flask: add compat mode guest support

... which has been missing since the introduction of the new interface
in the 4.2 development cycle.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Keir Fraser <keir@xen.org>

xen/arch/x86/x86_64/compat/entry.S

@@ -404,7 +404,7 @@ ENTRY(compat_hypercall_table)
         .quad compat_vcpu_op
         .quad compat_ni_hypercall       /* 25 */
         .quad compat_mmuext_op
-        .quad do_xsm_op
+        .quad compat_xsm_op
         .quad compat_nmi_op
         .quad compat_sched_op
         .quad compat_callback_op        /* 30 */

xen/include/Makefile

@@ -27,6 +27,7 @@ headers-$(CONFIG_X86)     += compat/arch-x86/xen-mca.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen-$(compat-arch-y).h
 headers-y                 += compat/arch-$(compat-arch-y).h compat/xlat.h
+headers-$(FLASK_ENABLE)   += compat/xsm/flask_op.h
 
 cppflags-y                := -include public/xen-compat.h
 cppflags-$(CONFIG_X86)    += -m32
@@ -69,7 +70,9 @@ compat/xlat.h: xlat.lst $(filter-out compat/xlat.h,$(headers-y)) $(BASEDIR)/tool
 	export PYTHON=$(PYTHON); \
 	grep -v '^[	 ]*#' xlat.lst | \
 	while read what name hdr; do \
-		$(SHELL) $(BASEDIR)/tools/get-fields.sh "$$what" compat_$$name $$(echo compat/$$hdr | sed 's,@arch@,$(compat-arch-y),g') || exit $$?; \
+		hdr="compat/$$(echo $$hdr | sed 's,@arch@,$(compat-arch-y),g')"; \
+		echo '$(headers-y)' | grep -q "$$hdr" || continue; \
+		$(SHELL) $(BASEDIR)/tools/get-fields.sh "$$what" compat_$$name $$hdr || exit $$?; \
 	done >$@.new
 	mv -f $@.new $@
 

xen/include/xlat.lst

@@ -99,3 +99,16 @@
 !	vcpu_set_singleshot_timer	vcpu.h
 ?	xenoprof_init			xenoprof.h
 ?	xenoprof_passive		xenoprof.h
+?	flask_access			xsm/flask_op.h
+!	flask_boolean			xsm/flask_op.h
+?	flask_cache_stats		xsm/flask_op.h
+?	flask_hash_stats		xsm/flask_op.h
+!	flask_load			xsm/flask_op.h
+?	flask_ocontext			xsm/flask_op.h
+?	flask_peersid			xsm/flask_op.h
+?	flask_relabel			xsm/flask_op.h
+?	flask_setavc_threshold		xsm/flask_op.h
+?	flask_setenforce		xsm/flask_op.h
+!	flask_sid_context		xsm/flask_op.h
+?	flask_transition		xsm/flask_op.h
+!	flask_userlist			xsm/flask_op.h

xen/include/xsm/dummy.h

@@ -412,6 +412,13 @@ static XSM_INLINE long xsm_do_xsm_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
     return -ENOSYS;
 }
 
+#ifdef CONFIG_COMPAT
+static XSM_INLINE int xsm_do_compat_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
+{
+    return -ENOSYS;
+}
+#endif
+
 static XSM_INLINE char *xsm_show_irq_sid(int irq)
 {
     return NULL;

xen/include/xsm/xsm.h

@@ -129,6 +129,9 @@ struct xsm_operations {
     int (*tmem_control)(void);
 
     long (*do_xsm_op) (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op);
+#ifdef CONFIG_COMPAT
+    int (*do_compat_op) (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op);
+#endif
 
     int (*hvm_param) (struct domain *d, unsigned long op);
     int (*hvm_param_nested) (struct domain *d);
@@ -499,6 +502,13 @@ static inline long xsm_do_xsm_op (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
     return xsm_ops->do_xsm_op(op);
 }
 
+#ifdef CONFIG_COMPAT
+static inline int xsm_do_compat_op (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
+{
+    return xsm_ops->do_compat_op(op);
+}
+#endif
+
 static inline int xsm_hvm_param (xsm_default_t def, struct domain *d, unsigned long op)
 {
     return xsm_ops->hvm_param(d, op);

xen/xsm/dummy.c

@@ -105,6 +105,9 @@ void xsm_fixup_ops (struct xsm_operations *ops)
     set_to_dummy_if_null(ops, hvm_param_nested);
 
     set_to_dummy_if_null(ops, do_xsm_op);
+#ifdef CONFIG_COMPAT
+    set_to_dummy_if_null(ops, do_compat_op);
+#endif
 
     set_to_dummy_if_null(ops, add_to_physmap);
     set_to_dummy_if_null(ops, remove_from_physmap);

xen/xsm/flask/flask_op.c

@@ -7,7 +7,7 @@
  *  it under the terms of the GNU General Public License version 2,
  *  as published by the Free Software Foundation.
  */
-
+#ifndef COMPAT
 #include <xen/errno.h>
 #include <xen/event.h>
 #include <xsm/xsm.h>
@@ -20,6 +20,10 @@
 #include <objsec.h>
 #include <conditional.h>
 
+#define ret_t long
+#define _copy_to_guest copy_to_guest
+#define _copy_from_guest copy_from_guest
+
 #ifdef FLASK_DEVELOP
 int flask_enforcing = 0;
 integer_param("flask_enforcing", flask_enforcing);
@@ -95,6 +99,8 @@ static int flask_copyin_string(XEN_GUEST_HANDLE_PARAM(char) u_buf, char **buf,
     return 0;
 }
 
+#endif /* COMPAT */
+
 static int flask_security_user(struct xen_flask_userlist *arg)
 {
     char *user;
@@ -119,7 +125,7 @@ static int flask_security_user(struct xen_flask_userlist *arg)
 
     arg->size = nsids;
 
-    if ( copy_to_guest(arg->u.sids, sids, nsids) )
+    if ( _copy_to_guest(arg->u.sids, sids, nsids) )
         rv = -EFAULT;
 
     xfree(sids);
@@ -128,6 +134,8 @@ static int flask_security_user(struct xen_flask_userlist *arg)
     return rv;
 }
 
+#ifndef COMPAT
+
 static int flask_security_relabel(struct xen_flask_transition *arg)
 {
     int rv;
@@ -208,6 +216,8 @@ static int flask_security_setenforce(struct xen_flask_setenforce *arg)
     return 0;
 }
 
+#endif /* COMPAT */
+
 static int flask_security_context(struct xen_flask_sid_context *arg)
 {
     int rv;
@@ -252,7 +262,7 @@ static int flask_security_sid(struct xen_flask_sid_context *arg)
 
     arg->size = len;
 
-    if ( !rv && copy_to_guest(arg->context, context, len) )
+    if ( !rv && _copy_to_guest(arg->context, context, len) )
         rv = -EFAULT;
 
     xfree(context);
@@ -260,6 +270,8 @@ static int flask_security_sid(struct xen_flask_sid_context *arg)
     return rv;
 }
 
+#ifndef COMPAT
+
 int flask_disable(void)
 {
     static int flask_disabled = 0;
@@ -302,6 +314,8 @@ static int flask_security_setavc_threshold(struct xen_flask_setavc_threshold *ar
     return rv;
 }
 
+#endif /* COMPAT */
+
 static int flask_security_resolve_bool(struct xen_flask_boolean *arg)
 {
     char *name;
@@ -382,24 +396,6 @@ static int flask_security_set_bool(struct xen_flask_boolean *arg)
     return rv;
 }
 
-static int flask_security_commit_bools(void)
-{
-    int rv;
-
-    spin_lock(&sel_sem);
-
-    rv = domain_has_security(current->domain, SECURITY__SETBOOL);
-    if ( rv )
-        goto out;
-
-    if ( bool_pending_values )
-        rv = security_set_bools(bool_num, bool_pending_values);
-    
- out:
-    spin_unlock(&sel_sem);
-    return rv;
-}
-
 static int flask_security_get_bool(struct xen_flask_boolean *arg)
 {
     int rv;
@@ -431,7 +427,7 @@ static int flask_security_get_bool(struct xen_flask_boolean *arg)
             rv = -ERANGE;
         arg->size = nameout_len;
  
-        if ( !rv && copy_to_guest(arg->name, nameout, nameout_len) )
+        if ( !rv && _copy_to_guest(arg->name, nameout, nameout_len) )
             rv = -EFAULT;
         xfree(nameout);
     }
@@ -441,6 +437,26 @@ static int flask_security_get_bool(struct xen_flask_boolean *arg)
     return rv;
 }
 
+#ifndef COMPAT
+
+static int flask_security_commit_bools(void)
+{
+    int rv;
+
+    spin_lock(&sel_sem);
+
+    rv = domain_has_security(current->domain, SECURITY__SETBOOL);
+    if ( rv )
+        goto out;
+
+    if ( bool_pending_values )
+        rv = security_set_bools(bool_num, bool_pending_values);
+
+ out:
+    spin_unlock(&sel_sem);
+    return rv;
+}
+
 static int flask_security_make_bools(void)
 {
     int ret = 0;
@@ -484,6 +500,7 @@ static int flask_security_avc_cachestats(struct xen_flask_cache_stats *arg)
 }
 
 #endif
+#endif /* COMPAT */
 
 static int flask_security_load(struct xen_flask_load *load)
 {
@@ -501,7 +518,7 @@ static int flask_security_load(struct xen_flask_load *load)
     if ( !buf )
         return -ENOMEM;
 
-    if ( copy_from_guest(buf, load->buffer, load->size) )
+    if ( _copy_from_guest(buf, load->buffer, load->size) )
     {
         ret = -EFAULT;
         goto out_free;
@@ -524,6 +541,8 @@ static int flask_security_load(struct xen_flask_load *load)
     return ret;
 }
 
+#ifndef COMPAT
+
 static int flask_ocontext_del(struct xen_flask_ocontext *arg)
 {
     int rv;
@@ -636,7 +655,9 @@ static int flask_relabel_domain(struct xen_flask_relabel *arg)
     return rc;
 }
 
-long do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op)
+#endif /* !COMPAT */
+
+ret_t do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op)
 {
     xen_flask_op_t op;
     int rv;
@@ -763,3 +784,52 @@ long do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op)
  out:
     return rv;
 }
+
+#ifndef COMPAT
+#undef _copy_to_guest
+#define _copy_to_guest copy_to_compat
+#undef _copy_from_guest
+#define _copy_from_guest copy_from_compat
+
+#include <compat/event_channel.h>
+#include <compat/xsm/flask_op.h>
+
+CHECK_flask_access;
+CHECK_flask_cache_stats;
+CHECK_flask_hash_stats;
+CHECK_flask_ocontext;
+CHECK_flask_peersid;
+CHECK_flask_relabel;
+CHECK_flask_setavc_threshold;
+CHECK_flask_setenforce;
+CHECK_flask_transition;
+
+#define COMPAT
+#define flask_copyin_string(ch, pb, sz, mx) ({ \
+	XEN_GUEST_HANDLE_PARAM(char) gh; \
+	guest_from_compat_handle(gh, ch); \
+	flask_copyin_string(gh, pb, sz, mx); \
+})
+
+#define xen_flask_load compat_flask_load
+#define flask_security_load compat_security_load
+
+#define xen_flask_userlist compat_flask_userlist
+#define flask_security_user compat_security_user
+
+#define xen_flask_sid_context compat_flask_sid_context
+#define flask_security_context compat_security_context
+#define flask_security_sid compat_security_sid
+
+#define xen_flask_boolean compat_flask_boolean
+#define flask_security_resolve_bool compat_security_resolve_bool
+#define flask_security_get_bool compat_security_get_bool
+#define flask_security_set_bool compat_security_set_bool
+
+#define xen_flask_op_t compat_flask_op_t
+#undef ret_t
+#define ret_t int
+#define do_flask_op compat_flask_op
+
+#include "flask_op.c"
+#endif

xen/xsm/flask/hooks.c

@@ -1464,6 +1464,7 @@ static int flask_map_gmfn_foreign(struct domain *d, struct domain *t)
 #endif
 
 long do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op);
+int compat_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op);
 
 static struct xsm_operations flask_ops = {
     .security_domaininfo = flask_security_domaininfo,
@@ -1538,6 +1539,9 @@ static struct xsm_operations flask_ops = {
     .hvm_param_nested = flask_hvm_param_nested,
 
     .do_xsm_op = do_flask_op,
+#ifdef CONFIG_COMPAT
+    .do_compat_op = compat_flask_op,
+#endif
 
     .add_to_physmap = flask_add_to_physmap,
     .remove_from_physmap = flask_remove_from_physmap,

xen/xsm/xsm_core.c

@@ -116,4 +116,9 @@ long do_xsm_op (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
     return xsm_do_xsm_op(op);
 }
 
-
+#ifdef CONFIG_COMPAT
+int compat_xsm_op (XEN_GUEST_HANDLE_PARAM(xsm_op_t) op)
+{
+    return xsm_do_compat_op(op);
+}
+#endif