diff options
author | Johannes Berg <johannes.berg@intel.com> | 2023-10-05 22:57:34 +0200 |
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committer | Kalle Valo <kvalo@kernel.org> | 2023-10-06 17:08:47 +0300 |
commit | 7d6904bf26b96ef087514cb7a8c50b62a4911c99 (patch) | |
tree | 2feaff8495d88c2102dc2e017b7afc5c58db02d6 /lib/crypto/mpi/mpi-sub-ui.c | |
parent | 9418edf8ff01e7a4904aac1aca4864ecdea37593 (diff) | |
parent | 22061bfc57fe08c77141dc876b4af75603c4d61d (diff) |
Merge wireless into wireless-next
Resolve several conflicts, mostly between changes/fixes in
wireless and the locking rework in wireless-next. One of
the conflicts actually shows a bug in wireless that we'll
want to fix separately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Diffstat (limited to 'lib/crypto/mpi/mpi-sub-ui.c')
-rw-r--r-- | lib/crypto/mpi/mpi-sub-ui.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/crypto/mpi/mpi-sub-ui.c b/lib/crypto/mpi/mpi-sub-ui.c new file mode 100644 index 000000000000..b41b082b5f3e --- /dev/null +++ b/lib/crypto/mpi/mpi-sub-ui.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpi-sub-ui.c - Subtract an unsigned integer from an MPI. + * + * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015 + * Free Software Foundation, Inc. + * + * This file was based on the GNU MP Library source file: + * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h + * + * The GNU MP Library is free software; you can redistribute it and/or modify + * it under the terms of either: + * + * * the GNU Lesser General Public License as published by the Free + * Software Foundation; either version 3 of the License, or (at your + * option) any later version. + * + * or + * + * * 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. + * + * or both in parallel, as here. + * + * The GNU MP Library 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 copies of the GNU General Public License and the + * GNU Lesser General Public License along with the GNU MP Library. If not, + * see https://www.gnu.org/licenses/. + */ + +#include "mpi-internal.h" + +int mpi_sub_ui(MPI w, MPI u, unsigned long vval) +{ + if (u->nlimbs == 0) { + if (mpi_resize(w, 1) < 0) + return -ENOMEM; + w->d[0] = vval; + w->nlimbs = (vval != 0); + w->sign = (vval != 0); + return 0; + } + + /* If not space for W (and possible carry), increase space. */ + if (mpi_resize(w, u->nlimbs + 1)) + return -ENOMEM; + + if (u->sign) { + mpi_limb_t cy; + + cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + w->d[u->nlimbs] = cy; + w->nlimbs = u->nlimbs + cy; + w->sign = 1; + } else { + /* The signs are different. Need exact comparison to determine + * which operand to subtract from which. + */ + if (u->nlimbs == 1 && u->d[0] < vval) { + w->d[0] = vval - u->d[0]; + w->nlimbs = 1; + w->sign = 1; + } else { + mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + /* Size can decrease with at most one limb. */ + w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0)); + w->sign = 0; + } + } + + mpi_normalize(w); + return 0; +} +EXPORT_SYMBOL_GPL(mpi_sub_ui); |