11ccea77eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 2627fce14SJosh Poimboeuf /* 3627fce14SJosh Poimboeuf * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> 4627fce14SJosh Poimboeuf */ 5627fce14SJosh Poimboeuf 6627fce14SJosh Poimboeuf #include <stdlib.h> 7627fce14SJosh Poimboeuf #include <string.h> 8627fce14SJosh Poimboeuf 9f7515d9fSJosh Poimboeuf #include <linux/objtool_types.h> 10ee819aedSJulien Thierry #include <asm/orc_types.h> 11ee819aedSJulien Thierry 127786032eSVasily Gorbik #include <objtool/check.h> 137786032eSVasily Gorbik #include <objtool/warn.h> 147786032eSVasily Gorbik #include <objtool/endianness.h> 15627fce14SJosh Poimboeuf 168b946cc3SPeter Zijlstra static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, 178b946cc3SPeter Zijlstra struct instruction *insn) 18627fce14SJosh Poimboeuf { 19ab4e0744SJosh Poimboeuf struct cfi_reg *bp = &cfi->regs[CFI_BP]; 20627fce14SJosh Poimboeuf 21ab4e0744SJosh Poimboeuf memset(orc, 0, sizeof(*orc)); 22627fce14SJosh Poimboeuf 238b946cc3SPeter Zijlstra if (!cfi) { 24*fb799447SJosh Poimboeuf /* 25*fb799447SJosh Poimboeuf * This is usually either unreachable nops/traps (which don't 26*fb799447SJosh Poimboeuf * trigger unreachable instruction warnings), or 27*fb799447SJosh Poimboeuf * STACK_FRAME_NON_STANDARD functions. 28*fb799447SJosh Poimboeuf */ 29*fb799447SJosh Poimboeuf orc->type = ORC_TYPE_UNDEFINED; 308b946cc3SPeter Zijlstra return 0; 318b946cc3SPeter Zijlstra } 328b946cc3SPeter Zijlstra 33f902cfddSJosh Poimboeuf switch (cfi->type) { 34*fb799447SJosh Poimboeuf case UNWIND_HINT_TYPE_UNDEFINED: 35*fb799447SJosh Poimboeuf orc->type = ORC_TYPE_UNDEFINED; 36*fb799447SJosh Poimboeuf return 0; 37*fb799447SJosh Poimboeuf case UNWIND_HINT_TYPE_END_OF_STACK: 38*fb799447SJosh Poimboeuf orc->type = ORC_TYPE_END_OF_STACK; 39*fb799447SJosh Poimboeuf return 0; 40f902cfddSJosh Poimboeuf case UNWIND_HINT_TYPE_CALL: 41f902cfddSJosh Poimboeuf orc->type = ORC_TYPE_CALL; 42f902cfddSJosh Poimboeuf break; 43f902cfddSJosh Poimboeuf case UNWIND_HINT_TYPE_REGS: 44f902cfddSJosh Poimboeuf orc->type = ORC_TYPE_REGS; 45f902cfddSJosh Poimboeuf break; 46f902cfddSJosh Poimboeuf case UNWIND_HINT_TYPE_REGS_PARTIAL: 47f902cfddSJosh Poimboeuf orc->type = ORC_TYPE_REGS_PARTIAL; 48f902cfddSJosh Poimboeuf break; 49f902cfddSJosh Poimboeuf default: 50f902cfddSJosh Poimboeuf WARN_FUNC("unknown unwind hint type %d", 51f902cfddSJosh Poimboeuf insn->sec, insn->offset, cfi->type); 52f902cfddSJosh Poimboeuf return -1; 53f902cfddSJosh Poimboeuf } 54f902cfddSJosh Poimboeuf 5500c8f01cSJosh Poimboeuf orc->signal = cfi->signal; 563eaecac8SJulien Thierry 57ab4e0744SJosh Poimboeuf switch (cfi->cfa.base) { 58627fce14SJosh Poimboeuf case CFI_SP: 59627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_SP; 60627fce14SJosh Poimboeuf break; 61627fce14SJosh Poimboeuf case CFI_SP_INDIRECT: 62627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_SP_INDIRECT; 63627fce14SJosh Poimboeuf break; 64627fce14SJosh Poimboeuf case CFI_BP: 65627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_BP; 66627fce14SJosh Poimboeuf break; 67627fce14SJosh Poimboeuf case CFI_BP_INDIRECT: 68627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_BP_INDIRECT; 69627fce14SJosh Poimboeuf break; 70627fce14SJosh Poimboeuf case CFI_R10: 71627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_R10; 72627fce14SJosh Poimboeuf break; 73627fce14SJosh Poimboeuf case CFI_R13: 74627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_R13; 75627fce14SJosh Poimboeuf break; 76627fce14SJosh Poimboeuf case CFI_DI: 77627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_DI; 78627fce14SJosh Poimboeuf break; 79627fce14SJosh Poimboeuf case CFI_DX: 80627fce14SJosh Poimboeuf orc->sp_reg = ORC_REG_DX; 81627fce14SJosh Poimboeuf break; 82627fce14SJosh Poimboeuf default: 83627fce14SJosh Poimboeuf WARN_FUNC("unknown CFA base reg %d", 84ab4e0744SJosh Poimboeuf insn->sec, insn->offset, cfi->cfa.base); 85627fce14SJosh Poimboeuf return -1; 86627fce14SJosh Poimboeuf } 87627fce14SJosh Poimboeuf 88627fce14SJosh Poimboeuf switch (bp->base) { 89627fce14SJosh Poimboeuf case CFI_UNDEFINED: 90627fce14SJosh Poimboeuf orc->bp_reg = ORC_REG_UNDEFINED; 91627fce14SJosh Poimboeuf break; 92627fce14SJosh Poimboeuf case CFI_CFA: 93627fce14SJosh Poimboeuf orc->bp_reg = ORC_REG_PREV_SP; 94627fce14SJosh Poimboeuf break; 95627fce14SJosh Poimboeuf case CFI_BP: 96627fce14SJosh Poimboeuf orc->bp_reg = ORC_REG_BP; 97627fce14SJosh Poimboeuf break; 98627fce14SJosh Poimboeuf default: 99627fce14SJosh Poimboeuf WARN_FUNC("unknown BP base reg %d", 100627fce14SJosh Poimboeuf insn->sec, insn->offset, bp->base); 101627fce14SJosh Poimboeuf return -1; 102627fce14SJosh Poimboeuf } 103627fce14SJosh Poimboeuf 104ab4e0744SJosh Poimboeuf orc->sp_offset = cfi->cfa.offset; 105627fce14SJosh Poimboeuf orc->bp_offset = bp->offset; 106627fce14SJosh Poimboeuf 107627fce14SJosh Poimboeuf return 0; 108627fce14SJosh Poimboeuf } 109627fce14SJosh Poimboeuf 110ab4e0744SJosh Poimboeuf static int write_orc_entry(struct elf *elf, struct section *orc_sec, 111ef47cc01SPeter Zijlstra struct section *ip_sec, unsigned int idx, 112ab4e0744SJosh Poimboeuf struct section *insn_sec, unsigned long insn_off, 113ab4e0744SJosh Poimboeuf struct orc_entry *o) 114627fce14SJosh Poimboeuf { 115627fce14SJosh Poimboeuf struct orc_entry *orc; 116627fce14SJosh Poimboeuf 117627fce14SJosh Poimboeuf /* populate ORC data */ 118ab4e0744SJosh Poimboeuf orc = (struct orc_entry *)orc_sec->data->d_buf + idx; 119627fce14SJosh Poimboeuf memcpy(orc, o, sizeof(*orc)); 1200646c28bSChristophe Leroy orc->sp_offset = bswap_if_needed(elf, orc->sp_offset); 1210646c28bSChristophe Leroy orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); 122627fce14SJosh Poimboeuf 123f1974222SMatt Helsley /* populate reloc for ip */ 124ef47cc01SPeter Zijlstra if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32, 125ef47cc01SPeter Zijlstra insn_sec, insn_off)) 126627fce14SJosh Poimboeuf return -1; 127627fce14SJosh Poimboeuf 128627fce14SJosh Poimboeuf return 0; 129627fce14SJosh Poimboeuf } 130627fce14SJosh Poimboeuf 131ab4e0744SJosh Poimboeuf struct orc_list_entry { 132ab4e0744SJosh Poimboeuf struct list_head list; 133ab4e0744SJosh Poimboeuf struct orc_entry orc; 134ab4e0744SJosh Poimboeuf struct section *insn_sec; 135ab4e0744SJosh Poimboeuf unsigned long insn_off; 136ab4e0744SJosh Poimboeuf }; 137627fce14SJosh Poimboeuf 138ab4e0744SJosh Poimboeuf static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc, 139ab4e0744SJosh Poimboeuf struct section *sec, unsigned long offset) 140ab4e0744SJosh Poimboeuf { 141ab4e0744SJosh Poimboeuf struct orc_list_entry *entry = malloc(sizeof(*entry)); 142ab4e0744SJosh Poimboeuf 143ab4e0744SJosh Poimboeuf if (!entry) { 144ab4e0744SJosh Poimboeuf WARN("malloc failed"); 145ab4e0744SJosh Poimboeuf return -1; 146ab4e0744SJosh Poimboeuf } 147ab4e0744SJosh Poimboeuf 148ab4e0744SJosh Poimboeuf entry->orc = *orc; 149ab4e0744SJosh Poimboeuf entry->insn_sec = sec; 150ab4e0744SJosh Poimboeuf entry->insn_off = offset; 151ab4e0744SJosh Poimboeuf 152ab4e0744SJosh Poimboeuf list_add_tail(&entry->list, orc_list); 153ab4e0744SJosh Poimboeuf return 0; 154ab4e0744SJosh Poimboeuf } 155ab4e0744SJosh Poimboeuf 156c9c324dcSJosh Poimboeuf static unsigned long alt_group_len(struct alt_group *alt_group) 157c9c324dcSJosh Poimboeuf { 158c9c324dcSJosh Poimboeuf return alt_group->last_insn->offset + 159c9c324dcSJosh Poimboeuf alt_group->last_insn->len - 160c9c324dcSJosh Poimboeuf alt_group->first_insn->offset; 161c9c324dcSJosh Poimboeuf } 162c9c324dcSJosh Poimboeuf 163ab4e0744SJosh Poimboeuf int orc_create(struct objtool_file *file) 164ab4e0744SJosh Poimboeuf { 165ef47cc01SPeter Zijlstra struct section *sec, *orc_sec; 166ab4e0744SJosh Poimboeuf unsigned int nr = 0, idx = 0; 167ab4e0744SJosh Poimboeuf struct orc_list_entry *entry; 168ab4e0744SJosh Poimboeuf struct list_head orc_list; 169ab4e0744SJosh Poimboeuf 170*fb799447SJosh Poimboeuf struct orc_entry null = { .type = ORC_TYPE_UNDEFINED }; 171627fce14SJosh Poimboeuf 172ab4e0744SJosh Poimboeuf /* Build a deduplicated list of ORC entries: */ 173ab4e0744SJosh Poimboeuf INIT_LIST_HEAD(&orc_list); 174ab4e0744SJosh Poimboeuf for_each_sec(file, sec) { 175ab4e0744SJosh Poimboeuf struct orc_entry orc, prev_orc = {0}; 176ab4e0744SJosh Poimboeuf struct instruction *insn; 177ab4e0744SJosh Poimboeuf bool empty = true; 178ab4e0744SJosh Poimboeuf 179ab4e0744SJosh Poimboeuf if (!sec->text) 180ab4e0744SJosh Poimboeuf continue; 181ab4e0744SJosh Poimboeuf 182ab4e0744SJosh Poimboeuf sec_for_each_insn(file, sec, insn) { 183c9c324dcSJosh Poimboeuf struct alt_group *alt_group = insn->alt_group; 184c9c324dcSJosh Poimboeuf int i; 185c9c324dcSJosh Poimboeuf 186c9c324dcSJosh Poimboeuf if (!alt_group) { 1878b946cc3SPeter Zijlstra if (init_orc_entry(&orc, insn->cfi, insn)) 188ab4e0744SJosh Poimboeuf return -1; 189ab4e0744SJosh Poimboeuf if (!memcmp(&prev_orc, &orc, sizeof(orc))) 190ab4e0744SJosh Poimboeuf continue; 191c9c324dcSJosh Poimboeuf if (orc_list_add(&orc_list, &orc, sec, 192c9c324dcSJosh Poimboeuf insn->offset)) 193ab4e0744SJosh Poimboeuf return -1; 194ab4e0744SJosh Poimboeuf nr++; 195ab4e0744SJosh Poimboeuf prev_orc = orc; 196ab4e0744SJosh Poimboeuf empty = false; 197c9c324dcSJosh Poimboeuf continue; 198c9c324dcSJosh Poimboeuf } 199c9c324dcSJosh Poimboeuf 200c9c324dcSJosh Poimboeuf /* 201c9c324dcSJosh Poimboeuf * Alternatives can have different stack layout 202c9c324dcSJosh Poimboeuf * possibilities (but they shouldn't conflict). 203c9c324dcSJosh Poimboeuf * Instead of traversing the instructions, use the 204c9c324dcSJosh Poimboeuf * alt_group's flattened byte-offset-addressed CFI 205c9c324dcSJosh Poimboeuf * array. 206c9c324dcSJosh Poimboeuf */ 207c9c324dcSJosh Poimboeuf for (i = 0; i < alt_group_len(alt_group); i++) { 208c9c324dcSJosh Poimboeuf struct cfi_state *cfi = alt_group->cfi[i]; 209c9c324dcSJosh Poimboeuf if (!cfi) 210c9c324dcSJosh Poimboeuf continue; 2118b946cc3SPeter Zijlstra /* errors are reported on the original insn */ 2128b946cc3SPeter Zijlstra if (init_orc_entry(&orc, cfi, insn)) 213c9c324dcSJosh Poimboeuf return -1; 214c9c324dcSJosh Poimboeuf if (!memcmp(&prev_orc, &orc, sizeof(orc))) 215c9c324dcSJosh Poimboeuf continue; 216c9c324dcSJosh Poimboeuf if (orc_list_add(&orc_list, &orc, insn->sec, 217c9c324dcSJosh Poimboeuf insn->offset + i)) 218c9c324dcSJosh Poimboeuf return -1; 219c9c324dcSJosh Poimboeuf nr++; 220c9c324dcSJosh Poimboeuf prev_orc = orc; 221c9c324dcSJosh Poimboeuf empty = false; 222c9c324dcSJosh Poimboeuf } 223c9c324dcSJosh Poimboeuf 224c9c324dcSJosh Poimboeuf /* Skip to the end of the alt_group */ 225c9c324dcSJosh Poimboeuf insn = alt_group->last_insn; 226ab4e0744SJosh Poimboeuf } 227ab4e0744SJosh Poimboeuf 228ab4e0744SJosh Poimboeuf /* Add a section terminator */ 229ab4e0744SJosh Poimboeuf if (!empty) { 230fe255fe6SJoe Lawrence orc_list_add(&orc_list, &null, sec, sec->sh.sh_size); 231ab4e0744SJosh Poimboeuf nr++; 232ab4e0744SJosh Poimboeuf } 233ab4e0744SJosh Poimboeuf } 234ab4e0744SJosh Poimboeuf if (!nr) 235ab4e0744SJosh Poimboeuf return 0; 236ab4e0744SJosh Poimboeuf 237ab4e0744SJosh Poimboeuf /* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */ 238627fce14SJosh Poimboeuf sec = find_section_by_name(file->elf, ".orc_unwind"); 239627fce14SJosh Poimboeuf if (sec) { 240627fce14SJosh Poimboeuf WARN("file already has .orc_unwind section, skipping"); 241627fce14SJosh Poimboeuf return -1; 242627fce14SJosh Poimboeuf } 243ab4e0744SJosh Poimboeuf orc_sec = elf_create_section(file->elf, ".orc_unwind", 0, 244ab4e0744SJosh Poimboeuf sizeof(struct orc_entry), nr); 245ab4e0744SJosh Poimboeuf if (!orc_sec) 246627fce14SJosh Poimboeuf return -1; 247627fce14SJosh Poimboeuf 248ab4e0744SJosh Poimboeuf sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr); 249ce90aaf5SSimon Ser if (!sec) 250ce90aaf5SSimon Ser return -1; 251627fce14SJosh Poimboeuf 252ab4e0744SJosh Poimboeuf /* Write ORC entries to sections: */ 253ab4e0744SJosh Poimboeuf list_for_each_entry(entry, &orc_list, list) { 254ef47cc01SPeter Zijlstra if (write_orc_entry(file->elf, orc_sec, sec, idx++, 255ab4e0744SJosh Poimboeuf entry->insn_sec, entry->insn_off, 256ab4e0744SJosh Poimboeuf &entry->orc)) 257627fce14SJosh Poimboeuf return -1; 258627fce14SJosh Poimboeuf } 259627fce14SJosh Poimboeuf 260627fce14SJosh Poimboeuf return 0; 261627fce14SJosh Poimboeuf } 262