VBoot Reference: 18 Exabytes ought to be enough for everybody

src/platform/vboot_reference/common/utility_stub.c

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Stub implementations of utility functions which call their linux-specific
  * equivalents.
  */
 
 #include "utility.h"
 
@@ skipping 29 matching lines @@
   const unsigned char* us1 = s1;
   const unsigned char* us2 = s2;
   while (n--) {
     if (*us1++ != *us2++)
       match = 1;
   }
 
   return match;
 }
 
-void* StatefulMemcpy(MemcpyState* state, void* dst, int len) {
+void* StatefulMemcpy(MemcpyState* state, void* dst,
+                     uint64_t len) {
+  if (state->overrun)
+    return NULL;
   if (len > state->remaining_len) {
-    state->remaining_len = -1;
+    state->overrun = 1;
     return NULL;
   }
   Memcpy(dst, state->remaining_buf, len);
   state->remaining_buf += len;
   state->remaining_len -= len;
   return dst;
 }
 
-const void* StatefulMemcpy_r(MemcpyState* state, const void* src, int len) {
+const void* StatefulMemcpy_r(MemcpyState* state, const void* src,
+                             uint64_t len) {
+  if (state->overrun)
+    return NULL;
   if (len > state->remaining_len) {
-    state->remaining_len = -1;
+    state->overrun = 1;
     return NULL;
   }
   Memcpy(state->remaining_buf, src, len);
   state->remaining_buf += len;
   state->remaining_len -= len;
   return src;
 }