cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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compr_lzo.c (2257B)

      1/*
      2 * JFFS2 -- Journalling Flash File System, Version 2.
      3 *
      4 * Copyright © 2007 Nokia Corporation. All rights reserved.
      5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
      6 *
      7 * Created by Richard Purdie <rpurdie@openedhand.com>
      8 *
      9 * For licensing information, see the file 'LICENCE' in this directory.
     10 *
     11 */
     12
     13#include <linux/kernel.h>
     14#include <linux/sched.h>
     15#include <linux/vmalloc.h>
     16#include <linux/init.h>
     17#include <linux/lzo.h>
     18#include "compr.h"
     19
     20static void *lzo_mem;
     21static void *lzo_compress_buf;
     22static DEFINE_MUTEX(deflate_mutex);	/* for lzo_mem and lzo_compress_buf */
     23
     24static void free_workspace(void)
     25{
     26	vfree(lzo_mem);
     27	vfree(lzo_compress_buf);
     28}
     29
     30static int __init alloc_workspace(void)
     31{
     32	lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
     33	lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
     34
     35	if (!lzo_mem || !lzo_compress_buf) {
     36		free_workspace();
     37		return -ENOMEM;
     38	}
     39
     40	return 0;
     41}
     42
     43static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
     44			      uint32_t *sourcelen, uint32_t *dstlen)
     45{
     46	size_t compress_size;
     47	int ret;
     48
     49	mutex_lock(&deflate_mutex);
     50	ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
     51	if (ret != LZO_E_OK)
     52		goto fail;
     53
     54	if (compress_size > *dstlen)
     55		goto fail;
     56
     57	memcpy(cpage_out, lzo_compress_buf, compress_size);
     58	mutex_unlock(&deflate_mutex);
     59
     60	*dstlen = compress_size;
     61	return 0;
     62
     63 fail:
     64	mutex_unlock(&deflate_mutex);
     65	return -1;
     66}
     67
     68static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
     69				 uint32_t srclen, uint32_t destlen)
     70{
     71	size_t dl = destlen;
     72	int ret;
     73
     74	ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
     75
     76	if (ret != LZO_E_OK || dl != destlen)
     77		return -1;
     78
     79	return 0;
     80}
     81
     82static struct jffs2_compressor jffs2_lzo_comp = {
     83	.priority = JFFS2_LZO_PRIORITY,
     84	.name = "lzo",
     85	.compr = JFFS2_COMPR_LZO,
     86	.compress = &jffs2_lzo_compress,
     87	.decompress = &jffs2_lzo_decompress,
     88	.disabled = 0,
     89};
     90
     91int __init jffs2_lzo_init(void)
     92{
     93	int ret;
     94
     95	ret = alloc_workspace();
     96	if (ret < 0)
     97		return ret;
     98
     99	ret = jffs2_register_compressor(&jffs2_lzo_comp);
    100	if (ret)
    101		free_workspace();
    102
    103	return ret;
    104}
    105
    106void jffs2_lzo_exit(void)
    107{
    108	jffs2_unregister_compressor(&jffs2_lzo_comp);
    109	free_workspace();
    110}