On Mon, Sep 3, 2018 at 11:04 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Mon, Aug 6, 2018 at 4:32 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: >> 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. > > Hi Lars! How does this look to you? If you can Ack I assume Jens would > be able to take this. FWIW I've tested a simple drbd configuration before/after this change and things seem to be working correctly. -Kees > > Thanks! > > -Kees > >> >> [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 > > > > -- > Kees Cook > Pixel Security -- Kees Cook Pixel Security
