From: Kees Cook Subject: Re: [PATCH v2 4/4] fs/pstore: fs/squashfs: Change usage of LZ4 to comply with new LZ4 module version Date: Sat, 7 Jan 2017 13:33:37 -0800 Message-ID: References: <1482259992-16680-1-git-send-email-4sschmid@informatik.uni-hamburg.de> <1483808145-18417-1-git-send-email-4sschmid@informatik.uni-hamburg.de> <1483808145-18417-5-git-send-email-4sschmid@informatik.uni-hamburg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Andrew Morton , bongkyu.kim@lge.com, rsalvaterra@gmail.com, Sergey Senozhatsky , Greg KH , LKML , Herbert Xu , "David S. Miller" , linux-crypto , Anton Vorontsov , Colin Cross , Tony Luck , phillip@squashfs.org.uk To: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Return-path: Received: from mail-io0-f175.google.com ([209.85.223.175]:35800 "EHLO mail-io0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573AbdAGVdj (ORCPT ); Sat, 7 Jan 2017 16:33:39 -0500 Received: by mail-io0-f175.google.com with SMTP id j18so10086084ioe.2 for ; Sat, 07 Jan 2017 13:33:39 -0800 (PST) In-Reply-To: <1483808145-18417-5-git-send-email-4sschmid@informatik.uni-hamburg.de> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Sat, Jan 7, 2017 at 8:55 AM, Sven Schmidt <4sschmid@informatik.uni-hamburg.de> wrote: > This patch updates fs/pstore and fs/squashfs to use the updated functions from > the new LZ4 module. > > Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> > --- > fs/pstore/platform.c | 14 ++++++++------ > fs/squashfs/lz4_wrapper.c | 12 ++++++------ > 2 files changed, 14 insertions(+), 12 deletions(-) > > diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c > index 729677e..a0d8ca8 100644 > --- a/fs/pstore/platform.c > +++ b/fs/pstore/platform.c > @@ -342,31 +342,33 @@ static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen) > { > int ret; > > - ret = lz4_compress(in, inlen, out, &outlen, workspace); > + ret = LZ4_compress_default(in, out, inlen, outlen, workspace); > if (ret) { > + // ret is 0 means an error occured If that's true, then shouldn't the "if" logic be changed? Also, here and in all following comments are C++ style instead of kernel C-style. This should be "/* ret == 0 means an error occured */", though really, that should be obvious from the code and the comment isn't really needed. > pr_err("lz4_compress error, ret = %d!\n", ret); If it's always going to be zero here, is there a better place to get details on why it failed? > return -EIO; > } > > - return outlen; > + return ret; > } > > static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen) > { > int ret; > > - ret = lz4_decompress_unknownoutputsize(in, inlen, out, &outlen); > - if (ret) { > + ret = LZ4_decompress_safe(in, out, inlen, outlen); > + if (ret < 0) { > + // return value is < 0 in case of error > pr_err("lz4_decompress error, ret = %d!\n", ret); > return -EIO; > } > > - return outlen; > + return ret; > } > > static void allocate_lz4(void) > { > - big_oops_buf_sz = lz4_compressbound(psinfo->bufsize); > + big_oops_buf_sz = LZ4_compressBound(psinfo->bufsize); > big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); > if (big_oops_buf) { > workspace = kmalloc(LZ4_MEM_COMPRESS, GFP_KERNEL); > diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c > index ff4468b..a512399 100644 > --- a/fs/squashfs/lz4_wrapper.c > +++ b/fs/squashfs/lz4_wrapper.c > @@ -97,7 +97,6 @@ static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, > struct squashfs_lz4 *stream = strm; > void *buff = stream->input, *data; > int avail, i, bytes = length, res; > - size_t dest_len = output->length; > > for (i = 0; i < b; i++) { > avail = min(bytes, msblk->devblksize - offset); > @@ -108,12 +107,13 @@ static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, > put_bh(bh[i]); > } > > - res = lz4_decompress_unknownoutputsize(stream->input, length, > - stream->output, &dest_len); > - if (res) > + res = LZ4_decompress_safe(stream->input, stream->output, length, output->length); > + if (res < 0) { > + // res of less than 0 means an error occured > return -EIO; > + } > > - bytes = dest_len; > + bytes = res; > data = squashfs_first_page(output); > buff = stream->output; > while (data) { > @@ -128,7 +128,7 @@ static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, > } > squashfs_finish_page(output); > > - return dest_len; > + return res; > } > > const struct squashfs_decompressor squashfs_lz4_comp_ops = { > -- > 2.1.4 > -Kees -- Kees Cook Nexus Security