[Emacs-diffs] Changes to emacs/src/emacs.c

[Jan Djärv]

Index: emacs/src/emacs.c
diff -c emacs/src/emacs.c:1.342 emacs/src/emacs.c:1.343
*** emacs/src/emacs.c:1.342     Thu Jun 24 20:24:52 2004
--- emacs/src/emacs.c   Wed Oct 20 16:23:30 2004
***************
*** 67,72 ****
--- 67,76 ----
  #include <sys/resource.h>
  #endif
  
+ #ifdef HAVE_PERSONALITY_LINUX32
+ #include <sys/personality.h>
+ #endif
+ 
  #ifndef O_RDWR
  #define O_RDWR 2
  #endif
***************
*** 192,197 ****
--- 196,212 ----
     Tells GC how to save a copy of the stack.  */
  char *stack_bottom;
  
+ /* The address where the heap starts (from the first sbrk (0) call).  */
+ static void *my_heap_start;
+ 
+ /* The gap between BSS end and heap start as far as we can tell.  */
+ static unsigned long heap_bss_diff;
+ 
+ /* If the gap between BSS end and heap start is larger than this we try to
+    work around it, and if that fails, output a warning in dump-emacs.  */
+ #define MAX_HEAP_BSS_DIFF (1024*1024)
+ 
+ 
  #ifdef HAVE_WINDOW_SYSTEM
  extern Lisp_Object Vwindow_system;
  #endif /* HAVE_WINDOW_SYSTEM */
***************
*** 733,739 ****
        free (malloc_state_ptr);
      }
    else
!     malloc_using_checking = getenv ("MALLOC_CHECK_") != NULL;
  }
  
  void (*__malloc_initialize_hook) () = malloc_initialize_hook;
--- 748,758 ----
        free (malloc_state_ptr);
      }
    else
!     {
!       if (my_heap_start == 0)
!         my_heap_start = sbrk (0);
!       malloc_using_checking = getenv ("MALLOC_CHECK_") != NULL;
!     }
  }
  
  void (*__malloc_initialize_hook) () = malloc_initialize_hook;
***************
*** 809,814 ****
--- 828,844 ----
    stack_base = &dummy;
  #endif
  
+   if (!initialized)
+     {
+       extern char my_endbss[];
+       extern char *my_endbss_static;
+ 
+       if (my_heap_start == 0)
+         my_heap_start = sbrk (0);
+ 
+       heap_bss_diff = (char *)my_heap_start - max (my_endbss, 
my_endbss_static);
+     }
+ 
  #ifdef LINUX_SBRK_BUG
    __sbrk (1);
  #endif
***************
*** 852,857 ****
--- 882,909 ----
        }
      }
  
+ #ifdef HAVE_PERSONALITY_LINUX32
+   /* See if there is a gap between the end of BSS and the heap.
+      In that case, set personality and exec ourself again.  */
+   if (!initialized
+       && (strcmp (argv[argc-1], "dump") == 0
+           || strcmp (argv[argc-1], "bootstrap") == 0)
+       && heap_bss_diff > MAX_HEAP_BSS_DIFF)
+     {
+       if (! getenv ("EMACS_HEAP_EXEC"))
+         {
+           /* Set this so we only do this once.  */
+           putenv("EMACS_HEAP_EXEC=true");
+           personality (PER_LINUX32);
+           execvp (argv[0], argv);
+ 
+           /* If the exec fails, try to dump anyway.  */
+           perror ("execvp");
+         }
+     }
+ #endif /* HAVE_PERSONALITY_LINUX32 */
+ 
+ 
  /* Map in shared memory, if we are using that.  */
  #ifdef HAVE_SHM
    if (argmatch (argv, argc, "-nl", "--no-shared-memory", 6, NULL, &skip_args))
***************
*** 2130,2135 ****
--- 2182,2198 ----
    if (! noninteractive)
      error ("Dumping Emacs works only in batch mode");
  
+   if (heap_bss_diff > MAX_HEAP_BSS_DIFF)
+     {
+       fprintf (stderr, 
"**************************************************\n");
+       fprintf (stderr, "Warning: Your system has a gap between BSS and 
the\n");
+       fprintf (stderr, "heap.  This usually means that exec-shield or\n");
+       fprintf (stderr, "something similar is in effect.  The dump may 
fail\n");
+       fprintf (stderr, "because of this.  See the section about 
exec-shield\n");
+       fprintf (stderr, "in etc/PROBLEMS for more information.\n");
+       fprintf (stderr, 
"**************************************************\n");
+     }
+ 
    /* Bind `command-line-processed' to nil before dumping,
       so that the dumped Emacs will process its command line
       and set up to work with X windows if appropriate.  */