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.h"
9 #include "warn.h"
10
11 static const char *reg_name(unsigned int reg)
12 {
13 switch (reg) {
14 case ORC_REG_PREV_SP:
15 return "prevsp";
16 case ORC_REG_DX:
17 return "dx";
18 case ORC_REG_DI:
19 return "di";
20 case ORC_REG_BP:
21 return "bp";
22 case ORC_REG_SP:
23 return "sp";
24 case ORC_REG_R10:
25 return "r10";
26 case ORC_REG_R13:
27 return "r13";
28 case ORC_REG_BP_INDIRECT:
29 return "bp(ind)";
30 case ORC_REG_SP_INDIRECT:
31 return "sp(ind)";
32 default:
33 return "?";
34 }
35 }
36
37 static const char *orc_type_name(unsigned int type)
38 {
39 switch (type) {
40 case ORC_TYPE_CALL:
41 return "call";
42 case ORC_TYPE_REGS:
43 return "regs";
44 case ORC_TYPE_REGS_IRET:
45 return "iret";
46 default:
47 return "?";
48 }
49 }
50
51 static void print_reg(unsigned int reg, int offset)
52 {
53 if (reg == ORC_REG_BP_INDIRECT)
54 printf("(bp%+d)", offset);
55 else if (reg == ORC_REG_SP_INDIRECT)
56 printf("(sp%+d)", offset);
57 else if (reg == ORC_REG_UNDEFINED)
58 printf("(und)");
59 else
60 printf("%s%+d", reg_name(reg), offset);
61 }
62
63 int orc_dump(const char *_objname)
64 {
65 int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
66 struct orc_entry *orc = NULL;
67 char *name;
68 size_t nr_sections;
69 Elf64_Addr orc_ip_addr = 0;
70 size_t shstrtab_idx, strtab_idx = 0;
71 Elf *elf;
72 Elf_Scn *scn;
73 GElf_Shdr sh;
74 GElf_Rela rela;
75 GElf_Sym sym;
76 Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
77
78
79 objname = _objname;
80
81 elf_version(EV_CURRENT);
82
83 fd = open(objname, O_RDONLY);
84 if (fd == -1) {
85 perror("open");
86 return -1;
87 }
88
89 elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
90 if (!elf) {
91 WARN_ELF("elf_begin");
92 return -1;
93 }
94
95 if (elf_getshdrnum(elf, &nr_sections)) {
96 WARN_ELF("elf_getshdrnum");
97 return -1;
98 }
99
100 if (elf_getshdrstrndx(elf, &shstrtab_idx)) {
101 WARN_ELF("elf_getshdrstrndx");
102 return -1;
103 }
104
105 for (i = 0; i < nr_sections; i++) {
106 scn = elf_getscn(elf, i);
107 if (!scn) {
108 WARN_ELF("elf_getscn");
109 return -1;
110 }
111
112 if (!gelf_getshdr(scn, &sh)) {
113 WARN_ELF("gelf_getshdr");
114 return -1;
115 }
116
117 name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
118 if (!name) {
119 WARN_ELF("elf_strptr");
120 return -1;
121 }
122
123 data = elf_getdata(scn, NULL);
124 if (!data) {
125 WARN_ELF("elf_getdata");
126 return -1;
127 }
128
129 if (!strcmp(name, ".symtab")) {
130 symtab = data;
131 } else if (!strcmp(name, ".strtab")) {
132 strtab_idx = i;
133 } else if (!strcmp(name, ".orc_unwind")) {
134 orc = data->d_buf;
135 orc_size = sh.sh_size;
136 } else if (!strcmp(name, ".orc_unwind_ip")) {
137 orc_ip = data->d_buf;
138 orc_ip_addr = sh.sh_addr;
139 } else if (!strcmp(name, ".rela.orc_unwind_ip")) {
140 rela_orc_ip = data;
141 }
142 }
143
144 if (!symtab || !strtab_idx || !orc || !orc_ip)
145 return 0;
146
147 if (orc_size % sizeof(*orc) != 0) {
148 WARN("bad .orc_unwind section size");
149 return -1;
150 }
151
152 nr_entries = orc_size / sizeof(*orc);
153 for (i = 0; i < nr_entries; i++) {
154 if (rela_orc_ip) {
155 if (!gelf_getrela(rela_orc_ip, i, &rela)) {
156 WARN_ELF("gelf_getrela");
157 return -1;
158 }
159
160 if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) {
161 WARN_ELF("gelf_getsym");
162 return -1;
163 }
164
165 if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
166 scn = elf_getscn(elf, sym.st_shndx);
167 if (!scn) {
168 WARN_ELF("elf_getscn");
169 return -1;
170 }
171
172 if (!gelf_getshdr(scn, &sh)) {
173 WARN_ELF("gelf_getshdr");
174 return -1;
175 }
176
177 name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
178 if (!name) {
179 WARN_ELF("elf_strptr");
180 return -1;
181 }
182 } else {
183 name = elf_strptr(elf, strtab_idx, sym.st_name);
184 if (!name) {
185 WARN_ELF("elf_strptr");
186 return -1;
187 }
188 }
189
190 printf("%s+%llx:", name, (unsigned long long)rela.r_addend);
191
192 } else {
193 printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
194 }
195
196
197 printf(" sp:");
198
199 print_reg(orc[i].sp_reg, orc[i].sp_offset);
200
201 printf(" bp:");
202
203 print_reg(orc[i].bp_reg, orc[i].bp_offset);
204
205 printf(" type:%s end:%d\n",
206 orc_type_name(orc[i].type), orc[i].end);
207 }
208
209 elf_end(elf);
210 close(fd);
211
212 return 0;
213 }
214
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