1 files changed, 12 insertions, 181 deletions

diff --git a/linux/lib/xz/xz_dec_lzma2.c b/linux/lib/xz/xz_dec_lzma2.c
index c929f1c..08c3c80 100644
--- a/linux/lib/xz/xz_dec_lzma2.c
+++ b/linux/lib/xz/xz_dec_lzma2.c
@@ -2,7 +2,7 @@
  * LZMA2 decoder
  *
  * Authors: Lasse Collin <lasse.collin@tukaani.org>
- *          Igor Pavlov <https://7-zip.org/>
+ *          Igor Pavlov <http://7-zip.org/>
  *
  * This file has been put into the public domain.
  * You can do whatever you want with this file.
@@ -147,8 +147,8 @@ struct lzma_dec {
 
 	/*
 	 * LZMA properties or related bit masks (number of literal
-	 * context bits, a mask derived from the number of literal
-	 * position bits, and a mask derived from the number
+	 * context bits, a mask dervied from the number of literal
+	 * position bits, and a mask dervied from the number
 	 * position bits)
 	 */
 	uint32_t lc;
@@ -248,10 +248,6 @@ struct lzma2_dec {
 	 * before the first LZMA chunk.
 	 */
 	bool need_props;
-
-#ifdef XZ_DEC_MICROLZMA
-	bool pedantic_microlzma;
-#endif
 };
 
 struct xz_dec_lzma2 {
@@ -391,14 +387,7 @@ static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
 
 		*left -= copy_size;
 
-		/*
-		 * If doing in-place decompression in single-call mode and the
-		 * uncompressed size of the file is larger than the caller
-		 * thought (i.e. it is invalid input!), the buffers below may
-		 * overlap and cause undefined behavior with memcpy().
-		 * With valid inputs memcpy() would be fine here.
-		 */
-		memmove(dict->buf + dict->pos, b->in + b->in_pos, copy_size);
+		memcpy(dict->buf + dict->pos, b->in + b->in_pos, copy_size);
 		dict->pos += copy_size;
 
 		if (dict->full < dict->pos)
@@ -408,11 +397,7 @@ static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
 			if (dict->pos == dict->end)
 				dict->pos = 0;
 
-			/*
-			 * Like above but for multi-call mode: use memmove()
-			 * to avoid undefined behavior with invalid input.
-			 */
-			memmove(b->out + b->out_pos, b->in + b->in_pos,
+			memcpy(b->out + b->out_pos, b->in + b->in_pos,
 					copy_size);
 		}
 
@@ -423,12 +408,6 @@ static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
 	}
 }
 
-#ifdef XZ_DEC_MICROLZMA
-#	define DICT_FLUSH_SUPPORTS_SKIPPING true
-#else
-#	define DICT_FLUSH_SUPPORTS_SKIPPING false
-#endif
-
 /*
  * Flush pending data from dictionary to b->out. It is assumed that there is
  * enough space in b->out. This is guaranteed because caller uses dict_limit()
@@ -442,19 +421,8 @@ static uint32_t dict_flush(struct dictionary *dict, struct xz_buf *b)
 		if (dict->pos == dict->end)
 			dict->pos = 0;
 
-		/*
-		 * These buffers cannot overlap even if doing in-place
-		 * decompression because in multi-call mode dict->buf
-		 * has been allocated by us in this file; it's not
-		 * provided by the caller like in single-call mode.
-		 *
-		 * With MicroLZMA, b->out can be NULL to skip bytes that
-		 * the caller doesn't need. This cannot be done with XZ
-		 * because it would break BCJ filters.
-		 */
-		if (!DICT_FLUSH_SUPPORTS_SKIPPING || b->out != NULL)
-			memcpy(b->out + b->out_pos, dict->buf + dict->start,
-					copy_size);
+		memcpy(b->out + b->out_pos, dict->buf + dict->start,
+				copy_size);
 	}
 
 	dict->start = dict->pos;
@@ -516,11 +484,11 @@ static __always_inline void rc_normalize(struct rc_dec *rc)
 }
 
 /*
- * Decode one bit. In some versions, this function has been split in three
+ * Decode one bit. In some versions, this function has been splitted in three
  * functions so that the compiler is supposed to be able to more easily avoid
  * an extra branch. In this particular version of the LZMA decoder, this
  * doesn't seem to be a good idea (tested with GCC 3.3.6, 3.4.6, and 4.3.3
- * on x86). Using a non-split version results in nicer looking code too.
+ * on x86). Using a non-splitted version results in nicer looking code too.
  *
  * NOTE: This must return an int. Do not make it return a bool or the speed
  * of the code generated by GCC 3.x decreases 10-15 %. (GCC 4.3 doesn't care,
@@ -793,7 +761,7 @@ static bool lzma_main(struct xz_dec_lzma2 *s)
 }
 
 /*
- * Reset the LZMA decoder and range decoder state. Dictionary is not reset
+ * Reset the LZMA decoder and range decoder state. Dictionary is nore reset
  * here, because LZMA state may be reset without resetting the dictionary.
  */
 static void lzma_reset(struct xz_dec_lzma2 *s)
@@ -806,7 +774,6 @@ static void lzma_reset(struct xz_dec_lzma2 *s)
 	s->lzma.rep1 = 0;
 	s->lzma.rep2 = 0;
 	s->lzma.rep3 = 0;
-	s->lzma.len = 0;
 
 	/*
 	 * All probabilities are initialized to the same value. This hack
@@ -1179,7 +1146,6 @@ XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props)
 
 		if (DEC_IS_DYNALLOC(s->dict.mode)) {
 			if (s->dict.allocated < s->dict.size) {
-				s->dict.allocated = s->dict.size;
 				vfree(s->dict.buf);
 				s->dict.buf = vmalloc(s->dict.size);
 				if (s->dict.buf == NULL) {
@@ -1190,6 +1156,8 @@ XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props)
 		}
 	}
 
+	s->lzma.len = 0;
+
 	s->lzma2.sequence = SEQ_CONTROL;
 	s->lzma2.need_dict_reset = true;
 
@@ -1205,140 +1173,3 @@ XZ_EXTERN void xz_dec_lzma2_end(struct xz_dec_lzma2 *s)
 
 	kfree(s);
 }
-
-#ifdef XZ_DEC_MICROLZMA
-/* This is a wrapper struct to have a nice struct name in the public API. */
-struct xz_dec_microlzma {
-	struct xz_dec_lzma2 s;
-};
-
-enum xz_ret xz_dec_microlzma_run(struct xz_dec_microlzma *s_ptr,
-				 struct xz_buf *b)
-{
-	struct xz_dec_lzma2 *s = &s_ptr->s;
-
-	/*
-	 * sequence is SEQ_PROPERTIES before the first input byte,
-	 * SEQ_LZMA_PREPARE until a total of five bytes have been read,
-	 * and SEQ_LZMA_RUN for the rest of the input stream.
-	 */
-	if (s->lzma2.sequence != SEQ_LZMA_RUN) {
-		if (s->lzma2.sequence == SEQ_PROPERTIES) {
-			/* One byte is needed for the props. */
-			if (b->in_pos >= b->in_size)
-				return XZ_OK;
-
-			/*
-			 * Don't increment b->in_pos here. The same byte is
-			 * also passed to rc_read_init() which will ignore it.
-			 */
-			if (!lzma_props(s, ~b->in[b->in_pos]))
-				return XZ_DATA_ERROR;
-
-			s->lzma2.sequence = SEQ_LZMA_PREPARE;
-		}
-
-		/*
-		 * xz_dec_microlzma_reset() doesn't validate the compressed
-		 * size so we do it here. We have to limit the maximum size
-		 * to avoid integer overflows in lzma2_lzma(). 3 GiB is a nice
-		 * round number and much more than users of this code should
-		 * ever need.
-		 */
-		if (s->lzma2.compressed < RC_INIT_BYTES
-				|| s->lzma2.compressed > (3U << 30))
-			return XZ_DATA_ERROR;
-
-		if (!rc_read_init(&s->rc, b))
-			return XZ_OK;
-
-		s->lzma2.compressed -= RC_INIT_BYTES;
-		s->lzma2.sequence = SEQ_LZMA_RUN;
-
-		dict_reset(&s->dict, b);
-	}
-
-	/* This is to allow increasing b->out_size between calls. */
-	if (DEC_IS_SINGLE(s->dict.mode))
-		s->dict.end = b->out_size - b->out_pos;
-
-	while (true) {
-		dict_limit(&s->dict, min_t(size_t, b->out_size - b->out_pos,
-					   s->lzma2.uncompressed));
-
-		if (!lzma2_lzma(s, b))
-			return XZ_DATA_ERROR;
-
-		s->lzma2.uncompressed -= dict_flush(&s->dict, b);
-
-		if (s->lzma2.uncompressed == 0) {
-			if (s->lzma2.pedantic_microlzma) {
-				if (s->lzma2.compressed > 0 || s->lzma.len > 0
-						|| !rc_is_finished(&s->rc))
-					return XZ_DATA_ERROR;
-			}
-
-			return XZ_STREAM_END;
-		}
-
-		if (b->out_pos == b->out_size)
-			return XZ_OK;
-
-		if (b->in_pos == b->in_size
-				&& s->temp.size < s->lzma2.compressed)
-			return XZ_OK;
-	}
-}
-
-struct xz_dec_microlzma *xz_dec_microlzma_alloc(enum xz_mode mode,
-						uint32_t dict_size)
-{
-	struct xz_dec_microlzma *s;
-
-	/* Restrict dict_size to the same range as in the LZMA2 code. */
-	if (dict_size < 4096 || dict_size > (3U << 30))
-		return NULL;
-
-	s = kmalloc(sizeof(*s), GFP_KERNEL);
-	if (s == NULL)
-		return NULL;
-
-	s->s.dict.mode = mode;
-	s->s.dict.size = dict_size;
-
-	if (DEC_IS_MULTI(mode)) {
-		s->s.dict.end = dict_size;
-
-		s->s.dict.buf = vmalloc(dict_size);
-		if (s->s.dict.buf == NULL) {
-			kfree(s);
-			return NULL;
-		}
-	}
-
-	return s;
-}
-
-void xz_dec_microlzma_reset(struct xz_dec_microlzma *s, uint32_t comp_size,
-			    uint32_t uncomp_size, int uncomp_size_is_exact)
-{
-	/*
-	 * comp_size is validated in xz_dec_microlzma_run().
-	 * uncomp_size can safely be anything.
-	 */
-	s->s.lzma2.compressed = comp_size;
-	s->s.lzma2.uncompressed = uncomp_size;
-	s->s.lzma2.pedantic_microlzma = uncomp_size_is_exact;
-
-	s->s.lzma2.sequence = SEQ_PROPERTIES;
-	s->s.temp.size = 0;
-}
-
-void xz_dec_microlzma_end(struct xz_dec_microlzma *s)
-{
-	if (DEC_IS_MULTI(s->s.dict.mode))
-		vfree(s->s.dict.buf);
-
-	kfree(s);
-}
-#endif