Fix overlapping region assertion in mark_some if malloc redirect on Linux

* alloc.c [SET_REAL_HEAP_BOUNDS && INCLUDE_LINUX_THREAD_DESCR]
(GC_add_to_heap): If endp is greater than GC_greatest_real_heap_addr
then add [p,endp) region to the data roots exclusions; add comment.
* include/private/gc_priv.h [INCLUDE_LINUX_THREAD_DESCR]
(SET_REAL_HEAP_BOUNDS, GC_least_real_heap_addr,
GC_greatest_real_heap_addr): Define.

1 files changed, 6 insertions, 1 deletions

diff --git a/alloc.c b/alloc.c
index ef20d426..abd5d228 100644
--- a/alloc.c
+++ b/alloc.c
@@ -1438,8 +1438,13 @@ STATIC void GC_add_to_heap(struct hblk *p, size_t bytes)
       if ((word)p < GC_least_real_heap_addr
           || EXPECT(0 == GC_least_real_heap_addr, FALSE))
         GC_least_real_heap_addr = (word)p - sizeof(word);
-      if (endp > GC_greatest_real_heap_addr)
+      if (endp > GC_greatest_real_heap_addr) {
+#       ifdef INCLUDE_LINUX_THREAD_DESCR
+          /* Avoid heap intersection with the static data roots. */
+          GC_exclude_static_roots_inner((void *)p, (void *)endp);
+#       endif
         GC_greatest_real_heap_addr = endp;
+      }
 #   endif
     if (EXPECT(old_capacity > 0, FALSE)) {
 #     ifndef GWW_VDB