tools/objtool/orc_dump.c

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