1 files changed, 0 insertions, 847 deletions

diff --git a/cpukit/libmisc/xz/xz_dec_stream.c b/cpukit/libmisc/xz/xz_dec_stream.c
deleted file mode 100644
index d6525506a1..0000000000
--- a/cpukit/libmisc/xz/xz_dec_stream.c
+++ /dev/null
@@ -1,847 +0,0 @@
-/*
- * .xz Stream decoder
- *
- * Author: Lasse Collin <lasse.collin@tukaani.org>
- *
- * This file has been put into the public domain.
- * You can do whatever you want with this file.
- */
-
-#include "xz_private.h"
-#include "xz_stream.h"
-
-#ifdef XZ_USE_CRC64
-#	define IS_CRC64(check_type) ((check_type) == XZ_CHECK_CRC64)
-#else
-#	define IS_CRC64(check_type) false
-#endif
-
-/* Hash used to validate the Index field */
-struct xz_dec_hash {
-	vli_type unpadded;
-	vli_type uncompressed;
-	uint32_t crc32;
-};
-
-struct xz_dec {
-	/* Position in dec_main() */
-	enum {
-		SEQ_STREAM_HEADER,
-		SEQ_BLOCK_START,
-		SEQ_BLOCK_HEADER,
-		SEQ_BLOCK_UNCOMPRESS,
-		SEQ_BLOCK_PADDING,
-		SEQ_BLOCK_CHECK,
-		SEQ_INDEX,
-		SEQ_INDEX_PADDING,
-		SEQ_INDEX_CRC32,
-		SEQ_STREAM_FOOTER
-	} sequence;
-
-	/* Position in variable-length integers and Check fields */
-	uint32_t pos;
-
-	/* Variable-length integer decoded by dec_vli() */
-	vli_type vli;
-
-	/* Saved in_pos and out_pos */
-	size_t in_start;
-	size_t out_start;
-
-#ifdef XZ_USE_CRC64
-	/* CRC32 or CRC64 value in Block or CRC32 value in Index */
-	uint64_t crc;
-#else
-	/* CRC32 value in Block or Index */
-	uint32_t crc;
-#endif
-
-	/* Type of the integrity check calculated from uncompressed data */
-	enum xz_check check_type;
-
-	/* Operation mode */
-	enum xz_mode mode;
-
-	/*
-	 * True if the next call to xz_dec_run() is allowed to return
-	 * XZ_BUF_ERROR.
-	 */
-	bool allow_buf_error;
-
-	/* Information stored in Block Header */
-	struct {
-		/*
-		 * Value stored in the Compressed Size field, or
-		 * VLI_UNKNOWN if Compressed Size is not present.
-		 */
-		vli_type compressed;
-
-		/*
-		 * Value stored in the Uncompressed Size field, or
-		 * VLI_UNKNOWN if Uncompressed Size is not present.
-		 */
-		vli_type uncompressed;
-
-		/* Size of the Block Header field */
-		uint32_t size;
-	} block_header;
-
-	/* Information collected when decoding Blocks */
-	struct {
-		/* Observed compressed size of the current Block */
-		vli_type compressed;
-
-		/* Observed uncompressed size of the current Block */
-		vli_type uncompressed;
-
-		/* Number of Blocks decoded so far */
-		vli_type count;
-
-		/*
-		 * Hash calculated from the Block sizes. This is used to
-		 * validate the Index field.
-		 */
-		struct xz_dec_hash hash;
-	} block;
-
-	/* Variables needed when verifying the Index field */
-	struct {
-		/* Position in dec_index() */
-		enum {
-			SEQ_INDEX_COUNT,
-			SEQ_INDEX_UNPADDED,
-			SEQ_INDEX_UNCOMPRESSED
-		} sequence;
-
-		/* Size of the Index in bytes */
-		vli_type size;
-
-		/* Number of Records (matches block.count in valid files) */
-		vli_type count;
-
-		/*
-		 * Hash calculated from the Records (matches block.hash in
-		 * valid files).
-		 */
-		struct xz_dec_hash hash;
-	} index;
-
-	/*
-	 * Temporary buffer needed to hold Stream Header, Block Header,
-	 * and Stream Footer. The Block Header is the biggest (1 KiB)
-	 * so we reserve space according to that. buf[] has to be aligned
-	 * to a multiple of four bytes; the size_t variables before it
-	 * should guarantee this.
-	 */
-	struct {
-		size_t pos;
-		size_t size;
-		uint8_t buf[1024];
-	} temp;
-
-	struct xz_dec_lzma2 *lzma2;
-
-#ifdef XZ_DEC_BCJ
-	struct xz_dec_bcj *bcj;
-	bool bcj_active;
-#endif
-};
-
-#ifdef XZ_DEC_ANY_CHECK
-/* Sizes of the Check field with different Check IDs */
-static const uint8_t check_sizes[16] = {
-	0,
-	4, 4, 4,
-	8, 8, 8,
-	16, 16, 16,
-	32, 32, 32,
-	64, 64, 64
-};
-#endif
-
-/*
- * Fill s->temp by copying data starting from b->in[b->in_pos]. Caller
- * must have set s->temp.pos to indicate how much data we are supposed
- * to copy into s->temp.buf. Return true once s->temp.pos has reached
- * s->temp.size.
- */
-static bool fill_temp(struct xz_dec *s, struct xz_buf *b)
-{
-	size_t copy_size = min_t(size_t,
-			b->in_size - b->in_pos, s->temp.size - s->temp.pos);
-
-	memcpy(s->temp.buf + s->temp.pos, b->in + b->in_pos, copy_size);
-	b->in_pos += copy_size;
-	s->temp.pos += copy_size;
-
-	if (s->temp.pos == s->temp.size) {
-		s->temp.pos = 0;
-		return true;
-	}
-
-	return false;
-}
-
-/* Decode a variable-length integer (little-endian base-128 encoding) */
-static enum xz_ret dec_vli(struct xz_dec *s, const uint8_t *in,
-			   size_t *in_pos, size_t in_size)
-{
-	uint8_t byte;
-
-	if (s->pos == 0)
-		s->vli = 0;
-
-	while (*in_pos < in_size) {
-		byte = in[*in_pos];
-		++*in_pos;
-
-		s->vli |= (vli_type)(byte & 0x7F) << s->pos;
-
-		if ((byte & 0x80) == 0) {
-			/* Don't allow non-minimal encodings. */
-			if (byte == 0 && s->pos != 0)
-				return XZ_DATA_ERROR;
-
-			s->pos = 0;
-			return XZ_STREAM_END;
-		}
-
-		s->pos += 7;
-		if (s->pos == 7 * VLI_BYTES_MAX)
-			return XZ_DATA_ERROR;
-	}
-
-	return XZ_OK;
-}
-
-/*
- * Decode the Compressed Data field from a Block. Update and validate
- * the observed compressed and uncompressed sizes of the Block so that
- * they don't exceed the values possibly stored in the Block Header
- * (validation assumes that no integer overflow occurs, since vli_type
- * is normally uint64_t). Update the CRC32 or CRC64 value if presence of
- * the CRC32 or CRC64 field was indicated in Stream Header.
- *
- * Once the decoding is finished, validate that the observed sizes match
- * the sizes possibly stored in the Block Header. Update the hash and
- * Block count, which are later used to validate the Index field.
- */
-static enum xz_ret dec_block(struct xz_dec *s, struct xz_buf *b)
-{
-	enum xz_ret ret;
-
-	s->in_start = b->in_pos;
-	s->out_start = b->out_pos;
-
-#ifdef XZ_DEC_BCJ
-	if (s->bcj_active)
-		ret = xz_dec_bcj_run(s->bcj, s->lzma2, b);
-	else
-#endif
-		ret = xz_dec_lzma2_run(s->lzma2, b);
-
-	s->block.compressed += b->in_pos - s->in_start;
-	s->block.uncompressed += b->out_pos - s->out_start;
-
-	/*
-	 * There is no need to separately check for VLI_UNKNOWN, since
-	 * the observed sizes are always smaller than VLI_UNKNOWN.
-	 */
-	if (s->block.compressed > s->block_header.compressed
-			|| s->block.uncompressed
-				> s->block_header.uncompressed)
-		return XZ_DATA_ERROR;
-
-	if (s->check_type == XZ_CHECK_CRC32)
-		s->crc = xz_crc32(b->out + s->out_start,
-				b->out_pos - s->out_start, s->crc);
-#ifdef XZ_USE_CRC64
-	else if (s->check_type == XZ_CHECK_CRC64)
-		s->crc = xz_crc64(b->out + s->out_start,
-				b->out_pos - s->out_start, s->crc);
-#endif
-
-	if (ret == XZ_STREAM_END) {
-		if (s->block_header.compressed != VLI_UNKNOWN
-				&& s->block_header.compressed
-					!= s->block.compressed)
-			return XZ_DATA_ERROR;
-
-		if (s->block_header.uncompressed != VLI_UNKNOWN
-				&& s->block_header.uncompressed
-					!= s->block.uncompressed)
-			return XZ_DATA_ERROR;
-
-		s->block.hash.unpadded += s->block_header.size
-				+ s->block.compressed;
-
-#ifdef XZ_DEC_ANY_CHECK
-		s->block.hash.unpadded += check_sizes[s->check_type];
-#else
-		if (s->check_type == XZ_CHECK_CRC32)
-			s->block.hash.unpadded += 4;
-		else if (IS_CRC64(s->check_type))
-			s->block.hash.unpadded += 8;
-#endif
-
-		s->block.hash.uncompressed += s->block.uncompressed;
-		s->block.hash.crc32 = xz_crc32(
-				(const uint8_t *)&s->block.hash,
-				sizeof(s->block.hash), s->block.hash.crc32);
-
-		++s->block.count;
-	}
-
-	return ret;
-}
-
-/* Update the Index size and the CRC32 value. */
-static void index_update(struct xz_dec *s, const struct xz_buf *b)
-{
-	size_t in_used = b->in_pos - s->in_start;
-	s->index.size += in_used;
-	s->crc = xz_crc32(b->in + s->in_start, in_used, s->crc);
-}
-
-/*
- * Decode the Number of Records, Unpadded Size, and Uncompressed Size
- * fields from the Index field. That is, Index Padding and CRC32 are not
- * decoded by this function.
- *
- * This can return XZ_OK (more input needed), XZ_STREAM_END (everything
- * successfully decoded), or XZ_DATA_ERROR (input is corrupt).
- */
-static enum xz_ret dec_index(struct xz_dec *s, struct xz_buf *b)
-{
-	enum xz_ret ret;
-
-	do {
-		ret = dec_vli(s, b->in, &b->in_pos, b->in_size);
-		if (ret != XZ_STREAM_END) {
-			index_update(s, b);
-			return ret;
-		}
-
-		switch (s->index.sequence) {
-		case SEQ_INDEX_COUNT:
-			s->index.count = s->vli;
-
-			/*
-			 * Validate that the Number of Records field
-			 * indicates the same number of Records as
-			 * there were Blocks in the Stream.
-			 */
-			if (s->index.count != s->block.count)
-				return XZ_DATA_ERROR;
-
-			s->index.sequence = SEQ_INDEX_UNPADDED;
-			break;
-
-		case SEQ_INDEX_UNPADDED:
-			s->index.hash.unpadded += s->vli;
-			s->index.sequence = SEQ_INDEX_UNCOMPRESSED;
-			break;
-
-		case SEQ_INDEX_UNCOMPRESSED:
-			s->index.hash.uncompressed += s->vli;
-			s->index.hash.crc32 = xz_crc32(
-					(const uint8_t *)&s->index.hash,
-					sizeof(s->index.hash),
-					s->index.hash.crc32);
-			--s->index.count;
-			s->index.sequence = SEQ_INDEX_UNPADDED;
-			break;
-		}
-	} while (s->index.count > 0);
-
-	return XZ_STREAM_END;
-}
-
-/*
- * Validate that the next four or eight input bytes match the value
- * of s->crc. s->pos must be zero when starting to validate the first byte.
- * The "bits" argument allows using the same code for both CRC32 and CRC64.
- */
-static enum xz_ret crc_validate(struct xz_dec *s, struct xz_buf *b,
-				uint32_t bits)
-{
-	do {
-		if (b->in_pos == b->in_size)
-			return XZ_OK;
-
-		if (((s->crc >> s->pos) & 0xFF) != b->in[b->in_pos++])
-			return XZ_DATA_ERROR;
-
-		s->pos += 8;
-
-	} while (s->pos < bits);
-
-	s->crc = 0;
-	s->pos = 0;
-
-	return XZ_STREAM_END;
-}
-
-#ifdef XZ_DEC_ANY_CHECK
-/*
- * Skip over the Check field when the Check ID is not supported.
- * Returns true once the whole Check field has been skipped over.
- */
-static bool check_skip(struct xz_dec *s, struct xz_buf *b)
-{
-	while (s->pos < check_sizes[s->check_type]) {
-		if (b->in_pos == b->in_size)
-			return false;
-
-		++b->in_pos;
-		++s->pos;
-	}
-
-	s->pos = 0;
-
-	return true;
-}
-#endif
-
-/* Decode the Stream Header field (the first 12 bytes of the .xz Stream). */
-static enum xz_ret dec_stream_header(struct xz_dec *s)
-{
-	if (!memeq(s->temp.buf, HEADER_MAGIC, HEADER_MAGIC_SIZE))
-		return XZ_FORMAT_ERROR;
-
-	if (xz_crc32(s->temp.buf + HEADER_MAGIC_SIZE, 2, 0)
-			!= get_le32(s->temp.buf + HEADER_MAGIC_SIZE + 2))
-		return XZ_DATA_ERROR;
-
-	if (s->temp.buf[HEADER_MAGIC_SIZE] != 0)
-		return XZ_OPTIONS_ERROR;
-
-	/*
-	 * Of integrity checks, we support none (Check ID = 0),
-	 * CRC32 (Check ID = 1), and optionally CRC64 (Check ID = 4).
-	 * However, if XZ_DEC_ANY_CHECK is defined, we will accept other
-	 * check types too, but then the check won't be verified and
-	 * a warning (XZ_UNSUPPORTED_CHECK) will be given.
-	 */
-	s->check_type = s->temp.buf[HEADER_MAGIC_SIZE + 1];
-
-#ifdef XZ_DEC_ANY_CHECK
-	if (s->check_type > XZ_CHECK_MAX)
-		return XZ_OPTIONS_ERROR;
-
-	if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type))
-		return XZ_UNSUPPORTED_CHECK;
-#else
-	if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type))
-		return XZ_OPTIONS_ERROR;
-#endif
-
-	return XZ_OK;
-}
-
-/* Decode the Stream Footer field (the last 12 bytes of the .xz Stream) */
-static enum xz_ret dec_stream_footer(struct xz_dec *s)
-{
-	if (!memeq(s->temp.buf + 10, FOOTER_MAGIC, FOOTER_MAGIC_SIZE))
-		return XZ_DATA_ERROR;
-
-	if (xz_crc32(s->temp.buf + 4, 6, 0) != get_le32(s->temp.buf))
-		return XZ_DATA_ERROR;
-
-	/*
-	 * Validate Backward Size. Note that we never added the size of the
-	 * Index CRC32 field to s->index.size, thus we use s->index.size / 4
-	 * instead of s->index.size / 4 - 1.
-	 */
-	if ((s->index.size >> 2) != get_le32(s->temp.buf + 4))
-		return XZ_DATA_ERROR;
-
-	if (s->temp.buf[8] != 0 || s->temp.buf[9] != s->check_type)
-		return XZ_DATA_ERROR;
-
-	/*
-	 * Use XZ_STREAM_END instead of XZ_OK to be more convenient
-	 * for the caller.
-	 */
-	return XZ_STREAM_END;
-}
-
-/* Decode the Block Header and initialize the filter chain. */
-static enum xz_ret dec_block_header(struct xz_dec *s)
-{
-	enum xz_ret ret;
-
-	/*
-	 * Validate the CRC32. We know that the temp buffer is at least
-	 * eight bytes so this is safe.
-	 */
-	s->temp.size -= 4;
-	if (xz_crc32(s->temp.buf, s->temp.size, 0)
-			!= get_le32(s->temp.buf + s->temp.size))
-		return XZ_DATA_ERROR;
-
-	s->temp.pos = 2;
-
-	/*
-	 * Catch unsupported Block Flags. We support only one or two filters
-	 * in the chain, so we catch that with the same test.
-	 */
-#ifdef XZ_DEC_BCJ
-	if (s->temp.buf[1] & 0x3E)
-#else
-	if (s->temp.buf[1] & 0x3F)
-#endif
-		return XZ_OPTIONS_ERROR;
-
-	/* Compressed Size */
-	if (s->temp.buf[1] & 0x40) {
-		if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size)
-					!= XZ_STREAM_END)
-			return XZ_DATA_ERROR;
-
-		s->block_header.compressed = s->vli;
-	} else {
-		s->block_header.compressed = VLI_UNKNOWN;
-	}
-
-	/* Uncompressed Size */
-	if (s->temp.buf[1] & 0x80) {
-		if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size)
-				!= XZ_STREAM_END)
-			return XZ_DATA_ERROR;
-
-		s->block_header.uncompressed = s->vli;
-	} else {
-		s->block_header.uncompressed = VLI_UNKNOWN;
-	}
-
-#ifdef XZ_DEC_BCJ
-	/* If there are two filters, the first one must be a BCJ filter. */
-	s->bcj_active = s->temp.buf[1] & 0x01;
-	if (s->bcj_active) {
-		if (s->temp.size - s->temp.pos < 2)
-			return XZ_OPTIONS_ERROR;
-
-		ret = xz_dec_bcj_reset(s->bcj, s->temp.buf[s->temp.pos++]);
-		if (ret != XZ_OK)
-			return ret;
-
-		/*
-		 * We don't support custom start offset,
-		 * so Size of Properties must be zero.
-		 */
-		if (s->temp.buf[s->temp.pos++] != 0x00)
-			return XZ_OPTIONS_ERROR;
-	}
-#endif
-
-	/* Valid Filter Flags always take at least two bytes. */
-	if (s->temp.size - s->temp.pos < 2)
-		return XZ_DATA_ERROR;
-
-	/* Filter ID = LZMA2 */
-	if (s->temp.buf[s->temp.pos++] != 0x21)
-		return XZ_OPTIONS_ERROR;
-
-	/* Size of Properties = 1-byte Filter Properties */
-	if (s->temp.buf[s->temp.pos++] != 0x01)
-		return XZ_OPTIONS_ERROR;
-
-	/* Filter Properties contains LZMA2 dictionary size. */
-	if (s->temp.size - s->temp.pos < 1)
-		return XZ_DATA_ERROR;
-
-	ret = xz_dec_lzma2_reset(s->lzma2, s->temp.buf[s->temp.pos++]);
-	if (ret != XZ_OK)
-		return ret;
-
-	/* The rest must be Header Padding. */
-	while (s->temp.pos < s->temp.size)
-		if (s->temp.buf[s->temp.pos++] != 0x00)
-			return XZ_OPTIONS_ERROR;
-
-	s->temp.pos = 0;
-	s->block.compressed = 0;
-	s->block.uncompressed = 0;
-
-	return XZ_OK;
-}
-
-static enum xz_ret dec_main(struct xz_dec *s, struct xz_buf *b)
-{
-	enum xz_ret ret;
-
-	/*
-	 * Store the start position for the case when we are in the middle
-	 * of the Index field.
-	 */
-	s->in_start = b->in_pos;
-
-	while (true) {
-		switch (s->sequence) {
-		case SEQ_STREAM_HEADER:
-			/*
-			 * Stream Header is copied to s->temp, and then
-			 * decoded from there. This way if the caller
-			 * gives us only little input at a time, we can
-			 * still keep the Stream Header decoding code
-			 * simple. Similar approach is used in many places
-			 * in this file.
-			 */
-			if (!fill_temp(s, b))
-				return XZ_OK;
-
-			/*
-			 * If dec_stream_header() returns
-			 * XZ_UNSUPPORTED_CHECK, it is still possible
-			 * to continue decoding if working in multi-call
-			 * mode. Thus, update s->sequence before calling
-			 * dec_stream_header().
-			 */
-			s->sequence = SEQ_BLOCK_START;
-
-			ret = dec_stream_header(s);
-			if (ret != XZ_OK)
-				return ret;
-
-		case SEQ_BLOCK_START:
-			/* We need one byte of input to continue. */
-			if (b->in_pos == b->in_size)
-				return XZ_OK;
-
-			/* See if this is the beginning of the Index field. */
-			if (b->in[b->in_pos] == 0) {
-				s->in_start = b->in_pos++;
-				s->sequence = SEQ_INDEX;
-				break;
-			}
-
-			/*
-			 * Calculate the size of the Block Header and
-			 * prepare to decode it.
-			 */
-			s->block_header.size
-				= ((uint32_t)b->in[b->in_pos] + 1) * 4;
-
-			s->temp.size = s->block_header.size;
-			s->temp.pos = 0;
-			s->sequence = SEQ_BLOCK_HEADER;
-
-		case SEQ_BLOCK_HEADER:
-			if (!fill_temp(s, b))
-				return XZ_OK;
-
-			ret = dec_block_header(s);
-			if (ret != XZ_OK)
-				return ret;
-
-			s->sequence = SEQ_BLOCK_UNCOMPRESS;
-
-		case SEQ_BLOCK_UNCOMPRESS:
-			ret = dec_block(s, b);
-			if (ret != XZ_STREAM_END)
-				return ret;
-
-			s->sequence = SEQ_BLOCK_PADDING;
-
-		case SEQ_BLOCK_PADDING:
-			/*
-			 * Size of Compressed Data + Block Padding
-			 * must be a multiple of four. We don't need
-			 * s->block.compressed for anything else
-			 * anymore, so we use it here to test the size
-			 * of the Block Padding field.
-			 */
-			while (s->block.compressed & 3) {
-				if (b->in_pos == b->in_size)
-					return XZ_OK;
-
-				if (b->in[b->in_pos++] != 0)
-					return XZ_DATA_ERROR;
-
-				++s->block.compressed;
-			}
-
-			s->sequence = SEQ_BLOCK_CHECK;
-
-		case SEQ_BLOCK_CHECK:
-			if (s->check_type == XZ_CHECK_CRC32) {
-				ret = crc_validate(s, b, 32);
-				if (ret != XZ_STREAM_END)
-					return ret;
-			}
-			else if (IS_CRC64(s->check_type)) {
-				ret = crc_validate(s, b, 64);
-				if (ret != XZ_STREAM_END)
-					return ret;
-			}
-#ifdef XZ_DEC_ANY_CHECK
-			else if (!check_skip(s, b)) {
-				return XZ_OK;
-			}
-#endif
-
-			s->sequence = SEQ_BLOCK_START;
-			break;
-
-		case SEQ_INDEX:
-			ret = dec_index(s, b);
-			if (ret != XZ_STREAM_END)
-				return ret;
-
-			s->sequence = SEQ_INDEX_PADDING;
-
-		case SEQ_INDEX_PADDING:
-			while ((s->index.size + (b->in_pos - s->in_start))
-					& 3) {
-				if (b->in_pos == b->in_size) {
-					index_update(s, b);
-					return XZ_OK;
-				}
-
-				if (b->in[b->in_pos++] != 0)
-					return XZ_DATA_ERROR;
-			}
-
-			/* Finish the CRC32 value and Index size. */
-			index_update(s, b);
-
-			/* Compare the hashes to validate the Index field. */
-			if (!memeq(&s->block.hash, &s->index.hash,
-					sizeof(s->block.hash)))
-				return XZ_DATA_ERROR;
-
-			s->sequence = SEQ_INDEX_CRC32;
-
-		case SEQ_INDEX_CRC32:
-			ret = crc_validate(s, b, 32);
-			if (ret != XZ_STREAM_END)
-				return ret;
-
-			s->temp.size = STREAM_HEADER_SIZE;
-			s->sequence = SEQ_STREAM_FOOTER;
-
-		case SEQ_STREAM_FOOTER:
-			if (!fill_temp(s, b))
-				return XZ_OK;
-
-			return dec_stream_footer(s);
-		}
-	}
-
-	/* Never reached */
-}
-
-/*
- * xz_dec_run() is a wrapper for dec_main() to handle some special cases in
- * multi-call and single-call decoding.
- *
- * In multi-call mode, we must return XZ_BUF_ERROR when it seems clear that we
- * are not going to make any progress anymore. This is to prevent the caller
- * from calling us infinitely when the input file is truncated or otherwise
- * corrupt. Since zlib-style API allows that the caller fills the input buffer
- * only when the decoder doesn't produce any new output, we have to be careful
- * to avoid returning XZ_BUF_ERROR too easily: XZ_BUF_ERROR is returned only
- * after the second consecutive call to xz_dec_run() that makes no progress.
- *
- * In single-call mode, if we couldn't decode everything and no error
- * occurred, either the input is truncated or the output buffer is too small.
- * Since we know that the last input byte never produces any output, we know
- * that if all the input was consumed and decoding wasn't finished, the file
- * must be corrupt. Otherwise the output buffer has to be too small or the
- * file is corrupt in a way that decoding it produces too big output.
- *
- * If single-call decoding fails, we reset b->in_pos and b->out_pos back to
- * their original values. This is because with some filter chains there won't
- * be any valid uncompressed data in the output buffer unless the decoding
- * actually succeeds (that's the price to pay of using the output buffer as
- * the workspace).
- */
-XZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b)
-{
-	size_t in_start;
-	size_t out_start;
-	enum xz_ret ret;
-
-	if (DEC_IS_SINGLE(s->mode))
-		xz_dec_reset(s);
-
-	in_start = b->in_pos;
-	out_start = b->out_pos;
-	ret = dec_main(s, b);
-
-	if (DEC_IS_SINGLE(s->mode)) {
-		if (ret == XZ_OK)
-			ret = b->in_pos == b->in_size
-					? XZ_DATA_ERROR : XZ_BUF_ERROR;
-
-		if (ret != XZ_STREAM_END) {
-			b->in_pos = in_start;
-			b->out_pos = out_start;
-		}
-
-	} else if (ret == XZ_OK && in_start == b->in_pos
-			&& out_start == b->out_pos) {
-		if (s->allow_buf_error)
-			ret = XZ_BUF_ERROR;
-
-		s->allow_buf_error = true;
-	} else {
-		s->allow_buf_error = false;
-	}
-
-	return ret;
-}
-
-XZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max)
-{
-	struct xz_dec *s = kmalloc(sizeof(*s), GFP_KERNEL);
-	if (s == NULL)
-		return NULL;
-
-	s->mode = mode;
-
-#ifdef XZ_DEC_BCJ
-	s->bcj = xz_dec_bcj_create(DEC_IS_SINGLE(mode));
-	if (s->bcj == NULL)
-		goto error_bcj;
-#endif
-
-	s->lzma2 = xz_dec_lzma2_create(mode, dict_max);
-	if (s->lzma2 == NULL)
-		goto error_lzma2;
-
-	xz_dec_reset(s);
-	return s;
-
-error_lzma2:
-#ifdef XZ_DEC_BCJ
-	xz_dec_bcj_end(s->bcj);
-error_bcj:
-#endif
-	kfree(s);
-	return NULL;
-}
-
-XZ_EXTERN void xz_dec_reset(struct xz_dec *s)
-{
-	s->sequence = SEQ_STREAM_HEADER;
-	s->allow_buf_error = false;
-	s->pos = 0;
-	s->crc = 0;
-	memzero(&s->block, sizeof(s->block));
-	memzero(&s->index, sizeof(s->index));
-	s->temp.pos = 0;
-	s->temp.size = STREAM_HEADER_SIZE;
-}
-
-XZ_EXTERN void xz_dec_end(struct xz_dec *s)
-{
-	if (s != NULL) {
-		xz_dec_lzma2_end(s->lzma2);
-#ifdef XZ_DEC_BCJ
-		xz_dec_bcj_end(s->bcj);
-#endif
-		kfree(s);
-	}
-}