diff -urw gc-7.2.orig/CMakeLists.txt gc-7.2/CMakeLists.txt
--- gc-7.2.orig/CMakeLists.txt	2012-08-09 15:25:12.000000000 -0500
+++ gc-7.2/CMakeLists.txt	2012-10-13 16:23:05.089626000 -0500
@@ -140,6 +140,11 @@
                 ADD_DEFINITIONS("-D_REENTRANT")
                 ADD_DEFINITIONS("-D_PTHREADS")
         ENDIF()
+        IF ( "HOST" MATCHES .*-.*-dragonfly.*)
+                ADD_DEFINITIONS("-DGC_DRAGONFLY_THREADS")
+                ADD_DEFINITIONS("-D_REENTRANT")
+                ADD_DEFINITIONS("-D_PTHREADS")
+        ENDIF()
         IF ( "HOST" MATCHES .*-.*-solaris.*)
                 ADD_DEFINITIONS("-DGC_SOLARIS_THREADS")
                 ADD_DEFINITIONS("-DTHREAD_LOCAL_ALLOC")
diff -urw gc-7.2.orig/configure gc-7.2/configure
--- gc-7.2.orig/configure	2012-08-09 15:25:12.000000000 -0500
+++ gc-7.2/configure	2012-10-13 16:20:05.062617000 -0500
@@ -5003,6 +5003,15 @@
 
         THREADDLLIBS="-lpthread -lrt"
         ;;
+     *-*-dragonfly*)
+        $as_echo "#define GC_DRAGONFLY_THREADS 1" >>confdefs.h
+
+        $as_echo "#define _REENTRANT 1" >>confdefs.h
+
+        $as_echo "#define _PTHREADS 1" >>confdefs.h
+
+        THREADDLLIBS="-lpthread -lrt"
+        ;;
      *-*-solaris*)
         $as_echo "#define GC_SOLARIS_THREADS 1" >>confdefs.h
 
diff -urw gc-7.2.orig/dyn_load.c gc-7.2/dyn_load.c
--- gc-7.2.orig/dyn_load.c	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/dyn_load.c	2012-10-13 16:16:10.960939000 -0500
@@ -83,6 +83,10 @@
 #   define ELFSIZE ARCH_ELFSIZE
 #endif
 
+#if defined(__DragonFly__)
+#   include <dlfcn.h>
+#endif
+
 #if defined(SCO_ELF) || defined(DGUX) || defined(HURD) \
     || (defined(__ELF__) && (defined(LINUX) || defined(FREEBSD) \
                              || defined(NETBSD) || defined(OPENBSD)))
@@ -405,6 +409,13 @@
 # define DL_ITERATE_PHDR_STRONG
 #endif
 
+#if defined(__DragonFly__)
+  /* On the DragonFlyBSD system, any target system at major version FIXME */
+  /* have dl_iterate_phdr; therefore, we need not make it weak as above. */
+# define HAVE_DL_ITERATE_PHDR
+# define DL_ITERATE_PHDR_STRONG
+#endif
+
 #if defined(HAVE_DL_ITERATE_PHDR)
 
 # ifdef PT_GNU_RELRO
@@ -646,7 +657,8 @@
         return(0);
     }
     if( cachedResult == 0 ) {
-#     if defined(NETBSD) && defined(RTLD_DI_LINKMAP)
+#     if (defined(NETBSD) && defined(RTLD_DI_LINKMAP)) \
+          || defined(__DragonFly__)
         struct link_map *lm = NULL;
         if (!dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &lm))
             cachedResult = lm;
diff -urw gc-7.2.orig/extra/threadlibs.c gc-7.2/extra/threadlibs.c
--- gc-7.2.orig/extra/threadlibs.c	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/extra/threadlibs.c	2012-10-13 16:23:32.885602000 -0500
@@ -49,7 +49,7 @@
           printf("-pthread\n");
 #       endif
 #   endif
-#   if defined(GC_NETBSD_THREADS)
+#   if defined(GC_NETBSD_THREADS) || defined(GC_DRAGONFLY_THREADS)
           printf("-lpthread -lrt\n");
 #   endif
 
diff -urw gc-7.2.orig/include/gc_config_macros.h gc-7.2/include/gc_config_macros.h
--- gc-7.2.orig/include/gc_config_macros.h	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/include/gc_config_macros.h	2012-10-13 16:30:50.679991000 -0500
@@ -67,8 +67,9 @@
     || defined(GC_GNU_THREADS) || defined(GC_HPUX_THREADS) \
     || defined(GC_IRIX_THREADS) || defined(GC_LINUX_THREADS) \
     || defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS) \
-    || defined(GC_OSF1_THREADS) || defined(GC_SOLARIS_THREADS) \
-    || defined(GC_WIN32_THREADS) || defined(GC_RTEMS_PTHREADS)
+    || defined(GC_DRAGONFLY_THREADS) || defined(GC_OSF1_THREADS) \
+    || defined(GC_SOLARIS_THREADS) || defined(GC_WIN32_THREADS) \
+    || defined(GC_RTEMS_PTHREADS)
 # ifndef GC_THREADS
 #   define GC_THREADS
 # endif
@@ -99,8 +100,10 @@
        && !defined(GC_OSF1_THREADS) && !defined(GC_IRIX_THREADS)
     /* FIXME: Should we really need for FreeBSD and NetBSD to check     */
     /* that no other GC_xxx_THREADS macro is set?                       */
-#   if defined(__FreeBSD__) || defined(__DragonFly__)
+#   if defined(__FreeBSD__)
 #     define GC_FREEBSD_THREADS
+#   elif defined(__DragonFly__)
+#     define GC_DRAGONFLY_THREADS
 #   elif defined(__NetBSD__)
 #     define GC_NETBSD_THREADS
 #   endif
@@ -131,7 +134,8 @@
 # define GC_PTHREADS
 #endif
 
-#if !defined(_PTHREADS) && defined(GC_NETBSD_THREADS)
+#if !defined(_PTHREADS) \
+    && (defined(GC_NETBSD_THREADS) || defined(GC_DRAGONFLY_THREADS))
 # define _PTHREADS
 #endif
 
diff -urw gc-7.2.orig/include/private/config.h.in gc-7.2/include/private/config.h.in
--- gc-7.2.orig/include/private/config.h.in	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/include/private/config.h.in	2012-10-13 16:29:14.313420000 -0500
@@ -63,6 +63,9 @@
 /* Define to support NetBSD pthreads. */
 #undef GC_NETBSD_THREADS
 
+/* Define to support DragonFly pthreads. */
+#undef GC_DRAGONFLY_THREADS
+
 /* Define to support OpenBSD pthreads. */
 #undef GC_OPENBSD_THREADS
 
diff -urw gc-7.2.orig/include/private/gcconfig.h gc-7.2/include/private/gcconfig.h
--- gc-7.2.orig/include/private/gcconfig.h	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/include/private/gcconfig.h	2012-10-13 16:30:15.411245000 -0500
@@ -2549,6 +2549,9 @@
 #if defined(GC_NETBSD_THREADS) && !defined(NETBSD)
 # error --> inconsistent configuration
 #endif
+#if defined(GC_DRAGONFLY_THREADS) && !defined(__DragonFly__)
+# error --> inconsistent configuration
+#endif
 #if defined(GC_FREEBSD_THREADS) && !defined(FREEBSD)
 # error --> inconsistent configuration
 #endif
diff -urw gc-7.2.orig/include/private/thread_local_alloc.h gc-7.2/include/private/thread_local_alloc.h
--- gc-7.2.orig/include/private/thread_local_alloc.h	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/include/private/thread_local_alloc.h	2012-10-13 16:29:39.672517000 -0500
@@ -47,7 +47,8 @@
 #   define USE_COMPILER_TLS
 # elif defined(GC_DGUX386_THREADS) || defined(GC_OSF1_THREADS) \
        || defined(GC_DARWIN_THREADS) || defined(GC_AIX_THREADS) \
-       || defined(GC_NETBSD_THREADS) || defined(GC_RTEMS_PTHREADS)
+       || defined(GC_NETBSD_THREADS) || defined(GC_DRAGONFLY_THREADS) \
+       || defined(GC_RTEMS_PTHREADS)
 #   define USE_PTHREAD_SPECIFIC
 # elif defined(GC_HPUX_THREADS)
 #   ifdef __GNUC__
diff -urw gc-7.2.orig/pthread_stop_world.c gc-7.2/pthread_stop_world.c
--- gc-7.2.orig/pthread_stop_world.c	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/pthread_stop_world.c	2012-10-13 16:23:51.004956000 -0500
@@ -130,7 +130,7 @@
 
 #ifndef SIG_THR_RESTART
 #  if defined(GC_HPUX_THREADS) || defined(GC_OSF1_THREADS) \
-      || defined(GC_NETBSD_THREADS)
+      || defined(GC_NETBSD_THREADS) || defined(GC_DRAGONFLY_THREADS)
 #    ifdef _SIGRTMIN
 #      define SIG_THR_RESTART _SIGRTMIN + 5
 #    else
diff -urw gc-7.2.orig/pthread_support.c gc-7.2/pthread_support.c
--- gc-7.2.orig/pthread_support.c	2012-08-09 15:25:13.000000000 -0500
+++ gc-7.2/pthread_support.c	2012-10-13 16:22:07.768255000 -0500
@@ -73,7 +73,8 @@
 # include <sys/sysctl.h>
 #endif /* GC_DARWIN_THREADS */
 
-#if defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS)
+#if defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS) \
+    || defined(GC_DRAGONFLY_THREADS)
 # include <sys/param.h>
 # include <sys/sysctl.h>
 #endif /* GC_NETBSD_THREADS */
@@ -917,7 +918,8 @@
 #endif /* GC_DGUX386_THREADS */
 
 #if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS) \
-    || defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS)
+    || defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS) \
+    || defined(GC_DRAGONFLY_THREADS)
   static int get_ncpu(void)
   {
     int mib[] = {CTL_HW,HW_NCPU};
@@ -1006,7 +1008,8 @@
       GC_nprocs = sysconf(_SC_NPROC_ONLN);
       if (GC_nprocs <= 0) GC_nprocs = 1;
 #   elif defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS) \
-         || defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS)
+         || defined(GC_NETBSD_THREADS) || defined(GC_OPENBSD_THREADS) \
+         || defined(GC_DRAGONFLY_THREADS)
       GC_nprocs = get_ncpu();
 #   elif defined(GC_LINUX_THREADS) || defined(GC_DGUX386_THREADS)
       GC_nprocs = GC_get_nprocs();