/*      $OpenBSD: rtld_machine.c,v 1.36 2023/01/29 20:30:21 gnezdo Exp $ */

/*
 * Copyright (c) 2004 Dale Rahn
 *
 * 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 ``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.
 *
 */

#define _DYN_LOADER
#define LDSO_ARCH_IS_RELA_

#include <sys/types.h>
#include <sys/exec_elf.h>
#include <sys/syscall.h>
#include <sys/unistd.h>

#include <machine/reloc.h>

#include "util.h"
#include "resolve.h"

int64_t pcookie __attribute__((section(".openbsd.randomdata"))) __dso_hidden;

void _dl_bind_start(void); /* XXX */
Elf_Addr _dl_bind(elf_object_t *object, int reloff);
#define _RF_S           0x80000000              /* Resolve symbol */
#define _RF_A           0x40000000              /* Use addend */
#define _RF_P           0x20000000              /* Location relative */
#define _RF_G           0x10000000              /* GOT offset */
#define _RF_B           0x08000000              /* Load address relative */
#define _RF_E           0x02000000              /* ERROR */
#define _RF_SZ(s)       (((s) & 0xff) << 8)     /* memory target size */
#define _RF_RS(s)       ((s) & 0xff)            /* right shift */
static const int reloc_target_flags[] = {
        0,                                              /* 0    R_SH_NONE */
        _RF_S|_RF_A|            _RF_SZ(32) | _RF_RS(0), /* 1    R_SH_DIR32 */
        _RF_S|_RF_P|_RF_A|      _RF_SZ(32) | _RF_RS(0), /* 2  REL32 */
        _RF_E,                                          /* 3    R_SH_DIR8WPN */
        _RF_E,                                          /* 4    R_SH_IND12W */
        _RF_E,                                          /* 5    R_SH_DIR8WPL */
        _RF_E,                                          /* 6    R_SH_DIR8WPZ */
        _RF_E,                                          /* 7    R_SH_DIR8BP */
        _RF_E,                                          /* 8    R_SH_DIR8W */
        _RF_E,                                          /* 9    R_SH_DIR8L */
        _RF_E,                                          /* 10   R_SH_LOOP_START */
        _RF_E,                                          /* 11   R_SH_LOOP_END */
        _RF_E,                                          /* 12   Unused */
        _RF_E,                                          /* 13   Unused */
        _RF_E,                                          /* 14   Unused */
        _RF_E,                                          /* 15   Unused */
        _RF_E,                                          /* 16   Unused */
        _RF_E,                                          /* 17   Unused */
        _RF_E,                                          /* 18   Unused */
        _RF_E,                                          /* 19   Unused */
        _RF_E,                                          /* 20   Unused */
        _RF_E,                                          /* 21   Unused */
        _RF_E,                                          /* 22   R_SH_GNU_VTINHERIT */
        _RF_E,                                          /* 23   R_SH_GNU_VTENTRY */
        _RF_E,                                          /* 24   R_SH_SWITCH8 */
        _RF_E,                                          /* 25   R_SH_SWITCH16 */
        _RF_E,                                          /* 26   R_SH_SWITCH32 */
        _RF_E,                                          /* 27   R_SH_USES */
        _RF_E,                                          /* 28   R_SH_COUNT */
        _RF_E,                                          /* 29   R_SH_ALIGN */
        _RF_E,                                          /* 30   R_SH_CODE */
        _RF_E,                                          /* 31   R_SH_DATA */
        _RF_E,                                          /* 32   R_SH_LABEL */
        _RF_E,                                          /* 33   R_SH_DIR16 */
        _RF_E,                                          /* 34   R_SH_DIR8 */
        _RF_E,                                          /* 35   R_SH_DIR8UL */
        _RF_E,                                          /* 36   R_SH_DIR8UW */
        _RF_E,                                          /* 37   R_SH_DIR8U */
        _RF_E,                                          /* 38   R_SH_DIR8SW */
        _RF_E,                                          /* 39   R_SH_DIR8S */
        _RF_E,                                          /* 40   R_SH_DIR4UL */
        _RF_E,                                          /* 41   R_SH_DIR4UW */
        _RF_E,                                          /* 42   R_SH_DIR4U */
        _RF_E,                                          /* 43   R_SH_PSHA */
        _RF_E,                                          /* 44   R_SH_PSHL */
        _RF_E,                                          /* 45   R_SH_DIR5U */
        _RF_E,                                          /* 46   R_SH_DIR6U */
        _RF_E,                                          /* 47   R_SH_DIR6S */
        _RF_E,                                          /* 48   R_SH_DIR10S */
        _RF_E,                                          /* 49   R_SH_DIR10SW */
        _RF_E,                                          /* 50   R_SH_DIR10SL */
        _RF_E,                                          /* 51   R_SH_DIR10SQ */
        _RF_E,                                          /* 52   XXXX */
        _RF_E,                                          /* 53   R_SH_DIR16S */
        _RF_E,                                          /* 54   Unused */
        _RF_E,                                          /* 55   Unused */
        _RF_E,                                          /* 56   Unused */
        _RF_E,                                          /* 57   Unused */
        _RF_E,                                          /* 58   Unused */
        _RF_E,                                          /* 59   Unused */
        _RF_E,                                          /* 60   Unused */
        _RF_E,                                          /* 61   Unused */
        _RF_E,                                          /* 62   Unused */
        _RF_E,                                          /* 63   Unused */
        _RF_E,                                          /* 64   Unused */
        _RF_E,                                          /* 65   Unused */
        _RF_E,                                          /* 66   Unused */
        _RF_E,                                          /* 67   Unused */
        _RF_E,                                          /* 68   Unused */
        _RF_E,                                          /* 69   Unused */
        _RF_E,                                          /* 70   Unused */
        _RF_E,                                          /* 71   Unused */
        _RF_E,                                          /* 72   Unused */
        _RF_E,                                          /* 73   Unused */
        _RF_E,                                          /* 74   Unused */
        _RF_E,                                          /* 75   Unused */
        _RF_E,                                          /* 76   Unused */
        _RF_E,                                          /* 77   Unused */
        _RF_E,                                          /* 78   Unused */
        _RF_E,                                          /* 79   Unused */
        _RF_E,                                          /* 80   Unused */
        _RF_E,                                          /* 81   Unused */
        _RF_E,                                          /* 82   Unused */
        _RF_E,                                          /* 83   Unused */
        _RF_E,                                          /* 84   Unused */
        _RF_E,                                          /* 85   Unused */
        _RF_E,                                          /* 86   Unused */
        _RF_E,                                          /* 87   Unused */
        _RF_E,                                          /* 88   Unused */
        _RF_E,                                          /* 89   Unused */
        _RF_E,                                          /* 90   Unused */
        _RF_E,                                          /* 91   Unused */
        _RF_E,                                          /* 92   Unused */
        _RF_E,                                          /* 93   Unused */
        _RF_E,                                          /* 94   Unused */
        _RF_E,                                          /* 95   Unused */
        _RF_E,                                          /* 96   Unused */
        _RF_E,                                          /* 97   Unused */
        _RF_E,                                          /* 98   Unused */
        _RF_E,                                          /* 99   Unused */
        _RF_E,                                          /* 100  Unused */
        _RF_E,                                          /* 101  Unused */
        _RF_E,                                          /* 102  Unused */
        _RF_E,                                          /* 103  Unused */
        _RF_E,                                          /* 104  Unused */
        _RF_E,                                          /* 105  Unused */
        _RF_E,                                          /* 106  Unused */
        _RF_E,                                          /* 107  Unused */
        _RF_E,                                          /* 108  Unused */
        _RF_E,                                          /* 109  Unused */
        _RF_E,                                          /* 110  Unused */
        _RF_E,                                          /* 111  Unused */
        _RF_E,                                          /* 112  Unused */
        _RF_E,                                          /* 113  Unused */
        _RF_E,                                          /* 114  Unused */
        _RF_E,                                          /* 115  Unused */
        _RF_E,                                          /* 116  Unused */
        _RF_E,                                          /* 117  Unused */
        _RF_E,                                          /* 118  Unused */
        _RF_E,                                          /* 119  Unused */
        _RF_E,                                          /* 120  Unused */
        _RF_E,                                          /* 121  Unused */
        _RF_E,                                          /* 122  Unused */
        _RF_E,                                          /* 123  Unused */
        _RF_E,                                          /* 124  Unused */
        _RF_E,                                          /* 125  Unused */
        _RF_E,                                          /* 126  Unused */
        _RF_E,                                          /* 127  Unused */
        _RF_E,                                          /* 128  Unused */
        _RF_E,                                          /* 129  Unused */
        _RF_E,                                          /* 130  Unused */
        _RF_E,                                          /* 131  Unused */
        _RF_E,                                          /* 132  Unused */
        _RF_E,                                          /* 133  Unused */
        _RF_E,                                          /* 134  Unused */
        _RF_E,                                          /* 135  Unused */
        _RF_E,                                          /* 136  Unused */
        _RF_E,                                          /* 137  Unused */
        _RF_E,                                          /* 138  Unused */
        _RF_E,                                          /* 139  Unused */
        _RF_E,                                          /* 140  Unused */
        _RF_E,                                          /* 141  Unused */
        _RF_E,                                          /* 142  Unused */
        _RF_E,                                          /* 143  Unused */
        _RF_E,                                          /* 144  R_SH_TLS_GD_32 */
        _RF_E,                                          /* 145  R_SH_TLS_LD_32 */
        _RF_E,                                          /* 146  R_SH_TLS_LDO_32 */
        _RF_E,                                          /* 147  R_SH_TLS_IE_32 */
        _RF_E,                                          /* 148  R_SH_TLS_LE_32 */
        _RF_E,                                          /* 149  R_SH_TLS_DTPMOD32 */
        _RF_E,                                          /* 150  R_SH_TLS_DTPOFF32 */
        _RF_E,                                          /* 151  R_SH_TLS_TPOFF32 */
        _RF_E,                                          /* 152 Unused */
        _RF_E,                                          /* 153 Unused */
        _RF_E,                                          /* 154 Unused */
        _RF_E,                                          /* 155 Unused */
        _RF_E,                                          /* 156 Unused */
        _RF_E,                                          /* 157 Unused */
        _RF_E,                                          /* 158 Unused */
        _RF_E,                                          /* 159 Unused */
        _RF_E,                                          /* 160  R_SH_GOT32 */
        _RF_E,                                          /* 161  R_SH_PLT32 */
        _RF_S|                  _RF_SZ(32) | _RF_RS(0), /* 162  COPY */
        _RF_S|_RF_A|            _RF_SZ(32) | _RF_RS(0), /* 163  GLOB_DAT */
        _RF_S|                  _RF_SZ(32) | _RF_RS(0), /* 164  JMP_SLOT */
              _RF_A|    _RF_B|  _RF_SZ(32) | _RF_RS(0), /* 165 RELATIVE */
};

#define RELOC_RESOLVE_SYMBOL(t)         ((reloc_target_flags[t] & _RF_S) != 0)
#define RELOC_PC_RELATIVE(t)            ((reloc_target_flags[t] & _RF_P) != 0)
#define RELOC_BASE_RELATIVE(t)          ((reloc_target_flags[t] & _RF_B) != 0)
#define RELOC_USE_ADDEND(t)             ((reloc_target_flags[t] & _RF_A) != 0)
#define RELOC_TARGET_SIZE(t)            ((reloc_target_flags[t] >> 8) & 0xff)
#define RELOC_VALUE_RIGHTSHIFT(t)       (reloc_target_flags[t] & 0xff)
#define RELOC_ERROR(t) \
        ((t) >= nitems(reloc_target_flags) || (reloc_target_flags[t] & _RF_E))

static const int reloc_target_bitmask[] = {
#define _BM(x)  (x == 32? ~0 : ~(-(1UL << (x))))
        _BM(0),         /* 0    R_SH_NONE */
        _BM(32),        /* 1    R_SH_DIR32 */
        _BM(32),        /* 2    R_SH_REL32 */
        _BM(8),         /* 3    R_SH_DIR8WPN */
        _BM(12),        /* 4    R_SH_IND12W */
        _BM(8),         /* 5    R_SH_DIR8WPL */
        _BM(8),         /* 6    R_SH_DIR8WPZ */
        _BM(8),         /* 7    R_SH_DIR8BP */
        _BM(8),         /* 8    R_SH_DIR8W */
        _BM(8),         /* 9    R_SH_DIR8L */
        _BM(0),         /* 10   R_SH_LOOP_START */
        _BM(0),         /* 11   R_SH_LOOP_END */
        _BM(0),         /* 12   Unused */
        _BM(0),         /* 13   Unused */
        _BM(0),         /* 14   Unused */
        _BM(0),         /* 15   Unused */
        _BM(0),         /* 16   Unused */
        _BM(0),         /* 17   Unused */
        _BM(0),         /* 18   Unused */
        _BM(0),         /* 19   Unused */
        _BM(0),         /* 20   Unused */
        _BM(0),         /* 21   Unused */
        _BM(0),         /* 22   R_SH_GNU_VTINHERIT */
        _BM(0),         /* 23   R_SH_GNU_VTENTRY */
        _BM(0),         /* 24   R_SH_SWITCH8 */
        _BM(0),         /* 25   R_SH_SWITCH16 */
        _BM(0),         /* 26   R_SH_SWITCH32 */
        _BM(0),         /* 27   R_SH_USES */
        _BM(0),         /* 28   R_SH_COUNT */
        _BM(0),         /* 29   R_SH_ALIGN */
        _BM(0),         /* 30   R_SH_CODE */
        _BM(0),         /* 31   R_SH_DATA */
        _BM(0),         /* 32   R_SH_LABEL */
        _BM(0),         /* 33   R_SH_DIR16 */
        _BM(0),         /* 34   R_SH_DIR8 */
        _BM(0),         /* 35   R_SH_DIR8UL */
        _BM(0),         /* 36   R_SH_DIR8UW */
        _BM(0),         /* 37   R_SH_DIR8U */
        _BM(0),         /* 38   R_SH_DIR8SW */
        _BM(0),         /* 39   R_SH_DIR8S */
        _BM(0),         /* 40   R_SH_DIR4UL */
        _BM(0),         /* 41   R_SH_DIR4UW */
        _BM(0),         /* 42   R_SH_DIR4U */
        _BM(0),         /* 43   R_SH_PSHA */
        _BM(0),         /* 44   R_SH_PSHL */
        _BM(0),         /* 45   R_SH_DIR5U */
        _BM(0),         /* 46   R_SH_DIR6U */
        _BM(0),         /* 47   R_SH_DIR6S */
        _BM(0),         /* 48   R_SH_DIR10S */
        _BM(0),         /* 49   R_SH_DIR10SW */
        _BM(0),         /* 50   R_SH_DIR10SL */
        _BM(0),         /* 51   R_SH_DIR10SQ */
        _BM(0),         /* 52   xxx */
        _BM(0),         /* 53   R_SH_DIR16S */
        _BM(0),         /* 54   Unused */
        _BM(0),         /* 55   Unused */
        _BM(0),         /* 56   Unused */
        _BM(0),         /* 57   Unused */
        _BM(0),         /* 58   Unused */
        _BM(0),         /* 59   Unused */
        _BM(0),         /* 60   Unused */
        _BM(0),         /* 61   Unused */
        _BM(0),         /* 62   Unused */
        _BM(0),         /* 63   Unused */
        _BM(0),         /* 64   Unused */
        _BM(0),         /* 65   Unused */
        _BM(0),         /* 66   Unused */
        _BM(0),         /* 67   Unused */
        _BM(0),         /* 68   Unused */
        _BM(0),         /* 69   Unused */
        _BM(0),         /* 70   Unused */
        _BM(0),         /* 71   Unused */
        _BM(0),         /* 72   Unused */
        _BM(0),         /* 73   Unused */
        _BM(0),         /* 74   Unused */
        _BM(0),         /* 75   Unused */
        _BM(0),         /* 76   Unused */
        _BM(0),         /* 77   Unused */
        _BM(0),         /* 78   Unused */
        _BM(0),         /* 79   Unused */
        _BM(0),         /* 80   Unused */
        _BM(0),         /* 81   Unused */
        _BM(0),         /* 82   Unused */
        _BM(0),         /* 83   Unused */
        _BM(0),         /* 84   Unused */
        _BM(0),         /* 85   Unused */
        _BM(0),         /* 86   Unused */
        _BM(0),         /* 87   Unused */
        _BM(0),         /* 88   Unused */
        _BM(0),         /* 89   Unused */
        _BM(0),         /* 90   Unused */
        _BM(0),         /* 91   Unused */
        _BM(0),         /* 92   Unused */
        _BM(0),         /* 93   Unused */
        _BM(0),         /* 94   Unused */
        _BM(0),         /* 95   Unused */
        _BM(0),         /* 96   Unused */
        _BM(0),         /* 97   Unused */
        _BM(0),         /* 98   Unused */
        _BM(0),         /* 99   Unused */
        _BM(0),         /* 100  Unused */
        _BM(0),         /* 101  Unused */
        _BM(0),         /* 102  Unused */
        _BM(0),         /* 103  Unused */
        _BM(0),         /* 104  Unused */
        _BM(0),         /* 105  Unused */
        _BM(0),         /* 106  Unused */
        _BM(0),         /* 107  Unused */
        _BM(0),         /* 108  Unused */
        _BM(0),         /* 109  Unused */
        _BM(0),         /* 110  Unused */
        _BM(0),         /* 111  Unused */
        _BM(0),         /* 112  Unused */
        _BM(0),         /* 113  Unused */
        _BM(0),         /* 114  Unused */
        _BM(0),         /* 115  Unused */
        _BM(0),         /* 116  Unused */
        _BM(0),         /* 117  Unused */
        _BM(0),         /* 118  Unused */
        _BM(0),         /* 119  Unused */
        _BM(0),         /* 120  Unused */
        _BM(0),         /* 121  Unused */
        _BM(0),         /* 122  Unused */
        _BM(0),         /* 123  Unused */
        _BM(0),         /* 124  Unused */
        _BM(0),         /* 125  Unused */
        _BM(0),         /* 126  Unused */
        _BM(0),         /* 127  Unused */
        _BM(0),         /* 128  Unused */
        _BM(0),         /* 129  Unused */
        _BM(0),         /* 130  Unused */
        _BM(0),         /* 131  Unused */
        _BM(0),         /* 132  Unused */
        _BM(0),         /* 133  Unused */
        _BM(0),         /* 134  Unused */
        _BM(0),         /* 135  Unused */
        _BM(0),         /* 136  Unused */
        _BM(0),         /* 137  Unused */
        _BM(0),         /* 138  Unused */
        _BM(0),         /* 139  Unused */
        _BM(0),         /* 140  Unused */
        _BM(0),         /* 141  Unused */
        _BM(0),         /* 142  Unused */
        _BM(0),         /* 143  Unused */
        _BM(0),         /* 144  R_SH_TLS_GD_32 */
        _BM(0),         /* 145  R_SH_TLS_LD_32 */
        _BM(0),         /* 146  R_SH_TLS_LDO_32 */
        _BM(0),         /* 147  R_SH_TLS_IE_32 */
        _BM(0),         /* 148  R_SH_TLS_LE_32 */
        _BM(0),         /* 149  R_SH_TLS_DTPMOD32 */
        _BM(0),         /* 150  R_SH_TLS_DTPOFF32 */
        _BM(0),         /* 151  R_SH_TLS_TPOFF32 */
        _BM(0),         /* 152  xxx */
        _BM(0),         /* 153  xxx */
        _BM(0),         /* 154  xxx */
        _BM(0),         /* 155  xxx */
        _BM(0),         /* 156  xxx */
        _BM(0),         /* 157  xxx */
        _BM(0),         /* 158  xxx */
        _BM(0),         /* 159  xxx */
        _BM(0),         /* 160  R_SH_GOT32 */
        _BM(0),         /* 161  R_SH_PLT32 */
        _BM(0),         /* 162  R_SH_COPY */
        _BM(32),        /* 163  R_SH_GLOB_DAT */
        _BM(0),         /* 164  R_SH_JMP_SLOT */
        _BM(32),        /* 165  R_SH_RELATIVE */
#undef _BM
};
#define RELOC_VALUE_BITMASK(t)  (reloc_target_bitmask[t])

#define R_TYPE(x) R_SH_ ## x

void _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rel);

void
_dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rel)
{
        *where = value + rel->r_addend;
}

int
_dl_md_reloc(elf_object_t *object, int rel, int relasz)
{
        long    i;
        long    numrela;
        long    relrel;
        int     fails = 0;
        Elf_Addr loff;
        Elf_Addr prev_value = 0;
        const Elf_Sym *prev_sym = NULL;
        Elf_RelA *rels;

        loff = object->obj_base;
        numrela = object->Dyn.info[relasz] / sizeof(Elf_RelA);
        relrel = rel == DT_RELA ? object->relacount : 0;
        rels = (Elf_RelA *)(object->Dyn.info[rel]);

        if (rels == NULL)
                return 0;

        if (relrel > numrela)
                _dl_die("relacount > numrel: %ld > %ld", relrel, numrela);

        /* tight loop for leading RELATIVE relocs */
        for (i = 0; i < relrel; i++, rels++) {
                Elf_Addr *where;

                where = (Elf_Addr *)(rels->r_offset + loff);
                *where = rels->r_addend + loff;
        }
        for (; i < numrela; i++, rels++) {
                Elf_Addr *where, value, mask;
                Elf_Word type;
                const Elf_Sym *sym;
                const char *symn;

                type = ELF_R_TYPE(rels->r_info);

                if (RELOC_ERROR(type))
                        _dl_die("bad relocation obj %s %ld %d",
                            object->load_name, i, type);

                if (type == R_TYPE(NONE))
                        continue;

                if (type == R_TYPE(JMP_SLOT) && rel != DT_JMPREL)
                        continue;

                where = (Elf_Addr *)(rels->r_offset + loff);

                if (RELOC_USE_ADDEND(type))
#ifdef LDSO_ARCH_IS_RELA_
                        value = rels->r_addend;
#else
                        value = *where & RELOC_VALUE_BITMASK(type);
#endif
                else
                        value = 0;


                sym = NULL;
                symn = NULL;
                if (RELOC_RESOLVE_SYMBOL(type)) {
                        sym = object->dyn.symtab;
                        sym += ELF_R_SYM(rels->r_info);
                        symn = object->dyn.strtab + sym->st_name;

                        if (sym->st_shndx != SHN_UNDEF &&
                            ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
                                value += loff;
                        } else if (sym == prev_sym) {
                                value += prev_value;
                        } else {
                                struct sym_res sr;

                                sr = _dl_find_symbol(symn,
                                    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
                                    ((type == R_TYPE(JMP_SLOT)) ?
                                        SYM_PLT : SYM_NOTPLT),
                                    sym, object);
                                if (sr.sym == NULL) {
resolve_failed:
                                        if (ELF_ST_BIND(sym->st_info) !=
                                            STB_WEAK)
                                                fails++;
                                        continue;
                                }
                                prev_sym = sym;
                                prev_value = (Elf_Addr)(sr.obj->obj_base +
                                    sr.sym->st_value);
                                value += prev_value;
                        }
                }

                if (type == R_TYPE(JMP_SLOT)) {
                        _dl_reloc_plt((Elf_Word *)where, value, rels);
                        continue;
                }

                if (type == R_TYPE(COPY)) {
                        void *dstaddr = where;
                        const void *srcaddr;
                        const Elf_Sym *dstsym = sym;
                        struct sym_res sr;

                        sr = _dl_find_symbol(symn,
                            SYM_SEARCH_OTHER|SYM_WARNNOTFOUND|SYM_NOTPLT,
                            dstsym, object);
                        if (sr.sym == NULL)
                                goto resolve_failed;

                        srcaddr = (void *)(sr.obj->obj_base + sr.sym->st_value);
                        _dl_bcopy(srcaddr, dstaddr, dstsym->st_size);
                        continue;
                }

                if (RELOC_PC_RELATIVE(type))
                        value -= (Elf_Addr)where;
                if (RELOC_BASE_RELATIVE(type))
                        value += loff;

                mask = RELOC_VALUE_BITMASK(type);
                value >>= RELOC_VALUE_RIGHTSHIFT(type);
                value &= mask;

                *where &= ~mask;
                *where |= value;
        }

        return fails;
}

/*
 *      Relocate the Global Offset Table (GOT).
 *      This is done by calling _dl_md_reloc on DT_JMPREL for DL_BIND_NOW,
 *      otherwise the lazy binding plt initialization is performed.
 */
int
_dl_md_reloc_got(elf_object_t *object, int lazy)
{
        int     fails = 0;
        Elf_Addr *pltgot = (Elf_Addr *)object->Dyn.info[DT_PLTGOT];
        int i, num;
        Elf_RelA *rel;

        if (object->Dyn.info[DT_PLTREL] != DT_RELA)
                return 0;

        if (!lazy) {
                fails = _dl_md_reloc(object, DT_JMPREL, DT_PLTRELSZ);
        } else {
                rel = (Elf_RelA *)(object->Dyn.info[DT_JMPREL]);
                num = (object->Dyn.info[DT_PLTRELSZ]) / sizeof(Elf_RelA);

                for (i = 0; i < num; i++, rel++) {
                        Elf_Addr *where, value;
                        Elf_Word type;

                        where = (Elf_Addr *)(rel->r_offset + object->obj_base);
                        type = ELF_R_TYPE(rel->r_info);
                        if (RELOC_USE_ADDEND(type))
                                value = rel->r_addend;
                        else
                                value = 0;
                        *where += object->obj_base + value;
                }

                pltgot[1] = (Elf_Addr)object;
                pltgot[2] = (Elf_Addr)_dl_bind_start;
        }

        return fails;
}

Elf_Addr
_dl_bind(elf_object_t *object, int reloff)
{
        Elf_RelA *rel;
        const Elf_Sym *sym;
        const char *symn;
        struct sym_res sr;
        uint64_t cookie = pcookie;
        struct {
                struct __kbind param;
                Elf_Addr newval;
        } buf;

        rel = (Elf_RelA *)(object->Dyn.info[DT_JMPREL] + reloff);

        sym = object->dyn.symtab;
        sym += ELF_R_SYM(rel->r_info);
        symn = object->dyn.strtab + sym->st_name;

        sr = _dl_find_symbol(symn, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT,
            sym, object);
        if (sr.sym == NULL)
                _dl_die("lazy binding failed!");

        buf.newval = sr.obj->obj_base + sr.sym->st_value;

        if (__predict_false(sr.obj->traced) && _dl_trace_plt(sr.obj, symn))
                return buf.newval;

        buf.param.kb_addr = (Elf_Addr *)(object->obj_base + rel->r_offset);
        buf.param.kb_size = sizeof(Elf_Addr);

        /* directly code the syscall, so that it's actually inline here */
        {
                register long syscall_num __asm("r0") = SYS_kbind;
                register void *arg1 __asm("r4") = &buf;
                register long  arg2 __asm("r5") = sizeof(buf);
                register long  arg3 __asm("r6") = 0xffffffff &  cookie;
                register long  arg4 __asm("r7") = 0xffffffff & (cookie >> 32);

                __asm volatile("trapa #0x80" : "+r" (syscall_num)
                    : "r" (arg1), "r" (arg2), "r" (arg3), "r" (arg4)
                    : "r1", "cc", "memory");
        }

        return buf.newval;
}