1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
4 */
5
6#include <unistd.h>
7#include <asm/orc_types.h>
8#include <objtool/objtool.h>
9#include <objtool/orc.h>
10#include <objtool/warn.h>
11
12int orc_dump(const char *filename)
13{
14 int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
15 struct orc_entry *orc = NULL;
16 char *name;
17 size_t nr_sections;
18 Elf64_Addr orc_ip_addr = 0;
19 size_t shstrtab_idx, strtab_idx = 0;
20 Elf *elf;
21 Elf_Scn *scn;
22 GElf_Shdr sh;
23 GElf_Rela rela;
24 GElf_Sym sym;
25 Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
26 struct elf dummy_elf = {};
27
28 elf_version(EV_CURRENT);
29
30 fd = open(file: filename, O_RDONLY);
31 if (fd == -1) {
32 perror(s: "open");
33 return -1;
34 }
35
36 elf = elf_begin(fildes: fd, ELF_C_READ_MMAP, NULL);
37 if (!elf) {
38 ERROR_ELF("elf_begin");
39 return -1;
40 }
41
42 if (!elf64_getehdr(elf: elf)) {
43 ERROR_ELF("elf64_getehdr");
44 return -1;
45 }
46 memcpy(dest: &dummy_elf.ehdr, src: elf64_getehdr(elf: elf), n: sizeof(dummy_elf.ehdr));
47
48 if (elf_getshdrnum(elf: elf, dst: &nr_sections)) {
49 ERROR_ELF("elf_getshdrnum");
50 return -1;
51 }
52
53 if (elf_getshdrstrndx(elf: elf, dst: &shstrtab_idx)) {
54 ERROR_ELF("elf_getshdrstrndx");
55 return -1;
56 }
57
58 for (i = 0; i < nr_sections; i++) {
59 scn = elf_getscn(elf: elf, index: i);
60 if (!scn) {
61 ERROR_ELF("elf_getscn");
62 return -1;
63 }
64
65 if (!gelf_getshdr(scn: scn, dst: &sh)) {
66 ERROR_ELF("gelf_getshdr");
67 return -1;
68 }
69
70 name = elf_strptr(elf: elf, index: shstrtab_idx, offset: sh.sh_name);
71 if (!name) {
72 ERROR_ELF("elf_strptr");
73 return -1;
74 }
75
76 data = elf_getdata(scn: scn, NULL);
77 if (!data) {
78 ERROR_ELF("elf_getdata");
79 return -1;
80 }
81
82 if (!strcmp(s1: name, s2: ".symtab")) {
83 symtab = data;
84 } else if (!strcmp(s1: name, s2: ".strtab")) {
85 strtab_idx = i;
86 } else if (!strcmp(s1: name, s2: ".orc_unwind")) {
87 orc = data->d_buf;
88 orc_size = sh.sh_size;
89 } else if (!strcmp(s1: name, s2: ".orc_unwind_ip")) {
90 orc_ip = data->d_buf;
91 orc_ip_addr = sh.sh_addr;
92 } else if (!strcmp(s1: name, s2: ".rela.orc_unwind_ip")) {
93 rela_orc_ip = data;
94 }
95 }
96
97 if (!symtab || !strtab_idx || !orc || !orc_ip)
98 return 0;
99
100 if (orc_size % sizeof(*orc) != 0) {
101 ERROR("bad .orc_unwind section size");
102 return -1;
103 }
104
105 nr_entries = orc_size / sizeof(*orc);
106 for (i = 0; i < nr_entries; i++) {
107 if (rela_orc_ip) {
108 if (!gelf_getrela(data: rela_orc_ip, ndx: i, dst: &rela)) {
109 ERROR_ELF("gelf_getrela");
110 return -1;
111 }
112
113 if (!gelf_getsym(data: symtab, GELF_R_SYM(rela.r_info), dst: &sym)) {
114 ERROR_ELF("gelf_getsym");
115 return -1;
116 }
117
118 if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
119 scn = elf_getscn(elf: elf, index: sym.st_shndx);
120 if (!scn) {
121 ERROR_ELF("elf_getscn");
122 return -1;
123 }
124
125 if (!gelf_getshdr(scn: scn, dst: &sh)) {
126 ERROR_ELF("gelf_getshdr");
127 return -1;
128 }
129
130 name = elf_strptr(elf: elf, index: shstrtab_idx, offset: sh.sh_name);
131 if (!name) {
132 ERROR_ELF("elf_strptr");
133 return -1;
134 }
135 } else {
136 name = elf_strptr(elf: elf, index: strtab_idx, offset: sym.st_name);
137 if (!name) {
138 ERROR_ELF("elf_strptr");
139 return -1;
140 }
141 }
142
143 printf(format: "%s+%llx:", name, (unsigned long long)rela.r_addend);
144
145 } else {
146 printf(format: "%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
147 }
148
149 orc_print_dump(dummy_elf: &dummy_elf, orc, i);
150 }
151
152 elf_end(elf: elf);
153 close(fd: fd);
154
155 return 0;
156}
157

source code of linux/tools/objtool/orc_dump.c