */
|
|
status = efivars->ops->set_variable(new_var->VariableName,
|
|
&new_var->VendorGuid,
|
|
new_var->Attributes,
|
|
new_var->DataSize,
|
|
new_var->Data);
|
|
|
|
if (status != EFI_SUCCESS) {
|
|
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
|
|
status);
|
|
spin_unlock(&efivars->lock);
|
|
return -EIO;
|
|
}
|
|
spin_unlock(&efivars->lock);
|
|
|
|
/* Create the entry in sysfs. Locking is not required here */
|
|
status = efivar_create_sysfs_entry(efivars,
|
|
utf16_strsize(new_var->VariableName,
|
|
1024),
|
|
new_var->VariableName,
|
|
&new_var->VendorGuid);
|
|
if (status) {
|
|
printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *bin_attr,
|
|
char *buf, loff_t pos, size_t count)
|
|
{
|
|
struct efi_variable *del_var = (struct efi_variable *)buf;
|
|
struct efivars *efivars = bin_attr->private;
|
|
struct efivar_entry *search_efivar, *n;
|
|
unsigned long strsize1, strsize2;
|
|
efi_status_t status = EFI_NOT_FOUND;
|
|
int found = 0;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EACCES;
|
|
|
|
spin_lock(&efivars->lock);
|
|
|
|
/*
|
|
* Does this variable already exist?
|
|
*/
|
|
list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
|
|
strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
|
|
strsize2 = utf16_strsize(del_var->VariableName, 1024);
|
|
if (strsize1 == strsize2 &&
|
|
!memcmp(&(search_efivar->var.VariableName),
|
|
del_var->VariableName, strsize1) &&
|
|
!efi_guidcmp(search_efivar->var.VendorGuid,
|
|
del_var->VendorGuid)) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
spin_unlock(&efivars->lock);
|
|
return -EINVAL;
|
|
}
|
|
/* force the Attributes/DataSize to 0 to ensure deletion */
|
|
del_var->Attributes = 0;
|
|
del_var->DataSize = 0;
|
|
|
|
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->del_var);
|
|
efivars->del_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);
|
|
|
|
efivars->efi_pstore_info = efi_pstore_info;
|
|
|
|
efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
|
|
if (efivars->efi_pstore_info.buf) {
|
|
efivars->efi_pstore_info.bufsize = 1024;
|
|
efivars->efi_pstore_info.data = efivars;
|
|
spin_lock_init(&efivars->efi_pstore_info.buf_lock);
|
|
pstore_register(&efivars->efi_pstore_info);
|
|
}
|
|
|
|
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);
|
|
if (error)
|
|
goto err_put;
|
|
|
|
/* 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);
|
|
goto err_unregister;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_unregister:
|
|
unregister_efivars(&__efivars);
|
|
err_put:
|
|
kobject_put(efi_kobj);
|
|
return error;
|
|
}
|
|
|
|
static void __exit
|
|
efivars_exit(void)
|
|
{
|
|
if (efi_enabled) {
|
|
unregister_efivars(&__efivars);
|
|
kobject_put(efi_kobj);
|
|
}
|
|
}
|
|
|
|
module_init(efivars_init);
|
|
module_exit(efivars_exit);
|
|
|