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![Jim Keniston](/assets/img/avatar_default.png)
Instead of always creating a huge (268K) deflate_workspace with the maximum compression parameters (windowBits=15, memLevel=8), allow the caller to obtain a smaller workspace by specifying smaller parameter values. For example, when capturing oops and panic reports to a medium with limited capacity, such as NVRAM, compression may be the only way to capture the whole report. In this case, a small workspace (24K works fine) is a win, whether you allocate the workspace when you need it (i.e., during an oops or panic) or at boot time. I've verified that this patch works with all accepted values of windowBits (positive and negative), memLevel, and compression level. Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Miller <davem@davemloft.net> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
381 lines
9.6 KiB
C
381 lines
9.6 KiB
C
/*
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* Cryptographic API.
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*
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* Zlib algorithm
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*
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* Copyright 2008 Sony Corporation
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*
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* Based on deflate.c, which is
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* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* FIXME: deflate transforms will require up to a total of about 436k of kernel
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* memory on i386 (390k for compression, the rest for decompression), as the
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* current zlib kernel code uses a worst case pre-allocation system by default.
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* This needs to be fixed so that the amount of memory required is properly
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* related to the winbits and memlevel parameters.
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*/
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#define pr_fmt(fmt) "%s: " fmt, __func__
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/zlib.h>
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#include <linux/vmalloc.h>
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#include <linux/interrupt.h>
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#include <linux/mm.h>
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#include <linux/net.h>
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#include <linux/slab.h>
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#include <crypto/internal/compress.h>
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#include <net/netlink.h>
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struct zlib_ctx {
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struct z_stream_s comp_stream;
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struct z_stream_s decomp_stream;
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int decomp_windowBits;
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};
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static void zlib_comp_exit(struct zlib_ctx *ctx)
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{
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struct z_stream_s *stream = &ctx->comp_stream;
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if (stream->workspace) {
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zlib_deflateEnd(stream);
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vfree(stream->workspace);
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stream->workspace = NULL;
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}
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}
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static void zlib_decomp_exit(struct zlib_ctx *ctx)
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{
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struct z_stream_s *stream = &ctx->decomp_stream;
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if (stream->workspace) {
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zlib_inflateEnd(stream);
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kfree(stream->workspace);
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stream->workspace = NULL;
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}
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}
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static int zlib_init(struct crypto_tfm *tfm)
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{
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return 0;
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}
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static void zlib_exit(struct crypto_tfm *tfm)
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{
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struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);
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zlib_comp_exit(ctx);
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zlib_decomp_exit(ctx);
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}
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static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
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unsigned int len)
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{
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struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &ctx->comp_stream;
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struct nlattr *tb[ZLIB_COMP_MAX + 1];
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int window_bits, mem_level;
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size_t workspacesize;
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int ret;
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ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
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if (ret)
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return ret;
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zlib_comp_exit(ctx);
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window_bits = tb[ZLIB_COMP_WINDOWBITS]
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? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
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: MAX_WBITS;
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mem_level = tb[ZLIB_COMP_MEMLEVEL]
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? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
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: DEF_MEM_LEVEL;
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workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
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stream->workspace = vzalloc(workspacesize);
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if (!stream->workspace)
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return -ENOMEM;
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ret = zlib_deflateInit2(stream,
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tb[ZLIB_COMP_LEVEL]
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? nla_get_u32(tb[ZLIB_COMP_LEVEL])
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: Z_DEFAULT_COMPRESSION,
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tb[ZLIB_COMP_METHOD]
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? nla_get_u32(tb[ZLIB_COMP_METHOD])
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: Z_DEFLATED,
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window_bits,
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mem_level,
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tb[ZLIB_COMP_STRATEGY]
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? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
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: Z_DEFAULT_STRATEGY);
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if (ret != Z_OK) {
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vfree(stream->workspace);
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stream->workspace = NULL;
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return -EINVAL;
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}
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return 0;
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}
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static int zlib_compress_init(struct crypto_pcomp *tfm)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->comp_stream;
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ret = zlib_deflateReset(stream);
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if (ret != Z_OK)
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return -EINVAL;
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return 0;
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}
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static int zlib_compress_update(struct crypto_pcomp *tfm,
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struct comp_request *req)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->comp_stream;
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pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
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stream->next_in = req->next_in;
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stream->avail_in = req->avail_in;
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stream->next_out = req->next_out;
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stream->avail_out = req->avail_out;
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ret = zlib_deflate(stream, Z_NO_FLUSH);
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switch (ret) {
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case Z_OK:
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break;
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case Z_BUF_ERROR:
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pr_debug("zlib_deflate could not make progress\n");
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return -EAGAIN;
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default:
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pr_debug("zlib_deflate failed %d\n", ret);
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return -EINVAL;
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}
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ret = req->avail_out - stream->avail_out;
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pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
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stream->avail_in, stream->avail_out,
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req->avail_in - stream->avail_in, ret);
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req->next_in = stream->next_in;
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req->avail_in = stream->avail_in;
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req->next_out = stream->next_out;
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req->avail_out = stream->avail_out;
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return ret;
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}
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static int zlib_compress_final(struct crypto_pcomp *tfm,
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struct comp_request *req)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->comp_stream;
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pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
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stream->next_in = req->next_in;
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stream->avail_in = req->avail_in;
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stream->next_out = req->next_out;
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stream->avail_out = req->avail_out;
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ret = zlib_deflate(stream, Z_FINISH);
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if (ret != Z_STREAM_END) {
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pr_debug("zlib_deflate failed %d\n", ret);
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return -EINVAL;
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}
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ret = req->avail_out - stream->avail_out;
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pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
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stream->avail_in, stream->avail_out,
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req->avail_in - stream->avail_in, ret);
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req->next_in = stream->next_in;
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req->avail_in = stream->avail_in;
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req->next_out = stream->next_out;
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req->avail_out = stream->avail_out;
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return ret;
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}
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static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params,
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unsigned int len)
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{
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struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &ctx->decomp_stream;
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struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
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int ret = 0;
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ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
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if (ret)
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return ret;
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zlib_decomp_exit(ctx);
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ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
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? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
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: DEF_WBITS;
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stream->workspace = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
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if (!stream->workspace)
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return -ENOMEM;
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ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
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if (ret != Z_OK) {
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kfree(stream->workspace);
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stream->workspace = NULL;
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return -EINVAL;
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}
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return 0;
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}
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static int zlib_decompress_init(struct crypto_pcomp *tfm)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->decomp_stream;
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ret = zlib_inflateReset(stream);
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if (ret != Z_OK)
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return -EINVAL;
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return 0;
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}
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static int zlib_decompress_update(struct crypto_pcomp *tfm,
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struct comp_request *req)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->decomp_stream;
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pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
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stream->next_in = req->next_in;
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stream->avail_in = req->avail_in;
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stream->next_out = req->next_out;
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stream->avail_out = req->avail_out;
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ret = zlib_inflate(stream, Z_SYNC_FLUSH);
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switch (ret) {
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case Z_OK:
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case Z_STREAM_END:
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break;
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case Z_BUF_ERROR:
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pr_debug("zlib_inflate could not make progress\n");
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return -EAGAIN;
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default:
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pr_debug("zlib_inflate failed %d\n", ret);
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return -EINVAL;
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}
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ret = req->avail_out - stream->avail_out;
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pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
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stream->avail_in, stream->avail_out,
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req->avail_in - stream->avail_in, ret);
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req->next_in = stream->next_in;
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req->avail_in = stream->avail_in;
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req->next_out = stream->next_out;
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req->avail_out = stream->avail_out;
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return ret;
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}
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static int zlib_decompress_final(struct crypto_pcomp *tfm,
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struct comp_request *req)
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{
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int ret;
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struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
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struct z_stream_s *stream = &dctx->decomp_stream;
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pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
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stream->next_in = req->next_in;
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stream->avail_in = req->avail_in;
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stream->next_out = req->next_out;
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stream->avail_out = req->avail_out;
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if (dctx->decomp_windowBits < 0) {
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ret = zlib_inflate(stream, Z_SYNC_FLUSH);
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/*
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* Work around a bug in zlib, which sometimes wants to taste an
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* extra byte when being used in the (undocumented) raw deflate
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* mode. (From USAGI).
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*/
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if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
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const void *saved_next_in = stream->next_in;
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u8 zerostuff = 0;
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stream->next_in = &zerostuff;
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stream->avail_in = 1;
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ret = zlib_inflate(stream, Z_FINISH);
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stream->next_in = saved_next_in;
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stream->avail_in = 0;
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}
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} else
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ret = zlib_inflate(stream, Z_FINISH);
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if (ret != Z_STREAM_END) {
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pr_debug("zlib_inflate failed %d\n", ret);
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return -EINVAL;
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}
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ret = req->avail_out - stream->avail_out;
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pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
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stream->avail_in, stream->avail_out,
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req->avail_in - stream->avail_in, ret);
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req->next_in = stream->next_in;
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req->avail_in = stream->avail_in;
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req->next_out = stream->next_out;
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req->avail_out = stream->avail_out;
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return ret;
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}
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static struct pcomp_alg zlib_alg = {
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.compress_setup = zlib_compress_setup,
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.compress_init = zlib_compress_init,
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.compress_update = zlib_compress_update,
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.compress_final = zlib_compress_final,
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.decompress_setup = zlib_decompress_setup,
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.decompress_init = zlib_decompress_init,
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.decompress_update = zlib_decompress_update,
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.decompress_final = zlib_decompress_final,
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.base = {
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.cra_name = "zlib",
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.cra_flags = CRYPTO_ALG_TYPE_PCOMPRESS,
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.cra_ctxsize = sizeof(struct zlib_ctx),
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.cra_module = THIS_MODULE,
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.cra_init = zlib_init,
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.cra_exit = zlib_exit,
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}
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};
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static int __init zlib_mod_init(void)
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{
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return crypto_register_pcomp(&zlib_alg);
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}
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static void __exit zlib_mod_fini(void)
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{
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crypto_unregister_pcomp(&zlib_alg);
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}
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module_init(zlib_mod_init);
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module_exit(zlib_mod_fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Zlib Compression Algorithm");
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MODULE_AUTHOR("Sony Corporation");
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