LXR uboot/tools/relocate-rela.c

   1// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
   2/*
   3 * Copyright 2013 Freescale Semiconductor, Inc.
   4 *
   5 * 64-bit and little-endian target only until we need to support a different
   6 * arch that needs this.
   7 */
   8
   9#include <elf.h>
  10#include <errno.h>
  11#include <inttypes.h>
  12#include <stdarg.h>
  13#include <stdbool.h>
  14#include <stdio.h>
  15#include <stdlib.h>
  16#include <string.h>
  17#include "compiler.h"
  18
  19#ifndef R_AARCH64_RELATIVE
  20#define R_AARCH64_RELATIVE      1027
  21#endif
  22
  23static const bool debug_en;
  24
  25static void debug(const char *fmt, ...)
  26{
  27        va_list args;
  28
  29        if (debug_en) {
  30                va_start(args, fmt);
  31                vprintf(fmt, args);
  32                va_end(args);
  33        }
  34}
  35
  36static bool supported_rela(Elf64_Rela *rela)
  37{
  38        uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */
  39        uint32_t type = rela->r_info & mask;
  40
  41        switch (type) {
  42#ifdef R_AARCH64_RELATIVE
  43        case R_AARCH64_RELATIVE:
  44                return true;
  45#endif
  46        default:
  47                fprintf(stderr, "warning: unsupported relocation type %"
  48                                PRIu32 " at %" PRIx64 "\n",
  49                        type, rela->r_offset);
  50
  51                return false;
  52        }
  53}
  54
  55static bool read_num(const char *str, uint64_t *num)
  56{
  57        char *endptr;
  58        *num = strtoull(str, &endptr, 16);
  59        return str[0] && !endptr[0];
  60}
  61
  62int main(int argc, char **argv)
  63{
  64        FILE *f;
  65        int i, num;
  66        uint64_t rela_start, rela_end, text_base;
  67
  68        if (argc != 5) {
  69                fprintf(stderr, "Statically apply ELF rela relocations\n");
  70                fprintf(stderr, "Usage: %s <bin file> <text base> " \
  71                                "<rela start> <rela end>\n", argv[0]);
  72                fprintf(stderr, "All numbers in hex.\n");
  73                return 1;
  74        }
  75
  76        f = fopen(argv[1], "r+b");
  77        if (!f) {
  78                fprintf(stderr, "%s: Cannot open %s: %s\n",
  79                        argv[0], argv[1], strerror(errno));
  80                return 2;
  81        }
  82
  83        if (!read_num(argv[2], &text_base) ||
  84            !read_num(argv[3], &rela_start) ||
  85            !read_num(argv[4], &rela_end)) {
  86                fprintf(stderr, "%s: bad number\n", argv[0]);
  87                return 3;
  88        }
  89
  90        if (rela_start > rela_end || rela_start < text_base ||
  91            (rela_end - rela_start) % sizeof(Elf64_Rela)) {
  92                fprintf(stderr, "%s: bad rela bounds\n", argv[0]);
  93                return 3;
  94        }
  95
  96        rela_start -= text_base;
  97        rela_end -= text_base;
  98
  99        num = (rela_end - rela_start) / sizeof(Elf64_Rela);
 100
 101        for (i = 0; i < num; i++) {
 102                Elf64_Rela rela, swrela;
 103                uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
 104                uint64_t addr;
 105
 106                if (fseek(f, pos, SEEK_SET) < 0) {
 107                        fprintf(stderr, "%s: %s: seek to %" PRIx64
 108                                        " failed: %s\n",
 109                                argv[0], argv[1], pos, strerror(errno));
 110                }
 111
 112                if (fread(&rela, sizeof(rela), 1, f) != 1) {
 113                        fprintf(stderr, "%s: %s: read rela failed at %"
 114                                        PRIx64 "\n",
 115                                argv[0], argv[1], pos);
 116                        return 4;
 117                }
 118
 119                swrela.r_offset = cpu_to_le64(rela.r_offset);
 120                swrela.r_info = cpu_to_le64(rela.r_info);
 121                swrela.r_addend = cpu_to_le64(rela.r_addend);
 122
 123                if (!supported_rela(&swrela))
 124                        continue;
 125
 126                debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n",
 127                      swrela.r_offset, swrela.r_info, swrela.r_addend);
 128
 129                if (swrela.r_offset < text_base) {
 130                        fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n",
 131                                argv[0], argv[1], pos);
 132                        return 4;
 133                }
 134
 135                addr = swrela.r_offset - text_base;
 136
 137                if (fseek(f, addr, SEEK_SET) < 0) {
 138                        fprintf(stderr, "%s: %s: seek to %"
 139                                        PRIx64 " failed: %s\n",
 140                                argv[0], argv[1], addr, strerror(errno));
 141                }
 142
 143                if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
 144                        fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n",
 145                                argv[0], argv[1], addr);
 146                        return 4;
 147                }
 148        }
 149
 150        if (fclose(f) < 0) {
 151                fprintf(stderr, "%s: %s: close failed: %s\n",
 152                        argv[0], argv[1], strerror(errno));
 153                return 4;
 154        }
 155
 156        return 0;
 157}
 158