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

[deliverable/linux.git] / drivers / firmware / efi / vars.c

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 7f2ea21c730dd76a86f3ab5a1e253878878960a7..34b741940494a24682e6cbf0e96d3246468a4fd6 100644 (file)
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -202,29 +202,44 @@ static const struct variable_validate variable_validate[] = {
        { NULL_GUID, "", NULL },
 };
 
+/*
+ * Check if @var_name matches the pattern given in @match_name.
+ *
+ * @var_name: an array of @len non-NUL characters.
+ * @match_name: a NUL-terminated pattern string, optionally ending in "*". A
+ *              final "*" character matches any trailing characters @var_name,
+ *              including the case when there are none left in @var_name.
+ * @match: on output, the number of non-wildcard characters in @match_name
+ *         that @var_name matches, regardless of the return value.
+ * @return: whether @var_name fully matches @match_name.
+ */
 static bool
 variable_matches(const char *var_name, size_t len, const char *match_name,
                 int *match)
 {
        for (*match = 0; ; (*match)++) {
                char c = match_name[*match];
-               char u = var_name[*match];
 
-               /* Wildcard in the matching name means we've matched */
-               if (c == '*')
+               switch (c) {
+               case '*':
+                       /* Wildcard in @match_name means we've matched. */
                        return true;
 
-               /* Case sensitive match */
-               if (!c && *match == len)
-                       return true;
+               case '\0':
+                       /* @match_name has ended. Has @var_name too? */
+                       return (*match == len);
 
-               if (c != u)
+               default:
+                       /*
+                        * We've reached a non-wildcard char in @match_name.
+                        * Continue only if there's an identical character in
+                        * @var_name.
+                        */
+                       if (*match < len && c == var_name[*match])
+                               continue;
                        return false;
-
-               if (!c)
-                       return true;
+               }
        }
-       return true;
 }
 
 bool
@@ -300,7 +315,18 @@ check_var_size(u32 attributes, unsigned long size)
        if (!fops->query_variable_store)
                return EFI_UNSUPPORTED;
 
-       return fops->query_variable_store(attributes, size);
+       return fops->query_variable_store(attributes, size, false);
+}
+
+static efi_status_t
+check_var_size_nonblocking(u32 attributes, unsigned long size)
+{
+       const struct efivar_operations *fops = __efivars->ops;
+
+       if (!fops->query_variable_store)
+               return EFI_UNSUPPORTED;
+
+       return fops->query_variable_store(attributes, size, true);
 }
 
 static int efi_status_to_err(efi_status_t status)
@@ -681,7 +707,8 @@ efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
        if (!spin_trylock_irqsave(&__efivars->lock, flags))
                return -EBUSY;
 
-       status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
+       status = check_var_size_nonblocking(attributes,
+                                           size + ucs2_strsize(name, 1024));
        if (status != EFI_SUCCESS) {
                spin_unlock_irqrestore(&__efivars->lock, flags);
                return -ENOSPC;