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Message-ID: <A5ED84D3BB3A384992CBB9C77DEDA4D41AFD20E4@USINDEM103.corp.hds.com>
Date: Fri, 26 Apr 2013 15:43:07 +0000
From: Seiji Aguchi <seiji.aguchi@....com>
To: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"mingo@...nel.org" <mingo@...nel.org>,
"hpa@...or.com" <hpa@...or.com>,
"Seiji Aguchi" <seiji.aguchi@....com>,
"mjg59@...f.ucam.org" <mjg59@...f.ucam.org>,
"tony.luck@...el.com" <tony.luck@...el.com>,
"matt.fleming@...el.com" <matt.fleming@...el.com>,
"jk@...abs.org" <jk@...abs.org>, "teg@...m.no" <teg@...m.no>,
"tglx@...utronix.de" <tglx@...utronix.de>,
"mikew@...gle.com" <mikew@...gle.com>,
"linux-tip-commits@...r.kernel.org"
<linux-tip-commits@...r.kernel.org>
Subject: RE: [tip:x86/efi2] efivars: efivar_entry API
> +static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
> {
> efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
> - struct efivars *efivars = __efivars;
> + struct pstore_read_data *cb_data = data;
> char name[DUMP_NAME_LEN];
> int i;
> int cnt;
> - 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-%d-%lu",
> - type, &part, &cnt, &time) == 4) {
> - *id = part;
> - *count = cnt;
> - timespec->tv_sec = time;
> - timespec->tv_nsec = 0;
> - } else if (sscanf(name, "dump-type%u-%u-%lu",
> - type, &part, &time) == 3) {
> - /*
> - * Check if an old format,
> - * which doesn't support holding
> - * multiple logs, remains.
> - */
> - *id = part;
> - *count = 0;
> - timespec->tv_sec = time;
> - timespec->tv_nsec = 0;
> - } else {
> - efivars->walk_entry = list_entry(
> - efivars->walk_entry->list.next,
> - struct efivar_entry, list);
> - continue;
> - }
> + unsigned int part;
> + unsigned long time, size;
>
> - 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;
> + 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-%lu",
> + cb_data->type, &part, &cnt, &time) == 4) {
> + *cb_data->id = part;
> + *cb_data->count = cnt;
> + cb_data->timespec->tv_sec = time;
> + cb_data->timespec->tv_nsec = 0;
> + } else if (sscanf(name, "dump-type%u-%u-%lu",
> + cb_data->type, &part, &time) == 3) {
> + /*
> + * Check if an old format,
> + * which doesn't support holding
> + * multiple logs, remains.
> + */
> + *cb_data->id = part;
> + *cb_data->count = 0;
> + cb_data->timespec->tv_sec = time;
> + cb_data->timespec->tv_nsec = 0;
> + } else
> + return 0;
> +
> + __efivar_entry_size(entry, &size);
I tested pstore_read() as well.
And /dev/pstore/dmesg-efi-X was empty....
This must be __efivar_entry_get() instead of __efivar_entry_size().
(We may have to introduce _efivar_entry_get_locked() to avoid deadlock.)
I think it is a final bug report related to this new API patch.
Seiji
> + *cb_data->buf = kmalloc(size, GFP_KERNEL);
> + if (*cb_data->buf == NULL)
> + return -ENOMEM;
> + memcpy(*cb_data->buf, entry->var.Data, size);
> + return size;
> +}
> +
> +static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
> + int *count, struct timespec *timespec,
> + char **buf, struct pstore_info *psi)
> +{
> + struct pstore_read_data data;
> +
> + data.id = id;
> + data.type = type;
> + data.count = count;
> + data.timespec = timespec;
> + data.buf = buf;
> +
> + return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
> + (struct efivar_entry **)&psi->data);
> }
>
> static int efi_pstore_write(enum pstore_type_id type,
> @@ -1382,36 +1222,7 @@ static int efi_pstore_write(enum pstore_type_id type,
> char name[DUMP_NAME_LEN];
> efi_char16_t efi_name[DUMP_NAME_LEN];
> efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
> - struct efivars *efivars = __efivars;
> int i, ret = 0;
> - efi_status_t status = EFI_NOT_FOUND;
> - unsigned long flags;
> -
> - if (pstore_cannot_block_path(reason)) {
> - /*
> - * If the lock is taken by another cpu in non-blocking path,
> - * this driver returns without entering firmware to avoid
> - * hanging up.
> - */
> - if (!spin_trylock_irqsave(&efivars->lock, flags))
> - return -EBUSY;
> - } else
> - spin_lock_irqsave(&efivars->lock, flags);
> -
> - /*
> - * Check if there is a space enough to log.
> - * size: a size of logging data
> - * DUMP_NAME_LEN * 2: a maximum size of variable name
> - */
> -
> - status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
> - size + DUMP_NAME_LEN * 2);
> -
> - if (status) {
> - spin_unlock_irqrestore(&efivars->lock, flags);
> - *id = part;
> - return -ENOSPC;
> - }
>
> sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
> get_seconds());
> @@ -1419,10 +1230,9 @@ static int efi_pstore_write(enum pstore_type_id type,
> 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_irqrestore(&efivars->lock, flags);
> + ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
> + !pstore_cannot_block_path(reason),
> + size, psi->buf);
>
> if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled)
> schedule_work(&efivar_work);
> @@ -1431,69 +1241,79 @@ static int efi_pstore_write(enum pstore_type_id type,
> return ret;
> };
>
> -static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
> - struct timespec time, struct pstore_info *psi)
> +struct pstore_erase_data {
> + u64 id;
> + enum pstore_type_id type;
> + int count;
> + struct timespec time;
> + efi_char16_t *name;
> +};
> +
> +/*
> + * Clean up an entry with the same name
> + */
> +static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
> {
> - char name[DUMP_NAME_LEN];
> - efi_char16_t efi_name[DUMP_NAME_LEN];
> - char name_old[DUMP_NAME_LEN];
> - efi_char16_t efi_name_old[DUMP_NAME_LEN];
> + struct pstore_erase_data *ed = data;
> efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
> - struct efivars *efivars = __efivars;
> - struct efivar_entry *entry, *found = NULL;
> + efi_char16_t efi_name_old[DUMP_NAME_LEN];
> + efi_char16_t *efi_name = ed->name;
> + unsigned long utf16_len = utf16_strlen(ed->name);
> + char name_old[DUMP_NAME_LEN];
> int i;
>
> - sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
> - time.tv_sec);
> + if (efi_guidcmp(entry->var.VendorGuid, vendor))
> + return 0;
>
> - spin_lock_irq(&efivars->lock);
> + if (utf16_strncmp(entry->var.VariableName,
> + efi_name, (size_t)utf16_len)) {
> + /*
> + * Check if an old format, which doesn't support
> + * holding multiple logs, remains.
> + */
> + sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
> + (unsigned int)ed->id, ed->time.tv_sec);
>
> - for (i = 0; i < DUMP_NAME_LEN; i++)
> - efi_name[i] = name[i];
> + for (i = 0; i < DUMP_NAME_LEN; i++)
> + efi_name_old[i] = name_old[i];
>
> - /*
> - * Clean up an entry with the same name
> - */
> + if (utf16_strncmp(entry->var.VariableName, efi_name_old,
> + utf16_strlen(efi_name_old)))
> + return 0;
> + }
>
> - 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))) {
> - /*
> - * Check if an old format,
> - * which doesn't support holding
> - * multiple logs, remains.
> - */
> - sprintf(name_old, "dump-type%u-%u-%lu", type,
> - (unsigned int)id, time.tv_sec);
> + /* found */
> + __efivar_entry_delete(entry);
> + return 1;
> +}
>
> - for (i = 0; i < DUMP_NAME_LEN; i++)
> - efi_name_old[i] = name_old[i];
> +static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
> + struct timespec time, struct pstore_info *psi)
> +{
> + struct pstore_erase_data edata;
> + struct efivar_entry *entry;
> + char name[DUMP_NAME_LEN];
> + efi_char16_t efi_name[DUMP_NAME_LEN];
> + int found, i;
>
> - if (utf16_strncmp(entry->var.VariableName, efi_name_old,
> - utf16_strlen(efi_name_old)))
> - continue;
> - }
> + sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
> + time.tv_sec);
>
> - /* found */
> - found = entry;
> - efivars->ops->set_variable(entry->var.VariableName,
> - &entry->var.VendorGuid,
> - PSTORE_EFI_ATTRIBUTES,
> - 0, NULL);
> - break;
> - }
> + for (i = 0; i < DUMP_NAME_LEN; i++)
> + efi_name[i] = name[i];
>
> - if (found)
> - list_del(&found->list);
> + edata.id = id;
> + edata.type = type;
> + edata.count = count;
> + edata.time = time;
> + edata.name = efi_name;
>
> - spin_unlock_irq(&efivars->lock);
> + efivar_entry_iter_begin();
> + found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
> + efivar_entry_iter_end();
>
> if (found)
> - efivar_unregister(found);
> + efivar_unregister(entry);
>
> return 0;
> }
> @@ -1508,19 +1328,17 @@ static struct pstore_info efi_pstore_info = {
> .erase = efi_pstore_erase,
> };
>
> -static void efivar_pstore_register(struct efivars *efivars)
> +static void efivar_pstore_register(void)
> {
> - 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);
> + efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
> + if (efi_pstore_info.buf) {
> + efi_pstore_info.bufsize = 1024;
> + spin_lock_init(&efi_pstore_info.buf_lock);
> + pstore_register(&efi_pstore_info);
> }
> }
> #else
> -static void efivar_pstore_register(struct efivars *efivars)
> +static void efivar_pstore_register(void)
> {
> return;
> }
> @@ -1531,76 +1349,41 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
> char *buf, loff_t pos, size_t count)
> {
> struct efi_variable *new_var = (struct efi_variable *)buf;
> - struct efivars *efivars = __efivars;
> - struct efivar_entry *search_efivar, *n;
> - unsigned long strsize1, strsize2;
> - efi_status_t status = EFI_NOT_FOUND;
> - int found = 0;
> + struct efivar_entry *new_entry;
> + int err;
>
> 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) {
> + efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
> printk(KERN_ERR "efivars: Malformed variable content\n");
> return -EINVAL;
> }
>
> - spin_lock_irq(&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_irq(&efivars->lock);
> - return -EINVAL;
> - }
> + new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
> + if (!new_entry)
> + return -ENOMEM;
>
> - status = check_var_size_locked(efivars, new_var->Attributes,
> - new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
> + memcpy(&new_entry->var, new_var, sizeof(*new_var));
>
> - if (status && status != EFI_UNSUPPORTED) {
> - spin_unlock_irq(&efivars->lock);
> - return efi_status_to_err(status);
> + err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize,
> + new_var->Data, &efivar_sysfs_list);
> + if (err) {
> + if (err == -EEXIST)
> + err = -EINVAL;
> + goto out;
> }
>
> - /* 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_irq(&efivars->lock);
> - return -EIO;
> - }
> - spin_unlock_irq(&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");
> + if (efivar_create_sysfs_entry(new_entry)) {
> + printk(KERN_WARNING "efivars: failed to create sysfs entry.\n");
> + kfree(new_entry);
> }
> return count;
> +
> +out:
> + kfree(new_entry);
> + return err;
> }
>
> static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
> @@ -1608,70 +1391,40 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
> char *buf, loff_t pos, size_t count)
> {
> struct efi_variable *del_var = (struct efi_variable *)buf;
> - struct efivars *efivars = __efivars;
> - struct efivar_entry *search_efivar, *n;
> - unsigned long strsize1, strsize2;
> - efi_status_t status = EFI_NOT_FOUND;
> - int found = 0;
> + struct efivar_entry *entry;
> + int err = 0;
>
> if (!capable(CAP_SYS_ADMIN))
> return -EACCES;
>
> - spin_lock_irq(&efivars->lock);
> + efivar_entry_iter_begin();
> + entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid,
> + &efivar_sysfs_list, true);
> + if (!entry)
> + err = -EINVAL;
> + else if (__efivar_entry_delete(entry))
> + err = -EIO;
>
> - /*
> - * 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_irq(&efivars->lock);
> - return -EINVAL;
> - }
> - /* force the Attributes/DataSize to 0 to ensure deletion */
> - del_var->Attributes = 0;
> - del_var->DataSize = 0;
> + efivar_entry_iter_end();
>
> - status = efivars->ops->set_variable(del_var->VariableName,
> - &del_var->VendorGuid,
> - del_var->Attributes,
> - del_var->DataSize,
> - del_var->Data);
> + if (err)
> + return err;
>
> - if (status != EFI_SUCCESS) {
> - printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
> - status);
> - spin_unlock_irq(&efivars->lock);
> - return -EIO;
> - }
> - list_del(&search_efivar->list);
> - /* We need to release this lock before unregistering. */
> - spin_unlock_irq(&efivars->lock);
> - efivar_unregister(search_efivar);
> + efivar_unregister(entry);
>
> /* It's dead Jim.... */
> return count;
> }
>
> -static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
> +static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
> + struct list_head *head)
> {
> struct efivar_entry *entry, *n;
> - struct efivars *efivars = __efivars;
> unsigned long strsize1, strsize2;
> bool found = false;
>
> strsize1 = utf16_strsize(variable_name, 1024);
> - list_for_each_entry_safe(entry, n, &efivars->list, list) {
> + list_for_each_entry_safe(entry, n, head, list) {
> strsize2 = utf16_strsize(entry->var.VariableName, 1024);
> if (strsize1 == strsize2 &&
> !memcmp(variable_name, &(entry->var.VariableName),
> @@ -1685,6 +1438,20 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
> return found;
> }
>
> +static int efivar_update_sysfs_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, &efivar_sysfs_list, false))
> + return 0;
> +
> + memcpy(entry->var.VariableName, name, name_size);
> + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
> +
> + return 1;
> +}
> +
> /*
> * Returns the size of variable_name, in bytes, including the
> * terminating NULL character, or variable_name_size if no NULL
> @@ -1712,52 +1479,26 @@ static unsigned long var_name_strnsize(efi_char16_t *variable_name,
>
> static void efivar_update_sysfs_entries(struct work_struct *work)
> {
> - struct efivars *efivars = __efivars;
> - efi_guid_t vendor;
> - efi_char16_t *variable_name;
> - unsigned long variable_name_size = 1024;
> - efi_status_t status = EFI_NOT_FOUND;
> - bool found;
> + struct efivar_entry *entry;
> + int err;
> +
> + entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> + if (!entry)
> + return;
>
> /* Add new sysfs entries */
> while (1) {
> - variable_name = kzalloc(variable_name_size, GFP_KERNEL);
> - if (!variable_name) {
> - pr_err("efivars: Memory allocation failed.\n");
> - return;
> - }
> + memset(entry, 0, sizeof(*entry));
>
> - spin_lock_irq(&efivars->lock);
> - found = false;
> - while (1) {
> - variable_name_size = 1024;
> - status = efivars->ops->get_next_variable(
> - &variable_name_size,
> - variable_name,
> - &vendor);
> - if (status != EFI_SUCCESS) {
> - break;
> - } else {
> - if (!variable_is_present(variable_name,
> - &vendor)) {
> - found = true;
> - break;
> - }
> - }
> - }
> - spin_unlock_irq(&efivars->lock);
> -
> - if (!found) {
> - kfree(variable_name);
> + err = efivar_init(efivar_update_sysfs_entry, entry,
> + true, false, &efivar_sysfs_list);
> + if (!err)
> break;
> - } else {
> - variable_name_size = var_name_strnsize(variable_name,
> - variable_name_size);
> - efivar_create_sysfs_entry(efivars,
> - variable_name_size,
> - variable_name, &vendor);
> - }
> +
> + efivar_create_sysfs_entry(entry);
> }
> +
> + kfree(entry);
> }
>
> /*
> @@ -1804,45 +1545,37 @@ static struct attribute_group efi_subsys_attr_group = {
>
> 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.
> +/**
> + * efivar_create_sysfs_entry - create a new entry in sysfs
> + * @new_var: efivar entry to create
> + *
> * 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)
> +efivar_create_sysfs_entry(struct efivar_entry *new_var)
> {
> int i, short_name_size;
> char *short_name;
> - struct efivar_entry *new_efivar;
> + unsigned long variable_name_size;
> + efi_char16_t *variable_name;
> +
> + variable_name = new_var->var.VariableName;
> + variable_name_size = utf16_strlen(variable_name) * sizeof(efi_char16_t);
>
> /*
> * Length of the variable bytes in ASCII, plus the '-' separator,
> * plus the GUID, plus trailing NUL
> */
> short_name_size = variable_name_size / sizeof(efi_char16_t)
> - + 1 + GUID_LEN + 1;
> + + 1 + EFI_VARIABLE_GUID_LEN + 1;
>
> short_name = kzalloc(short_name_size, GFP_KERNEL);
> - new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
>
> - if (!short_name || !new_efivar) {
> + if (!short_name) {
> kfree(short_name);
> - kfree(new_efivar);
> return 1;
> }
>
> - 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++) {
> @@ -1852,30 +1585,25 @@ efivar_create_sysfs_entry(struct efivars *efivars,
> private variables from another's. */
>
> *(short_name + strlen(short_name)) = '-';
> - efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
> + efi_guid_unparse(&new_var->var.VendorGuid,
> + 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;
> - }
> + new_var->kobj.kset = efivars_kset;
>
> - kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
> + i = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
> + NULL, "%s", short_name);
> kfree(short_name);
> - short_name = NULL;
> + if (i)
> + return 1;
>
> - spin_lock_irq(&efivars->lock);
> - list_add(&new_efivar->list, &efivars->list);
> - spin_unlock_irq(&efivars->lock);
> + kobject_uevent(&new_var->kobj, KOBJ_ADD);
> + efivar_entry_add(new_var, &efivar_sysfs_list);
>
> return 0;
> }
>
> static int
> -create_efivars_bin_attributes(struct efivars *efivars)
> +create_efivars_bin_attributes(void)
> {
> struct bin_attribute *attr;
> int error;
> @@ -1888,8 +1616,7 @@ create_efivars_bin_attributes(struct efivars *efivars)
> attr->attr.name = "new_var";
> attr->attr.mode = 0200;
> attr->write = efivar_create;
> - attr->private = efivars;
> - efivars->new_var = attr;
> + efivars_new_var = attr;
>
> /* del_var */
> attr = kzalloc(sizeof(*attr), GFP_KERNEL);
> @@ -1900,61 +1627,59 @@ create_efivars_bin_attributes(struct efivars *efivars)
> attr->attr.name = "del_var";
> attr->attr.mode = 0200;
> attr->write = efivar_delete;
> - attr->private = efivars;
> - efivars->del_var = attr;
> + efivars_del_var = attr;
>
> - sysfs_bin_attr_init(efivars->new_var);
> - sysfs_bin_attr_init(efivars->del_var);
> + 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);
> + 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);
> +
> + 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);
> + 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;
> + kfree(efivars_del_var);
> + efivars_del_var = NULL;
> + kfree(efivars_new_var);
> + efivars_new_var = NULL;
> return error;
> }
>
> -void unregister_efivars(struct efivars *efivars)
> +static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
> + unsigned long name_size, void *data)
> {
> - struct efivar_entry *entry, *n;
> + struct efivar_entry *entry;
>
> - __efivars = NULL;
> + entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> + if (!entry)
> + return -ENOMEM;
>
> - list_for_each_entry_safe(entry, n, &efivars->list, list) {
> - spin_lock_irq(&efivars->lock);
> - list_del(&entry->list);
> - spin_unlock_irq(&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);
> - kobject_put(efivars->kobject);
> - kset_unregister(efivars->kset);
> + memcpy(entry->var.VariableName, name, name_size);
> + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
> +
> + efivar_create_sysfs_entry(entry);
> +
> + return 0;
> +}
> +
> +static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
> +{
> + efivar_entry_remove(entry);
> + efivar_unregister(entry);
> + return 0;
> }
> -EXPORT_SYMBOL_GPL(unregister_efivars);
>
> /*
> * Print a warning when duplicate EFI variables are encountered and
> @@ -1985,43 +1710,91 @@ static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
> kfree(s8);
> }
>
> -int register_efivars(struct efivars *efivars,
> - const struct efivar_operations *ops,
> - struct kobject *parent_kobj)
> +static struct kobject *efivars_kobj;
> +
> +void efivars_sysfs_exit(void)
> {
> - 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;
> + /* Remove all entries and destroy */
> + __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL);
> +
> + 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);
> + kobject_put(efivars_kobj);
> + kset_unregister(efivars_kset);
> +}
>
> - __efivars = efivars;
> +int efivars_sysfs_init(void)
> +{
> + struct kobject *parent_kobj = efivars_kobject();
> + int error = 0;
>
> - variable_name = kzalloc(variable_name_size, GFP_KERNEL);
> - if (!variable_name) {
> - printk(KERN_ERR "efivars: Memory allocation failed.\n");
> - return -ENOMEM;
> - }
> + /* No efivars has been registered yet */
> + if (!parent_kobj)
> + return 0;
>
> - spin_lock_init(&efivars->lock);
> - INIT_LIST_HEAD(&efivars->list);
> - efivars->ops = ops;
> + printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
> + EFIVARS_DATE);
>
> - efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
> - if (!efivars->kset) {
> + 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;
> + return -ENOMEM;
> }
>
> - efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
> - if (!efivars->kobject) {
> + efivars_kobj = kobject_create_and_add("efivars", parent_kobj);
> + if (!efivars_kobj) {
> pr_err("efivars: Subsystem registration failed.\n");
> - error = -ENOMEM;
> - kset_unregister(efivars->kset);
> - goto out;
> + kset_unregister(efivars_kset);
> + return -ENOMEM;
> + }
> +
> + efivar_init(efivars_sysfs_callback, NULL, false,
> + true, &efivar_sysfs_list);
> +
> + error = create_efivars_bin_attributes();
> + if (error)
> + efivars_sysfs_exit();
> +
> + return error;
> +}
> +EXPORT_SYMBOL_GPL(efivars_sysfs_init);
> +
> +/**
> + * efivar_init - build the initial list of EFI variables
> + * @func: callback function to invoke for every variable
> + * @data: function-specific data to pass to @func
> + * @atomic: do we need to execute the @func-loop atomically?
> + * @duplicates: error if we encounter duplicates on @head?
> + * @head: initialised head of variable list
> + *
> + * Get every EFI variable from the firmware and invoke @func. @func
> + * should call efivar_entry_add() to build the list of variables.
> + *
> + * Returns 0 on success, or a kernel error code on failure.
> + */
> +int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
> + void *data, bool atomic, bool duplicates,
> + struct list_head *head)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + unsigned long variable_name_size = 1024;
> + efi_char16_t *variable_name;
> + efi_status_t status;
> + efi_guid_t vendor_guid;
> + int err = 0;
> +
> + variable_name = kzalloc(variable_name_size, GFP_KERNEL);
> + if (!variable_name) {
> + printk(KERN_ERR "efivars: Memory allocation failed.\n");
> + return -ENOMEM;
> }
>
> + spin_lock_irq(&__efivars->lock);
> +
> /*
> * Per EFI spec, the maximum storage allocated for both
> * the variable name and variable data is 1024 bytes.
> @@ -2035,6 +1808,9 @@ int register_efivars(struct efivars *efivars,
> &vendor_guid);
> switch (status) {
> case EFI_SUCCESS:
> + if (!atomic)
> + spin_unlock_irq(&__efivars->lock);
> +
> variable_name_size = var_name_strnsize(variable_name,
> variable_name_size);
>
> @@ -2046,17 +1822,24 @@ int register_efivars(struct efivars *efivars,
> * we'll ever see a different variable name,
> * and may end up looping here forever.
> */
> - if (variable_is_present(variable_name, &vendor_guid)) {
> + if (duplicates &&
> + variable_is_present(variable_name, &vendor_guid, head)) {
> dup_variable_bug(variable_name, &vendor_guid,
> variable_name_size);
> + if (!atomic)
> + spin_lock_irq(&__efivars->lock);
> +
> status = EFI_NOT_FOUND;
> break;
> }
>
> - efivar_create_sysfs_entry(efivars,
> - variable_name_size,
> - variable_name,
> - &vendor_guid);
> + err = func(variable_name, vendor_guid, variable_name_size, data);
> + if (err)
> + status = EFI_NOT_FOUND;
> +
> + if (!atomic)
> + spin_lock_irq(&__efivars->lock);
> +
> break;
> case EFI_NOT_FOUND:
> break;
> @@ -2066,40 +1849,637 @@ int register_efivars(struct efivars *efivars,
> status = EFI_NOT_FOUND;
> break;
> }
> +
> } while (status != EFI_NOT_FOUND);
>
> - error = create_efivars_bin_attributes(efivars);
> - if (error)
> - unregister_efivars(efivars);
> + spin_unlock_irq(&__efivars->lock);
> +
> + kfree(variable_name);
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(efivar_init);
> +
> +/**
> + * efivar_entry_add - add entry to variable list
> + * @entry: entry to add to list
> + * @head: list head
> + */
> +void efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
> +{
> + spin_lock_irq(&__efivars->lock);
> + list_add(&entry->list, head);
> + spin_unlock_irq(&__efivars->lock);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_add);
> +
> +/**
> + * efivar_entry_remove - remove entry from variable list
> + * @entry: entry to remove from list
> + */
> +void efivar_entry_remove(struct efivar_entry *entry)
> +{
> + spin_lock_irq(&__efivars->lock);
> + list_del(&entry->list);
> + spin_unlock_irq(&__efivars->lock);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_remove);
> +
> +/*
> + * efivar_entry_list_del_unlock - remove entry from variable list
> + * @entry: entry to remove
> + *
> + * Remove @entry from the variable list and release the list lock.
> + *
> + * NOTE: slightly weird locking semantics here - we expect to be
> + * called with the efivars lock already held, and we release it before
> + * returning. This is because this function is usually called after
> + * set_variable() while the lock is still held.
> + */
> +static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
> +{
> + WARN_ON(!spin_is_locked(&__efivars->lock));
> +
> + list_del(&entry->list);
> + spin_unlock_irq(&__efivars->lock);
> +}
> +
> +/**
> + * __efivar_entry_delete - delete an EFI variable
> + * @entry: entry containing EFI variable to delete
> + *
> + * Delete the variable from the firmware and remove @entry from the
> + * variable list. It is the caller's responsibility to free @entry
> + * once we return.
> + *
> + * This function differs from efivar_entry_delete() because it is
> + * safe to be called from within a efivar_entry_iter_begin() and
> + * efivar_entry_iter_end() region, unlike efivar_entry_delete().
> + *
> + * Returns 0 on success, or a converted EFI status code if
> + * set_variable() fails. If set_variable() fails the entry remains
> + * on the list.
> + */
> +int __efivar_entry_delete(struct efivar_entry *entry)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> +
> + WARN_ON(!spin_is_locked(&__efivars->lock));
> +
> + status = ops->set_variable(entry->var.VariableName,
> + &entry->var.VendorGuid,
> + 0, 0, NULL);
> + if (status)
> + return efi_status_to_err(status);
> +
> + list_del(&entry->list);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(__efivar_entry_delete);
> +
> +/**
> + * efivar_entry_delete - delete variable and remove entry from list
> + * @entry: entry containing variable to delete
> + *
> + * Delete the variable from the firmware and remove @entry from the
> + * variable list. It is the caller's responsibility to free @entry
> + * once we return.
> + *
> + * Returns 0 on success, or a converted EFI status code if
> + * set_variable() fails.
> + */
> +int efivar_entry_delete(struct efivar_entry *entry)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> +
> + spin_lock_irq(&__efivars->lock);
> + status = ops->set_variable(entry->var.VariableName,
> + &entry->var.VendorGuid,
> + 0, 0, NULL);
> + if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
> + spin_unlock_irq(&__efivars->lock);
> + return efi_status_to_err(status);
> + }
> +
> + efivar_entry_list_del_unlock(entry);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_delete);
> +
> +/**
> + * efivar_entry_set - call set_variable()
> + * @entry: entry containing the EFI variable to write
> + * @attributes: variable attributes
> + * @size: size of @data buffer
> + * @data: buffer containing variable data
> + * @head: head of variable list
> + *
> + * Calls set_variable() for an EFI variable. If creating a new EFI
> + * variable, this function is usually followed by efivar_entry_add().
> + *
> + * Before writing the variable, the remaining EFI variable storage
> + * space is checked to ensure there is enough room available.
> + *
> + * If @head is not NULL a lookup is performed to determine whether
> + * the entry is already on the list.
> + *
> + * Returns 0 on success, -EEXIST if a lookup is performed and the entry
> + * already exists on the list, or a converted EFI status code if
> + * set_variable() fails.
> + */
> +int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
> + unsigned long size, void *data, struct list_head *head)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> + efi_char16_t *name = entry->var.VariableName;
> + efi_guid_t vendor = entry->var.VendorGuid;
> +
> + spin_lock_irq(&__efivars->lock);
> +
> + if (head && efivar_entry_find(name, vendor, head, false)) {
> + spin_unlock_irq(&__efivars->lock);
> + return -EEXIST;
> + }
> +
> + status = check_var_size(attributes, size + utf16_strsize(name, 1024));
> + if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
> + status = ops->set_variable(name, &vendor,
> + attributes, size, data);
> +
> + spin_unlock_irq(&__efivars->lock);
> +
> + return efi_status_to_err(status);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_set);
> +
> +/**
> + * efivar_entry_set_safe - call set_variable() if enough space in firmware
> + * @name: buffer containing the variable name
> + * @vendor: variable vendor guid
> + * @attributes: variable attributes
> + * @block: can we block in this context?
> + * @size: size of @data buffer
> + * @data: buffer containing variable data
> + *
> + * Ensures there is enough free storage in the firmware for this variable, and
> + * if so, calls set_variable(). If creating a new EFI variable, this function
> + * is usually followed by efivar_entry_add().
> + *
> + * Returns 0 on success, -ENOSPC if the firmware does not have enough
> + * space for set_variable() to succeed, or a converted EFI status code
> + * if set_variable() fails.
> + */
> +int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
> + bool block, unsigned long size, void *data)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + unsigned long flags;
> + efi_status_t status;
> +
> + if (!ops->query_variable_info)
> + return -ENOSYS;
> +
> + if (!block && !spin_trylock_irqsave(&__efivars->lock, flags))
> + return -EBUSY;
> + else
> + spin_lock_irqsave(&__efivars->lock, flags);
> +
> + status = check_var_size(attributes, size + utf16_strsize(name, 1024));
> + if (status != EFI_SUCCESS) {
> + spin_unlock_irqrestore(&__efivars->lock, flags);
> + return -ENOSPC;
> + }
> +
> + status = ops->set_variable(name, &vendor, attributes, size, data);
> +
> + spin_unlock_irqrestore(&__efivars->lock, flags);
> +
> + return efi_status_to_err(status);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
> +
> +/**
> + * efivar_entry_find - search for an entry
> + * @name: the EFI variable name
> + * @guid: the EFI variable vendor's guid
> + * @head: head of the variable list
> + * @remove: should we remove the entry from the list?
> + *
> + * Search for an entry on the variable list that has the EFI variable
> + * name @name and vendor guid @guid. If an entry is found on the list
> + * and @remove is true, the entry is removed from the list.
> + *
> + * The caller MUST call efivar_entry_iter_begin() and
> + * efivar_entry_iter_end() before and after the invocation of this
> + * function, respectively.
> + *
> + * Returns the entry if found on the list, %NULL otherwise.
> + */
> +struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
> + struct list_head *head, bool remove)
> +{
> + struct efivar_entry *entry, *n;
> + int strsize1, strsize2;
> + bool found = false;
> +
> + WARN_ON(!spin_is_locked(&__efivars->lock));
> +
> + list_for_each_entry_safe(entry, n, head, list) {
> + strsize1 = utf16_strsize(name, 1024);
> + strsize2 = utf16_strsize(entry->var.VariableName, 1024);
> + if (strsize1 == strsize2 &&
> + !memcmp(name, &(entry->var.VariableName), strsize1) &&
> + !efi_guidcmp(guid, entry->var.VendorGuid)) {
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found)
> + return NULL;
> +
> + if (remove)
> + list_del(&entry->list);
> +
> + return entry;
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_find);
> +
> +/**
> + * __efivar_entry_size - obtain the size of a variable
> + * @entry: entry for this variable
> + * @size: location to store the variable's size
> + *
> + * The caller MUST call efivar_entry_iter_begin() and
> + * efivar_entry_iter_end() before and after the invocation of this
> + * function, respectively.
> + */
> +int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> +
> + WARN_ON(!spin_is_locked(&__efivars->lock));
> +
> + *size = 0;
> + status = ops->get_variable(entry->var.VariableName,
> + &entry->var.VendorGuid, NULL, size, NULL);
> + if (status != EFI_BUFFER_TOO_SMALL)
> + return efi_status_to_err(status);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(__efivar_entry_size);
> +
> +/**
> + * efivar_entry_size - obtain the size of a variable
> + * @entry: entry for this variable
> + * @size: location to store the variable's size
> + */
> +int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> +
> + *size = 0;
> +
> + spin_lock_irq(&__efivars->lock);
> + status = ops->get_variable(entry->var.VariableName,
> + &entry->var.VendorGuid, NULL, size, NULL);
> + spin_unlock_irq(&__efivars->lock);
> +
> + if (status != EFI_BUFFER_TOO_SMALL)
> + return efi_status_to_err(status);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_size);
> +
> +/**
> + * efivar_entry_get - call get_variable()
> + * @entry: read data for this variable
> + * @attributes: variable attributes
> + * @size: size of @data buffer
> + * @data: buffer to store variable data
> + */
> +int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
> + unsigned long *size, void *data)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_status_t status;
> +
> + spin_lock_irq(&__efivars->lock);
> + status = ops->get_variable(entry->var.VariableName,
> + &entry->var.VendorGuid,
> + attributes, size, data);
> + spin_unlock_irq(&__efivars->lock);
> +
> + return efi_status_to_err(status);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_get);
> +
> +/**
> + * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
> + * @entry: entry containing variable to set and get
> + * @attributes: attributes of variable to be written
> + * @size: size of data buffer
> + * @data: buffer containing data to write
> + * @set: did the set_variable() call succeed?
> + *
> + * This is a pretty special (complex) function. See efivarfs_file_write().
> + *
> + * Atomically call set_variable() for @entry and if the call is
> + * successful, return the new size of the variable from get_variable()
> + * in @size. The success of set_variable() is indicated by @set.
> + *
> + * Returns 0 on success, -EINVAL if the variable data is invalid,
> + * -ENOSPC if the firmware does not have enough available space, or a
> + * converted EFI status code if either of set_variable() or
> + * get_variable() fail.
> + *
> + * If the EFI variable does not exist when calling set_variable()
> + * (EFI_NOT_FOUND), @entry is removed from the variable list.
> + */
> +int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
> + unsigned long *size, void *data, bool *set)
> +{
> + const struct efivar_operations *ops = __efivars->ops;
> + efi_char16_t *name = entry->var.VariableName;
> + efi_guid_t *vendor = &entry->var.VendorGuid;
> + efi_status_t status;
> + int err;
> +
> + *set = false;
> +
> + if (efivar_validate(&entry->var, data, *size) == false)
> + return -EINVAL;
> +
> + /*
> + * The lock here protects the get_variable call, the conditional
> + * set_variable call, and removal of the variable from the efivars
> + * list (in the case of an authenticated delete).
> + */
> + spin_lock_irq(&__efivars->lock);
> +
> + /*
> + * Ensure that the available space hasn't shrunk below the safe level
> + */
> + status = check_var_size(attributes, *size + utf16_strsize(name, 1024));
> + if (status != EFI_SUCCESS) {
> + if (status != EFI_UNSUPPORTED) {
> + err = efi_status_to_err(status);
> + goto out;
> + }
> +
> + if (*size > 65536) {
> + err = -ENOSPC;
> + goto out;
> + }
> + }
> +
> + status = ops->set_variable(name, vendor, attributes, *size, data);
> + if (status != EFI_SUCCESS) {
> + err = efi_status_to_err(status);
> + goto out;
> + }
> +
> + *set = true;
> +
> + /*
> + * Writing to the variable may have caused a change in size (which
> + * could either be an append or an overwrite), or the variable to be
> + * deleted. Perform a GetVariable() so we can tell what actually
> + * happened.
> + */
> + *size = 0;
> + status = ops->get_variable(entry->var.VariableName,
> + &entry->var.VendorGuid,
> + NULL, size, NULL);
> +
> + if (status == EFI_NOT_FOUND)
> + efivar_entry_list_del_unlock(entry);
> + else
> + spin_unlock_irq(&__efivars->lock);
> +
> + if (status && status != EFI_BUFFER_TOO_SMALL)
> + return efi_status_to_err(status);
> +
> + return 0;
> +
> +out:
> + spin_unlock_irq(&__efivars->lock);
> + return err;
> +
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
> +
> +/**
> + * efivar_entry_iter_begin - begin iterating the variable list
> + *
> + * Lock the variable list to prevent entry insertion and removal until
> + * efivar_entry_iter_end() is called. This function is usually used in
> + * conjunction with __efivar_entry_iter() or efivar_entry_iter().
> + */
> +void efivar_entry_iter_begin(void)
> +{
> + spin_lock_irq(&__efivars->lock);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
> +
> +/**
> + * efivar_entry_iter_end - finish iterating the variable list
> + *
> + * Unlock the variable list and allow modifications to the list again.
> + */
> +void efivar_entry_iter_end(void)
> +{
> + spin_unlock_irq(&__efivars->lock);
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
> +
> +/**
> + * __efivar_entry_iter - iterate over variable list
> + * @func: callback function
> + * @head: head of the variable list
> + * @data: function-specific data to pass to callback
> + * @prev: entry to begin iterating from
> + *
> + * Iterate over the list of EFI variables and call @func with every
> + * entry on the list. It is safe for @func to remove entries in the
> + * list via efivar_entry_delete().
> + *
> + * You MUST call efivar_enter_iter_begin() before this function, and
> + * efivar_entry_iter_end() afterwards.
> + *
> + * It is possible to begin iteration from an arbitrary entry within
> + * the list by passing @prev. @prev is updated on return to point to
> + * the last entry passed to @func. To begin iterating from the
> + * beginning of the list @prev must be %NULL.
> + *
> + * The restrictions for @func are the same as documented for
> + * efivar_entry_iter().
> + */
> +int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
> + struct list_head *head, void *data,
> + struct efivar_entry **prev)
> +{
> + struct efivar_entry *entry, *n;
> + int err = 0;
> +
> + if (!prev || !*prev) {
> + list_for_each_entry_safe(entry, n, head, list) {
> + err = func(entry, data);
> + if (err)
> + break;
> + }
> +
> + if (prev)
> + *prev = entry;
> +
> + return err;
> + }
> +
> +
> + list_for_each_entry_safe_continue((*prev), n, head, list) {
> + err = func(*prev, data);
> + if (err)
> + break;
> + }
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(__efivar_entry_iter);
> +
> +/**
> + * efivar_entry_iter - iterate over variable list
> + * @func: callback function
> + * @head: head of variable list
> + * @data: function-specific data to pass to callback
> + *
> + * Iterate over the list of EFI variables and call @func with every
> + * entry on the list. It is safe for @func to remove entries in the
> + * list via efivar_entry_delete() while iterating.
> + *
> + * Some notes for the callback function:
> + * - a non-zero return value indicates an error and terminates the loop
> + * - @func is called from atomic context
> + */
> +int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
> + struct list_head *head, void *data)
> +{
> + int err = 0;
> +
> + efivar_entry_iter_begin();
> + err = __efivar_entry_iter(func, head, data, NULL);
> + efivar_entry_iter_end();
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(efivar_entry_iter);
> +
> +/**
> + * efivars_kobject - get the kobject for the registered efivars
> + *
> + * If efivars_register() has not been called we return NULL,
> + * otherwise return the kobject used at registration time.
> + */
> +struct kobject *efivars_kobject(void)
> +{
> + if (!__efivars)
> + return NULL;
> +
> + return __efivars->kobject;
> +}
> +EXPORT_SYMBOL_GPL(efivars_kobject);
> +
> +/**
> + * efivars_register - register an efivars
> + * @efivars: efivars to register
> + * @ops: efivars operations
> + * @kobject: @efivars-specific kobject
> + *
> + * Only a single efivars can be registered at any time.
> + */
> +int efivars_register(struct efivars *efivars,
> + const struct efivar_operations *ops,
> + struct kobject *kobject)
> +{
> + spin_lock_init(&efivars->lock);
> + efivars->ops = ops;
> + efivars->kobject = kobject;
> +
> + __efivars = efivars;
>
> if (!efivars_pstore_disable)
> - efivar_pstore_register(efivars);
> + efivar_pstore_register();
>
> register_filesystem(&efivarfs_type);
>
> -out:
> - kfree(variable_name);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(efivars_register);
>
> - return error;
> +/**
> + * efivars_unregister - unregister an efivars
> + * @efivars: efivars to unregister
> + *
> + * The caller must have already removed every entry from the list,
> + * failure to do so is an error.
> + */
> +int efivars_unregister(struct efivars *efivars)
> +{
> + int rv;
> +
> + if (!__efivars) {
> + printk(KERN_ERR "efivars not registered\n");
> + rv = -EINVAL;
> + goto out;
> + }
> +
> + if (__efivars != efivars) {
> + rv = -EINVAL;
> + goto out;
> + }
> +
> + __efivars = NULL;
> +
> + rv = 0;
> +out:
> + return rv;
> }
> -EXPORT_SYMBOL_GPL(register_efivars);
> +EXPORT_SYMBOL_GPL(efivars_unregister);
>
> static struct efivars generic_efivars;
> static struct efivar_operations generic_ops;
>
> static int generic_ops_register(void)
> {
> + int error;
> +
> generic_ops.get_variable = efi.get_variable;
> generic_ops.set_variable = efi.set_variable;
> generic_ops.get_next_variable = efi.get_next_variable;
> generic_ops.query_variable_info = efi.query_variable_info;
>
> - return register_efivars(&generic_efivars, &generic_ops, efi_kobj);
> + error = efivars_register(&generic_efivars, &generic_ops, efi_kobj);
> + if (error)
> + return error;
> +
> + error = efivars_sysfs_init();
> + if (error)
> + efivars_unregister(&generic_efivars);
> +
> + return error;
> }
>
> static void generic_ops_unregister(void)
> {
> - unregister_efivars(&generic_efivars);
> + efivars_sysfs_exit();
> + efivars_unregister(&generic_efivars);
> }
>
> /*
> @@ -2113,15 +2493,12 @@ static void generic_ops_unregister(void)
> static int __init
> efivars_init(void)
> {
> - int error = 0;
> -
> - printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
> - EFIVARS_DATE);
> + int error;
>
> if (!efi_enabled(EFI_RUNTIME_SERVICES))
> return 0;
>
> - /* For now we'll register the efi directory at /sys/firmware/efi */
> + /* 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");
> diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c
> index c409a75..757b2d9 100644
> --- a/drivers/firmware/google/gsmi.c
> +++ b/drivers/firmware/google/gsmi.c
> @@ -882,12 +882,19 @@ static __init int gsmi_init(void)
> goto out_remove_bin_file;
> }
>
> - ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj);
> + ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj);
> if (ret) {
> printk(KERN_INFO "gsmi: Failed to register efivars\n");
> goto out_remove_sysfs_files;
> }
>
> + ret = efivars_sysfs_init();
> + if (ret) {
> + printk(KERN_INFO "gsmi: Failed to create efivars files\n");
> + efivars_unregister(&efivars);
> + goto out_remove_sysfs_files;
> + }
> +
> register_reboot_notifier(&gsmi_reboot_notifier);
> register_die_notifier(&gsmi_die_notifier);
> atomic_notifier_chain_register(&panic_notifier_list,
> @@ -919,7 +926,7 @@ static void __exit gsmi_exit(void)
> unregister_die_notifier(&gsmi_die_notifier);
> atomic_notifier_chain_unregister(&panic_notifier_list,
> &gsmi_panic_notifier);
> - unregister_efivars(&efivars);
> + efivars_unregister(&efivars);
>
> sysfs_remove_files(gsmi_kobj, gsmi_attrs);
> sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index d1d782a..cd561b3 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -663,6 +663,12 @@ static inline int efi_enabled(int facility)
> EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS | \
> EFI_VARIABLE_APPEND_WRITE)
> /*
> + * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
> + * not including trailing NUL
> + */
> +#define EFI_VARIABLE_GUID_LEN 36
> +
> +/*
> * The type of search to perform when calling boottime->locate_handle
> */
> #define EFI_LOCATE_ALL_HANDLES 0
> @@ -762,19 +768,75 @@ struct efivars {
> * which is protected by the BKL, so that path is safe.
> */
> spinlock_t lock;
> - struct list_head list;
> struct kset *kset;
> struct kobject *kobject;
> - 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,
> +/*
> + * 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 efi_variable var;
> + struct list_head list;
> + struct kobject kobj;
> +};
> +
> +int efivars_register(struct efivars *efivars,
> const struct efivar_operations *ops,
> - struct kobject *parent_kobj);
> -void unregister_efivars(struct efivars *efivars);
> + struct kobject *kobject);
> +int efivars_unregister(struct efivars *efivars);
> +struct kobject *efivars_kobject(void);
> +
> +int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
> + void *data, bool atomic, bool duplicates,
> + struct list_head *head);
> +
> +void efivar_entry_add(struct efivar_entry *entry, struct list_head *head);
> +void efivar_entry_remove(struct efivar_entry *entry);
> +
> +int __efivar_entry_delete(struct efivar_entry *entry);
> +int efivar_entry_delete(struct efivar_entry *entry);
> +
> +int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size);
> +int efivar_entry_size(struct efivar_entry *entry, unsigned long *size);
> +int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
> + unsigned long *size, void *data);
> +int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
> + unsigned long size, void *data, struct list_head *head);
> +int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
> + unsigned long *size, void *data, bool *set);
> +int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
> + bool block, unsigned long size, void *data);
> +
> +void efivar_entry_iter_begin(void);
> +void efivar_entry_iter_end(void);
> +
> +int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
> + struct list_head *head, void *data,
> + struct efivar_entry **prev);
> +int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
> + struct list_head *head, void *data);
> +
> +struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
> + struct list_head *head, bool remove);
> +
> +bool efivar_validate(struct efi_variable *var, u8 *data, unsigned long len);
> +
> +int efivars_sysfs_init(void);
>
> #endif /* CONFIG_EFI_VARS */
>
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