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 <linux/objtool.h>
8 #include <asm/orc_types.h>
9 #include <objtool/objtool.h>
10 #include <objtool/warn.h>
11 #include <objtool/endianness.h>
12
reg_name(unsigned int reg)13 static const char *reg_name(unsigned int reg)
14 {
15 switch (reg) {
16 case ORC_REG_PREV_SP:
17 return "prevsp";
18 case ORC_REG_DX:
19 return "dx";
20 case ORC_REG_DI:
21 return "di";
22 case ORC_REG_BP:
23 return "bp";
24 case ORC_REG_SP:
25 return "sp";
26 case ORC_REG_R10:
27 return "r10";
28 case ORC_REG_R13:
29 return "r13";
30 case ORC_REG_BP_INDIRECT:
31 return "bp(ind)";
32 case ORC_REG_SP_INDIRECT:
33 return "sp(ind)";
34 default:
35 return "?";
36 }
37 }
38
orc_type_name(unsigned int type)39 static const char *orc_type_name(unsigned int type)
40 {
41 switch (type) {
42 case UNWIND_HINT_TYPE_CALL:
43 return "call";
44 case UNWIND_HINT_TYPE_REGS:
45 return "regs";
46 case UNWIND_HINT_TYPE_REGS_PARTIAL:
47 return "regs (partial)";
48 default:
49 return "?";
50 }
51 }
52
print_reg(unsigned int reg,int offset)53 static void print_reg(unsigned int reg, int offset)
54 {
55 if (reg == ORC_REG_BP_INDIRECT)
56 printf("(bp%+d)", offset);
57 else if (reg == ORC_REG_SP_INDIRECT)
58 printf("(sp)%+d", offset);
59 else if (reg == ORC_REG_UNDEFINED)
60 printf("(und)");
61 else
62 printf("%s%+d", reg_name(reg), offset);
63 }
64
orc_dump(const char * _objname)65 int orc_dump(const char *_objname)
66 {
67 int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
68 struct orc_entry *orc = NULL;
69 char *name;
70 size_t nr_sections;
71 Elf64_Addr orc_ip_addr = 0;
72 size_t shstrtab_idx, strtab_idx = 0;
73 Elf *elf;
74 Elf_Scn *scn;
75 GElf_Shdr sh;
76 GElf_Rela rela;
77 GElf_Sym sym;
78 Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
79
80
81 objname = _objname;
82
83 elf_version(EV_CURRENT);
84
85 fd = open(objname, O_RDONLY);
86 if (fd == -1) {
87 perror("open");
88 return -1;
89 }
90
91 elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
92 if (!elf) {
93 WARN_ELF("elf_begin");
94 return -1;
95 }
96
97 if (elf_getshdrnum(elf, &nr_sections)) {
98 WARN_ELF("elf_getshdrnum");
99 return -1;
100 }
101
102 if (elf_getshdrstrndx(elf, &shstrtab_idx)) {
103 WARN_ELF("elf_getshdrstrndx");
104 return -1;
105 }
106
107 for (i = 0; i < nr_sections; i++) {
108 scn = elf_getscn(elf, i);
109 if (!scn) {
110 WARN_ELF("elf_getscn");
111 return -1;
112 }
113
114 if (!gelf_getshdr(scn, &sh)) {
115 WARN_ELF("gelf_getshdr");
116 return -1;
117 }
118
119 name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
120 if (!name) {
121 WARN_ELF("elf_strptr");
122 return -1;
123 }
124
125 data = elf_getdata(scn, NULL);
126 if (!data) {
127 WARN_ELF("elf_getdata");
128 return -1;
129 }
130
131 if (!strcmp(name, ".symtab")) {
132 symtab = data;
133 } else if (!strcmp(name, ".strtab")) {
134 strtab_idx = i;
135 } else if (!strcmp(name, ".orc_unwind")) {
136 orc = data->d_buf;
137 orc_size = sh.sh_size;
138 } else if (!strcmp(name, ".orc_unwind_ip")) {
139 orc_ip = data->d_buf;
140 orc_ip_addr = sh.sh_addr;
141 } else if (!strcmp(name, ".rela.orc_unwind_ip")) {
142 rela_orc_ip = data;
143 }
144 }
145
146 if (!symtab || !strtab_idx || !orc || !orc_ip)
147 return 0;
148
149 if (orc_size % sizeof(*orc) != 0) {
150 WARN("bad .orc_unwind section size");
151 return -1;
152 }
153
154 nr_entries = orc_size / sizeof(*orc);
155 for (i = 0; i < nr_entries; i++) {
156 if (rela_orc_ip) {
157 if (!gelf_getrela(rela_orc_ip, i, &rela)) {
158 WARN_ELF("gelf_getrela");
159 return -1;
160 }
161
162 if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) {
163 WARN_ELF("gelf_getsym");
164 return -1;
165 }
166
167 if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
168 scn = elf_getscn(elf, sym.st_shndx);
169 if (!scn) {
170 WARN_ELF("elf_getscn");
171 return -1;
172 }
173
174 if (!gelf_getshdr(scn, &sh)) {
175 WARN_ELF("gelf_getshdr");
176 return -1;
177 }
178
179 name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
180 if (!name) {
181 WARN_ELF("elf_strptr");
182 return -1;
183 }
184 } else {
185 name = elf_strptr(elf, strtab_idx, sym.st_name);
186 if (!name) {
187 WARN_ELF("elf_strptr");
188 return -1;
189 }
190 }
191
192 printf("%s+%llx:", name, (unsigned long long)rela.r_addend);
193
194 } else {
195 printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
196 }
197
198
199 printf(" sp:");
200
201 print_reg(orc[i].sp_reg, bswap_if_needed(orc[i].sp_offset));
202
203 printf(" bp:");
204
205 print_reg(orc[i].bp_reg, bswap_if_needed(orc[i].bp_offset));
206
207 printf(" type:%s end:%d\n",
208 orc_type_name(orc[i].type), orc[i].end);
209 }
210
211 elf_end(elf);
212 close(fd);
213
214 return 0;
215 }
216