In preparing to remove all stack VLA usage from the kernel[1], this removes the discouraged use of AHASH_REQUEST_ON_STACK in favor of the smaller SHASH_DESC_ON_STACK by converting from ahash-wrapped-shash to direct shash. By removing a layer of indirection this both improves performance and reduces stack usage. The stack allocation will be made a fixed size in a later patch to the crypto subsystem. The bulk of the lines in this change are simple s/ahash/shash/, but the main logic differences are in drbd_csum_ee() and drbd_csum_bio(), which externalizes the page walking with k(un)map_atomic() instead of using scattergather. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- I'm calling this "v7" just for general sanity over the naming of the patch when it was part of the large crypto series of changes. Really, it's v2. v7: use kmap for possible highmem page addresses (Lars). --- drivers/block/drbd/drbd_int.h | 13 +++--- drivers/block/drbd/drbd_main.c | 14 +++---- drivers/block/drbd/drbd_nl.c | 39 ++++++------------ drivers/block/drbd/drbd_receiver.c | 35 +++++++++-------- drivers/block/drbd/drbd_worker.c | 63 +++++++++++++++--------------- 5 files changed, 76 insertions(+), 88 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index bc4ed2ed40a2..97d8e290c2be 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -726,10 +726,10 @@ struct drbd_connection { struct list_head transfer_log; /* all requests not yet fully processed */ struct crypto_shash *cram_hmac_tfm; - struct crypto_ahash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ - struct crypto_ahash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ - struct crypto_ahash *csums_tfm; - struct crypto_ahash *verify_tfm; + struct crypto_shash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ + struct crypto_shash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ + struct crypto_shash *csums_tfm; + struct crypto_shash *verify_tfm; void *int_dig_in; void *int_dig_vv; @@ -1533,8 +1533,9 @@ static inline void ov_out_of_sync_print(struct drbd_device *device) } -extern void drbd_csum_bio(struct crypto_ahash *, struct bio *, void *); -extern void drbd_csum_ee(struct crypto_ahash *, struct drbd_peer_request *, void *); +extern void drbd_csum_bio(struct crypto_shash *, struct bio *, void *); +extern void drbd_csum_ee(struct crypto_shash *, struct drbd_peer_request *, + void *); /* worker callbacks */ extern int w_e_end_data_req(struct drbd_work *, int); extern int w_e_end_rsdata_req(struct drbd_work *, int); diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index a80809bd3057..ccb54791d39c 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -1377,7 +1377,7 @@ void drbd_send_ack_dp(struct drbd_peer_device *peer_device, enum drbd_packet cmd struct p_data *dp, int data_size) { if (peer_device->connection->peer_integrity_tfm) - data_size -= crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm); + data_size -= crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm); _drbd_send_ack(peer_device, cmd, dp->sector, cpu_to_be32(data_size), dp->block_id); } @@ -1690,7 +1690,7 @@ int drbd_send_dblock(struct drbd_peer_device *peer_device, struct drbd_request * sock = &peer_device->connection->data; p = drbd_prepare_command(peer_device, sock); digest_size = peer_device->connection->integrity_tfm ? - crypto_ahash_digestsize(peer_device->connection->integrity_tfm) : 0; + crypto_shash_digestsize(peer_device->connection->integrity_tfm) : 0; if (!p) return -EIO; @@ -1796,7 +1796,7 @@ int drbd_send_block(struct drbd_peer_device *peer_device, enum drbd_packet cmd, p = drbd_prepare_command(peer_device, sock); digest_size = peer_device->connection->integrity_tfm ? - crypto_ahash_digestsize(peer_device->connection->integrity_tfm) : 0; + crypto_shash_digestsize(peer_device->connection->integrity_tfm) : 0; if (!p) return -EIO; @@ -2561,11 +2561,11 @@ void conn_free_crypto(struct drbd_connection *connection) { drbd_free_sock(connection); - crypto_free_ahash(connection->csums_tfm); - crypto_free_ahash(connection->verify_tfm); + crypto_free_shash(connection->csums_tfm); + crypto_free_shash(connection->verify_tfm); crypto_free_shash(connection->cram_hmac_tfm); - crypto_free_ahash(connection->integrity_tfm); - crypto_free_ahash(connection->peer_integrity_tfm); + crypto_free_shash(connection->integrity_tfm); + crypto_free_shash(connection->peer_integrity_tfm); kfree(connection->int_dig_in); kfree(connection->int_dig_vv); diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index b4f02768ba47..d15703b1ffe8 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -2303,10 +2303,10 @@ check_net_options(struct drbd_connection *connection, struct net_conf *new_net_c } struct crypto { - struct crypto_ahash *verify_tfm; - struct crypto_ahash *csums_tfm; + struct crypto_shash *verify_tfm; + struct crypto_shash *csums_tfm; struct crypto_shash *cram_hmac_tfm; - struct crypto_ahash *integrity_tfm; + struct crypto_shash *integrity_tfm; }; static int @@ -2324,36 +2324,21 @@ alloc_shash(struct crypto_shash **tfm, char *tfm_name, int err_alg) return NO_ERROR; } -static int -alloc_ahash(struct crypto_ahash **tfm, char *tfm_name, int err_alg) -{ - if (!tfm_name[0]) - return NO_ERROR; - - *tfm = crypto_alloc_ahash(tfm_name, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(*tfm)) { - *tfm = NULL; - return err_alg; - } - - return NO_ERROR; -} - static enum drbd_ret_code alloc_crypto(struct crypto *crypto, struct net_conf *new_net_conf) { char hmac_name[CRYPTO_MAX_ALG_NAME]; enum drbd_ret_code rv; - rv = alloc_ahash(&crypto->csums_tfm, new_net_conf->csums_alg, + rv = alloc_shash(&crypto->csums_tfm, new_net_conf->csums_alg, ERR_CSUMS_ALG); if (rv != NO_ERROR) return rv; - rv = alloc_ahash(&crypto->verify_tfm, new_net_conf->verify_alg, + rv = alloc_shash(&crypto->verify_tfm, new_net_conf->verify_alg, ERR_VERIFY_ALG); if (rv != NO_ERROR) return rv; - rv = alloc_ahash(&crypto->integrity_tfm, new_net_conf->integrity_alg, + rv = alloc_shash(&crypto->integrity_tfm, new_net_conf->integrity_alg, ERR_INTEGRITY_ALG); if (rv != NO_ERROR) return rv; @@ -2371,9 +2356,9 @@ alloc_crypto(struct crypto *crypto, struct net_conf *new_net_conf) static void free_crypto(struct crypto *crypto) { crypto_free_shash(crypto->cram_hmac_tfm); - crypto_free_ahash(crypto->integrity_tfm); - crypto_free_ahash(crypto->csums_tfm); - crypto_free_ahash(crypto->verify_tfm); + crypto_free_shash(crypto->integrity_tfm); + crypto_free_shash(crypto->csums_tfm); + crypto_free_shash(crypto->verify_tfm); } int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info) @@ -2450,17 +2435,17 @@ int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info) rcu_assign_pointer(connection->net_conf, new_net_conf); if (!rsr) { - crypto_free_ahash(connection->csums_tfm); + crypto_free_shash(connection->csums_tfm); connection->csums_tfm = crypto.csums_tfm; crypto.csums_tfm = NULL; } if (!ovr) { - crypto_free_ahash(connection->verify_tfm); + crypto_free_shash(connection->verify_tfm); connection->verify_tfm = crypto.verify_tfm; crypto.verify_tfm = NULL; } - crypto_free_ahash(connection->integrity_tfm); + crypto_free_shash(connection->integrity_tfm); connection->integrity_tfm = crypto.integrity_tfm; if (connection->cstate >= C_WF_REPORT_PARAMS && connection->agreed_pro_version >= 100) /* Do this without trying to take connection->data.mutex again. */ diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index be9450f5ad1c..76243e9ef277 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1732,7 +1732,7 @@ static int receive_Barrier(struct drbd_connection *connection, struct packet_inf } /* quick wrapper in case payload size != request_size (write same) */ -static void drbd_csum_ee_size(struct crypto_ahash *h, +static void drbd_csum_ee_size(struct crypto_shash *h, struct drbd_peer_request *r, void *d, unsigned int payload_size) { @@ -1769,7 +1769,7 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector, digest_size = 0; if (!trim && peer_device->connection->peer_integrity_tfm) { - digest_size = crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm); /* * FIXME: Receive the incoming digest into the receive buffer * here, together with its struct p_data? @@ -1905,7 +1905,7 @@ static int recv_dless_read(struct drbd_peer_device *peer_device, struct drbd_req digest_size = 0; if (peer_device->connection->peer_integrity_tfm) { - digest_size = crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm); err = drbd_recv_all_warn(peer_device->connection, dig_in, digest_size); if (err) return err; @@ -3540,7 +3540,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in int p_proto, p_discard_my_data, p_two_primaries, cf; struct net_conf *nc, *old_net_conf, *new_net_conf = NULL; char integrity_alg[SHARED_SECRET_MAX] = ""; - struct crypto_ahash *peer_integrity_tfm = NULL; + struct crypto_shash *peer_integrity_tfm = NULL; void *int_dig_in = NULL, *int_dig_vv = NULL; p_proto = be32_to_cpu(p->protocol); @@ -3621,7 +3621,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in * change. */ - peer_integrity_tfm = crypto_alloc_ahash(integrity_alg, 0, CRYPTO_ALG_ASYNC); + peer_integrity_tfm = crypto_alloc_shash(integrity_alg, 0, CRYPTO_ALG_ASYNC); if (IS_ERR(peer_integrity_tfm)) { peer_integrity_tfm = NULL; drbd_err(connection, "peer data-integrity-alg %s not supported\n", @@ -3629,7 +3629,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in goto disconnect; } - hash_size = crypto_ahash_digestsize(peer_integrity_tfm); + hash_size = crypto_shash_digestsize(peer_integrity_tfm); int_dig_in = kmalloc(hash_size, GFP_KERNEL); int_dig_vv = kmalloc(hash_size, GFP_KERNEL); if (!(int_dig_in && int_dig_vv)) { @@ -3659,7 +3659,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in mutex_unlock(&connection->resource->conf_update); mutex_unlock(&connection->data.mutex); - crypto_free_ahash(connection->peer_integrity_tfm); + crypto_free_shash(connection->peer_integrity_tfm); kfree(connection->int_dig_in); kfree(connection->int_dig_vv); connection->peer_integrity_tfm = peer_integrity_tfm; @@ -3677,7 +3677,7 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in disconnect_rcu_unlock: rcu_read_unlock(); disconnect: - crypto_free_ahash(peer_integrity_tfm); + crypto_free_shash(peer_integrity_tfm); kfree(int_dig_in); kfree(int_dig_vv); conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); @@ -3689,15 +3689,16 @@ static int receive_protocol(struct drbd_connection *connection, struct packet_in * return: NULL (alg name was "") * ERR_PTR(error) if something goes wrong * or the crypto hash ptr, if it worked out ok. */ -static struct crypto_ahash *drbd_crypto_alloc_digest_safe(const struct drbd_device *device, +static struct crypto_shash *drbd_crypto_alloc_digest_safe( + const struct drbd_device *device, const char *alg, const char *name) { - struct crypto_ahash *tfm; + struct crypto_shash *tfm; if (!alg[0]) return NULL; - tfm = crypto_alloc_ahash(alg, 0, CRYPTO_ALG_ASYNC); + tfm = crypto_alloc_shash(alg, 0, 0); if (IS_ERR(tfm)) { drbd_err(device, "Can not allocate \"%s\" as %s (reason: %ld)\n", alg, name, PTR_ERR(tfm)); @@ -3750,8 +3751,8 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i struct drbd_device *device; struct p_rs_param_95 *p; unsigned int header_size, data_size, exp_max_sz; - struct crypto_ahash *verify_tfm = NULL; - struct crypto_ahash *csums_tfm = NULL; + struct crypto_shash *verify_tfm = NULL; + struct crypto_shash *csums_tfm = NULL; struct net_conf *old_net_conf, *new_net_conf = NULL; struct disk_conf *old_disk_conf = NULL, *new_disk_conf = NULL; const int apv = connection->agreed_pro_version; @@ -3898,14 +3899,14 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i if (verify_tfm) { strcpy(new_net_conf->verify_alg, p->verify_alg); new_net_conf->verify_alg_len = strlen(p->verify_alg) + 1; - crypto_free_ahash(peer_device->connection->verify_tfm); + crypto_free_shash(peer_device->connection->verify_tfm); peer_device->connection->verify_tfm = verify_tfm; drbd_info(device, "using verify-alg: \"%s\"\n", p->verify_alg); } if (csums_tfm) { strcpy(new_net_conf->csums_alg, p->csums_alg); new_net_conf->csums_alg_len = strlen(p->csums_alg) + 1; - crypto_free_ahash(peer_device->connection->csums_tfm); + crypto_free_shash(peer_device->connection->csums_tfm); peer_device->connection->csums_tfm = csums_tfm; drbd_info(device, "using csums-alg: \"%s\"\n", p->csums_alg); } @@ -3949,9 +3950,9 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i mutex_unlock(&connection->resource->conf_update); /* just for completeness: actually not needed, * as this is not reached if csums_tfm was ok. */ - crypto_free_ahash(csums_tfm); + crypto_free_shash(csums_tfm); /* but free the verify_tfm again, if csums_tfm did not work out */ - crypto_free_ahash(verify_tfm); + crypto_free_shash(verify_tfm); conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); return -EIO; } diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 5e793dd7adfb..0b41fb0181a6 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -295,60 +295,61 @@ void drbd_request_endio(struct bio *bio) complete_master_bio(device, &m); } -void drbd_csum_ee(struct crypto_ahash *tfm, struct drbd_peer_request *peer_req, void *digest) +void drbd_csum_ee(struct crypto_shash *tfm, struct drbd_peer_request *peer_req, void *digest) { - AHASH_REQUEST_ON_STACK(req, tfm); - struct scatterlist sg; + SHASH_DESC_ON_STACK(desc, tfm); struct page *page = peer_req->pages; struct page *tmp; unsigned len; + void *src; - ahash_request_set_tfm(req, tfm); - ahash_request_set_callback(req, 0, NULL, NULL); + desc->tfm = tfm; + desc->flags = 0; - sg_init_table(&sg, 1); - crypto_ahash_init(req); + crypto_shash_init(desc); + src = kmap_atomic(page); while ((tmp = page_chain_next(page))) { /* all but the last page will be fully used */ - sg_set_page(&sg, page, PAGE_SIZE, 0); - ahash_request_set_crypt(req, &sg, NULL, sg.length); - crypto_ahash_update(req); + crypto_shash_update(desc, src, PAGE_SIZE); + kunmap_atomic(src); page = tmp; + src = kmap_atomic(page); } /* and now the last, possibly only partially used page */ len = peer_req->i.size & (PAGE_SIZE - 1); - sg_set_page(&sg, page, len ?: PAGE_SIZE, 0); - ahash_request_set_crypt(req, &sg, digest, sg.length); - crypto_ahash_finup(req); - ahash_request_zero(req); + crypto_shash_update(desc, src, len ?: PAGE_SIZE); + kunmap_atomic(src); + + crypto_shash_final(desc, digest); + shash_desc_zero(desc); } -void drbd_csum_bio(struct crypto_ahash *tfm, struct bio *bio, void *digest) +void drbd_csum_bio(struct crypto_shash *tfm, struct bio *bio, void *digest) { - AHASH_REQUEST_ON_STACK(req, tfm); - struct scatterlist sg; + SHASH_DESC_ON_STACK(desc, tfm); struct bio_vec bvec; struct bvec_iter iter; - ahash_request_set_tfm(req, tfm); - ahash_request_set_callback(req, 0, NULL, NULL); + desc->tfm = tfm; + desc->flags = 0; - sg_init_table(&sg, 1); - crypto_ahash_init(req); + crypto_shash_init(desc); bio_for_each_segment(bvec, bio, iter) { - sg_set_page(&sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset); - ahash_request_set_crypt(req, &sg, NULL, sg.length); - crypto_ahash_update(req); + u8 *src; + + src = kmap_atomic(bvec.bv_page); + crypto_shash_update(desc, src + bvec.bv_offset, bvec.bv_len); + kunmap_atomic(src); + /* REQ_OP_WRITE_SAME has only one segment, * checksum the payload only once. */ if (bio_op(bio) == REQ_OP_WRITE_SAME) break; } - ahash_request_set_crypt(req, NULL, digest, 0); - crypto_ahash_final(req); - ahash_request_zero(req); + crypto_shash_final(desc, digest); + shash_desc_zero(desc); } /* MAYBE merge common code with w_e_end_ov_req */ @@ -367,7 +368,7 @@ static int w_e_send_csum(struct drbd_work *w, int cancel) if (unlikely((peer_req->flags & EE_WAS_ERROR) != 0)) goto out; - digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->csums_tfm); digest = kmalloc(digest_size, GFP_NOIO); if (digest) { sector_t sector = peer_req->i.sector; @@ -1205,7 +1206,7 @@ int w_e_end_csum_rs_req(struct drbd_work *w, int cancel) * a real fix would be much more involved, * introducing more locking mechanisms */ if (peer_device->connection->csums_tfm) { - digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->csums_tfm); D_ASSERT(device, digest_size == di->digest_size); digest = kmalloc(digest_size, GFP_NOIO); } @@ -1255,7 +1256,7 @@ int w_e_end_ov_req(struct drbd_work *w, int cancel) if (unlikely(cancel)) goto out; - digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->verify_tfm); digest = kmalloc(digest_size, GFP_NOIO); if (!digest) { err = 1; /* terminate the connection in case the allocation failed */ @@ -1327,7 +1328,7 @@ int w_e_end_ov_reply(struct drbd_work *w, int cancel) di = peer_req->digest; if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { - digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm); + digest_size = crypto_shash_digestsize(peer_device->connection->verify_tfm); digest = kmalloc(digest_size, GFP_NOIO); if (digest) { drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest); -- 2.17.1 -- Kees Cook Pixel Security
