[PATCH v1 1/2] make check_blocklists() not depend on an envblk data type

[Jon McCune <jonmccune@google.com>]

Signed-off-by: Jon McCune <jonmccune@google.com>

This is a small patch that makes check_blocklists() more generally useful,
and facilitates the next patch.

---
 grub-core/commands/loadenv.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/grub-core/commands/loadenv.c b/grub-core/commands/loadenv.c
index c0a42c5..691d163 100644
--- a/grub-core/commands/loadenv.c
+++ b/grub-core/commands/loadenv.c
@@ -202,7 +202,7 @@ free_blocklists (struct blocklist *p)
 }
 
 static grub_err_t
-check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
+check_blocklists (const char* expected_file_data, struct blocklist *blocklists,
                   grub_file_t file)
 {
   grub_size_t total_length;
@@ -210,7 +210,6 @@ check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
   grub_disk_t disk;
   grub_disk_addr_t part_start;
   struct blocklist *p;
-  char *buf;
 
   /* Sanity checks.  */
   total_length = 0;
@@ -243,7 +242,6 @@ check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
 
   part_start = grub_partition_get_start (disk->partition);
 
-  buf = grub_envblk_buffer (envblk);
   for (p = blocklists, index = 0; p; index += p->length, p = p->next)
     {
       char blockbuf[GRUB_DISK_SECTOR_SIZE];
@@ -252,7 +250,7 @@ check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
                           p->offset, p->length, blockbuf))
         return grub_errno;
 
-      if (grub_memcmp (buf + index, blockbuf, p->length) != 0)
+      if (grub_memcmp (expected_file_data + index, blockbuf, p->length) != 0)
 	return grub_error (GRUB_ERR_FILE_READ_ERROR, "invalid blocklist");
     }
 
@@ -350,7 +348,7 @@ grub_cmd_save_env (grub_extcmd_context_t ctxt, int argc, char **args)
   if (! envblk)
     goto fail;
 
-  if (check_blocklists (envblk, ctx.head, file))
+  if (check_blocklists (grub_envblk_buffer (envblk), ctx.head, file))
     goto fail;
 
   while (argc)
-- 
1.8.3