* malloc_wrapper.cc: Change 'use_internal_malloc' to 'use_internal' throughout.

(export_malloc_called): Delete.
(internal_malloc_determined): New variable.
(malloc_init): Control calculation of internal/external malloc based on
'internal_malloc_determined'.  Use import_address() to determine if malloc in
user_data is ours or not.
* miscfuncs.cc (thread_wrapper): Make static.
(__import_address): Define new function.
* miscfuncs.h (import_address): New define.
(__import_address): Declare new function.

4 files changed, 51 insertions, 32 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 908545c54..2c5b7e3a3 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,19 @@
 2013-01-20  Christopher Faylor  <me.cygwin2013@cgf.cx>
 
+	* malloc_wrapper.cc: Change 'use_internal_malloc' to 'use_internal'
+	throughout.
+	(export_malloc_called): Delete.
+	(internal_malloc_determined): New variable.
+	(malloc_init): Control calculation of internal/external malloc based on
+	'internal_malloc_determined'.  Use import_address() to determine if
+	malloc in user_data is ours or not.
+	* miscfuncs.cc (thread_wrapper): Make static.
+	(__import_address): Define new function.
+	* miscfuncs.h (import_address): New define.
+	(__import_address): Declare new function.
+
+2013-01-20  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
 	* sigproc.cc (sig_dispatch_pending): Add correct regparm attributes to
 	match declaration.
 	(pid_exists): Ditto.
diff --git a/winsup/cygwin/malloc_wrapper.cc b/winsup/cygwin/malloc_wrapper.cc
index 86b74d564..241766f64 100644
--- a/winsup/cygwin/malloc_wrapper.cc
+++ b/winsup/cygwin/malloc_wrapper.cc
@@ -1,10 +1,7 @@
 /* malloc_wrapper.cc
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
-   2006, 2007 Red Hat, Inc.
-
-   Originally written by Steve Chamberlain of Cygnus Support
-   sac@cygnus.com
+   2006, 2007, 2013 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -19,6 +16,7 @@ details. */
 #include "fhandler.h"
 #include "dtable.h"
 #include "perprocess.h"
+#include "miscfuncs.h"
 #include "cygmalloc.h"
 #ifndef MALLOC_DEBUG
 #include <malloc.h>
@@ -31,8 +29,8 @@ extern "C" struct mallinfo dlmallinfo ();
    problems if malloced on our heap and free'd on theirs.
 */
 
-static int export_malloc_called;
-static int use_internal_malloc = 1;
+static bool use_internal = true;
+static bool internal_malloc_determined;
 
 /* These routines are used by the application if it
    doesn't provide its own malloc. */
@@ -41,7 +39,7 @@ extern "C" void
 free (void *p)
 {
   malloc_printf ("(%p), called by %p", p, __builtin_return_address (0));
-  if (!use_internal_malloc)
+  if (!use_internal)
     user_data->free (p);
   else
     {
@@ -55,8 +53,7 @@ extern "C" void *
 malloc (size_t size)
 {
   void *res;
-  export_malloc_called = 1;
-  if (!use_internal_malloc)
+  if (!use_internal)
     res = user_data->malloc (size);
   else
     {
@@ -72,7 +69,7 @@ extern "C" void *
 realloc (void *p, size_t size)
 {
   void *res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     res = user_data->realloc (p, size);
   else
     {
@@ -99,7 +96,7 @@ extern "C" void *
 calloc (size_t nmemb, size_t size)
 {
   void *res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     res = user_data->calloc (nmemb, size);
   else
     {
@@ -117,7 +114,7 @@ posix_memalign (void **memptr, size_t alignment, size_t bytes)
   save_errno save;
 
   void *res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     return ENOSYS;
   if ((alignment & (alignment - 1)) != 0)
     return EINVAL;
@@ -135,7 +132,7 @@ extern "C" void *
 memalign (size_t alignment, size_t bytes)
 {
   void *res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     {
       set_errno (ENOSYS);
       res = NULL;
@@ -154,7 +151,7 @@ extern "C" void *
 valloc (size_t bytes)
 {
   void *res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     {
       set_errno (ENOSYS);
       res = NULL;
@@ -173,7 +170,7 @@ extern "C" size_t
 malloc_usable_size (void *p)
 {
   size_t res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     {
       set_errno (ENOSYS);
       res = 0;
@@ -192,7 +189,7 @@ extern "C" int
 malloc_trim (size_t pad)
 {
   size_t res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     {
       set_errno (ENOSYS);
       res = 0;
@@ -211,7 +208,7 @@ extern "C" int
 mallopt (int p, int v)
 {
   int res;
-  if (!use_internal_malloc)
+  if (!use_internal)
     {
       set_errno (ENOSYS);
       res = 0;
@@ -229,7 +226,7 @@ mallopt (int p, int v)
 extern "C" void
 malloc_stats ()
 {
-  if (!use_internal_malloc)
+  if (!use_internal)
     set_errno (ENOSYS);
   else
     {
@@ -243,7 +240,7 @@ extern "C" struct mallinfo
 mallinfo ()
 {
   struct mallinfo m;
-  if (!use_internal_malloc)
+  if (!use_internal)
     set_errno (ENOSYS);
   else
     {
@@ -284,16 +281,12 @@ malloc_init ()
      calls to malloc/free/realloc to application provided. This may
      happen if some other dll calls cygwin's malloc, but main code provides
      its own malloc */
-  if (!in_forkee)
+  if (!internal_malloc_determined)
     {
-      user_data->free (user_data->malloc (16));
-      if (export_malloc_called)
-	malloc_printf ("using internal malloc");
-      else
-	{
-	  use_internal_malloc = 0;
-	  malloc_printf ("using external malloc");
-	}
+      extern void *_sigfe_malloc;
+      use_internal = import_address (user_data->malloc) == &_sigfe_malloc;
+      malloc_printf ("using %s malloc", use_internal ? "internal" : "external");
+      internal_malloc_determined = true;
     }
 #endif
 }
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index 001461620..2d3f52c3a 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -1,7 +1,7 @@
 /* miscfuncs.cc: misc funcs that don't belong anywhere else
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Red Hat, Inc.
+   2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -433,6 +433,15 @@ slashify (const char *src, char *dst, bool trailing_slash_p)
   *dst++ = 0;
 }
 
+/* Return an address from the import jmp table of main program.  */
+void * __attribute__ ((regparm (1)))
+__import_address (void *imp)
+{
+  const char *ptr = (const char *) imp;
+  const uintptr_t *jmpto = (uintptr_t *) *((uintptr_t *) (ptr + 2));
+  return (void *) *jmpto;
+}
+
 /* CygwinCreateThread.
 
    Replacement function for CreateThread.  What we do here is to remove
@@ -448,7 +457,7 @@ struct thread_wrapper_arg
   PBYTE stacklimit;
 };
 
-DWORD WINAPI
+static DWORD WINAPI
 thread_wrapper (VOID *arg)
 {
   /* Just plain paranoia. */
diff --git a/winsup/cygwin/miscfuncs.h b/winsup/cygwin/miscfuncs.h
index 355fa103c..7995475d8 100644
--- a/winsup/cygwin/miscfuncs.h
+++ b/winsup/cygwin/miscfuncs.h
@@ -1,7 +1,7 @@
 /* miscfuncs.h: main Cygwin header file.
 
-   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Red Hat, Inc.
+   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
+   2007, 2008, 2009, 2010, 2011, 2012, 2013 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -26,6 +26,9 @@ BOOL WINAPI WritePipeOverlapped (HANDLE h, LPCVOID buf, DWORD len,
 
 extern "C" void yield ();
 
+#define import_address(x) __import_address ((void *)(x))
+void * __stdcall __attribute__ ((regparm (1))) __import_address (void *);
+
 void backslashify (const char *, char *, bool);
 void slashify (const char *, char *, bool);
 #define isslash(c) ((c) == '/')