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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
93 lines
2 KiB
C
93 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Cryptographic API.
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*
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* Cipher operations.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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* 2002 Adam J. Richter <adam@yggdrasil.com>
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* 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
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*/
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#include <crypto/scatterwalk.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/scatterlist.h>
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static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
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{
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void *src = out ? buf : sgdata;
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void *dst = out ? sgdata : buf;
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memcpy(dst, src, nbytes);
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}
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void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
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size_t nbytes, int out)
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{
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for (;;) {
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unsigned int len_this_page = scatterwalk_pagelen(walk);
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u8 *vaddr;
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if (len_this_page > nbytes)
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len_this_page = nbytes;
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if (out != 2) {
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vaddr = scatterwalk_map(walk);
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memcpy_dir(buf, vaddr, len_this_page, out);
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scatterwalk_unmap(vaddr);
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}
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scatterwalk_advance(walk, len_this_page);
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if (nbytes == len_this_page)
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break;
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buf += len_this_page;
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nbytes -= len_this_page;
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scatterwalk_pagedone(walk, out & 1, 1);
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}
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}
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EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
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void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
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unsigned int start, unsigned int nbytes, int out)
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{
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struct scatter_walk walk;
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struct scatterlist tmp[2];
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if (!nbytes)
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return;
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sg = scatterwalk_ffwd(tmp, sg, start);
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scatterwalk_start(&walk, sg);
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scatterwalk_copychunks(buf, &walk, nbytes, out);
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scatterwalk_done(&walk, out, 0);
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}
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EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
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struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
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struct scatterlist *src,
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unsigned int len)
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{
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for (;;) {
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if (!len)
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return src;
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if (src->length > len)
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break;
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len -= src->length;
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src = sg_next(src);
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}
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sg_init_table(dst, 2);
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sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
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scatterwalk_crypto_chain(dst, sg_next(src), 2);
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return dst;
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}
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EXPORT_SYMBOL_GPL(scatterwalk_ffwd);
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