diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 6fd4414c4836..7fe8b5c686d2 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -22,6 +22,7 @@ config EFI_ESRT config EFI_VARS_PSTORE tristate "Register efivars backend for pstore" depends on PSTORE + select UCS2_STRING default y help Say Y here to enable use efivars as a backend to pstore. This diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c index 0d80cc7ff6ca..3bddc152fcd4 100644 --- a/drivers/firmware/efi/efi-pstore.c +++ b/drivers/firmware/efi/efi-pstore.c @@ -6,6 +6,8 @@ #include #include +MODULE_IMPORT_NS(EFIVAR); + #define DUMP_NAME_LEN 66 #define EFIVARS_DATA_SIZE_MAX 1024 @@ -20,18 +22,25 @@ module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); EFI_VARIABLE_BOOTSERVICE_ACCESS | \ EFI_VARIABLE_RUNTIME_ACCESS) -static LIST_HEAD(efi_pstore_list); -static DECLARE_WORK(efivar_work, NULL); - static int efi_pstore_open(struct pstore_info *psi) { - psi->data = NULL; + int err; + + err = efivar_lock(); + if (err) + return err; + + psi->data = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL); + if (!psi->data) + return -ENOMEM; + return 0; } static int efi_pstore_close(struct pstore_info *psi) { - psi->data = NULL; + efivar_unlock(); + kfree(psi->data); return 0; } @@ -40,22 +49,17 @@ 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) +static int efi_pstore_read_func(struct pstore_record *record, + efi_char16_t *varname) { - efi_guid_t vendor = LINUX_EFI_CRASH_GUID; + unsigned long wlen, size = EFIVARS_DATA_SIZE_MAX; char name[DUMP_NAME_LEN], data_type; - int i; + efi_status_t status; 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]; + ucs2_as_utf8(name, varname, DUMP_NAME_LEN); if (sscanf(name, "dump-type%u-%u-%d-%llu-%c", &record->type, &part, &cnt, &time, &data_type) == 5) { @@ -95,161 +99,75 @@ static int efi_pstore_read_func(struct efivar_entry *entry, } 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(); - kfree(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_entry_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 = &efi_pstore_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); + record->buf = kmalloc(size, 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) { + status = efivar_get_variable(varname, &LINUX_EFI_CRASH_GUID, NULL, + &size, record->buf); + if (status != EFI_SUCCESS) { kfree(record->buf); - record->buf = NULL; + return -EIO; } + + /* + * Store the name of the variable in the pstore_record priv field, so + * we can reuse it later if we need to delete the EFI variable from the + * variable store. + */ + wlen = (ucs2_strnlen(varname, DUMP_NAME_LEN) + 1) * sizeof(efi_char16_t); + record->priv = kmemdup(varname, wlen, GFP_KERNEL); + if (!record->priv) { + kfree(record->buf); + return -ENOMEM; + } + return size; } +static ssize_t efi_pstore_read(struct pstore_record *record) +{ + efi_char16_t *varname = record->psi->data; + efi_guid_t guid = LINUX_EFI_CRASH_GUID; + unsigned long varname_size; + efi_status_t status; + + for (;;) { + varname_size = EFIVARS_DATA_SIZE_MAX; + + /* + * If this is the first read() call in the pstore enumeration, + * varname will be the empty string, and the GetNextVariable() + * runtime service call will return the first EFI variable in + * its own enumeration order, ignoring the guid argument. + * + * Subsequent calls to GetNextVariable() must pass the name and + * guid values returned by the previous call, which is why we + * store varname in record->psi->data. Given that we only + * enumerate variables with the efi-pstore GUID, there is no + * need to record the guid return value. + */ + status = efivar_get_next_variable(&varname_size, varname, &guid); + if (status == EFI_NOT_FOUND) + return 0; + + if (status != EFI_SUCCESS) + return -EIO; + + /* skip variables that don't concern us */ + if (efi_guidcmp(guid, LINUX_EFI_CRASH_GUID)) + continue; + + return efi_pstore_read_func(record, varname); + } +} + 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; + efi_status_t status; + int i; record->id = generic_id(record->time.tv_sec, record->part, record->count); @@ -265,88 +183,26 @@ static int efi_pstore_write(struct pstore_record *record) for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; - ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES, - false, record->size, record->psi->buf); - - if (record->reason == KMSG_DUMP_OOPS && try_module_get(THIS_MODULE)) - if (!schedule_work(&efivar_work)) - module_put(THIS_MODULE); - - return ret; + if (efivar_trylock()) + return -EBUSY; + status = efivar_set_variable_locked(efi_name, &LINUX_EFI_CRASH_GUID, + PSTORE_EFI_ATTRIBUTES, + record->size, record->psi->buf, + true); + efivar_unlock(); + return status == EFI_SUCCESS ? 0 : -EIO; }; -/* - * 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, &efi_pstore_list, - efi_name, &entry); - efivar_entry_iter_end(); - - if (found && !entry->scanning) - kfree(entry); - - return found ? 0 : -ENOENT; -} - static int efi_pstore_erase(struct pstore_record *record) { - char name[DUMP_NAME_LEN]; - int ret; + efi_status_t status; - 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; + status = efivar_set_variable(record->priv, &LINUX_EFI_CRASH_GUID, + PSTORE_EFI_ATTRIBUTES, 0, NULL); - 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; + if (status != EFI_SUCCESS && status != EFI_NOT_FOUND) + return -EIO; + return 0; } static struct pstore_info efi_pstore_info = { @@ -360,74 +216,14 @@ static struct pstore_info efi_pstore_info = { .erase = efi_pstore_erase, }; -static int efi_pstore_callback(efi_char16_t *name, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct efivar_entry *entry; - - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return -ENOMEM; - - memcpy(entry->var.VariableName, name, name_size); - entry->var.VendorGuid = vendor; - - __efivar_entry_add(entry, &efi_pstore_list); - - return 0; -} - -static int efi_pstore_update_entry(efi_char16_t *name, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct efivar_entry *entry = data; - - if (efivar_entry_find(name, vendor, &efi_pstore_list, false)) - return 0; - - memcpy(entry->var.VariableName, name, name_size); - memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); - - return 1; -} - -static void efi_pstore_update_entries(struct work_struct *work) -{ - struct efivar_entry *entry; - int err; - - /* Add new sysfs entries */ - while (1) { - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return; - - err = efivar_init(efi_pstore_update_entry, entry, - false, &efi_pstore_list); - if (!err) - break; - - efivar_entry_add(entry, &efi_pstore_list); - } - - kfree(entry); - module_put(THIS_MODULE); -} - static __init int efivars_pstore_init(void) { - int ret; - - if (!efivars_kobject() || !efivar_supports_writes()) + if (!efivar_supports_writes()) return 0; if (efivars_pstore_disable) return 0; - ret = efivar_init(efi_pstore_callback, NULL, true, &efi_pstore_list); - if (ret) - return ret; - efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); if (!efi_pstore_info.buf) return -ENOMEM; @@ -440,8 +236,6 @@ static __init int efivars_pstore_init(void) efi_pstore_info.bufsize = 0; } - INIT_WORK(&efivar_work, efi_pstore_update_entries); - return 0; } diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c index c19db0b35c0d..8341fb15f62e 100644 --- a/drivers/firmware/efi/efivars.c +++ b/drivers/firmware/efi/efivars.c @@ -467,16 +467,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, else if (__efivar_entry_delete(entry)) err = -EIO; - if (err) { - efivar_entry_iter_end(); - return err; - } + efivar_entry_iter_end(); - if (!entry->scanning) { - efivar_entry_iter_end(); - efivar_unregister(entry); - } else - efivar_entry_iter_end(); + if (err) + return err; + + efivar_unregister(entry); /* It's dead Jim.... */ return count; diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index 41c82614a4b2..5640ffa81544 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -821,16 +821,8 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, if (!found) return NULL; - if (remove) { - if (entry->scanning) { - /* - * The entry will be deleted - * after scanning is completed. - */ - entry->deleting = true; - } else - list_del(&entry->list); - } + if (remove) + list_del(&entry->list); return entry; } diff --git a/include/linux/efi.h b/include/linux/efi.h index c828ab6f0e2a..08bc6215e3b4 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1043,8 +1043,6 @@ struct efivar_entry { struct efi_variable var; struct list_head list; struct kobject kobj; - bool scanning; - bool deleting; }; static inline void