From patchwork Wed Apr 24 16:13:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 10915141 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F233413B5 for ; Wed, 24 Apr 2019 16:14:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E2327281C3 for ; Wed, 24 Apr 2019 16:14:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D5E84289FA; Wed, 24 Apr 2019 16:14:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 482B5281DB for ; Wed, 24 Apr 2019 16:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731885AbfDXQN7 (ORCPT ); Wed, 24 Apr 2019 12:13:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51478 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730600AbfDXQN6 (ORCPT ); Wed, 24 Apr 2019 12:13:58 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0360C8AE7A; Wed, 24 Apr 2019 16:13:58 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-121-98.rdu2.redhat.com [10.10.121.98]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4981926191; Wed, 24 Apr 2019 16:13:56 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 03/11] keys: Simplify key description management From: David Howells To: ebiederm@xmission.com Cc: keyrings@vger.kernel.org, dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, dwalsh@redhat.com, vgoyal@redhat.com Date: Wed, 24 Apr 2019 17:13:55 +0100 Message-ID: <155612243551.8564.15079536597203351040.stgit@warthog.procyon.org.uk> In-Reply-To: <155612240208.8564.13865046977065545591.stgit@warthog.procyon.org.uk> References: <155612240208.8564.13865046977065545591.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 24 Apr 2019 16:13:58 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Simplify key description management by cramming the word containing the length with the first few chars of the description also. This simplifies the code that generates the index-key used by assoc_array. It should speed up key searching a bit too. Signed-off-by: David Howells --- include/linux/key.h | 14 ++++++++- security/keys/internal.h | 6 ++++ security/keys/key.c | 2 + security/keys/keyring.c | 70 +++++++++++++------------------------------- security/keys/persistent.c | 1 + 5 files changed, 43 insertions(+), 50 deletions(-) diff --git a/include/linux/key.h b/include/linux/key.h index aaa93fe3f587..33d87cb2d469 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -86,9 +86,20 @@ struct keyring_list; struct keyring_name; struct keyring_index_key { + union { + struct { +#ifdef __LITTLE_ENDIAN /* Put desc_len at the LSB of x */ + u8 desc_len; + char desc[sizeof(long) - 1]; /* First few chars of description */ +#else + char desc[sizeof(long) - 1]; /* First few chars of description */ + u8 desc_len; +#endif + }; + unsigned long x; + }; struct key_type *type; const char *description; - size_t desc_len; }; union key_payload { @@ -202,6 +213,7 @@ struct key { union { struct keyring_index_key index_key; struct { + unsigned long len_desc; struct key_type *type; /* type of key */ char *description; }; diff --git a/security/keys/internal.h b/security/keys/internal.h index 8f533c81aa8d..02592d24f13a 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -90,6 +90,12 @@ extern struct mutex key_construction_mutex; extern wait_queue_head_t request_key_conswq; +static inline void key_set_index_key(struct keyring_index_key *index_key) +{ + size_t n = min_t(size_t, index_key->desc_len, sizeof(index_key->desc)); + memcpy(index_key->desc, index_key->description, n); +} + extern struct key_type *key_type_lookup(const char *type); extern void key_type_put(struct key_type *ktype); diff --git a/security/keys/key.c b/security/keys/key.c index d705b950ce2a..1d0250a8990e 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -285,6 +285,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->index_key.description) goto no_memory_3; + key_set_index_key(&key->index_key); refcount_set(&key->usage, 1); init_rwsem(&key->sem); @@ -859,6 +860,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, goto error_free_prep; } index_key.desc_len = strlen(index_key.description); + key_set_index_key(&index_key); ret = __key_link_begin(keyring, &index_key, &edit); if (ret < 0) { diff --git a/security/keys/keyring.c b/security/keys/keyring.c index e14f09e3a4b0..7bb1f499996c 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -179,9 +179,9 @@ static unsigned long hash_key_type_and_desc(const struct keyring_index_key *inde int n, desc_len = index_key->desc_len; type = (unsigned long)index_key->type; - acc = mult_64x32_and_fold(type, desc_len + 13); acc = mult_64x32_and_fold(acc, 9207); + for (;;) { n = desc_len; if (n <= 0) @@ -215,23 +215,13 @@ static unsigned long hash_key_type_and_desc(const struct keyring_index_key *inde /* * Build the next index key chunk. * - * On 32-bit systems the index key is laid out as: - * - * 0 4 5 9... - * hash desclen typeptr desc[] - * - * On 64-bit systems: - * - * 0 8 9 17... - * hash desclen typeptr desc[] - * * We return it one word-sized chunk at a time. */ static unsigned long keyring_get_key_chunk(const void *data, int level) { const struct keyring_index_key *index_key = data; unsigned long chunk = 0; - long offset = 0; + const u8 *d; int desc_len = index_key->desc_len, n = sizeof(chunk); level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; @@ -239,33 +229,23 @@ static unsigned long keyring_get_key_chunk(const void *data, int level) case 0: return hash_key_type_and_desc(index_key); case 1: - return ((unsigned long)index_key->type << 8) | desc_len; + return index_key->x; case 2: - if (desc_len == 0) - return (u8)((unsigned long)index_key->type >> - (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); - n--; - offset = 1; - /* fall through */ + return (unsigned long)index_key->type; default: - offset += sizeof(chunk) - 1; - offset += (level - 3) * sizeof(chunk); - if (offset >= desc_len) + level -= 3; + if (desc_len <= sizeof(index_key->desc)) return 0; - desc_len -= offset; + + d = index_key->description + sizeof(index_key->desc); + d += level * sizeof(long); + desc_len -= sizeof(index_key->desc); if (desc_len > n) desc_len = n; - offset += desc_len; do { chunk <<= 8; - chunk |= ((u8*)index_key->description)[--offset]; + chunk |= *d++; } while (--desc_len > 0); - - if (level == 2) { - chunk <<= 8; - chunk |= (u8)((unsigned long)index_key->type >> - (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); - } return chunk; } } @@ -304,39 +284,28 @@ static int keyring_diff_objects(const void *object, const void *data) seg_b = hash_key_type_and_desc(b); if ((seg_a ^ seg_b) != 0) goto differ; + level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; /* The number of bits contributed by the hash is controlled by a * constant in the assoc_array headers. Everything else thereafter we * can deal with as being machine word-size dependent. */ - level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; - seg_a = a->desc_len; - seg_b = b->desc_len; + seg_a = a->x; + seg_b = b->x; if ((seg_a ^ seg_b) != 0) goto differ; + level += sizeof(unsigned long); /* The next bit may not work on big endian */ - level++; seg_a = (unsigned long)a->type; seg_b = (unsigned long)b->type; if ((seg_a ^ seg_b) != 0) goto differ; - level += sizeof(unsigned long); - if (a->desc_len == 0) - goto same; - i = 0; - if (((unsigned long)a->description | (unsigned long)b->description) & - (sizeof(unsigned long) - 1)) { - do { - seg_a = *(unsigned long *)(a->description + i); - seg_b = *(unsigned long *)(b->description + i); - if ((seg_a ^ seg_b) != 0) - goto differ_plus_i; - i += sizeof(unsigned long); - } while (i < (a->desc_len & (sizeof(unsigned long) - 1))); - } + i = sizeof(a->desc); + if (a->desc_len <= i) + goto same; for (; i < a->desc_len; i++) { seg_a = *(unsigned char *)(a->description + i); @@ -662,6 +631,9 @@ static bool search_nested_keyrings(struct key *keyring, BUG_ON((ctx->flags & STATE_CHECKS) == 0 || (ctx->flags & STATE_CHECKS) == STATE_CHECKS); + if (ctx->index_key.description) + key_set_index_key(&ctx->index_key); + /* Check to see if this top-level keyring is what we are looking for * and whether it is valid or not. */ diff --git a/security/keys/persistent.c b/security/keys/persistent.c index d0cb5b32eff7..fc29ec59efa7 100644 --- a/security/keys/persistent.c +++ b/security/keys/persistent.c @@ -87,6 +87,7 @@ static long key_get_persistent(struct user_namespace *ns, kuid_t uid, index_key.type = &key_type_keyring; index_key.description = buf; index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid)); + key_set_index_key(&index_key); if (ns->persistent_keyring_register) { reg_ref = make_key_ref(ns->persistent_keyring_register, true);