efivarfs: add helper to convert from UC16 name and GUID to utf8 name

These will be used by a later patch to check for uniqueness on initial
EFI variable iteration.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
index 64d15d1bb6bfc021ae3da9a191e8002d866ab3ed..c10efc1ad0a7bb86f7c0e945ded4de1031dfa039 100644 (file)
--- a/fs/efivarfs/internal.h
+++ b/fs/efivarfs/internal.h
@@ -55,6 +55,7 @@ bool efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
                     unsigned long data_size);
 bool efivar_variable_is_removable(efi_guid_t vendor, const char *name,
                                  size_t len);
+char *efivar_get_utf8name(const efi_char16_t *name16, efi_guid_t *vendor);
 
 extern const struct file_operations efivarfs_file_operations;
 extern const struct inode_operations efivarfs_dir_inode_operations;

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index d3c8528274aa668522fda7e6c0917ce93c3d6629..b22441f7f7c6a1e1118f51805d6be54dcb7b49c2 100644 (file)
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -205,27 +205,16 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
        memcpy(entry->var.VariableName, name16, name_size);
        memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
 
-       len = ucs2_utf8size(entry->var.VariableName);
-
-       /* name, plus '-', plus GUID, plus NUL*/
-       name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
+       name = efivar_get_utf8name(name16, &vendor);
        if (!name)
                goto fail;
 
-       ucs2_as_utf8(name, entry->var.VariableName, len);
+       /* length of the variable name itself: remove GUID and separator */
+       len = strlen(name) - EFI_VARIABLE_GUID_LEN - 1;
 
        if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))
                is_removable = true;
 
-       name[len] = '-';
-
-       efi_guid_to_str(&entry->var.VendorGuid, name + len + 1);
-
-       name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
-
-       /* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
-       strreplace(name, '/', '!');
-
        inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
                                   is_removable);
        if (!inode)

diff --git a/fs/efivarfs/vars.c b/fs/efivarfs/vars.c
index f7d43c847ee9518cf3aa128688fdc15817e74941..13594087d9ee20885b1ce4d66407610cddde7cec 100644 (file)
--- a/fs/efivarfs/vars.c
+++ b/fs/efivarfs/vars.c
@@ -225,6 +225,31 @@ variable_matches(const char *var_name, size_t len, const char *match_name,
        }
 }
 
+char *
+efivar_get_utf8name(const efi_char16_t *name16, efi_guid_t *vendor)
+{
+       int len = ucs2_utf8size(name16);
+       char *name;
+
+       /* name, plus '-', plus GUID, plus NUL*/
+       name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
+       if (!name)
+               return NULL;
+
+       ucs2_as_utf8(name, name16, len);
+
+       name[len] = '-';
+
+       efi_guid_to_str(vendor, name + len + 1);
+
+       name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
+
+       /* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
+       strreplace(name, '/', '!');
+
+       return name;
+}
+
 bool
 efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
                unsigned long data_size)