librtld/i386/_relocate.c

	_relocate.c revision 5aefb6555731130ca4fd295960123d71f2d21fe8
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe/*
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * CDDL HEADER START
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe *
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * The contents of this file are subject to the terms of the
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * Common Development and Distribution License (the "License").
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * You may not use this file except in compliance with the License.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe *
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * or http://www.opensolaris.org/os/licensing.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * See the License for the specific language governing permissions
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * and limitations under the License.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe *
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe *
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * CDDL HEADER END
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe */
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe/*
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * Use is subject to license terms.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe */
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#pragma ident   "%Z%%M% %I% %E% SMI"
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#include    <string.h>
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#include    "machdep.h"
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#include    "reloc.h"
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#include    "_librtld.h"
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe#include    "_elf.h"
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe/*
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * Undo relocations that have been applied to a memory image.  Basically this
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * involves copying the original files relocation offset into the new image
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * being created.
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe */
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowevoid
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Loweundo_reloc(void *vrel, uchar_t *oaddr, uchar_t *iaddr, Reloc *reloc)
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe{
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    Rel *rel = vrel;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    /* LINTED */
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    ulong_t *_oaddr = (ulong_t *)oaddr;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    /* LINTED */
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    ulong_t *_iaddr = (ulong_t *)iaddr;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    switch (ELF_R_TYPE(rel->r_info)) {
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    case R_386_NONE:
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        break;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    case R_386_COPY:
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        (void) memset((void *)oaddr, 0, (size_t)reloc->r_size);
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        break;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    case R_386_JMP_SLOT:
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        if (_iaddr)
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe            *_oaddr = *_iaddr + reloc->r_value;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        else
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe            *_oaddr = reloc->r_value;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        break;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    default:
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        if (_iaddr)
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe            *_oaddr = *_iaddr;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        else
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe            *_oaddr = 0;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe        break;
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe    }
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe}
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe/*
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * Copy a relocation record and increment its value.  The record must reflect
d2a70789f056fc6c9ce3ab047b52126d80b0e3daRichard Lowe * the new address to which this image is fixed.  Note that .got entries
 * associated with .plt's must be fixed to the new base address.
 */
void
inc_reloc(void *vnrel, void *vorel, Reloc *reloc, uchar_t *oaddr,
    uchar_t *iaddr)
{
    Rel *nrel = vnrel;
    Rel *orel = vorel;
    /* LINTED */
    ulong_t *_oaddr = (ulong_t *)oaddr;
    /* LINTED */
    ulong_t *_iaddr = (ulong_t *)iaddr;

    if (ELF_R_TYPE(nrel->r_info) == R_386_JMP_SLOT) {
        if (_iaddr)
            *_oaddr = *_iaddr + reloc->r_value;
        else
            *_oaddr = reloc->r_value;
    }

    *nrel = *orel;
    nrel->r_offset += reloc->r_value;
}

/*
 * Clear a relocation record.  The relocation has been applied to the image and
 * thus the relocation must not occur again.
 */
void
clear_reloc(void *vrel)
{
    Rel *rel = vrel;

    rel->r_offset = 0;
    rel->r_info = ELF_R_INFO(0, R_386_NONE);
}

/*
 * Apply a relocation to an image being built from an input file.  Use the
 * runtime linkers routines to do the necessary magic.
 */
void
apply_reloc(void *vrel, Reloc *reloc, const char *name, uchar_t *oaddr,
    Rt_map *lmp)
{
    Rel *rel = vrel;
    Xword   type = ELF_R_TYPE(rel->r_info);
    Word    value = reloc->r_value;

    if (type == R_386_JMP_SLOT) {
        uintptr_t   addr, vaddr;

        if (FLAGS(lmp) & FLG_RT_FIXED)
            vaddr = 0;
        else
            vaddr = ADDR(lmp);
        addr = (uintptr_t)oaddr - rel->r_offset;
        /* LINTED */
        elf_plt_write((uintptr_t)addr, vaddr, rel,
            (uintptr_t)value, reloc->r_pltndx);

    } else if (type == R_386_COPY) {
        (void) memcpy((void *)oaddr, (void *)value,
            (size_t)reloc->r_size);
    } else {
        (void) do_reloc(type, oaddr, &value, reloc->r_name, name,
            LIST(lmp));
    }
}