root/lib/libkldelf/ef_aarch64.c
/*-
 * Copyright (c) 2005 Peter Grehan.
 * Copyright 1996-1998 John D. Polstra.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/endian.h>

#include <err.h>
#include <errno.h>
#include <gelf.h>

#include "kldelf.h"

/*
 * Apply relocations to the values obtained from the file. `relbase' is the
 * target relocation address of the section, and `dataoff/len' is the region
 * that is to be relocated, and has been copied to *dest
 */
static int
ef_aarch64_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype,
    GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest)
{
        char *where;
        GElf_Addr addr, addend;
        GElf_Size rtype, symidx;
        const GElf_Rela *rela;

        switch (reltype) {
        case ELF_T_RELA:
                rela = (const GElf_Rela *)reldata;
                where = (char *)dest + (relbase + rela->r_offset - dataoff);
                addend = rela->r_addend;
                rtype = GELF_R_TYPE(rela->r_info);
                symidx = GELF_R_SYM(rela->r_info);
                break;
        default:
                return (EINVAL);
        }

        if (where < (char *)dest || where >= (char *)dest + len)
                return (0);

        switch (rtype) {
        case R_AARCH64_RELATIVE:
                addr = relbase + addend;
                le64enc(where, addr);
                break;
        case R_AARCH64_ABS64:
                addr = EF_SYMADDR(ef, symidx) + addend;
                le64enc(where, addr);
                break;
        default:
                warnx("unhandled relocation type %d", (int)rtype);
                break;
        }
        return (0);
}

ELF_RELOC(ELFCLASS64, ELFDATA2LSB, EM_AARCH64, ef_aarch64_reloc);