elfloader-tool/src/binaries/efi/gnuefi/reloc_arm.c

/* SPDX-License-Identifier: BSD-3-Clause */

/*
 * reloc_arm.c - position independent x86 ELF shared object relocator
 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
 * Copyright (C) 1999 Hewlett-Packard Co.
 * Contributed by David Mosberger <davidm@hpl.hp.com>.
 *
 *    All rights reserved.
 *
 *    Redistribution and use in source and binary forms, with or without
 *    modification, are permitted provided that the following conditions
 *    are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * 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.
 *    * Neither the name of Hewlett-Packard Co. nor the names of its
 *      contributors may be used to endorse or promote products derived
 *      from this software without specific prior written permission.
 *
 *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER OR CONTRIBUTORS
 *    BE LIABLE FOR ANYDIRECT, 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 <elfloader_common.h>
#include <binaries/efi/efi.h>

#include <binaries/elf/elf.h>
#include <binaries/elf/elf32.h>

unsigned int _relocate(unsigned long ldbase, struct Elf32_Dyn *dyn,
                       void *image,
                       void *systab)
{
    long relsz = 0, relent = 0;
    struct Elf32_Rel *rel = 0;
    unsigned long *addr;
    int i;


    unsigned long total_offs = ldbase;
    if (!systab) {
        total_offs = ((unsigned long)image);
    }
    for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
        switch (dyn[i].d_tag) {
        case DT_REL:
            rel = (struct Elf32_Rel *)
                  ((unsigned long)dyn[i].d_un.d_ptr
                   + total_offs);
            break;

        case DT_RELSZ:
            relsz = dyn[i].d_un.d_val;
            break;

        case DT_RELENT:
            relent = dyn[i].d_un.d_val;
            break;

        default:
            break;
        }
    }

    if (!rel && relent == 0) {
        return EFI_SUCCESS;
    }

    if (!rel || relent == 0) {
        return EFI_LOAD_ERROR;
    }

    while (relsz > 0) {
        /* apply the relocs */
        switch (ELF32_R_TYPE(rel->r_info)) {
        case R_ARM_NONE:
            break;

        case R_ARM_RELATIVE:
            addr = (unsigned long *)
                   (total_offs + rel->r_offset);
            if (!systab) {
                *addr -= ldbase;
                *addr += total_offs;
            } else {
                *addr += ldbase;
            }
            break;

        default:
            break;
        }
        rel = (struct Elf32_Rel *)((char *) rel + relent);
        relsz -= relent;
    }
    return EFI_SUCCESS;
}