diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 46ebb1c7b..0b5097283 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,15 @@
+2007-02-08  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygwin.din (shm_open): Export.
+	(shm_unlink): Export.
+	* syscalls.cc (shm_open): New function.
+	(shm_unlink): New function.
+	* sysconf.cc (sca): Set value of _SC_SHARED_MEMORY_OBJECTS to
+	_POSIX_SHARED_MEMORY_OBJECTS.
+	* include/cygwin/version.h: Bump API minor number.
+	* include/sys/mman.h (shm_open): Add prototype.
+	(shm_unlink): Ditto.
+
 2007-02-08  Christopher Faylor <me@cgf.cx>
 	    Corinna Vinschen  <corinna@vinschen.de>
 
diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din
index 9fc024eef..b641a8462 100644
--- a/winsup/cygwin/cygwin.din
+++ b/winsup/cygwin/cygwin.din
@@ -1314,6 +1314,8 @@ shmat SIGFE
 shmctl SIGFE
 shmdt SIGFE
 shmget SIGFE
+shm_open SIGFE
+shm_unlink SIGFE
 shutdown = cygwin_shutdown SIGFE
 sigaction SIGFE
 sigaddset SIGFE
diff --git a/winsup/cygwin/include/cygwin/version.h b/winsup/cygwin/include/cygwin/version.h
index d015fade0..8ed2f7dff 100644
--- a/winsup/cygwin/include/cygwin/version.h
+++ b/winsup/cygwin/include/cygwin/version.h
@@ -302,12 +302,13 @@ details. */
       162: New struct ifreq.  Export if_nametoindex, if_indextoname,
 	   if_nameindex, if_freenameindex.
       163: Export posix_madvise, posix_memalign.
+      164: Export shm_open, shm_unlink.
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 163
+#define CYGWIN_VERSION_API_MINOR 164
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible
diff --git a/winsup/cygwin/include/sys/mman.h b/winsup/cygwin/include/sys/mman.h
index a3c8077b0..234de8074 100644
--- a/winsup/cygwin/include/sys/mman.h
+++ b/winsup/cygwin/include/sys/mman.h
@@ -67,6 +67,9 @@ extern int munlock (const void *__addr, size_t __len);
 
 extern int posix_madvise (void *__addr, size_t __len, int __advice);
 
+extern int shm_open (const char *__name, int __oflag, mode_t __mode);
+extern int shm_unlink (const char *__name);
+
 #ifdef __cplusplus
 };
 #endif /* __cplusplus */
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 6a0e45fb5..998fe0ed4 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -3346,3 +3346,49 @@ pclose (FILE *fp)
 
   return status;
 }
+
+#define SHM_STORAGE "/dev/shm"
+
+extern "C" int
+shm_open (const char *name, int oflag, mode_t mode)
+{
+  /* Name must start with a single slash. */
+  if (!name || name[0] != '/' || name[1] == '/'
+      || strlen (name) > CYG_MAX_PATH - sizeof (SHM_STORAGE))
+    {
+      debug_printf ("Invalid shared memory object name '%s'", name);
+      set_errno (EINVAL);
+      return -1;
+    }
+  /* Check for valid flags. */
+  if (((oflag & O_ACCMODE) != O_RDONLY && (oflag & O_ACCMODE) != O_RDWR)
+      || (oflag & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC)))
+    {
+      debug_printf ("Invalid oflag 0%o", oflag);
+      set_errno (EINVAL);
+      return -1;
+    }
+  /* Note that we require the existance of /dev/shm here.  We don't
+     create this directory from here.  That's the task of the installer. */
+  char shmname[CYG_MAX_PATH];
+  strcpy (shmname, SHM_STORAGE);
+  strcat (shmname, name);
+  return open (shmname, oflag, mode & 0777);
+}
+
+extern "C" int
+shm_unlink (const char *name)
+{
+  /* Name must start with a single slash. */
+  if (!name || name[0] != '/' || name[1] == '/'
+      || strlen (name) > CYG_MAX_PATH - sizeof (SHM_STORAGE))
+    {
+      debug_printf ("Invalid shared memory object name '%s'", name);
+      set_errno (EINVAL);
+      return -1;
+    }
+  char shmname[CYG_MAX_PATH];
+  strcpy (shmname, SHM_STORAGE);
+  strcat (shmname, name);
+  return unlink (shmname);
+}
diff --git a/winsup/cygwin/sysconf.cc b/winsup/cygwin/sysconf.cc
index 04f03f78e..f1f5d391e 100644
--- a/winsup/cygwin/sysconf.cc
+++ b/winsup/cygwin/sysconf.cc
@@ -149,7 +149,7 @@ static struct
   {cons, {c:-1L}},			/*  28, _SC_PRIORITIZED_IO */
   {cons, {c:_POSIX_REALTIME_SIGNALS}},	/*  29, _SC_REALTIME_SIGNALS */
   {cons, {c:_POSIX_SEMAPHORES}},	/*  30, _SC_SEMAPHORES */
-  {cons, {c:-1L}},			/*  31, _SC_SHARED_MEMORY_OBJECTS */
+  {cons, {c:_POSIX_SHARED_MEMORY_OBJECTS}},	/*  31, _SC_SHARED_MEMORY_OBJECTS */
   {cons, {c:_POSIX_SYNCHRONIZED_IO}},	/*  32, _SC_SYNCHRONIZED_IO */
   {cons, {c:_POSIX_TIMERS}},		/*  33, _SC_TIMERS */
   {nsup, {c:0}},			/*  34, _SC_AIO_LISTIO_MAX */