freebsd-dev/gnu/usr.bin/ld/i386/md.c
Nate Williams c79eac4c4c Weak symbol support from NetBSD. This should bring us in sync with the
NetBSD ld code except for local changes for dlopen() and friends and
the hashing on the minor value of the shlibs.  We should be binary
compatible now with all their libraries.

Obtained from: NetBSD
1995-03-04 17:49:20 +00:00

361 lines
7.5 KiB
C

/*
* Copyright (c) 1993 Paul Kranenburg
* 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 Paul Kranenburg.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* 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.
*
* $Id: md.c,v 1.11 1994/12/23 22:31:12 nate Exp $
*/
#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <err.h>
#include <fcntl.h>
#include <a.out.h>
#include <stab.h>
#include <string.h>
#include "ld.h"
/*
* Get relocation addend corresponding to relocation record RP
* from address ADDR
*/
long
md_get_addend(rp, addr)
struct relocation_info *rp;
unsigned char *addr;
{
switch (RELOC_TARGET_SIZE(rp)) {
case 0:
return get_byte(addr);
case 1:
return get_short(addr);
case 2:
return get_long(addr);
default:
errx(1, "Unsupported relocation size: %x",
RELOC_TARGET_SIZE(rp));
}
}
/*
* Put RELOCATION at ADDR according to relocation record RP.
*/
void
md_relocate(rp, relocation, addr, relocatable_output)
struct relocation_info *rp;
long relocation;
unsigned char *addr;
int relocatable_output;
{
switch (RELOC_TARGET_SIZE(rp)) {
case 0:
put_byte(addr, relocation);
break;
case 1:
put_short(addr, relocation);
break;
case 2:
put_long(addr, relocation);
break;
default:
errx(1, "Unsupported relocation size: %x",
RELOC_TARGET_SIZE(rp));
}
}
/*
* Machine dependent part of claim_rrs_reloc().
* Set RRS relocation type.
*/
int
md_make_reloc(rp, r, type)
struct relocation_info *rp, *r;
int type;
{
/* Relocation size */
r->r_length = rp->r_length;
if (RELOC_PCREL_P(rp))
r->r_pcrel = 1;
if (type & RELTYPE_RELATIVE)
r->r_relative = 1;
if (type & RELTYPE_COPY)
r->r_copy = 1;
return 0;
}
/*
* Set up a transfer from jmpslot at OFFSET (relative to the PLT table)
* to the binder slot (which is at offset 0 of the PLT).
*/
void
md_make_jmpslot(sp, offset, index)
jmpslot_t *sp;
long offset;
long index;
{
/*
* i386 PC-relative "fixed point" is located right after the
* instruction it pertains to.
*/
u_long fudge = - (sizeof(sp->opcode) + sizeof(sp->addr) + offset);
sp->opcode = CALL;
#if 0
sp->addr = fudge;
#else
sp->addr[0] = fudge & 0xffff;
sp->addr[1] = fudge >> 16;
#endif
sp->reloc_index = index;
}
/*
* Set up a "direct" transfer (ie. not through the run-time binder) from
* jmpslot at OFFSET to ADDR. Used by `ld' when the SYMBOLIC flag is on,
* and by `ld.so' after resolving the symbol.
* On the i386, we use the JMP instruction which is PC relative, so no
* further RRS relocations will be necessary for such a jmpslot.
*/
void
md_fix_jmpslot(sp, offset, addr)
jmpslot_t *sp;
long offset;
u_long addr;
{
u_long fudge = addr - (sizeof(sp->opcode) + sizeof(sp->addr) + offset);
sp->opcode = JUMP;
#if 0
sp->addr = fudge;
#else
sp->addr[0] = fudge & 0xffff;
sp->addr[1] = fudge >> 16;
#endif
sp->reloc_index = 0;
}
/*
* Update the relocation record for a RRS jmpslot.
*/
void
md_make_jmpreloc(rp, r, type)
struct relocation_info *rp, *r;
int type;
{
jmpslot_t *sp;
/*
* Fix relocation address to point to the correct
* location within this jmpslot.
*/
r->r_address += sizeof(sp->opcode);
/* Relocation size */
r->r_length = 2;
/* Set relocation type */
r->r_jmptable = 1;
if (type & RELTYPE_RELATIVE)
r->r_relative = 1;
}
/*
* Set relocation type for a RRS GOT relocation.
*/
void
md_make_gotreloc(rp, r, type)
struct relocation_info *rp, *r;
int type;
{
r->r_baserel = 1;
if (type & RELTYPE_RELATIVE)
r->r_relative = 1;
/* Relocation size */
r->r_length = 2;
}
/*
* Set relocation type for a RRS copy operation.
*/
void
md_make_cpyreloc(rp, r)
struct relocation_info *rp, *r;
{
/* Relocation size */
r->r_length = 2;
r->r_copy = 1;
}
void
md_set_breakpoint(where, savep)
long where;
long *savep;
{
*savep = *(long *)where;
*(char *)where = TRAP;
}
#ifndef RTLD
#ifdef __FreeBSD__
int netzmagic;
#endif
/*
* Initialize (output) exec header such that useful values are
* obtained from subsequent N_*() macro evaluations.
*/
void
md_init_header(hp, magic, flags)
struct exec *hp;
int magic, flags;
{
#ifdef NetBSD
if (oldmagic || magic == QMAGIC)
hp->a_midmag = magic;
else
N_SETMAGIC((*hp), magic, MID_I386, flags);
#endif
#ifdef __FreeBSD__
if (oldmagic)
hp->a_midmag = magic;
else if (netzmagic)
N_SETMAGIC_NET((*hp), magic, MID_I386, flags);
else
N_SETMAGIC((*hp), magic, MID_I386, flags);
#endif
/* TEXT_START depends on the value of outheader.a_entry. */
if (!(link_mode & SHAREABLE))
hp->a_entry = PAGSIZ;
}
#endif /* RTLD */
#ifdef NEED_SWAP
/*
* Byte swap routines for cross-linking.
*/
void
md_swapin_exec_hdr(h)
struct exec *h;
{
int skip = 0;
if (!N_BADMAG(*h))
skip = 1;
swap_longs((long *)h + skip, sizeof(*h)/sizeof(long) - skip);
}
void
md_swapout_exec_hdr(h)
struct exec *h;
{
/* NetBSD: Always leave magic alone */
int skip = 1;
#if 0
if (N_GETMAGIC(*h) == OMAGIC)
skip = 0;
#endif
swap_longs((long *)h + skip, sizeof(*h)/sizeof(long) - skip);
}
void
md_swapin_reloc(r, n)
struct relocation_info *r;
int n;
{
int bits;
for (; n; n--, r++) {
r->r_address = md_swap_long(r->r_address);
bits = ((int *)r)[1];
r->r_symbolnum = md_swap_long(bits) & 0x00ffffff;
r->r_pcrel = (bits & 1);
r->r_length = (bits >> 1) & 3;
r->r_extern = (bits >> 3) & 1;
r->r_baserel = (bits >> 4) & 1;
r->r_jmptable = (bits >> 5) & 1;
r->r_relative = (bits >> 6) & 1;
#ifdef N_SIZE
r->r_copy = (bits >> 7) & 1;
#endif
}
}
void
md_swapout_reloc(r, n)
struct relocation_info *r;
int n;
{
int bits;
for (; n; n--, r++) {
r->r_address = md_swap_long(r->r_address);
bits = md_swap_long(r->r_symbolnum) & 0xffffff00;
bits |= (r->r_pcrel & 1);
bits |= (r->r_length & 3) << 1;
bits |= (r->r_extern & 1) << 3;
bits |= (r->r_baserel & 1) << 4;
bits |= (r->r_jmptable & 1) << 5;
bits |= (r->r_relative & 1) << 6;
#ifdef N_SIZE
bits |= (r->r_copy & 1) << 7;
#endif
((int *)r)[1] = bits;
}
}
void
md_swapout_jmpslot(j, n)
jmpslot_t *j;
int n;
{
for (; n; n--, j++) {
j->opcode = md_swap_short(j->opcode);
j->addr[0] = md_swap_short(j->addr[0]);
j->addr[1] = md_swap_short(j->addr[1]);
j->reloc_index = md_swap_short(j->reloc_index);
}
}
#endif /* NEED_SWAP */