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/* Function to wire down text and data (including from shared libraries)
Copyright (C) 1996 Free Software Foundation, Inc.
Written by Michael I. Bushnell, p/BSG.
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
The GNU Hurd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include <link.h>
#include <mach.h>
#include <hurd.h>
/* Find the list of shared objects */
static struct link_map *
loaded (void)
{
Elf32_Dyn *d;
for (d = _DYNAMIC; d->d_tag != DT_NULL; ++d)
if (d->d_tag == DT_DEBUG)
{
struct r_debug *r = (void *) d->d_un.d_ptr;
return r->r_map;
}
return 0; /* ld broken */
}
/* Compute the extent of a particular shared object. */
static Elf32_Addr
map_extent (struct link_map *map)
{
/* Find the last load cmd; they are in ascending p_vaddr order. */
Elf32_Word n = map->l_phnum;
while (n-- > 0 && map->l_phdr[n].p_type != PT_LOAD);
return map->l_phdr[n].p_vaddr + map->l_phdr[n].p_filesz;
}
/* Wire down all memory currently allocated at START for LEN bytes;
host_priv is the privileged host port. */
static void
wire_segment_internal (vm_address_t start,
vm_size_t len,
host_priv_t host_priv)
{
vm_address_t addr;
vm_size_t size;
vm_prot_t protection;
vm_prot_t max_protection;
vm_inherit_t inheritance;
boolean_t shared;
mach_port_t object_name;
vm_offset_t offset;
error_t err;
volatile char *poke;
do
{
addr = start;
err = vm_region (mach_task_self (), &addr, &size, &protection,
&max_protection, &inheritance, &shared, &object_name,
&offset);
if (err)
return;
/* The current region begins at ADDR and is SIZE long. If it
extends beyond the LEN, prune it. */
if (addr + size > start + len)
size = len - (addr - start);
/* Set protection to allow all access possible */
vm_protect (mach_task_self (), addr, size, 0, max_protection);
/* Generate write faults */
for (poke = (char *) addr;
(vm_address_t) poke < addr + size;
poke += vm_page_size)
*poke = *poke;
/* Wire pages */
vm_wire (host_priv, mach_task_self (), addr, size, max_protection);
/* Set protection back to what it was */
vm_protect (mach_task_self (), addr, size, 0, protection);
mach_port_deallocate (mach_task_self (), object_name);
len -= (addr - start) + size;
start = addr + size;
}
while (len);
}
/* Wire down all memory currently allocated at START for LEN bytes. */
void
wire_segment (vm_address_t start,
vm_size_t len)
{
mach_port_t host, device;
error_t error;
error = get_privileged_ports (&host, &device);
if (!error)
{
wire_segment_internal (start, len, host);
mach_port_deallocate (mach_task_self (), host);
mach_port_deallocate (mach_task_self (), device);
}
}
/* Wire down all the text and data (including from shared libraries)
for the current program. */
void
wire_task_self ()
{
struct link_map *map;
mach_port_t host, device;
error_t error;
extern char _edata, _etext, __data_start;
error = get_privileged_ports (&host, &device);
if (error)
return;
map = loaded ();
if (!map)
{
extern void _start ();
vm_address_t text_start = (vm_address_t) &_start;
wire_segment_internal (text_start,
(vm_size_t) (&_etext - text_start),
host);
wire_segment_internal ((vm_address_t) &__data_start,
(vm_size_t) (&_edata - &__data_start),
host);
}
else
while (map)
wire_segment ((vm_address_t) map->l_addr, map_extent (map));
mach_port_deallocate (mach_task_self (), host);
mach_port_deallocate (mach_task_self (), device);
}
asm (".weak _start"); /* XXX hack to avoid recompilation. */
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