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 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