From: Eric Biggers <[email protected]> Simplify sb_mac() by using crypto_shash_digest() instead of an init+update+final sequence. This should also improve performance.
Signed-off-by: Eric Biggers <[email protected]> --- drivers/md/dm-integrity.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 97a8d5fc9ebb..e85c688fd91e 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -486,56 +486,46 @@ static void sb_set_version(struct dm_integrity_c *ic) else if (ic->meta_dev || ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) ic->sb->version = SB_VERSION_2; else ic->sb->version = SB_VERSION_1; } static int sb_mac(struct dm_integrity_c *ic, bool wr) { SHASH_DESC_ON_STACK(desc, ic->journal_mac); int r; - unsigned int size = crypto_shash_digestsize(ic->journal_mac); + unsigned int mac_size = crypto_shash_digestsize(ic->journal_mac); + __u8 *sb = (__u8 *)ic->sb; + __u8 *mac = sb + (1 << SECTOR_SHIFT) - mac_size; - if (sizeof(struct superblock) + size > 1 << SECTOR_SHIFT) { + if (sizeof(struct superblock) + mac_size > 1 << SECTOR_SHIFT) { dm_integrity_io_error(ic, "digest is too long", -EINVAL); return -EINVAL; } desc->tfm = ic->journal_mac; - r = crypto_shash_init(desc); - if (unlikely(r < 0)) { - dm_integrity_io_error(ic, "crypto_shash_init", r); - return r; - } - - r = crypto_shash_update(desc, (__u8 *)ic->sb, (1 << SECTOR_SHIFT) - size); - if (unlikely(r < 0)) { - dm_integrity_io_error(ic, "crypto_shash_update", r); - return r; - } - if (likely(wr)) { - r = crypto_shash_final(desc, (__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size); + r = crypto_shash_digest(desc, sb, mac - sb, mac); if (unlikely(r < 0)) { - dm_integrity_io_error(ic, "crypto_shash_final", r); + dm_integrity_io_error(ic, "crypto_shash_digest", r); return r; } } else { - __u8 result[HASH_MAX_DIGESTSIZE]; + __u8 actual_mac[HASH_MAX_DIGESTSIZE]; - r = crypto_shash_final(desc, result); + r = crypto_shash_digest(desc, sb, mac - sb, actual_mac); if (unlikely(r < 0)) { - dm_integrity_io_error(ic, "crypto_shash_final", r); + dm_integrity_io_error(ic, "crypto_shash_digest", r); return r; } - if (memcmp((__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size, result, size)) { + if (memcmp(mac, actual_mac, mac_size)) { dm_integrity_io_error(ic, "superblock mac", -EILSEQ); dm_audit_log_target(DM_MSG_PREFIX, "mac-superblock", ic->ti, 0); return -EILSEQ; } } return 0; } static int sync_rw_sb(struct dm_integrity_c *ic, blk_opf_t opf) base-commit: 2af9b20dbb39f6ebf9b9b6c090271594627d818e -- 2.42.0
