Fix assertion violation in register_dynlib_callback on Android

(a cherry-pick of commit 3cbd5ec35 from 'release-7_4')

* dyn_load.c [HAVE_DL_ITERATE_PHDR && PT_GNU_RELRO]
(GC_register_dynlib_callback): Round load_segs[j].end up to nearest
page boundary in the assertion; add comment.

1 files changed, 5 insertions, 1 deletions

diff --git a/dyn_load.c b/dyn_load.c
index 707ff766..a994d05d 100644
--- a/dyn_load.c
+++ b/dyn_load.c
@@ -467,11 +467,15 @@ STATIC int GC_register_dynlib_callback(struct dl_phdr_info * info,
                 if (load_segs[j].start2 != 0) {
                   WARN("More than one GNU_RELRO segment per load seg\n",0);
                 } else {
-                  GC_ASSERT(end <= load_segs[j].end);
+                  GC_ASSERT((word)end <=
+                            (((word)load_segs[j].end + GC_page_size - 1) &
+                             ~(GC_page_size - 1)));
                   /* Remove from the existing load segment */
                   load_segs[j].end2 = load_segs[j].end;
                   load_segs[j].end = start;
                   load_segs[j].start2 = end;
+                  /* Note that start2 may be greater than end2 because of   */
+                  /* p->p_memsz value multiple of page size.                */
                 }
                 break;
               }