400 строки
9.3 KiB
C
400 строки
9.3 KiB
C
#include <linux/efi.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pstore.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/ucs2_string.h>
|
|
|
|
#define DUMP_NAME_LEN 66
|
|
|
|
static bool efivars_pstore_disable =
|
|
IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
|
|
|
|
module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
|
|
|
|
#define PSTORE_EFI_ATTRIBUTES \
|
|
(EFI_VARIABLE_NON_VOLATILE | \
|
|
EFI_VARIABLE_BOOTSERVICE_ACCESS | \
|
|
EFI_VARIABLE_RUNTIME_ACCESS)
|
|
|
|
static int efi_pstore_open(struct pstore_info *psi)
|
|
{
|
|
psi->data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static int efi_pstore_close(struct pstore_info *psi)
|
|
{
|
|
psi->data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static inline u64 generic_id(u64 timestamp, unsigned int part, int count)
|
|
{
|
|
return (timestamp * 100 + part) * 1000 + count;
|
|
}
|
|
|
|
static int efi_pstore_read_func(struct efivar_entry *entry,
|
|
struct pstore_record *record)
|
|
{
|
|
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
|
|
char name[DUMP_NAME_LEN], data_type;
|
|
int i;
|
|
int cnt;
|
|
unsigned int part;
|
|
unsigned long size;
|
|
u64 time;
|
|
|
|
if (efi_guidcmp(entry->var.VendorGuid, vendor))
|
|
return 0;
|
|
|
|
for (i = 0; i < DUMP_NAME_LEN; i++)
|
|
name[i] = entry->var.VariableName[i];
|
|
|
|
if (sscanf(name, "dump-type%u-%u-%d-%llu-%c",
|
|
&record->type, &part, &cnt, &time, &data_type) == 5) {
|
|
record->id = generic_id(time, part, cnt);
|
|
record->part = part;
|
|
record->count = cnt;
|
|
record->time.tv_sec = time;
|
|
record->time.tv_nsec = 0;
|
|
if (data_type == 'C')
|
|
record->compressed = true;
|
|
else
|
|
record->compressed = false;
|
|
record->ecc_notice_size = 0;
|
|
} else if (sscanf(name, "dump-type%u-%u-%d-%llu",
|
|
&record->type, &part, &cnt, &time) == 4) {
|
|
record->id = generic_id(time, part, cnt);
|
|
record->part = part;
|
|
record->count = cnt;
|
|
record->time.tv_sec = time;
|
|
record->time.tv_nsec = 0;
|
|
record->compressed = false;
|
|
record->ecc_notice_size = 0;
|
|
} else if (sscanf(name, "dump-type%u-%u-%llu",
|
|
&record->type, &part, &time) == 3) {
|
|
/*
|
|
* Check if an old format,
|
|
* which doesn't support holding
|
|
* multiple logs, remains.
|
|
*/
|
|
record->id = generic_id(time, part, 0);
|
|
record->part = part;
|
|
record->count = 0;
|
|
record->time.tv_sec = time;
|
|
record->time.tv_nsec = 0;
|
|
record->compressed = false;
|
|
record->ecc_notice_size = 0;
|
|
} else
|
|
return 0;
|
|
|
|
entry->var.DataSize = 1024;
|
|
__efivar_entry_get(entry, &entry->var.Attributes,
|
|
&entry->var.DataSize, entry->var.Data);
|
|
size = entry->var.DataSize;
|
|
memcpy(record->buf, entry->var.Data,
|
|
(size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
|
|
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* efi_pstore_scan_sysfs_enter
|
|
* @pos: scanning entry
|
|
* @next: next entry
|
|
* @head: list head
|
|
*/
|
|
static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
|
|
struct efivar_entry *next,
|
|
struct list_head *head)
|
|
{
|
|
pos->scanning = true;
|
|
if (&next->list != head)
|
|
next->scanning = true;
|
|
}
|
|
|
|
/**
|
|
* __efi_pstore_scan_sysfs_exit
|
|
* @entry: deleting entry
|
|
* @turn_off_scanning: Check if a scanning flag should be turned off
|
|
*/
|
|
static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
|
|
bool turn_off_scanning)
|
|
{
|
|
if (entry->deleting) {
|
|
list_del(&entry->list);
|
|
efivar_entry_iter_end();
|
|
efivar_unregister(entry);
|
|
if (efivar_entry_iter_begin())
|
|
return -EINTR;
|
|
} else if (turn_off_scanning)
|
|
entry->scanning = false;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* efi_pstore_scan_sysfs_exit
|
|
* @pos: scanning entry
|
|
* @next: next entry
|
|
* @head: list head
|
|
* @stop: a flag checking if scanning will stop
|
|
*/
|
|
static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
|
|
struct efivar_entry *next,
|
|
struct list_head *head, bool stop)
|
|
{
|
|
int ret = __efi_pstore_scan_sysfs_exit(pos, true);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (stop)
|
|
ret = __efi_pstore_scan_sysfs_exit(next, &next->list != head);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* efi_pstore_sysfs_entry_iter
|
|
*
|
|
* @record: pstore record to pass to callback
|
|
*
|
|
* You MUST call efivar_enter_iter_begin() before this function, and
|
|
* efivar_entry_iter_end() afterwards.
|
|
*
|
|
*/
|
|
static int efi_pstore_sysfs_entry_iter(struct pstore_record *record)
|
|
{
|
|
struct efivar_entry **pos = (struct efivar_entry **)&record->psi->data;
|
|
struct efivar_entry *entry, *n;
|
|
struct list_head *head = &efivar_sysfs_list;
|
|
int size = 0;
|
|
int ret;
|
|
|
|
if (!*pos) {
|
|
list_for_each_entry_safe(entry, n, head, list) {
|
|
efi_pstore_scan_sysfs_enter(entry, n, head);
|
|
|
|
size = efi_pstore_read_func(entry, record);
|
|
ret = efi_pstore_scan_sysfs_exit(entry, n, head,
|
|
size < 0);
|
|
if (ret)
|
|
return ret;
|
|
if (size)
|
|
break;
|
|
}
|
|
*pos = n;
|
|
return size;
|
|
}
|
|
|
|
list_for_each_entry_safe_from((*pos), n, head, list) {
|
|
efi_pstore_scan_sysfs_enter((*pos), n, head);
|
|
|
|
size = efi_pstore_read_func((*pos), record);
|
|
ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
|
|
if (ret)
|
|
return ret;
|
|
if (size)
|
|
break;
|
|
}
|
|
*pos = n;
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* efi_pstore_read
|
|
*
|
|
* This function returns a size of NVRAM entry logged via efi_pstore_write().
|
|
* The meaning and behavior of efi_pstore/pstore are as below.
|
|
*
|
|
* size > 0: Got data of an entry logged via efi_pstore_write() successfully,
|
|
* and pstore filesystem will continue reading subsequent entries.
|
|
* size == 0: Entry was not logged via efi_pstore_write(),
|
|
* and efi_pstore driver will continue reading subsequent entries.
|
|
* size < 0: Failed to get data of entry logging via efi_pstore_write(),
|
|
* and pstore will stop reading entry.
|
|
*/
|
|
static ssize_t efi_pstore_read(struct pstore_record *record)
|
|
{
|
|
ssize_t size;
|
|
|
|
record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
|
|
if (!record->buf)
|
|
return -ENOMEM;
|
|
|
|
if (efivar_entry_iter_begin()) {
|
|
size = -EINTR;
|
|
goto out;
|
|
}
|
|
size = efi_pstore_sysfs_entry_iter(record);
|
|
efivar_entry_iter_end();
|
|
|
|
out:
|
|
if (size <= 0) {
|
|
kfree(record->buf);
|
|
record->buf = NULL;
|
|
}
|
|
return size;
|
|
}
|
|
|
|
static int efi_pstore_write(struct pstore_record *record)
|
|
{
|
|
char name[DUMP_NAME_LEN];
|
|
efi_char16_t efi_name[DUMP_NAME_LEN];
|
|
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
|
|
int i, ret = 0;
|
|
|
|
record->id = generic_id(record->time.tv_sec, record->part,
|
|
record->count);
|
|
|
|
/* Since we copy the entire length of name, make sure it is wiped. */
|
|
memset(name, 0, sizeof(name));
|
|
|
|
snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lld-%c",
|
|
record->type, record->part, record->count,
|
|
(long long)record->time.tv_sec,
|
|
record->compressed ? 'C' : 'D');
|
|
|
|
for (i = 0; i < DUMP_NAME_LEN; i++)
|
|
efi_name[i] = name[i];
|
|
|
|
ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
|
|
!pstore_cannot_block_path(record->reason),
|
|
record->size, record->psi->buf);
|
|
|
|
if (record->reason == KMSG_DUMP_OOPS)
|
|
efivar_run_worker();
|
|
|
|
return ret;
|
|
};
|
|
|
|
/*
|
|
* Clean up an entry with the same name
|
|
*/
|
|
static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
|
|
{
|
|
efi_char16_t *efi_name = data;
|
|
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
|
|
unsigned long ucs2_len = ucs2_strlen(efi_name);
|
|
|
|
if (efi_guidcmp(entry->var.VendorGuid, vendor))
|
|
return 0;
|
|
|
|
if (ucs2_strncmp(entry->var.VariableName, efi_name, (size_t)ucs2_len))
|
|
return 0;
|
|
|
|
if (entry->scanning) {
|
|
/*
|
|
* Skip deletion because this entry will be deleted
|
|
* after scanning is completed.
|
|
*/
|
|
entry->deleting = true;
|
|
} else
|
|
list_del(&entry->list);
|
|
|
|
/* found */
|
|
__efivar_entry_delete(entry);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int efi_pstore_erase_name(const char *name)
|
|
{
|
|
struct efivar_entry *entry = NULL;
|
|
efi_char16_t efi_name[DUMP_NAME_LEN];
|
|
int found, i;
|
|
|
|
for (i = 0; i < DUMP_NAME_LEN; i++) {
|
|
efi_name[i] = name[i];
|
|
if (name[i] == '\0')
|
|
break;
|
|
}
|
|
|
|
if (efivar_entry_iter_begin())
|
|
return -EINTR;
|
|
|
|
found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list,
|
|
efi_name, &entry);
|
|
efivar_entry_iter_end();
|
|
|
|
if (found && !entry->scanning)
|
|
efivar_unregister(entry);
|
|
|
|
return found ? 0 : -ENOENT;
|
|
}
|
|
|
|
static int efi_pstore_erase(struct pstore_record *record)
|
|
{
|
|
char name[DUMP_NAME_LEN];
|
|
int ret;
|
|
|
|
snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lld",
|
|
record->type, record->part, record->count,
|
|
(long long)record->time.tv_sec);
|
|
ret = efi_pstore_erase_name(name);
|
|
if (ret != -ENOENT)
|
|
return ret;
|
|
|
|
snprintf(name, sizeof(name), "dump-type%u-%u-%lld",
|
|
record->type, record->part, (long long)record->time.tv_sec);
|
|
ret = efi_pstore_erase_name(name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct pstore_info efi_pstore_info = {
|
|
.owner = THIS_MODULE,
|
|
.name = "efi",
|
|
.flags = PSTORE_FLAGS_DMESG,
|
|
.open = efi_pstore_open,
|
|
.close = efi_pstore_close,
|
|
.read = efi_pstore_read,
|
|
.write = efi_pstore_write,
|
|
.erase = efi_pstore_erase,
|
|
};
|
|
|
|
static __init int efivars_pstore_init(void)
|
|
{
|
|
if (!efi_enabled(EFI_RUNTIME_SERVICES))
|
|
return 0;
|
|
|
|
if (!efivars_kobject())
|
|
return 0;
|
|
|
|
if (efivars_pstore_disable)
|
|
return 0;
|
|
|
|
efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
|
|
if (!efi_pstore_info.buf)
|
|
return -ENOMEM;
|
|
|
|
efi_pstore_info.bufsize = 1024;
|
|
spin_lock_init(&efi_pstore_info.buf_lock);
|
|
|
|
if (pstore_register(&efi_pstore_info)) {
|
|
kfree(efi_pstore_info.buf);
|
|
efi_pstore_info.buf = NULL;
|
|
efi_pstore_info.bufsize = 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static __exit void efivars_pstore_exit(void)
|
|
{
|
|
if (!efi_pstore_info.bufsize)
|
|
return;
|
|
|
|
pstore_unregister(&efi_pstore_info);
|
|
kfree(efi_pstore_info.buf);
|
|
efi_pstore_info.buf = NULL;
|
|
efi_pstore_info.bufsize = 0;
|
|
}
|
|
|
|
module_init(efivars_pstore_init);
|
|
module_exit(efivars_pstore_exit);
|
|
|
|
MODULE_DESCRIPTION("EFI variable backend for pstore");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:efivars");
|