CSE2410 Fall 2014 Bounce

/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

/*

 * gcc -Wall -lproc -o extract_dmod extract_dmod.c

 *

 * use this tool to extract the mdb_v8.so from a core file for use with older

 * mdb or platforms with an out of date v8.so

 */

#include <stdio.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <strings.h>

#include <errno.h>

#include <libproc.h>

#include <sys/sysmacros.h>

const char *g_sym = "mdb_v8.so_start";

int

main(int argc, const char *argv[])

{

        int ifd, ofd, perr, toread, ret;

        struct ps_prochandle *p;

        GElf_Sym sym;

        prsyminfo_t si;

        char buf[1024];

        if (argc != 3) {

                fprintf(stderr, "pdump: <infile> <outfile>\n");

                return (1);

        }

        ifd = open(argv[1], O_RDONLY);

        if (ifd < 0) {

                fprintf(stderr, "failed to open: %s: %s\n",

                    argv[1], strerror(errno));

                return (1);

        }

        ofd = open(argv[2], O_RDWR | O_CREAT | O_TRUNC);

        if (ofd < 0) {

                fprintf(stderr, "failed to open: %s: %s\n",

                    argv[1], strerror(errno));

                return (1);

        }

        p = Pfgrab_core(ifd, NULL, &perr); 

        if (p == NULL) {

                fprintf(stderr, "failed to grab core file\n");

                return (1);

        }

        if (Pxlookup_by_name(p, NULL, "a.out", g_sym, &sym, &si) != 0) {

                fprintf(stderr, "failed to lookup symobl %s\n", g_sym);

                return (0);

        }

        while (sym.st_size > 0) {

                toread = MIN(sym.st_size, sizeof (buf));

                ret = Pread(p, buf, toread, sym.st_value);

                if (ret < 0) {

                        fprintf(stderr, "failed to Pread...\n");

                        return (1);

                }

                if (ret != 0)

                        ret = write(ofd, buf, ret);

                if (ret < 0) {

                        fprintf(stderr, "failed to write to output file %s\n",

                            strerror(errno));

                }

                sym.st_size -= ret;

                sym.st_value += ret;

        }

        return (0);

}