This should get the linux port to work...

src/backend/port/dynloader/linux.c

@@ -0,0 +1,114 @@
+/*-------------------------------------------------------------------------
+ *
+ * dynloader.c--
+ *	  Dynamic Loader for Postgres for Linux, generated from those for
+ *	  Ultrix.
+ *
+ *	  You need to install the dld library on your Linux system!
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/backend/port/dynloader/linux.c,v 1.1 1997/12/20 02:36:17 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <stdio.h>
+#ifdef HAVE_DLD_H
+#include <dld.h>
+#endif
+#include "postgres.h"
+#include "port-protos.h"
+#include "utils/elog.h"
+#include "fmgr.h"
+
+extern char pg_pathname[];
+
+void	   *
+pg_dlopen(char *filename)
+{
+#ifndef HAVE_DLD_H
+	elog(WARN, "dynamic load not supported");
+	return (NULL);
+#else
+	static int	dl_initialized = 0;
+
+	/*
+	 * initializes the dynamic loader with the executable's pathname.
+	 * (only needs to do this the first time pg_dlopen is called.)
+	 */
+	if (!dl_initialized)
+	{
+		if (dld_init(dld_find_executable(pg_pathname)))
+		{
+			return NULL;
+		}
+
+		/*
+		 * if there are undefined symbols, we want dl to search from the
+		 * following libraries also.
+		 */
+		dl_initialized = 1;
+	}
+
+	/*
+	 * link the file, then check for undefined symbols!
+	 */
+	if (dld_link(filename))
+	{
+		return NULL;
+	}
+
+	/*
+	 * If undefined symbols: try to link with the C and math libraries!
+	 * This could be smarter, if the dynamic linker was able to handle
+	 * shared libs!
+	 */
+	if (dld_undefined_sym_count > 0)
+	{
+		if (dld_link("/usr/lib/libc.a"))
+		{
+			elog(NOTICE, "dld: Cannot link C library!");
+			return NULL;
+		}
+		if (dld_undefined_sym_count > 0)
+		{
+			if (dld_link("/usr/lib/libm.a"))
+			{
+				elog(NOTICE, "dld: Cannot link math library!");
+				return NULL;
+			}
+			if (dld_undefined_sym_count > 0)
+			{
+				int			count = dld_undefined_sym_count;
+				char	  **list = dld_list_undefined_sym();
+
+				/* list the undefined symbols, if any */
+				elog(NOTICE, "dld: Undefined:");
+				do
+				{
+					elog(NOTICE, "  %s", *list);
+					list++;
+					count--;
+				} while (count > 0);
+
+				dld_unlink_by_file(filename, 1);
+				return NULL;
+			}
+		}
+	}
+
+	return (void *) strdup(filename);
+#endif
+}
+
+char	   *
+pg_dlerror()
+{
+#ifndef HAVE_DLD_H
+	return ("dynaloader unspported");
+#else
+	return dld_strerror(dld_errno);
+#endif
+}

src/backend/port/dynloader/linux.h

@@ -0,0 +1,42 @@
+/*-------------------------------------------------------------------------
+ *
+ * port-protos.h--
+ *	  port-specific prototypes for SunOS 4
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: linux.h,v 1.1 1997/12/20 02:36:18 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PORT_PROTOS_H
+#define PORT_PROTOS_H
+
+#include "fmgr.h"				/* for func_ptr */
+#include "utils/dynamic_loader.h"
+#ifdef LINUX_ELF
+#include "dlfcn.h"
+#endif
+
+/* dynloader.c */
+
+#ifndef LINUX_ELF
+#ifndef HAVE_DLD_H
+#define pg_dlsym(handle, funcname)		(NULL)
+#define pg_dlclose(handle)			   ({})
+#else
+#define pg_dlsym(handle, funcname)		((func_ptr) dld_get_func((funcname)))
+#define pg_dlclose(handle)			   ({ dld_unlink_by_file(handle, 1); free(handle); })
+#endif
+#else
+/* #define		pg_dlopen(f)	dlopen(f, 1) */
+#define pg_dlopen(f)	dlopen(f, 2)
+#define pg_dlsym		dlsym
+#define pg_dlclose		dlclose
+#define pg_dlerror		dlerror
+#endif
+
+/* port.c */
+
+#endif							/* PORT_PROTOS_H */