3 files changed, 24 insertions, 0 deletions

diff --git a/libexec/rtld-elf/map_object.c b/libexec/rtld-elf/map_object.c
index 33fb9a6053dc..2b1ef24c70aa 100644
--- a/libexec/rtld-elf/map_object.c
+++ b/libexec/rtld-elf/map_object.c
@@ -305,6 +305,9 @@ obj_free(Obj_Entry *obj)
 {
     Objlist_Entry *elm;
 
+    if (obj->tls_done) {
+	free_tls_offset(obj);
+    }
     free(obj->path);
     while (obj->needed != NULL) {
 	Needed_Entry *needed = obj->needed;
diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 29b94731a8a6..fbcf675ec9ef 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -2772,6 +2772,26 @@ allocate_tls_offset(Obj_Entry *obj)
     return true;
 }
 
+void
+free_tls_offset(Obj_Entry *obj)
+{
+#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
+    defined(__arm__)
+    /*
+     * If we were the last thing to allocate out of the static TLS
+     * block, we give our space back to the 'allocator'. This is a
+     * simplistic workaround to allow libGL.so.1 to be loaded and
+     * unloaded multiple times. We only handle the Variant II
+     * mechanism for now - this really needs a proper allocator.  
+     */
+    if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
+	== calculate_tls_end(tls_last_offset, tls_last_size)) {
+	tls_last_offset -= obj->tlssize;
+	tls_last_size = 0;
+    }
+#endif
+}
+
 void *
 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
 {
diff --git a/libexec/rtld-elf/rtld.h b/libexec/rtld-elf/rtld.h
index 69964d62b675..bee36aff1e70 100644
--- a/libexec/rtld-elf/rtld.h
+++ b/libexec/rtld-elf/rtld.h
@@ -238,6 +238,7 @@ void *allocate_tls(Obj_Entry *, void *, size_t, size_t);
 void free_tls(void *, size_t, size_t);
 void *allocate_module_tls(int index);
 bool allocate_tls_offset(Obj_Entry *obj);
+void free_tls_offset(Obj_Entry *obj);
 
 /*
  * MD function declarations.