forked from mirrors/linux
453431a549
As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
126 lines
2.7 KiB
C
126 lines
2.7 KiB
C
/* mpiutil.ac - Utility functions for MPI
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* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#include "mpi-internal.h"
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/****************
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* Note: It was a bad idea to use the number of limbs to allocate
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* because on a alpha the limbs are large but we normally need
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* integers of n bits - So we should chnage this to bits (or bytes).
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*
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* But mpi_alloc is used in a lot of places :-)
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*/
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MPI mpi_alloc(unsigned nlimbs)
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{
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MPI a;
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a = kmalloc(sizeof *a, GFP_KERNEL);
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if (!a)
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return a;
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if (nlimbs) {
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a->d = mpi_alloc_limb_space(nlimbs);
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if (!a->d) {
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kfree(a);
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return NULL;
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}
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} else {
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a->d = NULL;
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}
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a->alloced = nlimbs;
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a->nlimbs = 0;
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a->sign = 0;
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a->flags = 0;
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a->nbits = 0;
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return a;
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}
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EXPORT_SYMBOL_GPL(mpi_alloc);
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mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
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{
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size_t len = nlimbs * sizeof(mpi_limb_t);
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if (!len)
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return NULL;
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return kmalloc(len, GFP_KERNEL);
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}
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void mpi_free_limb_space(mpi_ptr_t a)
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{
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if (!a)
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return;
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kfree_sensitive(a);
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}
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void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
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{
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mpi_free_limb_space(a->d);
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a->d = ap;
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a->alloced = nlimbs;
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}
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/****************
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* Resize the array of A to NLIMBS. the additional space is cleared
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* (set to 0) [done by m_realloc()]
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*/
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int mpi_resize(MPI a, unsigned nlimbs)
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{
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void *p;
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if (nlimbs <= a->alloced)
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return 0; /* no need to do it */
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if (a->d) {
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p = kmalloc_array(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL);
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if (!p)
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return -ENOMEM;
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memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
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kfree_sensitive(a->d);
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a->d = p;
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} else {
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a->d = kcalloc(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL);
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if (!a->d)
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return -ENOMEM;
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}
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a->alloced = nlimbs;
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return 0;
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}
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void mpi_free(MPI a)
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{
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if (!a)
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return;
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if (a->flags & 4)
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kfree_sensitive(a->d);
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else
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mpi_free_limb_space(a->d);
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if (a->flags & ~7)
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pr_info("invalid flag value in mpi\n");
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kfree(a);
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}
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EXPORT_SYMBOL_GPL(mpi_free);
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MODULE_DESCRIPTION("Multiprecision maths library");
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MODULE_LICENSE("GPL");
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