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
23 static const bool debug_en;
24
debug(const char * fmt,...)25 static 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
supported_rela(Elf64_Rela * rela)36 static 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
read_num(const char * str,uint64_t * num)55 static 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
main(int argc,char ** argv)62 int 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