Fix infinite restarting of mark_some when a static root disappeared (Linux)

Issue #218 (bdwgc).

* dyn_load.c [USE_PROC_FOR_LIBRARIES] (GC_register_map_entries): Call
GC_remove_roots_subregion for each region which has prot starting
with "---"; add comment.
* include/private/gc_priv.h [USE_PROC_FOR_LIBRARIES]
(GC_remove_roots_subregion): Declare function.
* mark_rts.c[USE_PROC_FOR_LIBRARIES] (GC_remove_roots_subregion):
Implement.

1 files changed, 4 insertions, 0 deletions

diff --git a/dyn_load.c b/dyn_load.c
index 4072751e..6692321c 100644
--- a/dyn_load.c
+++ b/dyn_load.c
@@ -389,6 +389,10 @@ STATIC void GC_register_map_entries(char *maps)
               }
               if ((word)start < (word)end)
                   GC_add_roots_inner(start, end, TRUE);
+        } else if (prot[0] == '-' && prot[1] == '-' && prot[2] == '-') {
+            /* Even roots added statically might disappear partially    */
+            /* (e.g. the roots added by INCLUDE_LINUX_THREAD_DESCR).    */
+            GC_remove_roots_subregion(start, end);
         }
     }
 }