linux/drivers/firmware/efivars.c

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/*
* EFI Variables - efivars.c
*
* Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
* Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
*
* This code takes all variables accessible from EFI runtime and
* exports them via sysfs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Changelog:
*
* 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
* remove check for efi_enabled in exit
* add MODULE_VERSION
*
* 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
* minor bug fixes
*
* 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
* converted driver to export variable information via sysfs
* and moved to drivers/firmware directory
* bumped revision number to v0.07 to reflect conversion & move
*
* 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
* fix locking per Peter Chubb's findings
*
* 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
* move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
*
* 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
* use list_for_each_safe when deleting vars.
* remove ifdef CONFIG_SMP around include <linux/smp.h>
* v0.04 release to linux-ia64@linuxia64.org
*
* 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
* Moved vars from /proc/efi to /proc/efi/vars, and made
* efi.c own the /proc/efi directory.
* v0.03 release to linux-ia64@linuxia64.org
*
* 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
* At the request of Stephane, moved ownership of /proc/efi
* to efi.c, and now efivars lives under /proc/efi/vars.
*
* 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
* Feedback received from Stephane Eranian incorporated.
* efivar_write() checks copy_from_user() return value.
* efivar_read/write() returns proper errno.
* v0.02 release to linux-ia64@linuxia64.org
*
* 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
* v0.01 release to linux-ia64@linuxia64.org
*/
#include <linux/capability.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/smp.h>
#include <linux/efi.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/device.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <asm/uaccess.h>
#define EFIVARS_VERSION "0.08"
#define EFIVARS_DATE "2004-May-17"
MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
MODULE_DESCRIPTION("sysfs interface to EFI Variables");
MODULE_LICENSE("GPL");
MODULE_VERSION(EFIVARS_VERSION);
/*
* The maximum size of VariableName + Data = 1024
* Therefore, it's reasonable to save that much
* space in each part of the structure,
* and we use a page for reading/writing.
*/
struct efi_variable {
efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
efi_guid_t VendorGuid;
unsigned long DataSize;
__u8 Data[1024];
efi_status_t Status;
__u32 Attributes;
} __attribute__((packed));
struct efivar_entry {
struct efivars *efivars;
struct efi_variable var;
struct list_head list;
struct kobject kobj;
};
struct efivar_attribute {
struct attribute attr;
ssize_t (*show) (struct efivar_entry *entry, char *buf);
ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
};
#define EFIVAR_ATTR(_name, _mode, _show, _store) \
struct efivar_attribute efivar_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode}, \
.show = _show, \
.store = _store, \
};
#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
/*
* Prototype for sysfs creation function
*/
static int
efivar_create_sysfs_entry(struct efivars *efivars,
unsigned long variable_name_size,
efi_char16_t *variable_name,
efi_guid_t *vendor_guid);
/* Return the number of unicode characters in data */
static unsigned long
utf8_strlen(efi_char16_t *data, unsigned long maxlength)
{
unsigned long length = 0;
while (*data++ != 0 && length < maxlength)
length++;
return length;
}
/*
* Return the number of bytes is the length of this string
* Note: this is NOT the same as the number of unicode characters
*/
static inline unsigned long
utf8_strsize(efi_char16_t *data, unsigned long maxlength)
{
return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
}
static efi_status_t
get_var_data(struct efivars *efivars, struct efi_variable *var)
{
efi_status_t status;
spin_lock(&efivars->lock);
var->DataSize = 1024;
status = efivars->ops->get_variable(var->VariableName,
&var->VendorGuid,
&var->Attributes,
&var->DataSize,
var->Data);
spin_unlock(&efivars->lock);
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
status);
}
return status;
}
static ssize_t
efivar_guid_read(struct efivar_entry *entry, char *buf)
{
struct efi_variable *var = &entry->var;
char *str = buf;
if (!entry || !buf)
return 0;
efi_guid_unparse(&var->VendorGuid, str);
str += strlen(str);
str += sprintf(str, "\n");
return str - buf;
}
static ssize_t
efivar_attr_read(struct efivar_entry *entry, char *buf)
{
struct efi_variable *var = &entry->var;
char *str = buf;
efi_status_t status;
if (!entry || !buf)
return -EINVAL;
status = get_var_data(entry->efivars, var);
if (status != EFI_SUCCESS)
return -EIO;
if (var->Attributes & 0x1)
str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
if (var->Attributes & 0x2)
str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
if (var->Attributes & 0x4)
str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
return str - buf;
}
static ssize_t
efivar_size_read(struct efivar_entry *entry, char *buf)
{
struct efi_variable *var = &entry->var;
char *str = buf;
efi_status_t status;
if (!entry || !buf)
return -EINVAL;
status = get_var_data(entry->efivars, var);
if (status != EFI_SUCCESS)
return -EIO;
str += sprintf(str, "0x%lx\n", var->DataSize);
return str - buf;
}
static ssize_t
efivar_data_read(struct efivar_entry *entry, char *buf)
{
struct efi_variable *var = &entry->var;
efi_status_t status;
if (!entry || !buf)
return -EINVAL;
status = get_var_data(entry->efivars, var);
if (status != EFI_SUCCESS)
return -EIO;
memcpy(buf, var->Data, var->DataSize);
return var->DataSize;
}
/*
* We allow each variable to be edited via rewriting the
* entire efi variable structure.
*/
static ssize_t
efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
{
struct efi_variable *new_var, *var = &entry->var;
struct efivars *efivars = entry->efivars;
efi_status_t status = EFI_NOT_FOUND;
if (count != sizeof(struct efi_variable))
return -EINVAL;
new_var = (struct efi_variable *)buf;
/*
* If only updating the variable data, then the name
* and guid should remain the same
*/
if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
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;
}
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 inline void
efivar_unregister(struct efivar_entry *var)
{
kobject_put(&var->kobj);
}
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;
spin_lock(&efivars->lock);
/*
* Does this variable already exist?
*/
list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_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,
utf8_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 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_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);
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)
{
efivars: prevent oops on unload when efi is not enabled efivars_exit() should check for efi_enabled and not undo allocations when efi is not enabled. Otherwise there is an Oops during module unload: calling efivars_init+0x0/0x1000 [efivars] @ 2810 EFI Variables Facility v0.08 2004-May-17 initcall efivars_init+0x0/0x1000 [efivars] returned 0 after 5120 usecs Oops: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/module/firmware_class/initstate CPU 1 Modules linked in: efivars(-) af_packet tun nfsd lockd nfs_acl auth_rpcgss sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT xt_tcpudp nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables x_tables ipv6 cpufreq_ondemand acpi_cpufreq freq_table mperf binfmt_misc dm_mirror dm_region_hash dm_log dm_multipath scsi_dh dm_mod snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_hwdep mousedev snd_seq joydev snd_seq_device mac_hid evdev snd_pcm usbkbd usbmouse usbhid snd_timer hid tg3 snd sr_mod pcspkr rtc_cmos soundcore cdrom iTCO_wdt processor sg dcdbas i2c_i801 rtc_core iTCO_vendor_support intel_agp snd_page_alloc thermal_sys rtc_lib intel_gtt 8250_pnp button hwmon unix ide_pci_generic ide_core ata_generic pata_acpi ata_piix sd_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ssb mmc_core pcmcia pcmcia_core firmware_class ehci_hcd usbcore [last unloaded: dell_rbu] Pid: 2812, comm: rmmod Not tainted 2.6.39-rc6 #1 Dell Inc. OptiPlex 745 /0TY565 RIP: 0010:[<ffffffffa06a17f6>] [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars] RSP: 0018:ffff88005eedde98 EFLAGS: 00010283 RAX: ffffffffa06a23fc RBX: ffffffffa06a44c0 RCX: ffff88007c227a50 RDX: 0000000000000000 RSI: 00000055ac13db78 RDI: ffffffffa06a44c0 RBP: ffff88005eeddec8 R08: 0000000000000000 R09: ffff88005eeddd78 R10: ffffffffa06a4220 R11: ffff88005eeddd78 R12: fffffffffffff7d0 R13: 00007fff5a3aaec0 R14: 0000000000000000 R15: ffffffffa06a4508 FS: 00007fa8dcc4a6f0(0000) GS:ffff88007c200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 000000005d148000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rmmod (pid: 2812, threadinfo ffff88005eedc000, task ffff88006754b000) Stack: ffff88005eeddec8 ffffffffa06a4220 0000000000000000 00007fff5a3aaec0 0000000000000000 0000000000000001 ffff88005eedded8 ffffffffa06a2418 ffff88005eeddf78 ffffffff810d3598 ffffffffa06a4220 0000000000000880 Call Trace: [<ffffffffa06a2418>] efivars_exit+0x1c/0xc04 [efivars] [<ffffffff810d3598>] sys_delete_module+0x2d6/0x368 [<ffffffff812d1db9>] ? lockdep_sys_exit_thunk+0x35/0x67 [<ffffffff810fcba1>] ? audit_syscall_entry+0x172/0x1a5 [<ffffffff81575082>] system_call_fastpath+0x16/0x1b Code: 5c c9 c3 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 0f 1f 44 00 00 4c 8b 67 48 48 89 fb 4c 8d 7f 48 49 81 ec 30 08 00 00 <4d> 8b ac 24 30 08 00 00 49 81 ed 30 08 00 00 eb 59 48 89 df 48 RIP [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars] RSP <ffff88005eedde98> CR2: 0000000000000000 ---[ end trace aa99b99090f70baa ]--- Matt apparently removed such a check in 2004 (with no reason given): * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com> * remove check for efi_enabled in exit but there have been several changes since then. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Mike Waychison <mikew@google.com> Tested-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Cc: <matthew.e.tolentino@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-06 20:27:41 +00:00
if (efi_enabled) {
unregister_efivars(&__efivars);
kobject_put(efi_kobj);
}
}
module_init(efivars_init);
module_exit(efivars_exit);