NetBSD-5.0.2/sbin/modload/a.out.c
/* $NetBSD: a.out.c,v 1.6 2005/02/06 06:17:36 perry Exp $ */
/*
* Copyright (c) 1993 Terrence R. Lambert.
* All rights reserved.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Terrence R. Lambert.
* 4. The name Terrence R. Lambert may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``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 TERRENCE R. LAMBERT 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: a.out.c,v 1.6 2005/02/06 06:17:36 perry Exp $");
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/lkm.h>
#include <a.out.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include "modload.h"
/*
* Expected linker options:
*
* -A executable to link against
* -e entry point
* -o output file
* -T address to link to in hex (assumes it's a page boundry)
* <target> object file
*/
#define LINKCMD "ld -A %s -e _%s -o %s -T %p %s"
void
a_out_linkcmd(char **cmdp,
const char *kernel,
const char *entry,
const char *outfile,
const void *address,
const char *object,
const char *ldscript) /* XXX ignored on a.out */
{
asprintf(cmdp, LINKCMD, kernel, entry, outfile, address, object);
}
static int
a_out_read_header(int fd, struct exec *info_buf)
{
ssize_t n;
n = read(fd, info_buf, sizeof(*info_buf));
if (n < 0)
err(1, "failed reading %lu bytes", (u_long)sizeof(*info_buf));
if (n != sizeof(*info_buf)) {
if (debug)
fprintf(stderr, "failed to read %lu bytes",
(u_long)sizeof(*info_buf));
return -1;
}
/*
* Magic number...
*/
if (N_BADMAG(*info_buf))
errx(4, "not an a.out format file");
return 0;
}
int
a_out_mod_sizes(int fd,
size_t *modsize,
int *strtablen,
struct lmc_resrv *resrvp,
struct stat * sp)
{
struct exec info_buf;
if (a_out_read_header(fd, &info_buf) < 0)
return -1;
/*
* Calculate the size of the module
*/
*modsize = info_buf.a_text + info_buf.a_data + info_buf.a_bss;
*strtablen = sp->st_size - N_STROFF(info_buf);
if (symtab) {
/*
* XXX TODO: grovel through symbol table looking for
* just the symbol table stuff from the new module,
* and skip the stuff from the kernel.
*/
resrvp->sym_size = info_buf.a_syms + *strtablen;
resrvp->sym_symsize = info_buf.a_syms;
} else
resrvp->sym_size = resrvp->sym_symsize = 0;
return (0);
}
void *
a_out_mod_load(int fd)
{
struct exec info_buf;
size_t b;
ssize_t n;
char buf[10 * BUFSIZ];
/*
* Get the load module post load size... do this by reading the
* header and doing page counts.
*/
if (a_out_read_header(fd, &info_buf) < 0)
return NULL;
/*
* Seek to the text offset to start loading...
*/
if (lseek(fd, N_TXTOFF(info_buf), 0) == -1)
err(12, "lseek");
/*
* Transfer the relinked module to kernel memory in chunks of
* MODIOBUF size at a time.
*/
b = info_buf.a_text + info_buf.a_data;
while (b) {
n = read(fd, buf, MIN(b, sizeof(buf)));
if (n < 0)
err(1, "while reading from prelinked module");
if (n == 0)
errx(1, "EOF while reading from prelinked module");
loadbuf(buf, n);
b -= n;
}
return (void *)info_buf.a_entry;
}
void
a_out_mod_symload(int strtablen)
{
struct exec info_buf;
struct lmc_loadbuf ldbuf;
struct nlist *nlp;
char buf[10 * BUFSIZ];
char *symbuf;
int bytesleft, sz;
int numsyms; /* XXX unused? */
if (a_out_read_header(modfd, &info_buf) < 0)
return;
/*
* Seek to the symbol table to start loading it...
*/
if (lseek(modfd, N_SYMOFF(info_buf), SEEK_SET) == -1)
err(12, "lseek");
/*
* Transfer the symbol table entries. First, read them all in,
* then adjust their string table pointers, then
* copy in bulk. Then copy the string table itself.
*/
symbuf = malloc(info_buf.a_syms);
if (symbuf == 0)
err(13, "malloc");
if (read(modfd, symbuf, info_buf.a_syms) != info_buf.a_syms)
err(14, "read");
numsyms = info_buf.a_syms / sizeof(struct nlist);
for (nlp = (struct nlist *)symbuf;
(char *)nlp < symbuf + info_buf.a_syms; nlp++) {
int strx;
strx = nlp->n_un.n_strx;
if (strx != 0) {
/*
* If a valid name, set the name ptr to point at the
* loaded address for the string in the string table.
*/
if (strx > strtablen)
nlp->n_un.n_name = 0;
else
nlp->n_un.n_name = (char *)(strx +
resrv.sym_addr + info_buf.a_syms);
}
}
/*
* we've fixed the symbol table entries, now load them
*/
for (bytesleft = info_buf.a_syms; bytesleft > 0; bytesleft -= sz) {
sz = MIN(bytesleft, MODIOBUF);
ldbuf.cnt = sz;
ldbuf.data = symbuf;
if (ioctl(devfd, LMLOADSYMS, &ldbuf) == -1)
err(11, "error transferring sym buffer");
symbuf += sz;
}
free(symbuf - info_buf.a_syms);
/* and now read the string table and load it. */
for (bytesleft = strtablen; bytesleft > 0; bytesleft -= sz) {
sz = MIN(bytesleft, MODIOBUF);
read(modfd, buf, sz);
ldbuf.cnt = sz;
ldbuf.data = buf;
if (ioctl(devfd, LMLOADSYMS, &ldbuf) == -1)
err(11, "error transferring stringtable buffer");
}
}