// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
 */

#include <unistd.h>
#include <asm/orc_types.h>
#include <objtool/objtool.h>
#include <objtool/orc.h>
#include <objtool/warn.h>

int orc_dump(const char *filename)
{
        int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
        struct orc_entry *orc = NULL;
        char *name;
        size_t nr_sections;
        Elf64_Addr orc_ip_addr = 0;
        size_t shstrtab_idx, strtab_idx = 0;
        Elf *elf;
        Elf_Scn *scn;
        GElf_Shdr sh;
        GElf_Rela rela;
        GElf_Sym sym;
        Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
        struct elf dummy_elf = {};

        elf_version(EV_CURRENT);

        fd = open(filename, O_RDONLY);
        if (fd == -1) {
                perror("open");
                return -1;
        }

        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
        if (!elf) {
                ERROR_ELF("elf_begin");
                return -1;
        }

        if (!elf64_getehdr(elf)) {
                ERROR_ELF("elf64_getehdr");
                return -1;
        }
        memcpy(&dummy_elf.ehdr, elf64_getehdr(elf), sizeof(dummy_elf.ehdr));

        if (elf_getshdrnum(elf, &nr_sections)) {
                ERROR_ELF("elf_getshdrnum");
                return -1;
        }

        if (elf_getshdrstrndx(elf, &shstrtab_idx)) {
                ERROR_ELF("elf_getshdrstrndx");
                return -1;
        }

        for (i = 0; i < nr_sections; i++) {
                scn = elf_getscn(elf, i);
                if (!scn) {
                        ERROR_ELF("elf_getscn");
                        return -1;
                }

                if (!gelf_getshdr(scn, &sh)) {
                        ERROR_ELF("gelf_getshdr");
                        return -1;
                }

                name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
                if (!name) {
                        ERROR_ELF("elf_strptr");
                        return -1;
                }

                data = elf_getdata(scn, NULL);
                if (!data) {
                        ERROR_ELF("elf_getdata");
                        return -1;
                }

                if (!strcmp(name, ".symtab")) {
                        symtab = data;
                } else if (!strcmp(name, ".strtab")) {
                        strtab_idx = i;
                } else if (!strcmp(name, ".orc_unwind")) {
                        orc = data->d_buf;
                        orc_size = sh.sh_size;
                } else if (!strcmp(name, ".orc_unwind_ip")) {
                        orc_ip = data->d_buf;
                        orc_ip_addr = sh.sh_addr;
                } else if (!strcmp(name, ".rela.orc_unwind_ip")) {
                        rela_orc_ip = data;
                }
        }

        if (!symtab || !strtab_idx || !orc || !orc_ip)
                return 0;

        if (orc_size % sizeof(*orc) != 0) {
                ERROR("bad .orc_unwind section size");
                return -1;
        }

        nr_entries = orc_size / sizeof(*orc);
        for (i = 0; i < nr_entries; i++) {
                if (rela_orc_ip) {
                        if (!gelf_getrela(rela_orc_ip, i, &rela)) {
                                ERROR_ELF("gelf_getrela");
                                return -1;
                        }

                        if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) {
                                ERROR_ELF("gelf_getsym");
                                return -1;
                        }

                        if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
                                scn = elf_getscn(elf, sym.st_shndx);
                                if (!scn) {
                                        ERROR_ELF("elf_getscn");
                                        return -1;
                                }

                                if (!gelf_getshdr(scn, &sh)) {
                                        ERROR_ELF("gelf_getshdr");
                                        return -1;
                                }

                                name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
                                if (!name) {
                                        ERROR_ELF("elf_strptr");
                                        return -1;
                                }
                        } else {
                                name = elf_strptr(elf, strtab_idx, sym.st_name);
                                if (!name) {
                                        ERROR_ELF("elf_strptr");
                                        return -1;
                                }
                        }

                        printf("%s+%llx:", name, (unsigned long long)rela.r_addend);

                } else {
                        printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
                }

                orc_print_dump(&dummy_elf, orc, i);
        }

        elf_end(elf);
        close(fd);

        return 0;
}