diff options
Diffstat (limited to 'src/emacs.c')
| -rw-r--r-- | src/emacs.c | 65 |
1 files changed, 64 insertions, 1 deletions
diff --git a/src/emacs.c b/src/emacs.c index 6ecfdbd4231..bb601ea8643 100644 --- a/src/emacs.c +++ b/src/emacs.c @@ -67,6 +67,10 @@ Boston, MA 02111-1307, USA. */ #include <sys/resource.h> #endif +#ifdef HAVE_PERSONALITY_LINUX32 +#include <sys/personality.h> +#endif + #ifndef O_RDWR #define O_RDWR 2 #endif @@ -192,6 +196,17 @@ int display_arg; 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 */ @@ -733,7 +748,11 @@ malloc_initialize_hook () free (malloc_state_ptr); } else - malloc_using_checking = getenv ("MALLOC_CHECK_") != NULL; + { + if (my_heap_start == 0) + my_heap_start = sbrk (0); + malloc_using_checking = getenv ("MALLOC_CHECK_") != NULL; + } } void (*__malloc_initialize_hook) () = malloc_initialize_hook; @@ -809,6 +828,17 @@ main (argc, argv 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 @@ -852,6 +882,28 @@ main (argc, argv } } +#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)) @@ -2130,6 +2182,17 @@ You must run Emacs in batch mode in order to dump it. */) 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. */ |