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/* $OpenBSD: library.c,v 1.40 2005/05/23 19:22:11 drahn Exp $ */
/*
* Copyright (c) 2002 Dale Rahn
* Copyright (c) 1998 Per Fogelstrom, Opsycon AB
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#define _DYN_LOADER
#include <sys/types.h>
#include <sys/param.h>
#include <fcntl.h>
#include <sys/mman.h>
#include "syscall.h"
#include "archdep.h"
#include "resolve.h"
#define PFLAGS(X) ((((X) & PF_R) ? PROT_READ : 0) | \
(((X) & PF_W) ? PROT_WRITE : 0) | \
(((X) & PF_X) ? PROT_EXEC : 0))
void
_dl_load_list_free(struct load_list *load_list)
{
struct load_list *next;
while (load_list != NULL) {
next = load_list->next;
_dl_free(load_list);
load_list = next;
}
}
void
_dl_unload_shlib(elf_object_t *object)
{
if (object->refcount == 0) {
_dl_load_list_free(object->load_list);
_dl_munmap((void *)object->load_addr, object->load_size);
_dl_remove_object(object);
}
}
elf_object_t *
_dl_tryload_shlib(const char *libname, int type)
{
int libfile, i, align = _dl_pagesz - 1;
struct load_list *next_load, *load_list = NULL;
Elf_Addr maxva = 0, minva = 0x7fffffff; /* XXX Correct for 64bit? */
Elf_Addr libaddr, loff;
elf_object_t *object;
char hbuf[4096];
Elf_Dyn *dynp = 0;
Elf_Ehdr *ehdr;
Elf_Phdr *phdp;
struct stat sb;
#define ROUND_PG(x) (((x) + align) & ~(align))
#define TRUNC_PG(x) ((x) & ~(align))
object = _dl_lookup_object(libname);
if (object) {
object->refcount++;
return(object); /* Already loaded */
}
libfile = _dl_open(libname, O_RDONLY);
if (libfile < 0) {
_dl_errno = DL_CANT_OPEN;
return(0);
}
if ( _dl_fstat(libfile, &sb) < 0) {
_dl_errno = DL_CANT_OPEN;
return(0);
}
for (object = _dl_objects; object != NULL; object = object->next) {
if (object->dev == sb.st_dev &&
object->inode == sb.st_ino) {
_dl_close(libfile);
return(object);
}
}
_dl_read(libfile, hbuf, sizeof(hbuf));
ehdr = (Elf_Ehdr *)hbuf;
if (ehdr->e_ident[0] != ELFMAG0 || ehdr->e_ident[1] != ELFMAG1 ||
ehdr->e_ident[2] != ELFMAG2 || ehdr->e_ident[3] != ELFMAG3 ||
ehdr->e_type != ET_DYN || ehdr->e_machine != MACHID) {
_dl_close(libfile);
_dl_errno = DL_NOT_ELF;
return(0);
}
/*
* Alright, we might have a winner!
* Figure out how much VM space we need.
*/
phdp = (Elf_Phdr *)(hbuf + ehdr->e_phoff);
for (i = 0; i < ehdr->e_phnum; i++, phdp++) {
switch (phdp->p_type) {
case PT_LOAD:
if (phdp->p_vaddr < minva)
minva = phdp->p_vaddr;
if (phdp->p_vaddr + phdp->p_memsz > maxva)
maxva = phdp->p_vaddr + phdp->p_memsz;
break;
case PT_DYNAMIC:
dynp = (Elf_Dyn *)phdp->p_vaddr;
break;
default:
break;
}
}
minva = TRUNC_PG(minva);
maxva = ROUND_PG(maxva);
/*
* We map the entire area to see that we can get the VM
* space required. Map it unaccessible to start with.
*
* We must map the file we'll map later otherwise the VM
* system won't be able to align the mapping properly
* on VAC architectures.
*/
libaddr = (Elf_Addr)_dl_mmap(0, maxva - minva, PROT_NONE,
MAP_PRIVATE|MAP_FILE, libfile, 0);
if (_dl_check_error(libaddr)) {
_dl_printf("%s: rtld mmap failed mapping %s.\n",
_dl_progname, libname);
_dl_close(libfile);
_dl_errno = DL_CANT_MMAP;
return(0);
}
loff = libaddr - minva;
phdp = (Elf_Phdr *)(hbuf + ehdr->e_phoff);
for (i = 0; i < ehdr->e_phnum; i++, phdp++) {
if (phdp->p_type == PT_LOAD) {
char *start = (char *)(TRUNC_PG(phdp->p_vaddr)) + loff;
int off = (phdp->p_vaddr & align);
int size = off + phdp->p_filesz;
void *res;
res = _dl_mmap(start, ROUND_PG(size),
PFLAGS(phdp->p_flags),
MAP_FIXED|MAP_PRIVATE, libfile,
TRUNC_PG(phdp->p_offset));
next_load = _dl_malloc(sizeof(struct load_list));
next_load->next = load_list;
load_list = next_load;
next_load->start = start;
next_load->size = size;
next_load->prot = PFLAGS(phdp->p_flags);
if (_dl_check_error((long)res)) {
_dl_printf("%s: rtld mmap failed mapping %s.\n",
_dl_progname, libname);
_dl_close(libfile);
_dl_errno = DL_CANT_MMAP;
_dl_munmap((void *)libaddr, maxva - minva);
_dl_load_list_free(load_list);
return(0);
}
if (phdp->p_flags & PF_W) {
/* Zero out everything past the EOF */
if ((size & align) != 0)
_dl_memset(start + size, 0,
_dl_pagesz - (size & align));
if (ROUND_PG(size) ==
ROUND_PG(off + phdp->p_memsz))
continue;
start = start + ROUND_PG(size);
size = ROUND_PG(off + phdp->p_memsz) -
ROUND_PG(size);
res = _dl_mmap(start, size,
PFLAGS(phdp->p_flags),
MAP_FIXED|MAP_PRIVATE|MAP_ANON, -1, 0);
if (_dl_check_error((long)res)) {
_dl_printf("%s: rtld mmap failed mapping %s.\n",
_dl_progname, libname);
_dl_close(libfile);
_dl_errno = DL_CANT_MMAP;
_dl_munmap((void *)libaddr, maxva - minva);
_dl_load_list_free(load_list);
return(0);
}
}
}
}
_dl_close(libfile);
dynp = (Elf_Dyn *)((unsigned long)dynp + loff);
object = _dl_finalize_object(libname, dynp, 0, type, libaddr, loff);
if (object) {
object->load_size = maxva - minva; /*XXX*/
object->load_list = load_list;
/* set inode, dev from stat info */
object->dev = sb.st_dev;
object->inode = sb.st_ino;
} else {
/* XXX not possible. object cannot come back NULL */
_dl_munmap((void *)libaddr, maxva - minva);
_dl_load_list_free(load_list);
}
return(object);
}
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