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path: root/drivers/firmware/efivars.c
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Diffstat (limited to 'drivers/firmware/efivars.c')
-rw-r--r--drivers/firmware/efivars.c335
1 files changed, 276 insertions, 59 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 7b1c37497c9a..7320bf891706 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -79,6 +79,7 @@
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/pstore.h>
+#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/ramfs.h>
@@ -158,6 +159,13 @@ efivar_create_sysfs_entry(struct efivars *efivars,
efi_char16_t *variable_name,
efi_guid_t *vendor_guid);
+/*
+ * Prototype for workqueue functions updating sysfs entry
+ */
+
+static void efivar_update_sysfs_entries(struct work_struct *);
+static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
+
/* Return the number of unicode characters in data */
static unsigned long
utf16_strnlen(efi_char16_t *s, size_t maxlength)
@@ -405,10 +413,11 @@ static efi_status_t
get_var_data(struct efivars *efivars, struct efi_variable *var)
{
efi_status_t status;
+ unsigned long flags;
- spin_lock(&efivars->lock);
+ spin_lock_irqsave(&efivars->lock, flags);
status = get_var_data_locked(efivars, var);
- spin_unlock(&efivars->lock);
+ spin_unlock_irqrestore(&efivars->lock, flags);
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
@@ -537,14 +546,14 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
return -EINVAL;
}
- spin_lock(&efivars->lock);
+ spin_lock_irq(&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);
+ spin_unlock_irq(&efivars->lock);
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
@@ -674,7 +683,7 @@ static int efi_status_to_err(efi_status_t status)
err = -EACCES;
break;
case EFI_NOT_FOUND:
- err = -ENOENT;
+ err = -EIO;
break;
default:
err = -EINVAL;
@@ -713,7 +722,7 @@ static ssize_t efivarfs_file_write(struct file *file,
* amounts of memory. Pick a default size of 64K if
* QueryVariableInfo() isn't supported by the firmware.
*/
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
if (!efivars->ops->query_variable_info)
status = EFI_UNSUPPORTED;
@@ -723,7 +732,7 @@ static ssize_t efivarfs_file_write(struct file *file,
&remaining_size, &max_size);
}
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
if (status != EFI_SUCCESS) {
if (status != EFI_UNSUPPORTED)
@@ -754,7 +763,7 @@ static ssize_t efivarfs_file_write(struct file *file,
* set_variable call, and removal of the variable from the efivars
* list (in the case of an authenticated delete).
*/
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
status = efivars->ops->set_variable(var->var.VariableName,
&var->var.VendorGuid,
@@ -762,7 +771,7 @@ static ssize_t efivarfs_file_write(struct file *file,
data);
if (status != EFI_SUCCESS) {
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
kfree(data);
return efi_status_to_err(status);
@@ -783,20 +792,21 @@ static ssize_t efivarfs_file_write(struct file *file,
NULL);
if (status == EFI_BUFFER_TOO_SMALL) {
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
mutex_lock(&inode->i_mutex);
i_size_write(inode, newdatasize + sizeof(attributes));
mutex_unlock(&inode->i_mutex);
} else if (status == EFI_NOT_FOUND) {
list_del(&var->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
efivar_unregister(var);
drop_nlink(inode);
+ d_delete(file->f_dentry);
dput(file->f_dentry);
} else {
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
pr_warn("efivarfs: inconsistent EFI variable implementation? "
"status = %lx\n", status);
}
@@ -818,11 +828,11 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
void *data;
ssize_t size = 0;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
status = efivars->ops->get_variable(var->var.VariableName,
&var->var.VendorGuid,
&attributes, &datasize, NULL);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
if (status != EFI_BUFFER_TOO_SMALL)
return efi_status_to_err(status);
@@ -832,12 +842,12 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
if (!data)
return -ENOMEM;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
status = efivars->ops->get_variable(var->var.VariableName,
&var->var.VendorGuid,
&attributes, &datasize,
(data + sizeof(attributes)));
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
if (status != EFI_SUCCESS) {
size = efi_status_to_err(status);
@@ -899,6 +909,48 @@ static struct inode *efivarfs_get_inode(struct super_block *sb,
return inode;
}
+/*
+ * Return true if 'str' is a valid efivarfs filename of the form,
+ *
+ * VariableName-12345678-1234-1234-1234-1234567891bc
+ */
+static bool efivarfs_valid_name(const char *str, int len)
+{
+ static const char dashes[GUID_LEN] = {
+ [8] = 1, [13] = 1, [18] = 1, [23] = 1
+ };
+ const char *s = str + len - GUID_LEN;
+ int i;
+
+ /*
+ * We need a GUID, plus at least one letter for the variable name,
+ * plus the '-' separator
+ */
+ if (len < GUID_LEN + 2)
+ return false;
+
+ /* GUID should be right after the first '-' */
+ if (s - 1 != strchr(str, '-'))
+ return false;
+
+ /*
+ * Validate that 's' is of the correct format, e.g.
+ *
+ * 12345678-1234-1234-1234-123456789abc
+ */
+ for (i = 0; i < GUID_LEN; i++) {
+ if (dashes[i]) {
+ if (*s++ != '-')
+ return false;
+ } else {
+ if (!isxdigit(*s++))
+ return false;
+ }
+ }
+
+ return true;
+}
+
static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
{
guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
@@ -927,11 +979,7 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry,
struct efivar_entry *var;
int namelen, i = 0, err = 0;
- /*
- * We need a GUID, plus at least one letter for the variable name,
- * plus the '-' separator
- */
- if (dentry->d_name.len < GUID_LEN + 2)
+ if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
return -EINVAL;
inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
@@ -965,9 +1013,9 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry,
goto out;
kobject_uevent(&var->kobj, KOBJ_ADD);
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
list_add(&var->list, &efivars->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
d_instantiate(dentry, inode);
dget(dentry);
out:
@@ -984,7 +1032,7 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
struct efivars *efivars = var->efivars;
efi_status_t status;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
status = efivars->ops->set_variable(var->var.VariableName,
&var->var.VendorGuid,
@@ -992,17 +1040,95 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) {
list_del(&var->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
efivar_unregister(var);
- drop_nlink(dir);
+ drop_nlink(dentry->d_inode);
dput(dentry);
return 0;
}
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return -EINVAL;
};
+/*
+ * Compare two efivarfs file names.
+ *
+ * An efivarfs filename is composed of two parts,
+ *
+ * 1. A case-sensitive variable name
+ * 2. A case-insensitive GUID
+ *
+ * So we need to perform a case-sensitive match on part 1 and a
+ * case-insensitive match on part 2.
+ */
+static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str,
+ const struct qstr *name)
+{
+ int guid = len - GUID_LEN;
+
+ if (name->len != len)
+ return 1;
+
+ /* Case-sensitive compare for the variable name */
+ if (memcmp(str, name->name, guid))
+ return 1;
+
+ /* Case-insensitive compare for the GUID */
+ return strncasecmp(name->name + guid, str + guid, GUID_LEN);
+}
+
+static int efivarfs_d_hash(const struct dentry *dentry,
+ const struct inode *inode, struct qstr *qstr)
+{
+ unsigned long hash = init_name_hash();
+ const unsigned char *s = qstr->name;
+ unsigned int len = qstr->len;
+
+ if (!efivarfs_valid_name(s, len))
+ return -EINVAL;
+
+ while (len-- > GUID_LEN)
+ hash = partial_name_hash(*s++, hash);
+
+ /* GUID is case-insensitive. */
+ while (len--)
+ hash = partial_name_hash(tolower(*s++), hash);
+
+ qstr->hash = end_name_hash(hash);
+ return 0;
+}
+
+/*
+ * Retaining negative dentries for an in-memory filesystem just wastes
+ * memory and lookup time: arrange for them to be deleted immediately.
+ */
+static int efivarfs_delete_dentry(const struct dentry *dentry)
+{
+ return 1;
+}
+
+static struct dentry_operations efivarfs_d_ops = {
+ .d_compare = efivarfs_d_compare,
+ .d_hash = efivarfs_d_hash,
+ .d_delete = efivarfs_delete_dentry,
+};
+
+static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
+{
+ struct qstr q;
+
+ q.name = name;
+ q.len = strlen(name);
+
+ if (efivarfs_d_hash(NULL, NULL, &q))
+ return NULL;
+
+ return d_alloc(parent, &q);
+}
+
static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode = NULL;
@@ -1018,6 +1144,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = EFIVARFS_MAGIC;
sb->s_op = &efivarfs_ops;
+ sb->s_d_op = &efivarfs_d_ops;
sb->s_time_gran = 1;
inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0);
@@ -1058,24 +1185,24 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
if (!inode)
goto fail_name;
- dentry = d_alloc_name(root, name);
+ dentry = efivarfs_alloc_dentry(root, name);
if (!dentry)
goto fail_inode;
/* copied by the above to local storage in the dentry. */
kfree(name);
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
efivars->ops->get_variable(entry->var.VariableName,
&entry->var.VendorGuid,
&entry->var.Attributes,
&size,
NULL);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
mutex_lock(&inode->i_mutex);
inode->i_private = entry;
- i_size_write(inode, size+4);
+ i_size_write(inode, size + sizeof(entry->var.Attributes));
mutex_unlock(&inode->i_mutex);
d_add(dentry, inode);
}
@@ -1108,8 +1235,20 @@ static struct file_system_type efivarfs_type = {
.kill_sb = efivarfs_kill_sb,
};
+/*
+ * Handle negative dentry.
+ */
+static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+ d_add(dentry, NULL);
+ return NULL;
+}
+
static const struct inode_operations efivarfs_dir_inode_operations = {
- .lookup = simple_lookup,
+ .lookup = efivarfs_lookup,
.unlink = efivarfs_unlink,
.create = efivarfs_create,
};
@@ -1122,7 +1261,7 @@ static int efi_pstore_open(struct pstore_info *psi)
{
struct efivars *efivars = psi->data;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
efivars->walk_entry = list_first_entry(&efivars->list,
struct efivar_entry, list);
return 0;
@@ -1132,7 +1271,7 @@ static int efi_pstore_close(struct pstore_info *psi)
{
struct efivars *efivars = psi->data;
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return 0;
}
@@ -1208,8 +1347,18 @@ static int efi_pstore_write(enum pstore_type_id type,
int i, ret = 0;
u64 storage_space, remaining_space, max_variable_size;
efi_status_t status = EFI_NOT_FOUND;
-
- spin_lock(&efivars->lock);
+ 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.
@@ -1221,7 +1370,7 @@ static int efi_pstore_write(enum pstore_type_id type,
&remaining_space,
&max_variable_size);
if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
- spin_unlock(&efivars->lock);
+ spin_unlock_irqrestore(&efivars->lock, flags);
*id = part;
return -ENOSPC;
}
@@ -1235,13 +1384,10 @@ static int efi_pstore_write(enum pstore_type_id type,
efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
size, psi->buf);
- spin_unlock(&efivars->lock);
+ spin_unlock_irqrestore(&efivars->lock, flags);
- if (size)
- ret = efivar_create_sysfs_entry(efivars,
- utf16_strsize(efi_name,
- DUMP_NAME_LEN * 2),
- efi_name, &vendor);
+ if (reason == KMSG_DUMP_OOPS)
+ schedule_work(&efivar_work);
*id = part;
return ret;
@@ -1262,7 +1408,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
time.tv_sec);
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = name[i];
@@ -1306,7 +1452,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
if (found)
list_del(&found->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
if (found)
efivar_unregister(found);
@@ -1376,7 +1522,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
return -EINVAL;
}
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
/*
* Does this variable already exist?
@@ -1394,7 +1540,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
}
}
if (found) {
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return -EINVAL;
}
@@ -1408,10 +1554,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
status);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return -EIO;
}
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
/* Create the entry in sysfs. Locking is not required here */
status = efivar_create_sysfs_entry(efivars,
@@ -1439,7 +1585,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
/*
* Does this variable already exist?
@@ -1457,7 +1603,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
}
}
if (!found) {
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return -EINVAL;
}
/* force the Attributes/DataSize to 0 to ensure deletion */
@@ -1473,18 +1619,87 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
status);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return -EIO;
}
list_del(&search_efivar->list);
/* We need to release this lock before unregistering. */
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
efivar_unregister(search_efivar);
/* It's dead Jim.... */
return count;
}
+static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
+{
+ 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) {
+ strsize2 = utf16_strsize(entry->var.VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(variable_name, &(entry->var.VariableName),
+ strsize2) &&
+ !efi_guidcmp(entry->var.VendorGuid,
+ *vendor)) {
+ found = true;
+ break;
+ }
+ }
+ return found;
+}
+
+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;
+
+ /* 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;
+ }
+
+ 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);
+ break;
+ } else
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name, &vendor);
+ }
+}
+
/*
* Let's not leave out systab information that snuck into
* the efivars driver
@@ -1593,9 +1808,9 @@ efivar_create_sysfs_entry(struct efivars *efivars,
kfree(short_name);
short_name = NULL;
- spin_lock(&efivars->lock);
+ spin_lock_irq(&efivars->lock);
list_add(&new_efivar->list, &efivars->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
return 0;
}
@@ -1664,9 +1879,9 @@ 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);
+ spin_lock_irq(&efivars->lock);
list_del(&entry->list);
- spin_unlock(&efivars->lock);
+ spin_unlock_irq(&efivars->lock);
efivar_unregister(entry);
}
if (efivars->new_var)
@@ -1782,7 +1997,7 @@ efivars_init(void)
printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
EFIVARS_DATE);
- if (!efi_enabled)
+ if (!efi_enabled(EFI_RUNTIME_SERVICES))
return 0;
/* For now we'll register the efi directory at /sys/firmware/efi */
@@ -1822,7 +2037,9 @@ err_put:
static void __exit
efivars_exit(void)
{
- if (efi_enabled) {
+ cancel_work_sync(&efivar_work);
+
+ if (efi_enabled(EFI_RUNTIME_SERVICES)) {
unregister_efivars(&__efivars);
kobject_put(efi_kobj);
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-27 16:37:45 +0100