security/selinux: pass 'flags' arg to avc_audit() and avc_has_perm_flags()

This allows MAY_NOT_BLOCK to be passed, in RCU-walk mode, through
the new avc_has_perm_flags() to avc_audit() and thence the slow_avc_audit.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

security/selinux/avc.c

@@ -761,7 +761,23 @@ int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
 
 	rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
 
-	rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
+	rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata, 0);
+	if (rc2)
+		return rc2;
+	return rc;
+}
+
+int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
+		       u32 requested, struct common_audit_data *auditdata,
+		       int flags)
+{
+	struct av_decision avd;
+	int rc, rc2;
+
+	rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
+
+	rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc,
+			auditdata, flags);
 	if (rc2)
 		return rc2;
 	return rc;

security/selinux/hooks.c

@@ -1564,7 +1564,7 @@ static int cred_has_capability(const struct cred *cred,
 
 	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
 	if (audit == SECURITY_CAP_AUDIT) {
-		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
+		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
 		if (rc2)
 			return rc2;
 	}

security/selinux/include/avc.h

@@ -130,7 +130,8 @@ static inline int avc_audit(u32 ssid, u32 tsid,
 			    u16 tclass, u32 requested,
 			    struct av_decision *avd,
 			    int result,
-			    struct common_audit_data *a)
+			    struct common_audit_data *a,
+			    int flags)
 {
 	u32 audited, denied;
 	audited = avc_audit_required(requested, avd, result, 0, &denied);
@@ -138,7 +139,7 @@ static inline int avc_audit(u32 ssid, u32 tsid,
 		return 0;
 	return slow_avc_audit(ssid, tsid, tclass,
 			      requested, audited, denied, result,
-			      a, 0);
+			      a, flags);
 }
 
 #define AVC_STRICT 1 /* Ignore permissive mode. */
@@ -150,6 +151,10 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
 int avc_has_perm(u32 ssid, u32 tsid,
 		 u16 tclass, u32 requested,
 		 struct common_audit_data *auditdata);
+int avc_has_perm_flags(u32 ssid, u32 tsid,
+		       u16 tclass, u32 requested,
+		       struct common_audit_data *auditdata,
+		       int flags);
 
 u32 avc_policy_seqno(void);