Index: Makefile
--- Makefile.orig	2004-07-19 07:19:55.000000000 +0200
+++ Makefile	2016-05-21 20:07:21.471525741 +0200
@@ -43,4 +43,11 @@
 #stacktraverse.c: gen.py
 #	./gen.py > stacktraverse.c
 
-.include <bsd.lib.mk>
+all: libexecinfo.a
+
+libexecinfo.a: stacktraverse.o execinfo.o
+	ar rc libexecinfo.a stacktraverse.o execinfo.o
+
+.c.o:
+	$(CC) $(CFLAGS) -c -o $@ $<
+
Index: execinfo.c
--- execinfo.c.orig	2004-07-19 07:21:09.000000000 +0200
+++ execinfo.c	2016-05-21 20:08:51.551634945 +0200
@@ -28,7 +28,13 @@
 
 #include <sys/types.h>
 #include <sys/uio.h>
+#if defined(__linux__)
+#define __USE_GNU 1
+#endif
 #include <dlfcn.h>
+#if defined(__linux__)
+#undef __USE_GNU
+#endif
 #include <math.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -69,7 +75,8 @@
 char **
 backtrace_symbols(void *const *buffer, int size)
 {
-    int i, clen, alen, offset;
+    size_t clen, alen;
+    int i, offset;
     char **rval;
     char *cp;
     Dl_info info;
@@ -78,7 +85,6 @@
     rval = malloc(clen);
     if (rval == NULL)
         return NULL;
-    (char **)cp = &(rval[size]);
     for (i = 0; i < size; i++) {
         if (dladdr(buffer[i], &info) != 0) {
             if (info.dli_sname == NULL)
@@ -92,14 +98,14 @@
                    2 +                      /* " <" */
                    strlen(info.dli_sname) + /* "function" */
                    1 +                      /* "+" */
-                   D10(offset) +            /* "offset */
+                   10 +                     /* "offset */
                    5 +                      /* "> at " */
                    strlen(info.dli_fname) + /* "filename" */
                    1;                       /* "\0" */
             rval = realloc_safe(rval, clen + alen);
             if (rval == NULL)
                 return NULL;
-            snprintf(cp, alen, "%p <%s+%d> at %s",
+            snprintf((char *) rval + clen, alen, "%p <%s+%d> at %s",
               buffer[i], info.dli_sname, offset, info.dli_fname);
         } else {
             alen = 2 +                      /* "0x" */
@@ -108,12 +114,15 @@
             rval = realloc_safe(rval, clen + alen);
             if (rval == NULL)
                 return NULL;
-            snprintf(cp, alen, "%p", buffer[i]);
+            snprintf((char *) rval + clen, alen, "%p", buffer[i]);
         }
-        rval[i] = cp;
-        cp += alen;
+        rval[i] = (char *) clen;
+        clen += alen;
     }
 
+    for (i = 0; i < size; i++)
+        rval[i] += (long) rval;
+
     return rval;
 }
 
@@ -155,6 +164,6 @@
                 return;
             snprintf(buf, len, "%p\n", buffer[i]);
         }
-        write(fd, buf, len - 1);
+        write(fd, buf, strlen(buf));
     }
 }