libelf/common/error.c

	error.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <thread.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <libelf.h>
#include <libintl.h>
#include "msg.h"
#include "decl.h"

#define ELFERRSHIFT 16
#define SYSERRMASK  0xffff


/*
 * _elf_err has two values encoded in it, both the _elf_err # and
 * the system errno value (if relevant).  These values are encoded
 * in the upper & lower 16 bits of the 4 byte integer.
 */
static int      _elf_err = 0;

#if !defined(NATIVE_BUILD)

static thread_key_t errkey = THR_ONCE_KEY;
static thread_key_t bufkey = THR_ONCE_KEY;

#else   /* NATIVE_BUILD */

/*
 * This code is here to enable the building of a native version
 * of libelf.so when the build machine has not yet been upgraded
 * to a version of libc that provides thr_keycreate_once().
 * It should be deleted when solaris_nevada ships.
 * The code is not MT-safe in a relaxed memory model.
 */

static thread_key_t errkey = 0;
static thread_key_t bufkey = 0;

int
thr_keycreate_once(thread_key_t *keyp, void (*destructor)(void *))
{
    static mutex_t key_lock = DEFAULTMUTEX;
    thread_key_t key;
    int error;

    if (*keyp == 0) {
        mutex_lock(&key_lock);
        if (*keyp == 0) {
            error = thr_keycreate(&key, destructor);
            if (error) {
                mutex_unlock(&key_lock);
                return (error);
            }
            *keyp = key;
        }
        mutex_unlock(&key_lock);
    }

    return (0);
}

#endif  /* NATIVE_BUILD */


const char *
_libelf_msg(Msg mid)
{
    return (dgettext(MSG_ORIG(MSG_SUNW_OST_SGS), MSG_ORIG(mid)));
}


void
_elf_seterr(Msg lib_err, int sys_err)
{
    /*LINTED*/
    intptr_t encerr = ((int)lib_err << ELFERRSHIFT) |
        (sys_err & SYSERRMASK);

#ifndef __lock_lint
    if (thr_main()) {
        _elf_err = (int)encerr;
        return;
    }
#endif
    (void) thr_keycreate_once(&errkey, 0);
    (void) thr_setspecific(errkey, (void *)encerr);
}

int
_elf_geterr() {
#ifndef __lock_lint
    if (thr_main())
        return (_elf_err);
#endif
    return ((uintptr_t)pthread_getspecific(errkey));
}

const char *
elf_errmsg(int err)
{
    char            *errno_str;
    char            *elferr_str;
    char            *buffer = 0;
    int         syserr;
    int         elferr;
    static char     intbuf[MAXELFERR];

    if (err == 0) {
        if ((err = _elf_geterr()) == 0)
            return (0);
    } else if (err == -1) {
        if ((err = _elf_geterr()) == 0)
            /*LINTED*/ /* MSG_INTL(EINF_NULLERROR) */
            err = (int)EINF_NULLERROR << ELFERRSHIFT;
    }

    if (thr_main())
        buffer = intbuf;
    else {
        /*
         * If this is a threaded APP then we store the
         * errmsg buffer in Thread Specific Storage.
         *
         * Each thread has its own private buffer.
         */
        if (thr_keycreate_once(&bufkey, free) != 0)
            return (MSG_INTL(EBUG_THRDKEY));
        buffer = pthread_getspecific(bufkey);

        if (!buffer) {
            if ((buffer = malloc(MAXELFERR)) == 0)
                return (MSG_INTL(EMEM_ERRMSG));
            if (thr_setspecific(bufkey, buffer) != 0) {
                free(buffer);
                return (MSG_INTL(EBUG_THRDSET));
            }
        }
    }

    elferr = (int)((uint_t)err >> ELFERRSHIFT);
    syserr = err & SYSERRMASK;
    /*LINTED*/
    elferr_str = (char *)MSG_INTL(elferr);
    if (syserr && (errno_str = strerror(syserr)))
        (void) snprintf(buffer, MAXELFERR,
            MSG_ORIG(MSG_FMT_ERR), elferr_str, errno_str);
    else {
        (void) strncpy(buffer, elferr_str, MAXELFERR - 1);
        buffer[MAXELFERR - 1] = '\0';
    }

    return (buffer);
}

int
elf_errno()
{
    int rc = _elf_geterr();

    _elf_seterr(0, 0);
    return (rc);
}