diff options
Diffstat (limited to 'hurd/hurdinit.c')
| -rw-r--r-- | hurd/hurdinit.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/hurd/hurdinit.c b/hurd/hurdinit.c index bed78b8321..e7558c3ef7 100644 --- a/hurd/hurdinit.c +++ b/hurd/hurdinit.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc. +/* Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -197,3 +197,27 @@ _hurd_setproc (process_t procserver) return 0; } + +#ifndef PIC + +/* Map the page at address zero with no access allowed, so + dereferencing NULL will fault and no "anywhere" allocations + (e.g. the out of line memory containing the argument strings) + can be assigned address zero, which C says is not a valid pointer. + + When dynamically linked, this will be done by the dynamic linker + before we run. */ + +static void map0 (void) __attribute__ ((unused)); +text_set_element (_hurd_preinit_hook, map0); + +static void +map0 (void) +{ + vm_address_t addr = 0; + __vm_map (__mach_task_self (), + &addr, __vm_page_size, 0, 0, MACH_PORT_NULL, 0, 1, + VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY); +} + +#endif |