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