[NaCl SDK] nacl_io: handle null irt function pointers

native_client_sdk/src/libraries/nacl_io/kernel_wrap_bionic.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sys/types.h>  // Include something that will define __BIONIC__.
 
 // The entire file is wrapped in this #if. We do this so this .cc file can be
 // compiled, even on a non-bionic build.
 
 #if defined(__native_client__) && defined(__BIONIC__)
@@ skipping 320 matching lines @@
 
 static void assign_real_pointers() {
   static bool assigned = false;
   if (!assigned) {
     EXPAND_SYMBOL_LIST_OPERATION(ASSIGN_REAL_PTR)
     assigned = true;
   }
 }
 
 #define CHECK_REAL(func) \
-  if (!REAL(func))       \
-    assign_real_pointers();
-
-#define CHECK_REAL_NOSYS(func)  \
-  CHECK_REAL(func)              \
-  if (!REAL(func))              \
-    return ENOSYS;
+  if (!REAL(func)) {          \
+    assign_real_pointers();   \
+    if (!REAL(func))          \
+      return ENOSYS;          \
+  }
 
 // "real" functions, i.e. the unwrapped original functions.
 
 int _real_close(int fd) {
   CHECK_REAL(close);
   return REAL(close)(fd);
 }
 
 void _real_exit(int status) {
   REAL(exit)(status);
@@ skipping 71 matching lines @@
 int _real_lseek(int fd, int64_t offset, int whence, int64_t* new_offset) {
   CHECK_REAL(seek);
   nacl_abi_off_t nacl_new_offs;
   int ret = REAL(seek)(fd, offset, whence, &nacl_new_offs);
   *new_offset = static_cast<off_t>(nacl_new_offs);
   return ret;
 }
 
 int _real_lstat(const char* path, struct stat* buf) {
   struct nacl_abi_stat st;
-  CHECK_REAL(fstat);
+  CHECK_REAL(lstat);
 
   int err = REAL(lstat)(path, (struct stat*)&st);
   if (err) {
     errno = err;
     return -1;
   }
 
   nacl_stat_to_stat(&st, buf);
   return 0;
 }
@@ skipping 47 matching lines @@
   CHECK_REAL(truncate);
   return REAL(truncate)(pathname, len);
 }
 
 int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
   CHECK_REAL(write);
   return REAL(write)(fd, buf, count, nwrote);
 }
 
 int _real_getcwd(char* pathname, size_t len) {
-  CHECK_REAL_NOSYS(getcwd);
+  CHECK_REAL(getcwd);
   return REAL(getcwd)(pathname, len);
 }
 
 static bool s_wrapped = false;
 
 void kernel_wrap_init() {
   if (!s_wrapped) {
     assign_real_pointers();
     EXPAND_SYMBOL_LIST_OPERATION(USE_WRAP)
     s_wrapped = true;
   }
 }
 
 void kernel_wrap_uninit() {
   if (s_wrapped) {
     EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
     s_wrapped = false;
   }
 }
 
 EXTERN_C_END
 
 #endif  // defined(__native_client__) && defined(__BIONIC__)