xref: /openbmc/u-boot/tools/relocate-rela.c (revision e8f80a5a)
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