mpiutil.c

Go to the documentation of this file.

/* mpiutil.ac  -  Utility functions for MPI
 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "mpi-internal.h"

/****************
 * Note:  It was a bad idea to use the number of limbs to allocate
 *    because on a alpha the limbs are large but we normally need
 *    integers of n bits - So we should chnage this to bits (or bytes).
 *
 *    But mpi_alloc is used in a lot of places :-)
 */
MPI mpi_alloc(unsigned nlimbs)
{
    MPI a;

    a = kmalloc(sizeof *a, GFP_KERNEL);
    if (!a)
        return a;

    if (nlimbs) {
        a->d = mpi_alloc_limb_space(nlimbs);
        if (!a->d) {
            kfree(a);
            return NULL;
        }
    } else {
        a->d = NULL;
    }

    a->alloced = nlimbs;
    a->nlimbs = 0;
    a->sign = 0;
    a->flags = 0;
    a->nbits = 0;
    return a;
}
EXPORT_SYMBOL_GPL(mpi_alloc);

mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
{
    size_t len = nlimbs * sizeof(mpi_limb_t);

    if (!len)
        return NULL;

    return kmalloc(len, GFP_KERNEL);
}

void mpi_free_limb_space(mpi_ptr_t a)
{
    if (!a)
        return;

    kfree(a);
}

void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
{
    mpi_free_limb_space(a->d);
    a->d = ap;
    a->alloced = nlimbs;
}

/****************
 * Resize the array of A to NLIMBS. the additional space is cleared
 * (set to 0) [done by m_realloc()]
 */
int mpi_resize(MPI a, unsigned nlimbs)
{
    void *p;

    if (nlimbs <= a->alloced)
        return 0;   /* no need to do it */

    if (a->d) {
        p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
        if (!p)
            return -ENOMEM;
        memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
        kfree(a->d);
        a->d = p;
    } else {
        a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
        if (!a->d)
            return -ENOMEM;
    }
    a->alloced = nlimbs;
    return 0;
}

void mpi_free(MPI a)
{
    if (!a)
        return;

    if (a->flags & 4)
        kfree(a->d);
    else
        mpi_free_limb_space(a->d);

    if (a->flags & ~7)
        pr_info("invalid flag value in mpi\n");
    kfree(a);
}
EXPORT_SYMBOL_GPL(mpi_free);