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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 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> */ #include <stdlib.h> #include <string.h> #include <linux/objtool_types.h> #include <asm/orc_types.h> #include <objtool/check.h> #include <objtool/orc.h> #include <objtool/warn.h> #include <objtool/endianness.h> struct orc_list_entry { struct list_head list; struct orc_entry orc; struct section *insn_sec; unsigned long insn_off; }; static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc, struct section *sec, unsigned long offset) { struct orc_list_entry *entry = malloc(sizeof(*entry)); if (!entry) { WARN("malloc failed"); return -1; } entry->orc = *orc; entry->insn_sec = sec; entry->insn_off = offset; list_add_tail(&entry->list, orc_list); return 0; } static unsigned long alt_group_len(struct alt_group *alt_group) { return alt_group->last_insn->offset + alt_group->last_insn->len - alt_group->first_insn->offset; } int orc_create(struct objtool_file *file) { struct section *sec, *orc_sec; unsigned int nr = 0, idx = 0; struct orc_list_entry *entry; struct list_head orc_list; struct orc_entry null = { .type = ORC_TYPE_UNDEFINED }; /* Build a deduplicated list of ORC entries: */ INIT_LIST_HEAD(&orc_list); for_each_sec(file, sec) { struct orc_entry orc, prev_orc = {0}; struct instruction *insn; bool empty = true; if (!sec->text) continue; sec_for_each_insn(file, sec, insn) { struct alt_group *alt_group = insn->alt_group; int i; if (!alt_group) { if (init_orc_entry(&orc, insn->cfi, insn)) return -1; if (!memcmp(&prev_orc, &orc, sizeof(orc))) continue; if (orc_list_add(&orc_list, &orc, sec, insn->offset)) return -1; nr++; prev_orc = orc; empty = false; continue; } /* * Alternatives can have different stack layout * possibilities (but they shouldn't conflict). * Instead of traversing the instructions, use the * alt_group's flattened byte-offset-addressed CFI * array. */ for (i = 0; i < alt_group_len(alt_group); i++) { struct cfi_state *cfi = alt_group->cfi[i]; if (!cfi) continue; /* errors are reported on the original insn */ if (init_orc_entry(&orc, cfi, insn)) return -1; if (!memcmp(&prev_orc, &orc, sizeof(orc))) continue; if (orc_list_add(&orc_list, &orc, insn->sec, insn->offset + i)) return -1; nr++; prev_orc = orc; empty = false; } /* Skip to the end of the alt_group */ insn = alt_group->last_insn; } /* Add a section terminator */ if (!empty) { orc_list_add(&orc_list, &null, sec, sec->sh.sh_size); nr++; } } if (!nr) return 0; /* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */ sec = find_section_by_name(file->elf, ".orc_unwind"); if (sec) { WARN("file already has .orc_unwind section, skipping"); return -1; } orc_sec = elf_create_section(file->elf, ".orc_unwind", sizeof(struct orc_entry), nr); if (!orc_sec) return -1; sec = elf_create_section_pair(file->elf, ".orc_unwind_ip", sizeof(int), nr, nr); if (!sec) return -1; /* Write ORC entries to sections: */ list_for_each_entry(entry, &orc_list, list) { if (write_orc_entry(file->elf, orc_sec, sec, idx++, entry->insn_sec, entry->insn_off, &entry->orc)) return -1; } return 0; } |