tpcom.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* tpcom: Threaded Print Comment
*
* tpcom is a threaded version of the pcom program. It will create
* a new thread for each new ELF descriptor that it examines. It
* will then examine each elf descriptor and print the .comment section
* if found.
*
* This program demonstrates that libelf is MT-Safe and the usage
* of elf_begin(ELF_C_READ).
*/
#include <stdio.h>
#include <libelf.h>
#include <gelf.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <thread.h>
#define NUMLWPS 32 /* arbitrary number of LWPS */
static const char *CommentStr = ".comment";
/*
* arguments to be passed into process_elf().
*/
typedef struct {
Elf *pe_elf;
char *pe_file; /* elf member name */
int pe_fd;
short pe_member; /* is this an archive member? */
} pe_args;
static mutex_t printlock = DEFAULTMUTEX; /* printlock used to */
/* group output */
/* of comment sections */
static void
print_comment(Elf *elf, const char *file)
{
Elf_Scn * scn = 0;
GElf_Shdr shdr;
Elf_Data * data;
size_t shstrndx;
if (elf_getshstrndx(elf, &shstrndx) == 0) {
(void) fprintf(stderr, "%s: elf_getshstrndx() failed: %s\n",
file, elf_errmsg(0));
return;
}
while ((scn = elf_nextscn(elf, scn)) != 0) {
/*
* Do a string compare to examine each section header
* to see if it is a ".comment" section. If it is then
* this is the section we want to process.
*/
if (gelf_getshdr(scn, &shdr) == 0) {
(void) fprintf(stderr,
"%s: elf_getshdr() failed: %s\n",
file, elf_errmsg(0));
return;
}
if (strcmp(CommentStr, elf_strptr(elf, shstrndx,
shdr.sh_name)) == 0) {
int i;
char *ptr;
mutex_lock(&printlock);
(void) printf("%s .comment:\n", file);
/*
* Get the data associated with the .comment
* section.
*/
if ((data = elf_getdata(scn, 0)) == 0) {
(void) fprintf(stderr,
"%s: elf_getdata() failed: %s\n",
file, elf_errmsg(0));
mutex_unlock(&printlock);
return;
}
/*
* Data in a .comment section is a list of 'null'
* terminated strings. The following will print
* one string per line.
*/
for (i = 0, ptr = (char *)data->d_buf;
i < data->d_size; i++)
if (ptr[i]) {
(void) puts(&ptr[i]);
i += strlen(&ptr[i]);
}
(void) putchar('\n');
mutex_unlock(&printlock);
}
}
}
static void
process_elf(pe_args * pep)
{
Elf_Cmd cmd;
Elf * _elf;
switch (elf_kind(pep->pe_elf)) {
case ELF_K_ELF:
print_comment(pep->pe_elf, pep->pe_file);
break;
case ELF_K_AR:
cmd = ELF_C_READ;
while ((_elf = elf_begin(pep->pe_fd, cmd,
pep->pe_elf)) != 0) {
Elf_Arhdr * arhdr;
pe_args * _pep;
int rc;
if ((arhdr = elf_getarhdr(_elf)) == 0) {
(void) fprintf(stderr,
"%s: elf_getarhdr() failed: %s\n",
pep->pe_file, elf_errmsg(0));
}
cmd = elf_next(_elf);
_pep = malloc(sizeof (pe_args));
_pep->pe_elf = _elf;
_pep->pe_file = malloc(strlen(pep->pe_file) +
strlen(arhdr->ar_name) + 5);
(void) sprintf(_pep->pe_file,
"%s(%s)", pep->pe_file, arhdr->ar_name);
_pep->pe_fd = pep->pe_fd;
_pep->pe_member = 1;
if ((rc = thr_create(NULL, 0,
(void *(*)(void *))process_elf,
(void *)_pep, THR_DETACHED, 0)) != 0) {
(void) fprintf(stderr,
"thr_create() failed, rc = %d\n", rc);
}
}
break;
default:
if (!pep->pe_member) {
mutex_lock(&printlock);
(void) fprintf(stderr,
"%s: unexpected elf_kind(): 0x%x\n",
pep->pe_file, elf_kind(pep->pe_elf));
mutex_unlock(&printlock);
}
}
(void) elf_end(pep->pe_elf);
if (pep->pe_member)
free(pep->pe_file);
free(pep);
thr_exit(0);
}
int
main(int argc, char ** argv)
{
int i;
if (argc < 2) {
(void) printf("usage: %s elf_file ...\n", argv[0]);
return (1);
}
/*
* Initialize the elf library, must be called before elf_begin()
* can be called.
*/
if (elf_version(EV_CURRENT) == EV_NONE) {
(void) fprintf(stderr,
"elf_version() failed: %s\n", elf_errmsg(0));
return (1);
}
/*
* create an arbitrary number of LWP's to run the
* threads that will be created.
*/
if (thr_setconcurrency(NUMLWPS) != 0) {
(void) fprintf(stderr, "thread setconcurrency failed\n");
return (1);
}
for (i = 1; i < argc; i++) {
int fd;
Elf *elf;
pe_args *pep;
int rc;
char *elf_fname;
elf_fname = argv[i];
if ((fd = open(elf_fname, O_RDONLY)) == -1) {
perror("open");
continue;
}
/*
* Attempt to open an Elf descriptor Read/Write
* for each file.
*/
if ((elf = elf_begin(fd, ELF_C_READ, 0)) == NULL) {
mutex_lock(&printlock);
(void) fprintf(stderr, "elf_begin() failed: %s\n",
elf_errmsg(0));
mutex_unlock(&printlock);
(void) close(fd);
continue;
}
pep = malloc(sizeof (pe_args));
pep->pe_elf = elf;
pep->pe_file = elf_fname;
pep->pe_fd = fd;
pep->pe_member = 0;
if ((rc = thr_create(NULL, 0, (void *(*)(void *))process_elf,
(void *)pep, THR_DETACHED, 0)) != 0) {
mutex_lock(&printlock);
(void) fprintf(stderr,
"thr_create() failed with code: %d\n", rc);
mutex_unlock(&printlock);
return (1);
}
}
thr_exit(0);
return (0);
}