Index: kernel/generic/include/mm/as.h
===================================================================
--- kernel/generic/include/mm/as.h	(revision 83dab11c929c1a48613d4dc70ed8ca9113463484)
+++ kernel/generic/include/mm/as.h	(revision 36df27ebb72758daf4d2179e70f231ac0e059a83)
@@ -268,9 +268,9 @@
 extern as_area_t *as_area_create(as_t *, unsigned int, size_t, unsigned int,
     mem_backend_t *, mem_backend_data_t *, uintptr_t *, uintptr_t);
-extern int as_area_destroy(as_t *, uintptr_t);
-extern int as_area_resize(as_t *, uintptr_t, size_t, unsigned int);
-extern int as_area_share(as_t *, uintptr_t, size_t, as_t *, unsigned int,
+extern errno_t as_area_destroy(as_t *, uintptr_t);
+extern errno_t as_area_resize(as_t *, uintptr_t, size_t, unsigned int);
+extern errno_t as_area_share(as_t *, uintptr_t, size_t, as_t *, unsigned int,
     uintptr_t *, uintptr_t);
-extern int as_area_change_flags(as_t *, unsigned int, uintptr_t);
+extern errno_t as_area_change_flags(as_t *, unsigned int, uintptr_t);
 
 extern unsigned int as_area_get_flags(as_area_t *);
@@ -283,5 +283,5 @@
 
 #ifndef as_constructor_arch
-extern int as_constructor_arch(as_t *, unsigned int);
+extern errno_t as_constructor_arch(as_t *, unsigned int);
 #endif /* !def as_constructor_arch */
 
@@ -291,5 +291,5 @@
 
 #ifndef as_create_arch
-extern int as_create_arch(as_t *, unsigned int);
+extern errno_t as_create_arch(as_t *, unsigned int);
 #endif /* !def as_create_arch */
 
@@ -311,7 +311,7 @@
 extern sysarg_t sys_as_area_create(uintptr_t, size_t, unsigned int, uintptr_t,
     as_area_pager_info_t *);
-extern sysarg_t sys_as_area_resize(uintptr_t, size_t, unsigned int);
-extern sysarg_t sys_as_area_change_flags(uintptr_t, unsigned int);
-extern sysarg_t sys_as_area_destroy(uintptr_t);
+extern sys_errno_t sys_as_area_resize(uintptr_t, size_t, unsigned int);
+extern sys_errno_t sys_as_area_change_flags(uintptr_t, unsigned int);
+extern sys_errno_t sys_as_area_destroy(uintptr_t);
 
 /* Introspection functions. */
Index: kernel/generic/include/mm/page.h
===================================================================
--- kernel/generic/include/mm/page.h	(revision 83dab11c929c1a48613d4dc70ed8ca9113463484)
+++ kernel/generic/include/mm/page.h	(revision 36df27ebb72758daf4d2179e70f231ac0e059a83)
@@ -67,6 +67,6 @@
 extern void page_table_destroy(pte_t *);
 
-extern int page_find_mapping(uintptr_t, uintptr_t *);
-extern sysarg_t sys_page_find_mapping(uintptr_t, uintptr_t *);
+extern errno_t page_find_mapping(uintptr_t, uintptr_t *);
+extern sys_errno_t sys_page_find_mapping(uintptr_t, uintptr_t *);
 
 #endif
Index: kernel/generic/include/mm/slab.h
===================================================================
--- kernel/generic/include/mm/slab.h	(revision 83dab11c929c1a48613d4dc70ed8ca9113463484)
+++ kernel/generic/include/mm/slab.h	(revision 36df27ebb72758daf4d2179e70f231ac0e059a83)
@@ -94,5 +94,5 @@
 	size_t size;
 	
-	int (*constructor)(void *obj, unsigned int kmflag);
+	errno_t (*constructor)(void *obj, unsigned int kmflag);
 	size_t (*destructor)(void *obj);
 	
@@ -124,5 +124,5 @@
 
 extern slab_cache_t *slab_cache_create(const char *, size_t, size_t,
-    int (*)(void *, unsigned int), size_t (*)(void *), unsigned int);
+    errno_t (*)(void *, unsigned int), size_t (*)(void *), unsigned int);
 extern void slab_cache_destroy(slab_cache_t *);