Check DATASTART is less than DATAEND even assertions off

* dyn_load.c (GC_register_dynamic_libraries_dl_iterate_phdr):
Abort with the appropriate message if DATASTART is NULL or greater than
DATAEND (same for DATASTART2 and DATAEND2).
* os_dep.c (GC_init_linux_data_start, GC_register_data_segments):
Likewise.
* os_dep.c (GC_init_linux_data_start, GC_register_data_segments):
Remove assertion about DATASTART and DATAEND.
* os_dep.c (GC_init_linux_data_start): Code refactoring.

1 files changed, 9 insertions, 0 deletions

diff --git a/dyn_load.c b/dyn_load.c
index c8d051ab..0afdb86a 100644
--- a/dyn_load.c
+++ b/dyn_load.c
@@ -624,11 +624,20 @@ STATIC GC_bool GC_register_dynamic_libraries_dl_iterate_phdr(void)
 #     else
         dataend = DATAEND;
 #     endif
+      if (NULL == datastart || (word)datastart > (word)dataend)
+        ABORT_ARG2("Wrong DATASTART/END pair",
+                   ": %p .. %p", datastart, dataend);
 
       /* dl_iterate_phdr may forget the static data segment in  */
       /* statically linked executables.                         */
       GC_add_roots_inner(datastart, dataend, TRUE);
 #     if defined(DATASTART2)
+        if ((word)DATASTART2 - 1U >= (word)DATAEND2) {
+                        /* Subtract one to check also for NULL  */
+                        /* without a compiler warning.          */
+          ABORT_ARG2("Wrong DATASTART/END2 pair",
+                     ": %p .. %p", DATASTART2, DATAEND2);
+        }
         GC_add_roots_inner(DATASTART2, DATAEND2, TRUE);
 #     endif
   }