efi: Add support for using efivars as a pstore backend
EFI provides an area of nonvolatile storage managed by the firmware. We can use this as a pstore backend to maintain copies of oopses, aiding diagnosis. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Matthew Garrett
Tony Luck
parent
dee28e72b6
commit
5ee9c198a4
|
|
@ -78,6 +78,7 @@
|
|||
#include <linux/kobject.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/pstore.h>
|
||||
|
||||
#include <asm/uaccess.h>
|
||||
|
||||
|
|
@ -89,6 +90,8 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables");
|
|||
MODULE_LICENSE("GPL");
|
||||
MODULE_VERSION(EFIVARS_VERSION);
|
||||
|
||||
#define DUMP_NAME_LEN 52
|
||||
|
||||
/*
|
||||
* The maximum size of VariableName + Data = 1024
|
||||
* Therefore, it's reasonable to save that much
|
||||
|
|
@ -161,18 +164,28 @@ utf8_strsize(efi_char16_t *data, unsigned long maxlength)
|
|||
}
|
||||
|
||||
static efi_status_t
|
||||
get_var_data(struct efivars *efivars, struct efi_variable *var)
|
||||
get_var_data_locked(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);
|
||||
return status;
|
||||
}
|
||||
|
||||
static efi_status_t
|
||||
get_var_data(struct efivars *efivars, struct efi_variable *var)
|
||||
{
|
||||
efi_status_t status;
|
||||
|
||||
spin_lock(&efivars->lock);
|
||||
status = get_var_data_locked(efivars, var);
|
||||
spin_unlock(&efivars->lock);
|
||||
|
||||
if (status != EFI_SUCCESS) {
|
||||
printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
|
||||
status);
|
||||
|
|
@ -387,12 +400,176 @@ static struct kobj_type efivar_ktype = {
|
|||
.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, 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;
|
||||
memcpy(psi->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 u64 efi_pstore_write(enum pstore_type_id type, 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;
|
||||
|
||||
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);
|
||||
|
||||
for (i = 0; i < DUMP_NAME_LEN; i++) {
|
||||
if (efi_name[i] == 0) {
|
||||
found = entry;
|
||||
efivars->ops->set_variable(entry->var.VariableName,
|
||||
&entry->var.VendorGuid,
|
||||
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
|
||||
0, NULL);
|
||||
break;
|
||||
} else if (efi_name[i] != entry->var.VariableName[i]) {
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
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,
|
||||
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
|
||||
size, psi->buf);
|
||||
|
||||
spin_unlock(&efivars->lock);
|
||||
|
||||
if (found)
|
||||
efivar_unregister(found);
|
||||
|
||||
if (size)
|
||||
efivar_create_sysfs_entry(efivars, utf8_strsize(efi_name, DUMP_NAME_LEN * 2),
|
||||
efi_name, &vendor);
|
||||
|
||||
return part;
|
||||
};
|
||||
|
||||
static int efi_pstore_erase(enum pstore_type_id type, u64 id,
|
||||
struct pstore_info *psi)
|
||||
{
|
||||
efi_pstore_write(type, 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 *time, struct pstore_info *psi)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static u64 efi_pstore_write(enum pstore_type_id type, 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,
|
||||
|
|
@ -763,6 +940,16 @@ int register_efivars(struct efivars *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;
|
||||
mutex_init(&efivars->efi_pstore_info.buf_mutex);
|
||||
pstore_register(&efivars->efi_pstore_info);
|
||||
}
|
||||
|
||||
out:
|
||||
kfree(variable_name);
|
||||
|
||||
|
|
|
|||
|
|
@ -19,6 +19,7 @@
|
|||
#include <linux/rtc.h>
|
||||
#include <linux/ioport.h>
|
||||
#include <linux/pfn.h>
|
||||
#include <linux/pstore.h>
|
||||
|
||||
#include <asm/page.h>
|
||||
#include <asm/system.h>
|
||||
|
|
@ -211,6 +212,9 @@ typedef efi_status_t efi_set_virtual_address_map_t (unsigned long memory_map_siz
|
|||
#define UV_SYSTEM_TABLE_GUID \
|
||||
EFI_GUID( 0x3b13a7d4, 0x633e, 0x11dd, 0x93, 0xec, 0xda, 0x25, 0x56, 0xd8, 0x95, 0x93 )
|
||||
|
||||
#define LINUX_EFI_CRASH_GUID \
|
||||
EFI_GUID( 0xcfc8fc79, 0xbe2e, 0x4ddc, 0x97, 0xf0, 0x9f, 0x98, 0xbf, 0xe2, 0x98, 0xa0 )
|
||||
|
||||
typedef struct {
|
||||
efi_guid_t guid;
|
||||
unsigned long table;
|
||||
|
|
@ -426,6 +430,8 @@ struct efivars {
|
|||
struct kset *kset;
|
||||
struct bin_attribute *new_var, *del_var;
|
||||
const struct efivar_operations *ops;
|
||||
struct efivar_entry *walk_entry;
|
||||
struct pstore_info efi_pstore_info;
|
||||
};
|
||||
|
||||
int register_efivars(struct efivars *efivars,
|
||||
|
|
|
|||
Loading…
Reference in a new issue