Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Peter Anvin:
 "Three groups of fixes:

   1. Make sure we don't execute the early microcode patching if family
      < 6, since it would touch MSRs which don't exist on those
      families, causing crashes.

   2. The Xen partial emulation of HyperV can be dealt with more
      gracefully than just disabling the driver.

   3. More EFI variable space magic.  In particular, variables hidden
      from runtime code need to be taken into account too."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode: Verify the family before dispatching microcode patching
  x86, hyperv: Handle Xen emulation of Hyper-V more gracefully
  x86,efi: Implement efi_no_storage_paranoia parameter
  efi: Export efi_query_variable_store() for efivars.ko
  x86/Kconfig: Make EFI select UCS2_STRING
  efi: Distinguish between "remaining space" and actually used space
  efi: Pass boot services variable info to runtime code
  Move utf16 functions to kernel core and rename
  x86,efi: Check max_size only if it is non-zero.
  x86, efivars: firmware bug workarounds should be in platform code

2 files changed, 22 insertions, 77 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 42c759a4d04..3e532002e4d 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 7acafb80fd4..182ce947117 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)