From: Eric Biggers Date: Fri, 23 Dec 2022 20:36:30 +0000 (-0800) Subject: fsverity: store log2(digest_size) precomputed X-Git-Tag: v6.6.7~3542^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=579a12f78d889339488175cd9f353dba2bb8d047;p=platform%2Fkernel%2Flinux-starfive.git fsverity: store log2(digest_size) precomputed Add log_digestsize to struct merkle_tree_params so that it can be used in verify.c. Also save memory by using u8 for all the log_* fields. Signed-off-by: Eric Biggers Reviewed-by: Andrey Albershteyn Tested-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20221223203638.41293-4-ebiggers@kernel.org --- diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index 48b97f5..fc1c279 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -42,8 +42,9 @@ struct merkle_tree_params { unsigned int digest_size; /* same as hash_alg->digest_size */ unsigned int block_size; /* size of data and tree blocks */ unsigned int hashes_per_block; /* number of hashes per tree block */ - unsigned int log_blocksize; /* log2(block_size) */ - unsigned int log_arity; /* log2(hashes_per_block) */ + u8 log_digestsize; /* log2(digest_size) */ + u8 log_blocksize; /* log2(block_size) */ + u8 log_arity; /* log2(hashes_per_block) */ unsigned int num_levels; /* number of levels in Merkle tree */ u64 tree_size; /* Merkle tree size in bytes */ unsigned long tree_pages; /* Merkle tree size in pages */ diff --git a/fs/verity/open.c b/fs/verity/open.c index e356eefb..ca8de73 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -76,7 +76,8 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params, err = -EINVAL; goto out_err; } - params->log_arity = params->log_blocksize - ilog2(params->digest_size); + params->log_digestsize = ilog2(params->digest_size); + params->log_arity = log_blocksize - params->log_digestsize; params->hashes_per_block = 1 << params->log_arity; /* diff --git a/fs/verity/verify.c b/fs/verity/verify.c index 4c57a1b..d2fcb6a 100644 --- a/fs/verity/verify.c +++ b/fs/verity/verify.c @@ -35,7 +35,7 @@ static void hash_at_level(const struct merkle_tree_params *params, /* Offset of the wanted hash (in bytes) within the hash block */ *hoffset = (position & ((1 << params->log_arity) - 1)) << - (params->log_blocksize - params->log_arity); + params->log_digestsize; } static inline int cmp_hashes(const struct fsverity_info *vi,