From patchwork Wed May 30 14:11:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Enderborg X-Patchwork-Id: 10439089 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E905860327 for ; Wed, 30 May 2018 14:22:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B9D0D28E81 for ; Wed, 30 May 2018 14:22:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ADA8528EA2; Wed, 30 May 2018 14:22:04 +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=ham 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 86E642901D for ; Wed, 30 May 2018 14:21:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753070AbeE3OVy (ORCPT ); Wed, 30 May 2018 10:21:54 -0400 Received: from seldsegrel01.sonyericsson.com ([37.139.156.29]:11385 "EHLO SELDSEGREL01.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753131AbeE3OVk (ORCPT ); Wed, 30 May 2018 10:21:40 -0400 From: Peter Enderborg To: , Paul Moore , Stephen Smalley , Eric Paris , James Morris , Daniel Jurgens , Doug Ledford , , , , "Serge E . Hallyn" , "Paul E . McKenney" Subject: [PATCH V3 5/5 selinux-next] selinux: Switch to rcu read locks for avc_compute Date: Wed, 30 May 2018 16:11:04 +0200 Message-ID: <20180530141104.28569-6-peter.enderborg@sony.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180530141104.28569-1-peter.enderborg@sony.com> References: <20180530141104.28569-1-peter.enderborg@sony.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP To be able to preempt avc_compute we need preemptible locks, this patch switch the rwlock reads to rcu_read_lock. Signed-off-by: Peter Enderborg --- security/selinux/ss/services.c | 152 +++++++++++++++++++++-------------------- security/selinux/ss/services.h | 2 +- 2 files changed, 79 insertions(+), 75 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 954ebe490516..a9aa863c47a3 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -84,7 +84,7 @@ static struct selinux_ss selinux_ss; void selinux_ss_init(struct selinux_ss **ss) { - rwlock_init(&selinux_ss.policy_rwlock); + spin_lock_init(&selinux_ss.policy_lock); mutex_init(&selinux_ss.status_lock); selinux_ss.active_set = kzalloc(sizeof(struct selinux_ruleset), GFP_KERNEL); @@ -779,7 +779,7 @@ static int security_compute_validatetrans(struct selinux_state *state, if (!state->initialized) return 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -837,7 +837,7 @@ static int security_compute_validatetrans(struct selinux_state *state, } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -879,7 +879,7 @@ int security_bounded_transition(struct selinux_state *state, if (!state->initialized) return 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -944,7 +944,7 @@ int security_bounded_transition(struct selinux_state *state, kfree(old_name); } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -1035,7 +1035,7 @@ void security_compute_xperms_decision(struct selinux_state *state, memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); if (!state->initialized) goto allow; @@ -1092,7 +1092,7 @@ void security_compute_xperms_decision(struct selinux_state *state, } } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return; allow: memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); @@ -1122,7 +1122,7 @@ void security_compute_av(struct selinux_state *state, u16 tclass; struct context *scontext = NULL, *tcontext = NULL; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); avd_init(state, avd); xperms->len = 0; if (!state->initialized) @@ -1160,7 +1160,7 @@ void security_compute_av(struct selinux_state *state, map_decision(&state->ss->active_set->map, orig_tclass, avd, policydb->allow_unknown); out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return; allow: avd->allowed = 0xffffffff; @@ -1177,7 +1177,7 @@ void security_compute_av_user(struct selinux_state *state, struct sidtab *sidtab; struct context *scontext = NULL, *tcontext = NULL; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); avd_init(state, avd); if (!state->initialized) goto allow; @@ -1212,7 +1212,7 @@ void security_compute_av_user(struct selinux_state *state, context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, NULL); out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return; allow: avd->allowed = 0xffffffff; @@ -1319,7 +1319,7 @@ static int security_sid_to_context_core(struct selinux_state *state, rc = -EINVAL; goto out; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; if (force) @@ -1335,7 +1335,7 @@ static int security_sid_to_context_core(struct selinux_state *state, rc = context_struct_to_string(policydb, context, scontext, scontext_len); out_unlock: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); out: return rc; @@ -1491,7 +1491,7 @@ static int security_context_to_sid_core(struct selinux_state *state, if (!str) goto out; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; rc = string_to_context_struct(policydb, sidtab, scontext2, @@ -1505,7 +1505,7 @@ static int security_context_to_sid_core(struct selinux_state *state, rc = sidtab_context_to_sid(sidtab, &context, sid); context_destroy(&context); out_unlock: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); out: kfree(scontext2); kfree(str); @@ -1666,7 +1666,7 @@ static int security_compute_sid(struct selinux_state *state, context_init(&newcontext); - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); if (kern) { tclass = unmap_class(&state->ss->active_set->map, orig_tclass); @@ -1806,7 +1806,7 @@ static int security_compute_sid(struct selinux_state *state, /* Obtain the sid for the context. */ rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); out_unlock: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); context_destroy(&newcontext); out: return rc; @@ -2166,14 +2166,14 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len) if (rc) goto pdcerr; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); old_set = state->ss->active_set; rc = policydb_copy(&old_set->policydb, pdc, &storage, size); /* save seq */ seqno = state->ss->latest_granting; - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); policydb_flattened_free(storage); @@ -2232,16 +2232,18 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len) goto maperr; } + next_set->map.mapping = newmap.mapping; next_set->map.size = newmap.size; /* Install the new policydb and SID table. */ - write_lock_irq(&state->ss->policy_rwlock); - if (seqno == state->ss->latest_granting) { + spin_lock_irq(&state->ss->policy_lock); + if (likely(seqno == state->ss->latest_granting)) { security_load_policycaps(state, &next_set->policydb); seqno = ++state->ss->latest_granting; state->ss->active_set = next_set; - write_unlock_irq(&state->ss->policy_rwlock); + spin_unlock_irq(&state->ss->policy_lock); + synchronize_rcu(); avc_ss_reset(state->avc, seqno); selnl_notify_policyload(seqno); @@ -2260,7 +2262,7 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len) rc = 0; goto out; } else { - write_unlock_irq(&state->ss->policy_rwlock); + spin_unlock_irq(&state->ss->policy_lock); rc = -EAGAIN; } maperr: @@ -2285,9 +2287,9 @@ size_t security_policydb_len(struct selinux_state *state) struct policydb *p = &state->ss->active_set->policydb; size_t len; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); len = p->len; - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return len; } @@ -2306,7 +2308,7 @@ int security_port_sid(struct selinux_state *state, struct ocontext *c; int rc = 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2334,7 +2336,7 @@ int security_port_sid(struct selinux_state *state, } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2352,7 +2354,7 @@ int security_ib_pkey_sid(struct selinux_state *state, struct ocontext *c; int rc = 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2380,7 +2382,7 @@ int security_ib_pkey_sid(struct selinux_state *state, *out_sid = SECINITSID_UNLABELED; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2398,7 +2400,7 @@ int security_ib_endport_sid(struct selinux_state *state, struct ocontext *c; int rc = 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2427,7 +2429,7 @@ int security_ib_endport_sid(struct selinux_state *state, *out_sid = SECINITSID_UNLABELED; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2444,7 +2446,7 @@ int security_netif_sid(struct selinux_state *state, int rc = 0; struct ocontext *c; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2474,7 +2476,7 @@ int security_netif_sid(struct selinux_state *state, *if_sid = SECINITSID_NETIF; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2509,7 +2511,7 @@ int security_node_sid(struct selinux_state *state, int rc; struct ocontext *c; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2567,7 +2569,7 @@ int security_node_sid(struct selinux_state *state, rc = 0; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2609,7 +2611,7 @@ int security_get_user_sids(struct selinux_state *state, if (!state->initialized) goto out; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2663,7 +2665,7 @@ int security_get_user_sids(struct selinux_state *state, } rc = 0; out_unlock: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); if (rc || !mynel) { kfree(mysids); goto out; @@ -2705,7 +2707,7 @@ int security_get_user_sids(struct selinux_state *state, * cannot support xattr or use a fixed labeling behavior like * transition SIDs or task SIDs. * - * The caller must acquire the policy_rwlock before calling this function. + * The caller must acquire the policy_lock before calling this function. */ static inline int __security_genfs_sid(struct selinux_state *state, const char *fstype, @@ -2767,7 +2769,7 @@ static inline int __security_genfs_sid(struct selinux_state *state, * @sclass: file security class * @sid: SID for path * - * Acquire policy_rwlock before calling __security_genfs_sid() and release + * Acquire policy_lock before calling __security_genfs_sid() and release * it afterward. */ int security_genfs_sid(struct selinux_state *state, @@ -2778,9 +2780,9 @@ int security_genfs_sid(struct selinux_state *state, { int retval; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid); - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return retval; } @@ -2797,7 +2799,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb) struct superblock_security_struct *sbsec = sb->s_security; const char *fstype = sb->s_type->name; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; sidtab = state->ss->active_set->sidtab; @@ -2830,7 +2832,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb) } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -2847,7 +2849,7 @@ int security_get_bools(struct selinux_state *state, return 0; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; @@ -2880,7 +2882,7 @@ int security_get_bools(struct selinux_state *state, } rc = 0; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; err: if (*names) { @@ -2914,13 +2916,14 @@ int security_set_bools(struct selinux_state *state, int len, int *values) goto errout; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); old_set = state->ss->active_set; seqno = state->ss->latest_granting; memcpy(next_set, old_set, sizeof(struct selinux_ruleset)); rc = policydb_copy(&old_set->policydb, &next_set->policydb, &storage, size); - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); + if (rc) goto out; @@ -2956,12 +2959,13 @@ int security_set_bools(struct selinux_state *state, int len, int *values) rc = 0; out: if (!rc) { - write_lock_irq(&state->ss->policy_rwlock); + spin_lock_irq(&state->ss->policy_lock); if (seqno == state->ss->latest_granting) { seqno = ++state->ss->latest_granting; state->ss->active_set = next_set; rc = 0; - write_unlock_irq(&state->ss->policy_rwlock); + spin_unlock_irq(&state->ss->policy_lock); + synchronize_rcu(); avc_ss_reset(state->avc, seqno); selnl_notify_policyload(seqno); selinux_status_update_policyload(state, seqno); @@ -2970,7 +2974,7 @@ int security_set_bools(struct selinux_state *state, int len, int *values) kfree(old_set); } else { rc = -ENOMEM; - write_unlock_irq(&state->ss->policy_rwlock); + spin_unlock_irq(&state->ss->policy_lock); printk(KERN_ERR "SELinux: %s failed in seqno %d\n", __func__, rc); policydb_destroy(&next_set->policydb); @@ -2994,7 +2998,7 @@ int security_get_bool_value(struct selinux_state *state, int rc; int len; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); policydb = &state->ss->active_set->policydb; @@ -3005,7 +3009,7 @@ int security_get_bool_value(struct selinux_state *state, rc = policydb->bool_val_to_struct[index]->state; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -3065,7 +3069,7 @@ int security_sid_mls_copy(struct selinux_state *state, context_init(&newcon); - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = -EINVAL; context1 = sidtab_search(sidtab, sid); @@ -3108,7 +3112,7 @@ int security_sid_mls_copy(struct selinux_state *state, rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); out_unlock: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); context_destroy(&newcon); out: return rc; @@ -3170,7 +3174,7 @@ int security_net_peersid_resolve(struct selinux_state *state, if (!policydb->mls_enabled) return 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = -EINVAL; nlbl_ctx = sidtab_search(sidtab, nlbl_sid); @@ -3197,7 +3201,7 @@ int security_net_peersid_resolve(struct selinux_state *state, * expressive */ *peer_sid = xfrm_sid; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -3226,7 +3230,7 @@ int security_get_classes(struct selinux_state *state, return 0; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = -ENOMEM; *nclasses = policydb->p_classes.nprim; @@ -3244,7 +3248,7 @@ int security_get_classes(struct selinux_state *state, } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -3268,7 +3272,7 @@ int security_get_permissions(struct selinux_state *state, int rc, i; struct class_datum *match; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = -EINVAL; match = hashtab_search(policydb->p_classes.table, class); @@ -3297,11 +3301,11 @@ int security_get_permissions(struct selinux_state *state, goto err; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; err: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); for (i = 0; i < *nperms; i++) kfree((*perms)[i]); kfree(*perms); @@ -3334,9 +3338,9 @@ int security_policycap_supported(struct selinux_state *state, struct policydb *policydb = &state->ss->active_set->policydb; int rc; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = ebitmap_get_bit(&policydb->policycaps, req_cap); - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -3402,7 +3406,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) context_init(&tmprule->au_ctxt); - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); tmprule->au_seqno = state->ss->latest_granting; @@ -3443,7 +3447,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) } rc = 0; out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); if (rc) { selinux_audit_rule_free(tmprule); @@ -3494,7 +3498,7 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, return -ENOENT; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); if (rule->au_seqno < state->ss->latest_granting) { match = -ESTALE; @@ -3585,7 +3589,7 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, } out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return match; } @@ -3674,7 +3678,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state, return 0; } - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); if (secattr->flags & NETLBL_SECATTR_CACHE) *sid = *(u32 *)secattr->cache->data; @@ -3710,12 +3714,12 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state, } else *sid = SECSID_NULL; - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return 0; out_free: ebitmap_destroy(&ctx_new.range.level[0].cat); out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } @@ -3739,7 +3743,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state, if (!state->initialized) return 0; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = -ENOENT; ctx = sidtab_search(state->ss->active_set->sidtab, sid); @@ -3757,7 +3761,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state, mls_export_netlbl_lvl(policydb, ctx, secattr); rc = mls_export_netlbl_cat(policydb, ctx, secattr); out: - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); return rc; } #endif /* CONFIG_NETLABEL */ @@ -3787,9 +3791,9 @@ int security_read_policy(struct selinux_state *state, fp.data = *data; fp.len = *len; - read_lock(&state->ss->policy_rwlock); + rcu_read_lock(); rc = policydb_write(policydb, &fp); - read_unlock(&state->ss->policy_rwlock); + rcu_read_unlock(); if (rc) return rc; diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h index 9219649c70ed..84cbcf226551 100644 --- a/security/selinux/ss/services.h +++ b/security/selinux/ss/services.h @@ -33,7 +33,7 @@ struct selinux_ruleset { }; struct selinux_ss { struct selinux_ruleset *active_set; /* rcu pointer */ - rwlock_t policy_rwlock; + spinlock_t policy_lock; u32 latest_granting; struct page *status_page; struct mutex status_lock;