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 <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 }