[PATCH 3.14 12/19] efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version

Greg Kroah-Hartman
2016-03-14T18:00:59Z

From: Peter Jones <pjones@redhat.com>

commit e0d64e6a880e64545ad7d55786aa84ab76bac475 upstream.

Translate EFI's UCS-2 variable names to UTF-8 instead of just assuming
all variable names fit in ASCII.

Signed-off-by: Peter Jones <pjones@redhat.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/firmware/efi/efivars.c | 28 ++++++++++------------------
fs/efivarfs/super.c | 7 +++----
2 files changed, 13 insertions(+), 22 deletions(-)

--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -409,35 +409,27 @@ efivar_create_sysfs_entry(struct efivar_
{
int i, short_name_size;
char *short_name;
- unsigned long variable_name_size;
- efi_char16_t *variable_name;
-
- variable_name = new_var->var.VariableName;
- variable_name_size = ucs2_strlen(variable_name) * sizeof(efi_char16_t);
+ unsigned long utf8_name_size;
+ efi_char16_t *variable_name = new_var->var.VariableName;

/*
- * Length of the variable bytes in ASCII, plus the '-' separator,
+ * Length of the variable bytes in UTF8, plus the '-' separator,
* plus the GUID, plus trailing NUL
*/
- short_name_size = variable_name_size / sizeof(efi_char16_t)
- + 1 + EFI_VARIABLE_GUID_LEN + 1;
-
- short_name = kzalloc(short_name_size, GFP_KERNEL);
+ utf8_name_size = ucs2_utf8size(variable_name);
+ short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1;

+ short_name = kmalloc(short_name_size, GFP_KERNEL);
if (!short_name)
return 1;

- /* 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++) {
- short_name[i] = variable_name[i] & 0xFF;
- }
+ ucs2_as_utf8(short_name, variable_name, short_name_size);
+
/* This is ugly, but necessary to separate one vendor's
private variables from another's. */
-
- *(short_name + strlen(short_name)) = '-';
+ short_name[utf8_name_size] = '-';
efi_guid_unparse(&new_var->var.VendorGuid,
- short_name + strlen(short_name));
+ short_name + utf8_name_size + 1);

new_var->kobj.kset = efivars_kset;

--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -118,7 +118,7 @@ static int efivarfs_callback(efi_char16_
struct dentry *dentry, *root = sb->s_root;
unsigned long size = 0;
char *name;
- int len, i;
+ int len;
int err = -ENOMEM;

entry = kmalloc(sizeof(*entry), GFP_KERNEL);
@@ -128,15 +128,14 @@ static int efivarfs_callback(efi_char16_
memcpy(entry->var.VariableName, name16, name_size);
memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));

- len = ucs2_strlen(entry->var.VariableName);
+ len = ucs2_utf8size(entry->var.VariableName);

/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
if (!name)
goto fail;

- for (i = 0; i < len; i++)
- name[i] = entry->var.VariableName[i] & 0xFF;
+ ucs2_as_utf8(name, entry->var.VariableName, len);

name[len] = '-';