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 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 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 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 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 struct elf dummy_elf = {}; 80 81 82 objname = _objname; 83 84 elf_version(EV_CURRENT); 85 86 fd = open(objname, O_RDONLY); 87 if (fd == -1) { 88 perror("open"); 89 return -1; 90 } 91 92 elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); 93 if (!elf) { 94 WARN_ELF("elf_begin"); 95 return -1; 96 } 97 98 if (!elf64_getehdr(elf)) { 99 WARN_ELF("elf64_getehdr"); 100 return -1; 101 } 102 memcpy(&dummy_elf.ehdr, elf64_getehdr(elf), sizeof(dummy_elf.ehdr)); 103 104 if (elf_getshdrnum(elf, &nr_sections)) { 105 WARN_ELF("elf_getshdrnum"); 106 return -1; 107 } 108 109 if (elf_getshdrstrndx(elf, &shstrtab_idx)) { 110 WARN_ELF("elf_getshdrstrndx"); 111 return -1; 112 } 113 114 for (i = 0; i < nr_sections; i++) { 115 scn = elf_getscn(elf, i); 116 if (!scn) { 117 WARN_ELF("elf_getscn"); 118 return -1; 119 } 120 121 if (!gelf_getshdr(scn, &sh)) { 122 WARN_ELF("gelf_getshdr"); 123 return -1; 124 } 125 126 name = elf_strptr(elf, shstrtab_idx, sh.sh_name); 127 if (!name) { 128 WARN_ELF("elf_strptr"); 129 return -1; 130 } 131 132 data = elf_getdata(scn, NULL); 133 if (!data) { 134 WARN_ELF("elf_getdata"); 135 return -1; 136 } 137 138 if (!strcmp(name, ".symtab")) { 139 symtab = data; 140 } else if (!strcmp(name, ".strtab")) { 141 strtab_idx = i; 142 } else if (!strcmp(name, ".orc_unwind")) { 143 orc = data->d_buf; 144 orc_size = sh.sh_size; 145 } else if (!strcmp(name, ".orc_unwind_ip")) { 146 orc_ip = data->d_buf; 147 orc_ip_addr = sh.sh_addr; 148 } else if (!strcmp(name, ".rela.orc_unwind_ip")) { 149 rela_orc_ip = data; 150 } 151 } 152 153 if (!symtab || !strtab_idx || !orc || !orc_ip) 154 return 0; 155 156 if (orc_size % sizeof(*orc) != 0) { 157 WARN("bad .orc_unwind section size"); 158 return -1; 159 } 160 161 nr_entries = orc_size / sizeof(*orc); 162 for (i = 0; i < nr_entries; i++) { 163 if (rela_orc_ip) { 164 if (!gelf_getrela(rela_orc_ip, i, &rela)) { 165 WARN_ELF("gelf_getrela"); 166 return -1; 167 } 168 169 if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) { 170 WARN_ELF("gelf_getsym"); 171 return -1; 172 } 173 174 if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) { 175 scn = elf_getscn(elf, sym.st_shndx); 176 if (!scn) { 177 WARN_ELF("elf_getscn"); 178 return -1; 179 } 180 181 if (!gelf_getshdr(scn, &sh)) { 182 WARN_ELF("gelf_getshdr"); 183 return -1; 184 } 185 186 name = elf_strptr(elf, shstrtab_idx, sh.sh_name); 187 if (!name) { 188 WARN_ELF("elf_strptr"); 189 return -1; 190 } 191 } else { 192 name = elf_strptr(elf, strtab_idx, sym.st_name); 193 if (!name) { 194 WARN_ELF("elf_strptr"); 195 return -1; 196 } 197 } 198 199 printf("%s+%llx:", name, (unsigned long long)rela.r_addend); 200 201 } else { 202 printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i])); 203 } 204 205 206 printf(" sp:"); 207 208 print_reg(orc[i].sp_reg, bswap_if_needed(&dummy_elf, orc[i].sp_offset)); 209 210 printf(" bp:"); 211 212 print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset)); 213 214 printf(" type:%s end:%d\n", 215 orc_type_name(orc[i].type), orc[i].end); 216 } 217 218 elf_end(elf); 219 close(fd); 220 221 return 0; 222 } 223