* include/grub/partition.h (grub_partition_map): Change prototype of

embed to take a maximum value for nsectors.
	* include/grub/emu/hostdisk.h (grub_util_ldm_embed): Likewise.
	* include/grub/fs.h (grub_fs): Likewise.
	* grub-core/partmap/msdos.c (embed_signatures): New array.
	(pc_partition_map_embed): Check for and avoid sectors matching any
	of the signatures in embed_signatures, up to max_nsectors.
	* grub-core/partmap/gpt.c (gpt_partition_map_embed): Restrict
	returned sector map to max_nsectors.
	* grub-core/disk/ldm.c (grub_util_ldm_embed): Likewise.
	* grub-core/fs/btrfs.c (grub_btrfs_embed): Likewise.
	* grub-core/fs/zfs/zfs.c (grub_zfs_embed): Likewise.
	* util/grub-setup.c (setup): Allow for the embedding area being
	split into multiple blocklists.  Tell dest_partmap->embed the
	maximum number of sectors we care about.

grub-core/partmap/gpt.c

@@ -128,6 +128,7 @@ grub_gpt_partition_map_iterate (grub_disk_t disk,
 #ifdef GRUB_UTIL
 static grub_err_t
 gpt_partition_map_embed (struct grub_disk *disk_, unsigned int *nsectors,
+			 unsigned int max_nsectors,
 			 grub_embed_type_t embed_type,
 			 grub_disk_addr_t **sectors)
 {
@@ -183,6 +184,8 @@ gpt_partition_map_embed (struct grub_disk *disk_, unsigned int *nsectors,
 			  " embedding won't be possible"));
 
   *nsectors = len;
+  if (*nsectors > max_nsectors)
+    *nsectors = max_nsectors;
   *sectors = grub_malloc (*nsectors * sizeof (**sectors));
   if (!*sectors)
     return grub_errno;