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