tests/dump/dump.c

	dump.c revision 702941cd97e30d600c2c1275823bc58231b2c361
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2011, Joyent, Inc. All rights reserved.
 * Copyright (c) 2011, Robert Mustacchi, Inc. All rights reserved.
 * Copyright 2013, Richard Lowe.
 */

#include <err.h>
#include <fcntl.h>
#include <gelf.h>
#include <libctf.h>
#include <saveargs.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>

extern const char *__progname;

typedef struct symtab_sym {
    GElf_Sym ss_sym;
    char *ss_name;
    ctf_funcinfo_t ss_finfo;
    uint8_t *ss_data;
    size_t ss_size;
} symtab_sym_t;

static void
walk_symtab(Elf *elf, char *fname, ctf_file_t *fp,
    void (*callback)(ctf_file_t *, symtab_sym_t *))
{
    Elf_Scn *stab = NULL;
    Elf_Scn *text = NULL;
    Elf_Data *stabdata = NULL;
    Elf_Data *textdata = NULL;
    GElf_Ehdr ehdr;
    GElf_Shdr stabshdr;
    GElf_Shdr textshdr;
    int foundtext = 0, foundstab = 0;
    symtab_sym_t ss;

    if ((gelf_getehdr(elf, &ehdr)) == NULL)
        errx(1, "could not read ELF header from %s\n",
            fname);

    while ((stab = elf_nextscn(elf, stab)) != NULL) {
        (void) gelf_getshdr(stab, &stabshdr);

        if (stabshdr.sh_type == SHT_SYMTAB) {
            foundstab = 1;
            break;
        }
    }

    while ((text = elf_nextscn(elf, text)) != NULL) {
        (void) gelf_getshdr(text, &textshdr);

        if (strcmp(".text", elf_strptr(elf,
            ehdr.e_shstrndx, (size_t)textshdr.sh_name)) == 0) {
            foundtext = 1;
            break;
        }
    }

    if (!foundstab || !foundtext)
        return;

    stabdata = elf_getdata(stab, NULL);
    textdata = elf_rawdata(text,  NULL);
    for (unsigned symdx = 0;
        symdx < (stabshdr.sh_size / stabshdr.sh_entsize);
        symdx++) {
        (void) gelf_getsym(stabdata, symdx, &ss.ss_sym);

        if ((GELF_ST_TYPE(ss.ss_sym.st_info) != STT_FUNC) ||
            (ss.ss_sym.st_shndx == SHN_UNDEF))
            continue;

        ss.ss_name = elf_strptr(elf, stabshdr.sh_link,
            ss.ss_sym.st_name);
        ss.ss_data = ((uint8_t *)(textdata->d_buf)) +
            (ss.ss_sym.st_value - textshdr.sh_addr);

        if (ctf_func_info(fp, symdx, &ss.ss_finfo) == CTF_ERR) {
            fprintf(stderr, "failed to get funcinfo for: %s\n",
                ss.ss_name);
            continue;
        }

        (void) callback(fp, &ss);
    }
}

void
check_sym(ctf_file_t *ctfp, symtab_sym_t *ss)
{
    int rettype = ctf_type_kind(ctfp, ss->ss_finfo.ctc_return);
    int start_index = 0;

    if (ss->ss_finfo.ctc_argc == 0) /* No arguments, no point */
        return;

    if (((rettype == CTF_K_STRUCT) || (rettype == CTF_K_UNION)) &&
        ctf_type_size(ctfp, ss->ss_finfo.ctc_return) > 16)
        start_index = 1;

    if (saveargs_has_args(ss->ss_data, ss->ss_sym.st_size,
        ss->ss_finfo.ctc_argc, start_index) != SAVEARGS_NO_ARGS)
        printf("%s has %d saved args\n", ss->ss_name,
            ss->ss_finfo.ctc_argc);
}

int
main(int argc, char **argv)
{
    Elf     *elf;
    ctf_file_t  *ctfp;
    int errp, fd;

    if (ctf_version(CTF_VERSION) == -1)
        errx(1, "mismatched libctf versions\n");

    if (elf_version(EV_CURRENT) == EV_NONE)
        errx(1, "mismatched libelf versions\n");

    if (argc != 2)
        errx(2, "usage: %s <file>\n", __progname);

    if ((ctfp = ctf_open(argv[1], &errp)) == NULL)
        errx(1, "failed to ctf_open file: %s: %s\n", argv[1],
            ctf_errmsg(errp));

    if ((fd = open(argv[1], O_RDONLY)) == -1)
        errx(1, "could not open %s\n", argv[1]);

    if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
        errx(1, "could not interpret ELF from %s\n",
            argv[1]);

    walk_symtab(elf, argv[1], ctfp, check_sym);

    (void) elf_end(elf);
    (void) close(fd);

    return (0);
}