From 21193dcd1f3570ddfd8a04f4465e484c1f94252f Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 12 Feb 2009 14:50:49 -0500 Subject: SELinux: more careful use of avd in avc_has_perm_noaudit we are often needlessly jumping through hoops when it comes to avd entries in avc_has_perm_noaudit and we have extra initialization and memcpy which are just wasting performance. Try to clean the function up a bit. This patch resulted in a 13% drop in time spent in avc_has_perm_noaudit in my oprofile sampling of a tbench benchmark. Signed-off-by: Eric Paris Reviewed-by: Paul Moore Acked-by: Stephen Smalley Signed-off-by: James Morris --- security/selinux/avc.c | 43 ++++++++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 19 deletions(-) diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 0afb990fdfa4..2a84dec4adfe 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -350,12 +350,12 @@ out: return node; } -static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) +static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) { node->ae.ssid = ssid; node->ae.tsid = tsid; node->ae.tclass = tclass; - memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd)); + memcpy(&node->ae.avd, avd, sizeof(node->ae.avd)); } static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) @@ -435,31 +435,31 @@ static int avc_latest_notif_update(int seqno, int is_insert) * @ssid: source security identifier * @tsid: target security identifier * @tclass: target security class - * @ae: AVC entry + * @avd: resulting av decision * * Insert an AVC entry for the SID pair * (@ssid, @tsid) and class @tclass. * The access vectors and the sequence number are * normally provided by the security server in * response to a security_compute_av() call. If the - * sequence number @ae->avd.seqno is not less than the latest + * sequence number @avd->seqno is not less than the latest * revocation notification, then the function copies * the access vectors into a cache entry, returns * avc_node inserted. Otherwise, this function returns NULL. */ -static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae) +static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) { struct avc_node *pos, *node = NULL; int hvalue; unsigned long flag; - if (avc_latest_notif_update(ae->avd.seqno, 1)) + if (avc_latest_notif_update(avd->seqno, 1)) goto out; node = avc_alloc_node(); if (node) { hvalue = avc_hash(ssid, tsid, tclass); - avc_node_populate(node, ssid, tsid, tclass, ae); + avc_node_populate(node, ssid, tsid, tclass, avd); spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag); list_for_each_entry(pos, &avc_cache.slots[hvalue], list) { @@ -772,7 +772,7 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass, * Copy and replace original node. */ - avc_node_populate(node, ssid, tsid, tclass, &orig->ae); + avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd); switch (event) { case AVC_CALLBACK_GRANT: @@ -864,10 +864,10 @@ int avc_ss_reset(u32 seqno) int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested, unsigned flags, - struct av_decision *avd) + struct av_decision *in_avd) { struct avc_node *node; - struct avc_entry entry, *p_ae; + struct av_decision avd_entry, *avd; int rc = 0; u32 denied; @@ -878,26 +878,31 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, node = avc_lookup(ssid, tsid, tclass, requested); if (!node) { rcu_read_unlock(); - rc = security_compute_av(ssid, tsid, tclass, requested, &entry.avd); + + if (in_avd) + avd = in_avd; + else + avd = &avd_entry; + + rc = security_compute_av(ssid, tsid, tclass, requested, avd); if (rc) goto out; rcu_read_lock(); - node = avc_insert(ssid, tsid, tclass, &entry); + node = avc_insert(ssid, tsid, tclass, avd); + } else { + if (in_avd) + memcpy(in_avd, &node->ae.avd, sizeof(*in_avd)); + avd = &node->ae.avd; } - p_ae = node ? &node->ae : &entry; - - if (avd) - memcpy(avd, &p_ae->avd, sizeof(*avd)); - - denied = requested & ~(p_ae->avd.allowed); + denied = requested & ~(avd->allowed); if (denied) { if (flags & AVC_STRICT) rc = -EACCES; else if (!selinux_enforcing || security_permissive_sid(ssid)) avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, - tsid, tclass, p_ae->avd.seqno); + tsid, tclass, avd->seqno); else rc = -EACCES; } -- cgit v1.2.3