From 0efea84ef80c5f22eadfa5b3492a56451dca18e9 Mon Sep 17 00:00:00 2001
From: rossberg-chromium <rossberg@chromium.org>
Date: Mon, 5 Sep 2016 17:29:48 +0200
Subject: [PATCH] Check table elements before mutating

---
 ml-proto/spec/eval.ml      | 12 +++++-------
 ml-proto/test/imports.wast | 11 -----------
 ml-proto/test/linking.wast | 25 +++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/ml-proto/spec/eval.ml b/ml-proto/spec/eval.ml
index 3b03ac12ff..bc349ec588 100644
--- a/ml-proto/spec/eval.ml
+++ b/ml-proto/spec/eval.ml
@@ -328,16 +328,15 @@ let init_func c f =
   | AstFunc (inst, _) -> inst := c.instance
   | _ -> assert false
 
-let non_host_func c x =
-  let f = func c x in
-  ignore (func_type_of f x.at);
-  Some (Func f)
+let check_elem c seg =
+  let {init; _} = seg.it in
+  List.iter (fun x -> ignore (func_type_of (func c x) x.at)) init
 
 let init_table c seg =
   let {index; offset = e; init} = seg.it in
   let tab = table c index in
   let offset = int32 (eval_expr c e) e.at in
-  Table.blit tab offset (List.map (non_host_func c) init)
+  Table.blit tab offset (List.map (fun x -> Some (Func (func c x))) init)
 
 let init_memory c seg =
   let {index; offset = e; init} = seg.it in
@@ -369,14 +368,12 @@ let add_import (ext : extern) (imp : import) (inst : instance) : instance =
     );
     {inst with funcs = f :: inst.funcs}
   | ExternalTable tab, TableImport (TableType (lim, _)) ->
-    (* TODO: no checking of element type? *)
     check_limits (Table.limits tab) lim imp.it.ikind.at;
     {inst with tables = tab :: inst.tables}
   | ExternalMemory mem, MemoryImport (MemoryType lim) ->
     check_limits (Memory.limits mem) lim imp.it.ikind.at;
     {inst with memories = mem :: inst.memories}
   | ExternalGlobal glob, GlobalImport _ ->
-    (* TODO: no checking of value type? *)
     {inst with globals = ref glob :: inst.globals}
   | _ ->
     Link.error imp.it.ikind.at "type mismatch"
@@ -410,6 +407,7 @@ let init m externals =
   in
   let c = empty_config inst in
   List.iter (init_func c) fs;
+  List.iter (check_elem c) elems;
   List.iter (init_table c) elems;
   List.iter (init_memory c) data;
   List.iter2 (init_global c) gs globals;
diff --git a/ml-proto/test/imports.wast b/ml-proto/test/imports.wast
index 3c7e7de03d..4b032b1209 100644
--- a/ml-proto/test/imports.wast
+++ b/ml-proto/test/imports.wast
@@ -45,17 +45,6 @@
   "type mismatch"
 )
 
-(; TODO: check linking against other Wasm module
-(assert_unlinkable
-  (module (import "spectest" "func" (func (param i32))))
-  "type mismatch"
-)
-(assert_unlinkable
-  (module (import "spectest" "func" (func (result i32))))
-  "type mismatch"
-)
-;)
-
 (assert_unlinkable
   (module (import "spectest" "print" (func)) (table anyfunc (elem 0)))
   "invalid use of host function"
diff --git a/ml-proto/test/linking.wast b/ml-proto/test/linking.wast
index 8dc627e4f4..0f35578962 100644
--- a/ml-proto/test/linking.wast
+++ b/ml-proto/test/linking.wast
@@ -142,6 +142,18 @@
 
 (assert_trap (invoke $O "call" (i32.const 20)) "undefined")
 
+(assert_unlinkable
+  (module $Q
+    (func $host (import "spectest" "print"))
+    (table (import "M" "tab") 10 anyfunc)
+    (elem (i32.const 7) $own)
+    (elem (i32.const 9) $host)
+    (func $own (result i32) (i32.const 666))
+  )
+  "invalid use of host function"
+)
+(assert_trap (invoke $M "call" (i32.const 7)) "uninitialized")
+
 
 ;; Memories
 
@@ -201,3 +213,16 @@
 (assert_return (invoke $P "grow" (i32.const 0)) (i32.const 5))
 (assert_return (invoke $P "grow" (i32.const 1)) (i32.const -1))
 (assert_return (invoke $P "grow" (i32.const 0)) (i32.const 5))
+
+(assert_unlinkable
+  (module $Q
+    (func $host (import "spectest" "print"))
+    (memory (import "M" "mem") 1)
+    (table 10 anyfunc)
+    (data (i32.const 0) "abc")
+    (elem (i32.const 9) $host)
+    (func $own (result i32) (i32.const 666))
+  )
+  "invalid use of host function"
+)
+(assert_return (invoke $M "load" (i32.const 0)) (i32.const 0))