Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> */ #include <stdlib.h> #include <string.h> #include "orc.h" #include "check.h" #include "warn.h" int create_orc(struct objtool_file *file) { struct instruction *insn; for_each_insn(file, insn) { struct orc_entry *orc = &insn->orc; struct cfi_reg *cfa = &insn->state.cfa; struct cfi_reg *bp = &insn->state.regs[CFI_BP]; orc->end = insn->state.end; if (cfa->base == CFI_UNDEFINED) { orc->sp_reg = ORC_REG_UNDEFINED; continue; } switch (cfa->base) { case CFI_SP: orc->sp_reg = ORC_REG_SP; break; case CFI_SP_INDIRECT: orc->sp_reg = ORC_REG_SP_INDIRECT; break; case CFI_BP: orc->sp_reg = ORC_REG_BP; break; case CFI_BP_INDIRECT: orc->sp_reg = ORC_REG_BP_INDIRECT; break; case CFI_R10: orc->sp_reg = ORC_REG_R10; break; case CFI_R13: orc->sp_reg = ORC_REG_R13; break; case CFI_DI: orc->sp_reg = ORC_REG_DI; break; case CFI_DX: orc->sp_reg = ORC_REG_DX; break; default: WARN_FUNC("unknown CFA base reg %d", insn->sec, insn->offset, cfa->base); return -1; } switch(bp->base) { case CFI_UNDEFINED: orc->bp_reg = ORC_REG_UNDEFINED; break; case CFI_CFA: orc->bp_reg = ORC_REG_PREV_SP; break; case CFI_BP: orc->bp_reg = ORC_REG_BP; break; default: WARN_FUNC("unknown BP base reg %d", insn->sec, insn->offset, bp->base); return -1; } orc->sp_offset = cfa->offset; orc->bp_offset = bp->offset; orc->type = insn->state.type; } return 0; } static int create_orc_entry(struct section *u_sec, struct section *ip_relasec, unsigned int idx, struct section *insn_sec, unsigned long insn_off, struct orc_entry *o) { struct orc_entry *orc; struct rela *rela; if (!insn_sec->sym) { WARN("missing symbol for section %s", insn_sec->name); return -1; } /* populate ORC data */ orc = (struct orc_entry *)u_sec->data->d_buf + idx; memcpy(orc, o, sizeof(*orc)); /* populate rela for ip */ rela = malloc(sizeof(*rela)); if (!rela) { perror("malloc"); return -1; } memset(rela, 0, sizeof(*rela)); rela->sym = insn_sec->sym; rela->addend = insn_off; rela->type = R_X86_64_PC32; rela->offset = idx * sizeof(int); list_add_tail(&rela->list, &ip_relasec->rela_list); hash_add(ip_relasec->rela_hash, &rela->hash, rela->offset); return 0; } int create_orc_sections(struct objtool_file *file) { struct instruction *insn, *prev_insn; struct section *sec, *u_sec, *ip_relasec; unsigned int idx; struct orc_entry empty = { .sp_reg = ORC_REG_UNDEFINED, .bp_reg = ORC_REG_UNDEFINED, .type = ORC_TYPE_CALL, }; sec = find_section_by_name(file->elf, ".orc_unwind"); if (sec) { WARN("file already has .orc_unwind section, skipping"); return -1; } /* count the number of needed orcs */ idx = 0; for_each_sec(file, sec) { if (!sec->text) continue; prev_insn = NULL; sec_for_each_insn(file, sec, insn) { if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc, sizeof(struct orc_entry))) { idx++; } prev_insn = insn; } /* section terminator */ if (prev_insn) idx++; } if (!idx) return -1; /* create .orc_unwind_ip and .rela.orc_unwind_ip sections */ sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx); if (!sec) return -1; ip_relasec = elf_create_rela_section(file->elf, sec); if (!ip_relasec) return -1; /* create .orc_unwind section */ u_sec = elf_create_section(file->elf, ".orc_unwind", sizeof(struct orc_entry), idx); /* populate sections */ idx = 0; for_each_sec(file, sec) { if (!sec->text) continue; prev_insn = NULL; sec_for_each_insn(file, sec, insn) { if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc, sizeof(struct orc_entry))) { if (create_orc_entry(u_sec, ip_relasec, idx, insn->sec, insn->offset, &insn->orc)) return -1; idx++; } prev_insn = insn; } /* section terminator */ if (prev_insn) { if (create_orc_entry(u_sec, ip_relasec, idx, prev_insn->sec, prev_insn->offset + prev_insn->len, &empty)) return -1; idx++; } } if (elf_rebuild_rela_section(ip_relasec)) return -1; return 0; } |