Root/lib/mpi/mpiutil.c

1/* mpiutil.ac - Utility functions for MPI
2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 */
20
21#include "mpi-internal.h"
22
23/****************
24 * Note: It was a bad idea to use the number of limbs to allocate
25 * because on a alpha the limbs are large but we normally need
26 * integers of n bits - So we should chnage this to bits (or bytes).
27 *
28 * But mpi_alloc is used in a lot of places :-)
29 */
30MPI mpi_alloc(unsigned nlimbs)
31{
32    MPI a;
33
34    a = kmalloc(sizeof *a, GFP_KERNEL);
35    if (!a)
36        return a;
37
38    if (nlimbs) {
39        a->d = mpi_alloc_limb_space(nlimbs);
40        if (!a->d) {
41            kfree(a);
42            return NULL;
43        }
44    } else {
45        a->d = NULL;
46    }
47
48    a->alloced = nlimbs;
49    a->nlimbs = 0;
50    a->sign = 0;
51    a->flags = 0;
52    a->nbits = 0;
53    return a;
54}
55EXPORT_SYMBOL_GPL(mpi_alloc);
56
57mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
58{
59    size_t len = nlimbs * sizeof(mpi_limb_t);
60
61    if (!len)
62        return NULL;
63
64    return kmalloc(len, GFP_KERNEL);
65}
66
67void mpi_free_limb_space(mpi_ptr_t a)
68{
69    if (!a)
70        return;
71
72    kfree(a);
73}
74
75void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
76{
77    mpi_free_limb_space(a->d);
78    a->d = ap;
79    a->alloced = nlimbs;
80}
81
82/****************
83 * Resize the array of A to NLIMBS. the additional space is cleared
84 * (set to 0) [done by m_realloc()]
85 */
86int mpi_resize(MPI a, unsigned nlimbs)
87{
88    void *p;
89
90    if (nlimbs <= a->alloced)
91        return 0; /* no need to do it */
92
93    if (a->d) {
94        p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
95        if (!p)
96            return -ENOMEM;
97        memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
98        kfree(a->d);
99        a->d = p;
100    } else {
101        a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
102        if (!a->d)
103            return -ENOMEM;
104    }
105    a->alloced = nlimbs;
106    return 0;
107}
108
109void mpi_free(MPI a)
110{
111    if (!a)
112        return;
113
114    if (a->flags & 4)
115        kfree(a->d);
116    else
117        mpi_free_limb_space(a->d);
118
119    if (a->flags & ~7)
120        pr_info("invalid flag value in mpi\n");
121    kfree(a);
122}
123EXPORT_SYMBOL_GPL(mpi_free);
124
125MODULE_DESCRIPTION("Multiprecision maths library");
126MODULE_LICENSE("GPL");
127

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