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/objtool.h>
  9#include <objtool/warn.h>
 10#include <objtool/endianness.h>
 11
 12static 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
 38static const char *orc_type_name(unsigned int type)
 39{
 40	switch (type) {
 41	case ORC_TYPE_UNDEFINED:
 42		return "(und)";
 43	case ORC_TYPE_END_OF_STACK:
 44		return "end";
 45	case ORC_TYPE_CALL:
 46		return "call";
 47	case ORC_TYPE_REGS:
 48		return "regs";
 49	case ORC_TYPE_REGS_PARTIAL:
 50		return "regs (partial)";
 51	default:
 52		return "?";
 53	}
 54}
 55
 56static void print_reg(unsigned int reg, int offset)
 57{
 58	if (reg == ORC_REG_BP_INDIRECT)
 59		printf("(bp%+d)", offset);
 60	else if (reg == ORC_REG_SP_INDIRECT)
 61		printf("(sp)%+d", offset);
 62	else if (reg == ORC_REG_UNDEFINED)
 63		printf("(und)");
 64	else
 65		printf("%s%+d", reg_name(reg), offset);
 66}
 67
 68int orc_dump(const char *_objname)
 69{
 70	int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
 71	struct orc_entry *orc = NULL;
 72	char *name;
 73	size_t nr_sections;
 74	Elf64_Addr orc_ip_addr = 0;
 75	size_t shstrtab_idx, strtab_idx = 0;
 76	Elf *elf;
 77	Elf_Scn *scn;
 78	GElf_Shdr sh;
 79	GElf_Rela rela;
 80	GElf_Sym sym;
 81	Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
 82	struct elf dummy_elf = {};
 83
 84
 85	objname = _objname;
 86
 87	elf_version(EV_CURRENT);
 88
 89	fd = open(objname, O_RDONLY);
 90	if (fd == -1) {
 91		perror("open");
 92		return -1;
 93	}
 94
 95	elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
 96	if (!elf) {
 97		WARN_ELF("elf_begin");
 98		return -1;
 99	}
100
101	if (!elf64_getehdr(elf)) {
102		WARN_ELF("elf64_getehdr");
103		return -1;
104	}
105	memcpy(&dummy_elf.ehdr, elf64_getehdr(elf), sizeof(dummy_elf.ehdr));
106
107	if (elf_getshdrnum(elf, &nr_sections)) {
108		WARN_ELF("elf_getshdrnum");
109		return -1;
110	}
111
112	if (elf_getshdrstrndx(elf, &shstrtab_idx)) {
113		WARN_ELF("elf_getshdrstrndx");
114		return -1;
115	}
116
117	for (i = 0; i < nr_sections; i++) {
118		scn = elf_getscn(elf, i);
119		if (!scn) {
120			WARN_ELF("elf_getscn");
121			return -1;
122		}
123
124		if (!gelf_getshdr(scn, &sh)) {
125			WARN_ELF("gelf_getshdr");
126			return -1;
127		}
128
129		name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
130		if (!name) {
131			WARN_ELF("elf_strptr");
132			return -1;
133		}
134
135		data = elf_getdata(scn, NULL);
136		if (!data) {
137			WARN_ELF("elf_getdata");
138			return -1;
139		}
140
141		if (!strcmp(name, ".symtab")) {
142			symtab = data;
143		} else if (!strcmp(name, ".strtab")) {
144			strtab_idx = i;
145		} else if (!strcmp(name, ".orc_unwind")) {
146			orc = data->d_buf;
147			orc_size = sh.sh_size;
148		} else if (!strcmp(name, ".orc_unwind_ip")) {
149			orc_ip = data->d_buf;
150			orc_ip_addr = sh.sh_addr;
151		} else if (!strcmp(name, ".rela.orc_unwind_ip")) {
152			rela_orc_ip = data;
153		}
154	}
155
156	if (!symtab || !strtab_idx || !orc || !orc_ip)
157		return 0;
158
159	if (orc_size % sizeof(*orc) != 0) {
160		WARN("bad .orc_unwind section size");
161		return -1;
162	}
163
164	nr_entries = orc_size / sizeof(*orc);
165	for (i = 0; i < nr_entries; i++) {
166		if (rela_orc_ip) {
167			if (!gelf_getrela(rela_orc_ip, i, &rela)) {
168				WARN_ELF("gelf_getrela");
169				return -1;
170			}
171
172			if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) {
173				WARN_ELF("gelf_getsym");
174				return -1;
175			}
176
177			if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
178				scn = elf_getscn(elf, sym.st_shndx);
179				if (!scn) {
180					WARN_ELF("elf_getscn");
181					return -1;
182				}
183
184				if (!gelf_getshdr(scn, &sh)) {
185					WARN_ELF("gelf_getshdr");
186					return -1;
187				}
188
189				name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
190				if (!name) {
191					WARN_ELF("elf_strptr");
192					return -1;
193				}
194			} else {
195				name = elf_strptr(elf, strtab_idx, sym.st_name);
196				if (!name) {
197					WARN_ELF("elf_strptr");
198					return -1;
199				}
200			}
201
202			printf("%s+%llx:", name, (unsigned long long)rela.r_addend);
203
204		} else {
205			printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
206		}
207
208		printf("type:%s", orc_type_name(orc[i].type));
209
210		printf(" sp:");
211
212		print_reg(orc[i].sp_reg, bswap_if_needed(&dummy_elf, orc[i].sp_offset));
213
214		printf(" bp:");
215
216		print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset));
217
218		printf(" signal:%d\n", orc[i].signal);
219	}
220
221	elf_end(elf);
222	close(fd);
223
224	return 0;
225}