summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/kernel-parameters.txt6
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/boot/compressed/eboot.c47
-rw-r--r--arch/x86/include/asm/efi.h7
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h1
-rw-r--r--arch/x86/platform/efi/efi.c168
-rw-r--r--drivers/firmware/Kconfig1
-rw-r--r--drivers/firmware/efivars.c98
-rw-r--r--include/linux/efi.h9
-rw-r--r--include/linux/ucs2_string.h14
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/ucs2_string.c51
13 files changed, 325 insertions, 83 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4609e81dbc37..d1cc3a9fa14f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -788,6 +788,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
+ efi_no_storage_paranoia [EFI; X86]
+ Using this parameter you can use more than 50% of
+ your efi variable storage. Use this parameter only if
+ you are really sure that your UEFI does sane gc and
+ fulfills the spec otherwise your board may brick.
+
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 70c0f3da0476..15b5cef4aa38 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1549,6 +1549,7 @@ config X86_SMAP
config EFI
bool "EFI runtime service support"
depends on ACPI
+ select UCS2_STRING
---help---
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index c205035a6b96..8615f7581820 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -251,6 +251,51 @@ static void find_bits(unsigned long mask, u8 *pos, u8 *size)
*size = len;
}
+static efi_status_t setup_efi_vars(struct boot_params *params)
+{
+ struct setup_data *data;
+ struct efi_var_bootdata *efidata;
+ u64 store_size, remaining_size, var_size;
+ efi_status_t status;
+
+ if (!sys_table->runtime->query_variable_info)
+ return EFI_UNSUPPORTED;
+
+ data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+ while (data && data->next)
+ data = (struct setup_data *)(unsigned long)data->next;
+
+ status = efi_call_phys4(sys_table->runtime->query_variable_info,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS, &store_size,
+ &remaining_size, &var_size);
+
+ if (status != EFI_SUCCESS)
+ return status;
+
+ status = efi_call_phys3(sys_table->boottime->allocate_pool,
+ EFI_LOADER_DATA, sizeof(*efidata), &efidata);
+
+ if (status != EFI_SUCCESS)
+ return status;
+
+ efidata->data.type = SETUP_EFI_VARS;
+ efidata->data.len = sizeof(struct efi_var_bootdata) -
+ sizeof(struct setup_data);
+ efidata->data.next = 0;
+ efidata->store_size = store_size;
+ efidata->remaining_size = remaining_size;
+ efidata->max_var_size = var_size;
+
+ if (data)
+ data->next = (unsigned long)efidata;
+ else
+ params->hdr.setup_data = (unsigned long)efidata;
+
+}
+
static efi_status_t setup_efi_pci(struct boot_params *params)
{
efi_pci_io_protocol *pci;
@@ -1157,6 +1202,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
setup_graphics(boot_params);
+ setup_efi_vars(boot_params);
+
setup_efi_pci(boot_params);
status = efi_call_phys3(sys_table->boottime->allocate_pool,
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 60c89f30c727..2fb5d5884e23 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -102,6 +102,13 @@ extern void efi_call_phys_epilog(void);
extern void efi_unmap_memmap(void);
extern void efi_memory_uc(u64 addr, unsigned long size);
+struct efi_var_bootdata {
+ struct setup_data data;
+ u64 store_size;
+ u64 remaining_size;
+ u64 max_var_size;
+};
+
#ifdef CONFIG_EFI
static inline bool efi_is_native(void)
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index c15ddaf90710..08744242b8d2 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -6,6 +6,7 @@
#define SETUP_E820_EXT 1
#define SETUP_DTB 2
#define SETUP_PCI 3
+#define SETUP_EFI_VARS 4
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 5f2ecaf3f9d8..e4a86a677ce1 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -41,6 +41,7 @@
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/bcd.h>
+#include <linux/ucs2_string.h>
#include <asm/setup.h>
#include <asm/efi.h>
@@ -51,6 +52,13 @@
#define EFI_DEBUG 1
+/*
+ * There's some additional metadata associated with each
+ * variable. Intel's reference implementation is 60 bytes - bump that
+ * to account for potential alignment constraints
+ */
+#define VAR_METADATA_SIZE 64
+
struct efi __read_mostly efi = {
.mps = EFI_INVALID_TABLE_ADDR,
.acpi = EFI_INVALID_TABLE_ADDR,
@@ -69,6 +77,13 @@ struct efi_memory_map memmap;
static struct efi efi_phys __initdata;
static efi_system_table_t efi_systab __initdata;
+static u64 efi_var_store_size;
+static u64 efi_var_remaining_size;
+static u64 efi_var_max_var_size;
+static u64 boot_used_size;
+static u64 boot_var_size;
+static u64 active_size;
+
unsigned long x86_efi_facility;
/*
@@ -98,6 +113,15 @@ static int __init setup_add_efi_memmap(char *arg)
}
early_param("add_efi_memmap", setup_add_efi_memmap);
+static bool efi_no_storage_paranoia;
+
+static int __init setup_storage_paranoia(char *arg)
+{
+ efi_no_storage_paranoia = true;
+ return 0;
+}
+early_param("efi_no_storage_paranoia", setup_storage_paranoia);
+
static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
@@ -162,8 +186,53 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
efi_char16_t *name,
efi_guid_t *vendor)
{
- return efi_call_virt3(get_next_variable,
- name_size, name, vendor);
+ efi_status_t status;
+ static bool finished = false;
+ static u64 var_size;
+
+ status = efi_call_virt3(get_next_variable,
+ name_size, name, vendor);
+
+ if (status == EFI_NOT_FOUND) {
+ finished = true;
+ if (var_size < boot_used_size) {
+ boot_var_size = boot_used_size - var_size;
+ active_size += boot_var_size;
+ } else {
+ printk(KERN_WARNING FW_BUG "efi: Inconsistent initial sizes\n");
+ }
+ }
+
+ if (boot_used_size && !finished) {
+ unsigned long size;
+ u32 attr;
+ efi_status_t s;
+ void *tmp;
+
+ s = virt_efi_get_variable(name, vendor, &attr, &size, NULL);
+
+ if (s != EFI_BUFFER_TOO_SMALL || !size)
+ return status;
+
+ tmp = kmalloc(size, GFP_ATOMIC);
+
+ if (!tmp)
+ return status;
+
+ s = virt_efi_get_variable(name, vendor, &attr, &size, tmp);
+
+ if (s == EFI_SUCCESS && (attr & EFI_VARIABLE_NON_VOLATILE)) {
+ var_size += size;
+ var_size += ucs2_strsize(name, 1024);
+ active_size += size;
+ active_size += VAR_METADATA_SIZE;
+ active_size += ucs2_strsize(name, 1024);
+ }
+
+ kfree(tmp);
+ }
+
+ return status;
}
static efi_status_t virt_efi_set_variable(efi_char16_t *name,
@@ -172,9 +241,34 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
unsigned long data_size,
void *data)
{
- return efi_call_virt5(set_variable,
- name, vendor, attr,
- data_size, data);
+ efi_status_t status;
+ u32 orig_attr = 0;
+ unsigned long orig_size = 0;
+
+ status = virt_efi_get_variable(name, vendor, &orig_attr, &orig_size,
+ NULL);
+
+ if (status != EFI_BUFFER_TOO_SMALL)
+ orig_size = 0;
+
+ status = efi_call_virt5(set_variable,
+ name, vendor, attr,
+ data_size, data);
+
+ if (status == EFI_SUCCESS) {
+ if (orig_size) {
+ active_size -= orig_size;
+ active_size -= ucs2_strsize(name, 1024);
+ active_size -= VAR_METADATA_SIZE;
+ }
+ if (data_size) {
+ active_size += data_size;
+ active_size += ucs2_strsize(name, 1024);
+ active_size += VAR_METADATA_SIZE;
+ }
+ }
+
+ return status;
}
static efi_status_t virt_efi_query_variable_info(u32 attr,
@@ -682,6 +776,9 @@ void __init efi_init(void)
char vendor[100] = "unknown";
int i = 0;
void *tmp;
+ struct setup_data *data;
+ struct efi_var_bootdata *efi_var_data;
+ u64 pa_data;
#ifdef CONFIG_X86_32
if (boot_params.efi_info.efi_systab_hi ||
@@ -699,6 +796,22 @@ void __init efi_init(void)
if (efi_systab_init(efi_phys.systab))
return;
+ pa_data = boot_params.hdr.setup_data;
+ while (pa_data) {
+ data = early_ioremap(pa_data, sizeof(*efi_var_data));
+ if (data->type == SETUP_EFI_VARS) {
+ efi_var_data = (struct efi_var_bootdata *)data;
+
+ efi_var_store_size = efi_var_data->store_size;
+ efi_var_remaining_size = efi_var_data->remaining_size;
+ efi_var_max_var_size = efi_var_data->max_var_size;
+ }
+ pa_data = data->next;
+ early_iounmap(data, sizeof(*efi_var_data));
+ }
+
+ boot_used_size = efi_var_store_size - efi_var_remaining_size;
+
set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility);
/*
@@ -999,3 +1112,48 @@ u64 efi_mem_attributes(unsigned long phys_addr)
}
return 0;
}
+
+/*
+ * Some firmware has serious problems when using more than 50% of the EFI
+ * variable store, i.e. it triggers bugs that can brick machines. Ensure that
+ * we never use more than this safe limit.
+ *
+ * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
+ * store.
+ */
+efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
+{
+ efi_status_t status;
+ u64 storage_size, remaining_size, max_size;
+
+ status = efi.query_variable_info(attributes, &storage_size,
+ &remaining_size, &max_size);
+ if (status != EFI_SUCCESS)
+ return status;
+
+ if (!max_size && remaining_size > size)
+ printk_once(KERN_ERR FW_BUG "Broken EFI implementation"
+ " is returning MaxVariableSize=0\n");
+ /*
+ * Some firmware implementations refuse to boot if there's insufficient
+ * space in the variable store. We account for that by refusing the
+ * write if permitting it would reduce the available space to under
+ * 50%. However, some firmware won't reclaim variable space until
+ * after the used (not merely the actively used) space drops below
+ * a threshold. We can approximate that case with the value calculated
+ * above. If both the firmware and our calculations indicate that the
+ * available space would drop below 50%, refuse the write.
+ */
+
+ if (!storage_size || size > remaining_size ||
+ (max_size && size > max_size))
+ return EFI_OUT_OF_RESOURCES;
+
+ if (!efi_no_storage_paranoia &&
+ ((active_size + size + VAR_METADATA_SIZE > storage_size / 2) &&
+ (remaining_size - size < storage_size / 2)))
+ return EFI_OUT_OF_RESOURCES;
+
+ return EFI_SUCCESS;
+}
+EXPORT_SYMBOL_GPL(efi_query_variable_store);
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 42c759a4d047..3e532002e4d1 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -39,6 +39,7 @@ config FIRMWARE_MEMMAP
config EFI_VARS
tristate "EFI Variable Support via sysfs"
depends on EFI
+ select UCS2_STRING
default n
help
If you say Y here, you are able to get EFI (Extensible Firmware
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 7acafb80fd4c..182ce9471175 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -80,6 +80,7 @@
#include <linux/slab.h>
#include <linux/pstore.h>
#include <linux/ctype.h>
+#include <linux/ucs2_string.h>
#include <linux/fs.h>
#include <linux/ramfs.h>
@@ -172,51 +173,6 @@ static void efivar_update_sysfs_entries(struct work_struct *);
static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
static bool efivar_wq_enabled = true;
-/* Return the number of unicode characters in data */
-static unsigned long
-utf16_strnlen(efi_char16_t *s, size_t maxlength)
-{
- unsigned long length = 0;
-
- while (*s++ != 0 && length < maxlength)
- length++;
- return length;
-}
-
-static inline unsigned long
-utf16_strlen(efi_char16_t *s)
-{
- return utf16_strnlen(s, ~0UL);
-}
-
-/*
- * Return the number of bytes is the length of this string
- * Note: this is NOT the same as the number of unicode characters
- */
-static inline unsigned long
-utf16_strsize(efi_char16_t *data, unsigned long maxlength)
-{
- return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
-}
-
-static inline int
-utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
-{
- while (1) {
- if (len == 0)
- return 0;
- if (*a < *b)
- return -1;
- if (*a > *b)
- return 1;
- if (*a == 0) /* implies *b == 0 */
- return 0;
- a++;
- b++;
- len--;
- }
-}
-
static bool
validate_device_path(struct efi_variable *var, int match, u8 *buffer,
unsigned long len)
@@ -268,7 +224,7 @@ validate_load_option(struct efi_variable *var, int match, u8 *buffer,
u16 filepathlength;
int i, desclength = 0, namelen;
- namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
+ namelen = ucs2_strnlen(var->VariableName, sizeof(var->VariableName));
/* Either "Boot" or "Driver" followed by four digits of hex */
for (i = match; i < match+4; i++) {
@@ -291,7 +247,7 @@ validate_load_option(struct efi_variable *var, int match, u8 *buffer,
* There's no stored length for the description, so it has to be
* found by hand
*/
- desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
+ desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
/* Each boot entry must have a descriptor */
if (!desclength)
@@ -436,24 +392,12 @@ static efi_status_t
check_var_size_locked(struct efivars *efivars, u32 attributes,
unsigned long size)
{
- u64 storage_size, remaining_size, max_size;
- efi_status_t status;
const struct efivar_operations *fops = efivars->ops;
- if (!efivars->ops->query_variable_info)
+ if (!efivars->ops->query_variable_store)
return EFI_UNSUPPORTED;
- status = fops->query_variable_info(attributes, &storage_size,
- &remaining_size, &max_size);
-
- if (status != EFI_SUCCESS)
- return status;
-
- if (!storage_size || size > remaining_size || size > max_size ||
- (remaining_size - size) < (storage_size / 2))
- return EFI_OUT_OF_RESOURCES;
-
- return status;
+ return fops->query_variable_store(attributes, size);
}
@@ -593,7 +537,7 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
spin_lock_irq(&efivars->lock);
status = check_var_size_locked(efivars, new_var->Attributes,
- new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
+ new_var->DataSize + ucs2_strsize(new_var->VariableName, 1024));
if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
status = efivars->ops->set_variable(new_var->VariableName,
@@ -771,7 +715,7 @@ static ssize_t efivarfs_file_write(struct file *file,
* QueryVariableInfo() isn't supported by the firmware.
*/
- varsize = datasize + utf16_strsize(var->var.VariableName, 1024);
+ varsize = datasize + ucs2_strsize(var->var.VariableName, 1024);
status = check_var_size(efivars, attributes, varsize);
if (status != EFI_SUCCESS) {
@@ -1223,7 +1167,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
inode = NULL;
- len = utf16_strlen(entry->var.VariableName);
+ len = ucs2_strlen(entry->var.VariableName);
/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC);
@@ -1481,8 +1425,8 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
if (efi_guidcmp(entry->var.VendorGuid, vendor))
continue;
- if (utf16_strncmp(entry->var.VariableName, efi_name,
- utf16_strlen(efi_name))) {
+ if (ucs2_strncmp(entry->var.VariableName, efi_name,
+ ucs2_strlen(efi_name))) {
/*
* Check if an old format,
* which doesn't support holding
@@ -1494,8 +1438,8 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name_old[i] = name_old[i];
- if (utf16_strncmp(entry->var.VariableName, efi_name_old,
- utf16_strlen(efi_name_old)))
+ if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
+ ucs2_strlen(efi_name_old)))
continue;
}
@@ -1573,8 +1517,8 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
* 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);
+ strsize1 = ucs2_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = ucs2_strsize(new_var->VariableName, 1024);
if (strsize1 == strsize2 &&
!memcmp(&(search_efivar->var.VariableName),
new_var->VariableName, strsize1) &&
@@ -1590,7 +1534,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
}
status = check_var_size_locked(efivars, new_var->Attributes,
- new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
+ new_var->DataSize + ucs2_strsize(new_var->VariableName, 1024));
if (status && status != EFI_UNSUPPORTED) {
spin_unlock_irq(&efivars->lock);
@@ -1614,7 +1558,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
/* Create the entry in sysfs. Locking is not required here */
status = efivar_create_sysfs_entry(efivars,
- utf16_strsize(new_var->VariableName,
+ ucs2_strsize(new_var->VariableName,
1024),
new_var->VariableName,
&new_var->VendorGuid);
@@ -1644,8 +1588,8 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
* 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);
+ strsize1 = ucs2_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = ucs2_strsize(del_var->VariableName, 1024);
if (strsize1 == strsize2 &&
!memcmp(&(search_efivar->var.VariableName),
del_var->VariableName, strsize1) &&
@@ -1691,9 +1635,9 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
unsigned long strsize1, strsize2;
bool found = false;
- strsize1 = utf16_strsize(variable_name, 1024);
+ strsize1 = ucs2_strsize(variable_name, 1024);
list_for_each_entry_safe(entry, n, &efivars->list, list) {
- strsize2 = utf16_strsize(entry->var.VariableName, 1024);
+ strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
if (strsize1 == strsize2 &&
!memcmp(variable_name, &(entry->var.VariableName),
strsize2) &&
@@ -2131,7 +2075,7 @@ efivars_init(void)
ops.get_variable = efi.get_variable;
ops.set_variable = efi.set_variable;
ops.get_next_variable = efi.get_next_variable;
- ops.query_variable_info = efi.query_variable_info;
+ ops.query_variable_store = efi_query_variable_store;
error = register_efivars(&__efivars, &ops, efi_kobj);
if (error)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 9bf2f1fcae27..3d7df3d32c66 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -333,6 +333,7 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
unsigned long count,
u64 *max_size,
int *reset_type);
+typedef efi_status_t efi_query_variable_store_t(u32 attributes, unsigned long size);
/*
* EFI Configuration Table and GUID definitions
@@ -575,9 +576,15 @@ extern void efi_enter_virtual_mode (void); /* switch EFI to virtual mode, if pos
#ifdef CONFIG_X86
extern void efi_late_init(void);
extern void efi_free_boot_services(void);
+extern efi_status_t efi_query_variable_store(u32 attributes, unsigned long size);
#else
static inline void efi_late_init(void) {}
static inline void efi_free_boot_services(void) {}
+
+static inline efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
+{
+ return EFI_SUCCESS;
+}
#endif
extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);
extern u64 efi_get_iobase (void);
@@ -731,7 +738,7 @@ struct efivar_operations {
efi_get_variable_t *get_variable;
efi_get_next_variable_t *get_next_variable;
efi_set_variable_t *set_variable;
- efi_query_variable_info_t *query_variable_info;
+ efi_query_variable_store_t *query_variable_store;
};
struct efivars {
diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h
new file mode 100644
index 000000000000..cbb20afdbc01
--- /dev/null
+++ b/include/linux/ucs2_string.h
@@ -0,0 +1,14 @@
+#ifndef _LINUX_UCS2_STRING_H_
+#define _LINUX_UCS2_STRING_H_
+
+#include <linux/types.h> /* for size_t */
+#include <linux/stddef.h> /* for NULL */
+
+typedef u16 ucs2_char_t;
+
+unsigned long ucs2_strnlen(const ucs2_char_t *s, size_t maxlength);
+unsigned long ucs2_strlen(const ucs2_char_t *s);
+unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength);
+int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len);
+
+#endif /* _LINUX_UCS2_STRING_H_ */
diff --git a/lib/Kconfig b/lib/Kconfig
index 3958dc4389f9..fe01d418b09a 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -404,4 +404,7 @@ config OID_REGISTRY
help
Enable fast lookup object identifier registry.
+config UCS2_STRING
+ tristate
+
endmenu
diff --git a/lib/Makefile b/lib/Makefile
index d7946ff75b2e..6e2cc561f761 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -174,3 +174,5 @@ quiet_cmd_build_OID_registry = GEN $@
cmd_build_OID_registry = perl $(srctree)/$(src)/build_OID_registry $< $@
clean-files += oid_registry_data.c
+
+obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
new file mode 100644
index 000000000000..6f500ef2301d
--- /dev/null
+++ b/lib/ucs2_string.c
@@ -0,0 +1,51 @@
+#include <linux/ucs2_string.h>
+#include <linux/module.h>
+
+/* Return the number of unicode characters in data */
+unsigned long
+ucs2_strnlen(const ucs2_char_t *s, size_t maxlength)
+{
+ unsigned long length = 0;
+
+ while (*s++ != 0 && length < maxlength)
+ length++;
+ return length;
+}
+EXPORT_SYMBOL(ucs2_strnlen);
+
+unsigned long
+ucs2_strlen(const ucs2_char_t *s)
+{
+ return ucs2_strnlen(s, ~0UL);
+}
+EXPORT_SYMBOL(ucs2_strlen);
+
+/*
+ * Return the number of bytes is the length of this string
+ * Note: this is NOT the same as the number of unicode characters
+ */
+unsigned long
+ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
+{
+ return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t);
+}
+EXPORT_SYMBOL(ucs2_strsize);
+
+int
+ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
+{
+ while (1) {
+ if (len == 0)
+ return 0;
+ if (*a < *b)
+ return -1;
+ if (*a > *b)
+ return 1;
+ if (*a == 0) /* implies *b == 0 */
+ return 0;
+ a++;
+ b++;
+ len--;
+ }
+}
+EXPORT_SYMBOL(ucs2_strncmp);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-05 09:42:52 +0300