CHROMIUM: verity: statically allocate root_digest

BUG=chromium-os:9752
TEST=Ran dm-verity.git unit tests. Ran platform_DMVerityCorruption on H/W.

Change-Id: I96ed614444caeac93a7c4879c1f189265e98de44
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Reviewed-on: http://gerrit.chromium.org/gerrit/4466

diff --git a/drivers/md/dm-bht.c b/drivers/md/dm-bht.c
index a602929..a3b9c09 100644 (file)
--- a/drivers/md/dm-bht.c
+++ b/drivers/md/dm-bht.c
@@ -235,13 +235,6 @@ int dm_bht_create(struct dm_bht *bht, unsigned int block_count,
                goto bad_digest_len;
        }
 
-       bht->root_digest = (u8 *) kzalloc(bht->digest_size, GFP_KERNEL);
-       if (!bht->root_digest) {
-               DMERR("failed to allocate memory for root digest");
-               status = -ENOMEM;
-               goto bad_root_digest_alloc;
-       }
-
        /* Configure the tree */
        bht->block_count = block_count;
        DMDEBUG("Setting block_count %u", block_count);
@@ -312,8 +305,6 @@ bad_entries_alloc:
 bad_node_count:
 bad_level_alloc:
 bad_block_count:
-       kfree(bht->root_digest);
-bad_root_digest_alloc:
 bad_digest_len:
        for (cpu = 0; cpu < nr_cpu_ids; ++cpu)
                if (bht->hash_desc[cpu].tfm)
@@ -862,8 +853,6 @@ int dm_bht_destroy(struct dm_bht *bht)
        unsigned int depth;
        int cpu = 0;
 
-       kfree(bht->root_digest);
-
        depth = bht->depth;
        while (depth-- != 0) {
                struct dm_bht_entry *entry = bht->levels[depth].entries;
@@ -944,10 +933,6 @@ EXPORT_SYMBOL(dm_bht_set_write_cb);
  */
 int dm_bht_set_root_hexdigest(struct dm_bht *bht, const u8 *hexdigest)
 {
-       if (!bht->root_digest) {
-               DMCRIT("No allocation for root digest. Call dm_bht_create");
-               return -1;
-       }
        /* Make sure we have at least the bytes expected */
        if (strnlen((char *)hexdigest, bht->digest_size * 2) !=
            bht->digest_size * 2) {
@@ -976,12 +961,6 @@ int dm_bht_root_hexdigest(struct dm_bht *bht, u8 *hexdigest, int available)
                DMERR("hexdigest has too few bytes available");
                return -EINVAL;
        }
-       if (!bht->root_digest) {
-               DMERR("no root digest exists to export");
-               if (available > 0)
-                       *hexdigest = 0;
-               return -1;
-       }
        dm_bht_bin_to_hex(bht->root_digest, hexdigest, bht->digest_size);
        return 0;
 }

diff --git a/include/linux/dm-bht.h b/include/linux/dm-bht.h
index bbdca0e..7ac7345 100644 (file)
--- a/include/linux/dm-bht.h
+++ b/include/linux/dm-bht.h
@@ -96,7 +96,7 @@ struct dm_bht {
        sector_t sectors;  /* Number of disk sectors used */
 
        /* bool verified;  Full tree is verified */
-       u8 *root_digest;  /* hash_alg(levels[0].entries[*].nodes) */
+       u8 root_digest[DM_BHT_MAX_DIGEST_SIZE];
        struct dm_bht_level *levels;  /* in reverse order */
        mempool_t *entry_pool;
        /* Callbacks for reading and/or writing to the hash device */