35 files changed, 4271 insertions, 138 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index fa9bf2c06199..0ee67e08ad3e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -106,6 +106,8 @@ config LZO_COMPRESS
 config LZO_DECOMPRESS
         tristate
 
+source "lib/xz/Kconfig"
+
 #
 # These all provide a common interface (hence the apparent duplication with
 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
@@ -120,6 +122,10 @@ config DECOMPRESS_BZIP2
 config DECOMPRESS_LZMA
         tristate
 
+config DECOMPRESS_XZ
+        select XZ_DEC
+        tristate
+
 config DECOMPRESS_LZO
         select LZO_DECOMPRESS
         tristate
@@ -210,4 +216,7 @@ config GENERIC_ATOMIC64
 config LRU_CACHE
         tristate
 
+config AVERAGE
+        bool
+
 endmenu
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 28b42b9274d0..3967c2356e37 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -173,7 +173,8 @@ config LOCKUP_DETECTOR
           An NMI is generated every 60 seconds or so to check for hardlockups.
 
 config HARDLOCKUP_DETECTOR
-        def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI
+        def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
+                 !ARCH_HAS_NMI_WATCHDOG
 
 config BOOTPARAM_SOFTLOCKUP_PANIC
         bool "Panic (Reboot) On Soft Lockups"
@@ -656,7 +657,7 @@ config DEBUG_HIGHMEM
           Disable for production systems.
 
 config DEBUG_BUGVERBOSE
-        bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
+        bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
         depends on BUG
         depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
                    FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
@@ -728,8 +729,8 @@ config DEBUG_WRITECOUNT
           If unsure, say N.
 
 config DEBUG_MEMORY_INIT
-        bool "Debug memory initialisation" if EMBEDDED
-        default !EMBEDDED
+        bool "Debug memory initialisation" if EXPERT
+        default !EXPERT
         help
           Enable this for additional checks during memory initialisation.
           The sanity checks verify aspects of the VM such as the memory model
diff --git a/lib/Makefile b/lib/Makefile
index e6a3763b8212..cbb774f7d41d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -8,11 +8,11 @@ KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
 endif
 
 lib-y := ctype.o string.o vsprintf.o cmdline.o \
-         rbtree.o radix-tree.o dump_stack.o \
+         rbtree.o radix-tree.o dump_stack.o timerqueue.o\
          idr.o int_sqrt.o extable.o prio_tree.o \
          sha1.o irq_regs.o reciprocal_div.o argv_split.o \
          proportions.o prio_heap.o ratelimit.o show_mem.o \
-         is_single_threaded.o plist.o decompress.o flex_array.o
+         is_single_threaded.o plist.o decompress.o
 
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
@@ -21,7 +21,7 @@ lib-y	+= kobject.o kref.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
          bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
-         string_helpers.o gcd.o lcm.o list_sort.o uuid.o
+         string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
@@ -69,11 +69,13 @@ obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
 obj-$(CONFIG_REED_SOLOMON) += reed_solomon/
 obj-$(CONFIG_LZO_COMPRESS) += lzo/
 obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
+obj-$(CONFIG_XZ_DEC) += xz/
 obj-$(CONFIG_RAID6_PQ) += raid6/
 
 lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
 lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
 lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
+lib-$(CONFIG_DECOMPRESS_XZ) += decompress_unxz.o
 lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o
 
 obj-$(CONFIG_TEXTSEARCH) += textsearch.o
@@ -106,6 +108,8 @@ obj-$(CONFIG_GENERIC_ATOMIC64) += atomic64.o
 
 obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
 
+obj-$(CONFIG_AVERAGE) += average.o
+
 hostprogs-y     := gen_crc32table
 clean-files     := crc32table.h
 
diff --git a/lib/average.c b/lib/average.c
new file mode 100644
index 000000000000..5576c2841496
--- /dev/null
+++ b/lib/average.c
@@ -0,0 +1,61 @@
+/*
+ * lib/average.c
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/average.h>
+#include <linux/bug.h>
+#include <linux/log2.h>
+
+/**
+ * DOC: Exponentially Weighted Moving Average (EWMA)
+ *
+ * These are generic functions for calculating Exponentially Weighted Moving
+ * Averages (EWMA). We keep a structure with the EWMA parameters and a scaled
+ * up internal representation of the average value to prevent rounding errors.
+ * The factor for scaling up and the exponential weight (or decay rate) have to
+ * be specified thru the init fuction. The structure should not be accessed
+ * directly but only thru the helper functions.
+ */
+
+/**
+ * ewma_init() - Initialize EWMA parameters
+ * @avg: Average structure
+ * @factor: Factor to use for the scaled up internal value. The maximum value
+ *      of averages can be ULONG_MAX/(factor*weight). For performance reasons
+ *      factor has to be a power of 2.
+ * @weight: Exponential weight, or decay rate. This defines how fast the
+ *      influence of older values decreases. For performance reasons weight has
+ *      to be a power of 2.
+ *
+ * Initialize the EWMA parameters for a given struct ewma @avg.
+ */
+void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)
+{
+        WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));
+
+        avg->weight = ilog2(weight);
+        avg->factor = ilog2(factor);
+        avg->internal = 0;
+}
+EXPORT_SYMBOL(ewma_init);
+
+/**
+ * ewma_add() - Exponentially weighted moving average (EWMA)
+ * @avg: Average structure
+ * @val: Current value
+ *
+ * Add a sample to the average.
+ */
+struct ewma *ewma_add(struct ewma *avg, unsigned long val)
+{
+        avg->internal = avg->internal  ?
+                (((avg->internal << avg->weight) - avg->internal) +
+                        (val << avg->factor)) >> avg->weight :
+                (val << avg->factor);
+        return avg;
+}
+EXPORT_SYMBOL(ewma_add);
diff --git a/lib/debug_locks.c b/lib/debug_locks.c
index 5bf0020b9248..b1c177307677 100644
--- a/lib/debug_locks.c
+++ b/lib/debug_locks.c
@@ -8,7 +8,6 @@
  *
  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
  */
-#include <linux/kernel.h>
 #include <linux/rwsem.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
@@ -39,7 +38,6 @@ int debug_locks_off(void)
 {
         if (__debug_locks_off()) {
                 if (!debug_locks_silent) {
-                        oops_in_progress = 1;
                         console_verbose();
                         return 1;
                 }
diff --git a/lib/decompress.c b/lib/decompress.c
index a7606815541f..3d766b7f60ab 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -8,6 +8,7 @@
 
 #include <linux/decompress/bunzip2.h>
 #include <linux/decompress/unlzma.h>
+#include <linux/decompress/unxz.h>
 #include <linux/decompress/inflate.h>
 #include <linux/decompress/unlzo.h>
 
@@ -23,6 +24,9 @@
 #ifndef CONFIG_DECOMPRESS_LZMA
 # define unlzma NULL
 #endif
+#ifndef CONFIG_DECOMPRESS_XZ
+# define unxz NULL
+#endif
 #ifndef CONFIG_DECOMPRESS_LZO
 # define unlzo NULL
 #endif
@@ -36,6 +40,7 @@ static const struct compress_format {
         { {037, 0236}, "gzip", gunzip },
         { {0x42, 0x5a}, "bzip2", bunzip2 },
         { {0x5d, 0x00}, "lzma", unlzma },
+        { {0xfd, 0x37}, "xz", unxz },
         { {0x89, 0x4c}, "lzo", unlzo },
         { {0, 0}, NULL, NULL }
 };
diff --git a/lib/decompress_bunzip2.c b/lib/decompress_bunzip2.c
index 81c8bb1cc6aa..a7b80c1d6a0d 100644
--- a/lib/decompress_bunzip2.c
+++ b/lib/decompress_bunzip2.c
@@ -49,7 +49,6 @@
 #define PREBOOT
 #else
 #include <linux/decompress/bunzip2.h>
-#include <linux/slab.h>
 #endif /* STATIC */
 
 #include <linux/decompress/mm.h>
@@ -682,13 +681,12 @@ STATIC int INIT bunzip2(unsigned char *buf, int len,
                         int(*flush)(void*, unsigned int),
                         unsigned char *outbuf,
                         int *pos,
-                        void(*error_fn)(char *x))
+                        void(*error)(char *x))
 {
         struct bunzip_data *bd;
         int i = -1;
         unsigned char *inbuf;
 
-        set_error_fn(error_fn);
         if (flush)
                 outbuf = malloc(BZIP2_IOBUF_SIZE);
 
@@ -751,8 +749,8 @@ STATIC int INIT decompress(unsigned char *buf, int len,
                         int(*flush)(void*, unsigned int),
                         unsigned char *outbuf,
                         int *pos,
-                        void(*error_fn)(char *x))
+                        void(*error)(char *x))
 {
-        return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error_fn);
+        return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
 }
 #endif
diff --git a/lib/decompress_inflate.c b/lib/decompress_inflate.c
index fc686c7a0a0d..19ff89e34eec 100644
--- a/lib/decompress_inflate.c
+++ b/lib/decompress_inflate.c
@@ -19,7 +19,6 @@
 #include "zlib_inflate/inflate.h"
 
 #include "zlib_inflate/infutil.h"
-#include <linux/slab.h>
 
 #endif /* STATIC */
 
@@ -27,7 +26,7 @@
 
 #define GZIP_IOBUF_SIZE (16*1024)
 
-static int nofill(void *buffer, unsigned int len)
+static int INIT nofill(void *buffer, unsigned int len)
 {
         return -1;
 }
@@ -38,13 +37,12 @@ STATIC int INIT gunzip(unsigned char *buf, int len,
                        int(*flush)(void*, unsigned int),
                        unsigned char *out_buf,
                        int *pos,
-                       void(*error_fn)(char *x)) {
+                       void(*error)(char *x)) {
         u8 *zbuf;
         struct z_stream_s *strm;
         int rc;
         size_t out_len;
 
-        set_error_fn(error_fn);
         rc = -1;
         if (flush) {
                 out_len = 0x8000; /* 32 K */
@@ -100,13 +98,22 @@ STATIC int INIT gunzip(unsigned char *buf, int len,
          * possible asciz filename)
          */
         strm->next_in = zbuf + 10;
+        strm->avail_in = len - 10;
         /* skip over asciz filename */
         if (zbuf[3] & 0x8) {
-                while (strm->next_in[0])
-                        strm->next_in++;
-                strm->next_in++;
+                do {
+                        /*
+                         * If the filename doesn't fit into the buffer,
+                         * the file is very probably corrupt. Don't try
+                         * to read more data.
+                         */
+                        if (strm->avail_in == 0) {
+                                error("header error");
+                                goto gunzip_5;
+                        }
+                        --strm->avail_in;
+                } while (*strm->next_in++);
         }
-        strm->avail_in = len - (strm->next_in - zbuf);
 
         strm->next_out = out_buf;
         strm->avail_out = out_len;
diff --git a/lib/decompress_unlzma.c b/lib/decompress_unlzma.c
index ca82fde81c8f..476c65af9709 100644
--- a/lib/decompress_unlzma.c
+++ b/lib/decompress_unlzma.c
@@ -33,7 +33,6 @@
 #define PREBOOT
 #else
 #include <linux/decompress/unlzma.h>
-#include <linux/slab.h>
 #endif /* STATIC */
 
 #include <linux/decompress/mm.h>
@@ -74,6 +73,7 @@ struct rc {
         uint32_t code;
         uint32_t range;
         uint32_t bound;
+        void (*error)(char *);
 };
 
 
@@ -82,7 +82,7 @@ struct rc {
 #define RC_MODEL_TOTAL_BITS 11
 
 
-static int nofill(void *buffer, unsigned int len)
+static int INIT nofill(void *buffer, unsigned int len)
 {
         return -1;
 }
@@ -92,7 +92,7 @@ static void INIT rc_read(struct rc *rc)
 {
         rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
         if (rc->buffer_size <= 0)
-                error("unexpected EOF");
+                rc->error("unexpected EOF");
         rc->ptr = rc->buffer;
         rc->buffer_end = rc->buffer + rc->buffer_size;
 }
@@ -127,12 +127,6 @@ static inline void INIT rc_init_code(struct rc *rc)
 }
 
 
-/* Called once. TODO: bb_maybe_free() */
-static inline void INIT rc_free(struct rc *rc)
-{
-        free(rc->buffer);
-}
-
 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
 static void INIT rc_do_normalize(struct rc *rc)
 {
@@ -169,7 +163,7 @@ static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
         rc->range = rc->bound;
         *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
 }
-static inline void rc_update_bit_1(struct rc *rc, uint16_t *p)
+static inline void INIT rc_update_bit_1(struct rc *rc, uint16_t *p)
 {
         rc->range -= rc->bound;
         rc->code -= rc->bound;
@@ -319,32 +313,38 @@ static inline uint8_t INIT peek_old_byte(struct writer *wr,
 
 }
 
-static inline void INIT write_byte(struct writer *wr, uint8_t byte)
+static inline int INIT write_byte(struct writer *wr, uint8_t byte)
 {
         wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
         if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
                 wr->buffer_pos = 0;
                 wr->global_pos += wr->header->dict_size;
-                wr->flush((char *)wr->buffer, wr->header->dict_size);
+                if (wr->flush((char *)wr->buffer, wr->header->dict_size)
+                                != wr->header->dict_size)
+                        return -1;
         }
+        return 0;
 }
 
 
-static inline void INIT copy_byte(struct writer *wr, uint32_t offs)
+static inline int INIT copy_byte(struct writer *wr, uint32_t offs)
 {
-        write_byte(wr, peek_old_byte(wr, offs));
+        return write_byte(wr, peek_old_byte(wr, offs));
 }
 
-static inline void INIT copy_bytes(struct writer *wr,
+static inline int INIT copy_bytes(struct writer *wr,
                                          uint32_t rep0, int len)
 {
         do {
-                copy_byte(wr, rep0);
+                if (copy_byte(wr, rep0))
+                        return -1;
                 len--;
         } while (len != 0 && wr->buffer_pos < wr->header->dst_size);
+
+        return len;
 }
 
-static inline void INIT process_bit0(struct writer *wr, struct rc *rc,
+static inline int INIT process_bit0(struct writer *wr, struct rc *rc,
                                      struct cstate *cst, uint16_t *p,
                                      int pos_state, uint16_t *prob,
                                      int lc, uint32_t literal_pos_mask) {
@@ -378,16 +378,17 @@ static inline void INIT process_bit0(struct writer *wr, struct rc *rc,
                 uint16_t *prob_lit = prob + mi;
                 rc_get_bit(rc, prob_lit, &mi);
         }
-        write_byte(wr, mi);
         if (cst->state < 4)
                 cst->state = 0;
         else if (cst->state < 10)
                 cst->state -= 3;
         else
                 cst->state -= 6;
+
+        return write_byte(wr, mi);
 }
 
-static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
+static inline int INIT process_bit1(struct writer *wr, struct rc *rc,
                                             struct cstate *cst, uint16_t *p,
                                             int pos_state, uint16_t *prob) {
   int offset;
@@ -418,8 +419,7 @@ static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
 
                                 cst->state = cst->state < LZMA_NUM_LIT_STATES ?
                                         9 : 11;
-                                copy_byte(wr, cst->rep0);
-                                return;
+                                return copy_byte(wr, cst->rep0);
                         } else {
                                 rc_update_bit_1(rc, prob);
                         }
@@ -521,12 +521,15 @@ static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
                 } else
                         cst->rep0 = pos_slot;
                 if (++(cst->rep0) == 0)
-                        return;
+                        return 0;
+                if (cst->rep0 > wr->header->dict_size
+                                || cst->rep0 > get_pos(wr))
+                        return -1;
         }
 
         len += LZMA_MATCH_MIN_LEN;
 
-        copy_bytes(wr, cst->rep0, len);
+        return copy_bytes(wr, cst->rep0, len);
 }
 
 
@@ -536,7 +539,7 @@ STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
                               int(*flush)(void*, unsigned int),
                               unsigned char *output,
                               int *posp,
-                              void(*error_fn)(char *x)
+                              void(*error)(char *x)
         )
 {
         struct lzma_header header;
@@ -552,7 +555,7 @@ STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
         unsigned char *inbuf;
         int ret = -1;
 
-        set_error_fn(error_fn);
+        rc.error = error;
 
         if (buf)
                 inbuf = buf;
@@ -580,8 +583,10 @@ STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
                 ((unsigned char *)&header)[i] = *rc.ptr++;
         }
 
-        if (header.pos >= (9 * 5 * 5))
+        if (header.pos >= (9 * 5 * 5)) {
                 error("bad header");
+                goto exit_1;
+        }
 
         mi = 0;
         lc = header.pos;
@@ -627,21 +632,29 @@ STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
                 int pos_state = get_pos(&wr) & pos_state_mask;
                 uint16_t *prob = p + LZMA_IS_MATCH +
                         (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
-                if (rc_is_bit_0(&rc, prob))
-                        process_bit0(&wr, &rc, &cst, p, pos_state, prob,
-                                     lc, literal_pos_mask);
-                else {
-                        process_bit1(&wr, &rc, &cst, p, pos_state, prob);
+                if (rc_is_bit_0(&rc, prob)) {
+                        if (process_bit0(&wr, &rc, &cst, p, pos_state, prob,
+                                        lc, literal_pos_mask)) {
+                                error("LZMA data is corrupt");
+                                goto exit_3;
+                        }
+                } else {
+                        if (process_bit1(&wr, &rc, &cst, p, pos_state, prob)) {
+                                error("LZMA data is corrupt");
+                                goto exit_3;
+                        }
                         if (cst.rep0 == 0)
                                 break;
                 }
+                if (rc.buffer_size <= 0)
+                        goto exit_3;
         }
 
         if (posp)
                 *posp = rc.ptr-rc.buffer;
-        if (wr.flush)
-                wr.flush(wr.buffer, wr.buffer_pos);
-        ret = 0;
+        if (!wr.flush || wr.flush(wr.buffer, wr.buffer_pos) == wr.buffer_pos)
+                ret = 0;
+exit_3:
         large_free(p);
 exit_2:
         if (!output)
@@ -659,9 +672,9 @@ STATIC int INIT decompress(unsigned char *buf, int in_len,
                               int(*flush)(void*, unsigned int),
                               unsigned char *output,
                               int *posp,
-                              void(*error_fn)(char *x)
+                              void(*error)(char *x)
         )
 {
-        return unlzma(buf, in_len - 4, fill, flush, output, posp, error_fn);
+        return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
 }
 #endif
diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
index bcb3a4bd68ff..5a7a2adf4c4c 100644
--- a/lib/decompress_unlzo.c
+++ b/lib/decompress_unlzo.c
@@ -33,7 +33,6 @@
 #ifdef STATIC
 #include "lzo/lzo1x_decompress.c"
 #else
-#include <linux/slab.h>
 #include <linux/decompress/unlzo.h>
 #endif
 
@@ -49,14 +48,25 @@ static const unsigned char lzop_magic[] = {
 
 #define LZO_BLOCK_SIZE        (256*1024l)
 #define HEADER_HAS_FILTER      0x00000800L
+#define HEADER_SIZE_MIN       (9 + 7     + 4 + 8     + 1       + 4)
+#define HEADER_SIZE_MAX       (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
 
-STATIC inline int INIT parse_header(u8 *input, u8 *skip)
+STATIC inline int INIT parse_header(u8 *input, int *skip, int in_len)
 {
         int l;
         u8 *parse = input;
+        u8 *end = input + in_len;
         u8 level = 0;
         u16 version;
 
+        /*
+         * Check that there's enough input to possibly have a valid header.
+         * Then it is possible to parse several fields until the minimum
+         * size may have been used.
+         */
+        if (in_len < HEADER_SIZE_MIN)
+                return 0;
+
         /* read magic: 9 first bits */
         for (l = 0; l < 9; l++) {
                 if (*parse++ != lzop_magic[l])
@@ -74,6 +84,15 @@ STATIC inline int INIT parse_header(u8 *input, u8 *skip)
         else
                 parse += 4; /* flags */
 
+        /*
+         * At least mode, mtime_low, filename length, and checksum must
+         * be left to be parsed. If also mtime_high is present, it's OK
+         * because the next input buffer check is after reading the
+         * filename length.
+         */
+        if (end - parse < 8 + 1 + 4)
+                return 0;
+
         /* skip mode and mtime_low */
         parse += 8;
         if (version >= 0x0940)
@@ -81,6 +100,8 @@ STATIC inline int INIT parse_header(u8 *input, u8 *skip)
 
         l = *parse++;
         /* don't care about the file name, and skip checksum */
+        if (end - parse < l + 4)
+                return 0;
         parse += l + 4;
 
         *skip = parse - input;
@@ -91,16 +112,15 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
                                 int (*fill) (void *, unsigned int),
                                 int (*flush) (void *, unsigned int),
                                 u8 *output, int *posp,
-                                void (*error_fn) (char *x))
+                                void (*error) (char *x))
 {
-        u8 skip = 0, r = 0;
+        u8 r = 0;
+        int skip = 0;
         u32 src_len, dst_len;
         size_t tmp;
         u8 *in_buf, *in_buf_save, *out_buf;
         int ret = -1;
 
-        set_error_fn(error_fn);
-
         if (output) {
                 out_buf = output;
         } else if (!flush) {
@@ -119,8 +139,8 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
                 goto exit_1;
         } else if (input) {
                 in_buf = input;
-        } else if (!fill || !posp) {
-                error("NULL input pointer and missing position pointer or fill function");
+        } else if (!fill) {
+                error("NULL input pointer and missing fill function");
                 goto exit_1;
         } else {
                 in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
@@ -134,22 +154,47 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
         if (posp)
                 *posp = 0;
 
-        if (fill)
-                fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
+        if (fill) {
+                /*
+                 * Start from in_buf + HEADER_SIZE_MAX to make it possible
+                 * to use memcpy() to copy the unused data to the beginning
+                 * of the buffer. This way memmove() isn't needed which
+                 * is missing from pre-boot environments of most archs.
+                 */
+                in_buf += HEADER_SIZE_MAX;
+                in_len = fill(in_buf, HEADER_SIZE_MAX);
+        }
 
-        if (!parse_header(input, &skip)) {
+        if (!parse_header(in_buf, &skip, in_len)) {
                 error("invalid header");
                 goto exit_2;
         }
         in_buf += skip;
+        in_len -= skip;
+
+        if (fill) {
+                /* Move the unused data to the beginning of the buffer. */
+                memcpy(in_buf_save, in_buf, in_len);
+                in_buf = in_buf_save;
+        }
 
         if (posp)
                 *posp = skip;
 
         for (;;) {
                 /* read uncompressed block size */
+                if (fill && in_len < 4) {
+                        skip = fill(in_buf + in_len, 4 - in_len);
+                        if (skip > 0)
+                                in_len += skip;
+                }
+                if (in_len < 4) {
+                        error("file corrupted");
+                        goto exit_2;
+                }
                 dst_len = get_unaligned_be32(in_buf);
                 in_buf += 4;
+                in_len -= 4;
 
                 /* exit if last block */
                 if (dst_len == 0) {
@@ -164,8 +209,18 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
                 }
 
                 /* read compressed block size, and skip block checksum info */
+                if (fill && in_len < 8) {
+                        skip = fill(in_buf + in_len, 8 - in_len);
+                        if (skip > 0)
+                                in_len += skip;
+                }
+                if (in_len < 8) {
+                        error("file corrupted");
+                        goto exit_2;
+                }
                 src_len = get_unaligned_be32(in_buf);
                 in_buf += 8;
+                in_len -= 8;
 
                 if (src_len <= 0 || src_len > dst_len) {
                         error("file corrupted");
@@ -173,6 +228,15 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
                 }
 
                 /* decompress */
+                if (fill && in_len < src_len) {
+                        skip = fill(in_buf + in_len, src_len - in_len);
+                        if (skip > 0)
+                                in_len += skip;
+                }
+                if (in_len < src_len) {
+                        error("file corrupted");
+                        goto exit_2;
+                }
                 tmp = dst_len;
 
                 /* When the input data is not compressed at all,
@@ -190,17 +254,26 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
                         }
                 }
 
-                if (flush)
-                        flush(out_buf, dst_len);
+                if (flush && flush(out_buf, dst_len) != dst_len)
+                        goto exit_2;
                 if (output)
                         out_buf += dst_len;
                 if (posp)
                         *posp += src_len + 12;
+
+                in_buf += src_len;
+                in_len -= src_len;
                 if (fill) {
+                        /*
+                         * If there happens to still be unused data left in
+                         * in_buf, move it to the beginning of the buffer.
+                         * Use a loop to avoid memmove() dependency.
+                         */
+                        if (in_len > 0)
+                                for (skip = 0; skip < in_len; ++skip)
+                                        in_buf_save[skip] = in_buf[skip];
                         in_buf = in_buf_save;
-                        fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
-                } else
-                        in_buf += src_len;
+                }
         }
 
         ret = 0;
diff --git a/lib/decompress_unxz.c b/lib/decompress_unxz.c
new file mode 100644
index 000000000000..cecd23df2b9a
--- /dev/null
+++ b/lib/decompress_unxz.c
@@ -0,0 +1,397 @@
+/*
+ * Wrapper for decompressing XZ-compressed kernel, initramfs, and initrd
+ *
+ * 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.
+ */
+
+/*
+ * Important notes about in-place decompression
+ *
+ * At least on x86, the kernel is decompressed in place: the compressed data
+ * is placed to the end of the output buffer, and the decompressor overwrites
+ * most of the compressed data. There must be enough safety margin to
+ * guarantee that the write position is always behind the read position.
+ *
+ * The safety margin for XZ with LZMA2 or BCJ+LZMA2 is calculated below.
+ * Note that the margin with XZ is bigger than with Deflate (gzip)!
+ *
+ * The worst case for in-place decompression is that the beginning of
+ * the file is compressed extremely well, and the rest of the file is
+ * uncompressible. Thus, we must look for worst-case expansion when the
+ * compressor is encoding uncompressible data.
+ *
+ * The structure of the .xz file in case of a compresed kernel is as follows.
+ * Sizes (as bytes) of the fields are in parenthesis.
+ *
+ *    Stream Header (12)
+ *    Block Header:
+ *      Block Header (8-12)
+ *      Compressed Data (N)
+ *      Block Padding (0-3)
+ *      CRC32 (4)
+ *    Index (8-20)
+ *    Stream Footer (12)
+ *
+ * Normally there is exactly one Block, but let's assume that there are
+ * 2-4 Blocks just in case. Because Stream Header and also Block Header
+ * of the first Block don't make the decompressor produce any uncompressed
+ * data, we can ignore them from our calculations. Block Headers of possible
+ * additional Blocks have to be taken into account still. With these
+ * assumptions, it is safe to assume that the total header overhead is
+ * less than 128 bytes.
+ *
+ * Compressed Data contains LZMA2 or BCJ+LZMA2 encoded data. Since BCJ
+ * doesn't change the size of the data, it is enough to calculate the
+ * safety margin for LZMA2.
+ *
+ * LZMA2 stores the data in chunks. Each chunk has a header whose size is
+ * a maximum of 6 bytes, but to get round 2^n numbers, let's assume that
+ * the maximum chunk header size is 8 bytes. After the chunk header, there
+ * may be up to 64 KiB of actual payload in the chunk. Often the payload is
+ * quite a bit smaller though; to be safe, let's assume that an average
+ * chunk has only 32 KiB of payload.
+ *
+ * The maximum uncompressed size of the payload is 2 MiB. The minimum
+ * uncompressed size of the payload is in practice never less than the
+ * payload size itself. The LZMA2 format would allow uncompressed size
+ * to be less than the payload size, but no sane compressor creates such
+ * files. LZMA2 supports storing uncompressible data in uncompressed form,
+ * so there's never a need to create payloads whose uncompressed size is
+ * smaller than the compressed size.
+ *
+ * The assumption, that the uncompressed size of the payload is never
+ * smaller than the payload itself, is valid only when talking about
+ * the payload as a whole. It is possible that the payload has parts where
+ * the decompressor consumes more input than it produces output. Calculating
+ * the worst case for this would be tricky. Instead of trying to do that,
+ * let's simply make sure that the decompressor never overwrites any bytes
+ * of the payload which it is currently reading.
+ *
+ * Now we have enough information to calculate the safety margin. We need
+ *   - 128 bytes for the .xz file format headers;
+ *   - 8 bytes per every 32 KiB of uncompressed size (one LZMA2 chunk header
+ *     per chunk, each chunk having average payload size of 32 KiB); and
+ *   - 64 KiB (biggest possible LZMA2 chunk payload size) to make sure that
+ *     the decompressor never overwrites anything from the LZMA2 chunk
+ *     payload it is currently reading.
+ *
+ * We get the following formula:
+ *
+ *    safety_margin = 128 + uncompressed_size * 8 / 32768 + 65536
+ *                  = 128 + (uncompressed_size >> 12) + 65536
+ *
+ * For comparision, according to arch/x86/boot/compressed/misc.c, the
+ * equivalent formula for Deflate is this:
+ *
+ *    safety_margin = 18 + (uncompressed_size >> 12) + 32768
+ *
+ * Thus, when updating Deflate-only in-place kernel decompressor to
+ * support XZ, the fixed overhead has to be increased from 18+32768 bytes
+ * to 128+65536 bytes.
+ */
+
+/*
+ * STATIC is defined to "static" if we are being built for kernel
+ * decompression (pre-boot code). <linux/decompress/mm.h> will define
+ * STATIC to empty if it wasn't already defined. Since we will need to
+ * know later if we are being used for kernel decompression, we define
+ * XZ_PREBOOT here.
+ */
+#ifdef STATIC
+#       define XZ_PREBOOT
+#endif
+#ifdef __KERNEL__
+#       include <linux/decompress/mm.h>
+#endif
+#define XZ_EXTERN STATIC
+
+#ifndef XZ_PREBOOT
+#       include <linux/slab.h>
+#       include <linux/xz.h>
+#else
+/*
+ * Use the internal CRC32 code instead of kernel's CRC32 module, which
+ * is not available in early phase of booting.
+ */
+#define XZ_INTERNAL_CRC32 1
+
+/*
+ * For boot time use, we enable only the BCJ filter of the current
+ * architecture or none if no BCJ filter is available for the architecture.
+ */
+#ifdef CONFIG_X86
+#       define XZ_DEC_X86
+#endif
+#ifdef CONFIG_PPC
+#       define XZ_DEC_POWERPC
+#endif
+#ifdef CONFIG_ARM
+#       define XZ_DEC_ARM
+#endif
+#ifdef CONFIG_IA64
+#       define XZ_DEC_IA64
+#endif
+#ifdef CONFIG_SPARC
+#       define XZ_DEC_SPARC
+#endif
+
+/*
+ * This will get the basic headers so that memeq() and others
+ * can be defined.
+ */
+#include "xz/xz_private.h"
+
+/*
+ * Replace the normal allocation functions with the versions from
+ * <linux/decompress/mm.h>. vfree() needs to support vfree(NULL)
+ * when XZ_DYNALLOC is used, but the pre-boot free() doesn't support it.
+ * Workaround it here because the other decompressors don't need it.
+ */
+#undef kmalloc
+#undef kfree
+#undef vmalloc
+#undef vfree
+#define kmalloc(size, flags) malloc(size)
+#define kfree(ptr) free(ptr)
+#define vmalloc(size) malloc(size)
+#define vfree(ptr) do { if (ptr != NULL) free(ptr); } while (0)
+
+/*
+ * FIXME: Not all basic memory functions are provided in architecture-specific
+ * files (yet). We define our own versions here for now, but this should be
+ * only a temporary solution.
+ *
+ * memeq and memzero are not used much and any remotely sane implementation
+ * is fast enough. memcpy/memmove speed matters in multi-call mode, but
+ * the kernel image is decompressed in single-call mode, in which only
+ * memcpy speed can matter and only if there is a lot of uncompressible data
+ * (LZMA2 stores uncompressible chunks in uncompressed form). Thus, the
+ * functions below should just be kept small; it's probably not worth
+ * optimizing for speed.
+ */
+
+#ifndef memeq
+static bool memeq(const void *a, const void *b, size_t size)
+{
+        const uint8_t *x = a;
+        const uint8_t *y = b;
+        size_t i;
+
+        for (i = 0; i < size; ++i)
+                if (x[i] != y[i])
+                        return false;
+
+        return true;
+}
+#endif
+
+#ifndef memzero
+static void memzero(void *buf, size_t size)
+{
+        uint8_t *b = buf;
+        uint8_t *e = b + size;
+
+        while (b != e)
+                *b++ = '\0';
+}
+#endif
+
+#ifndef memmove
+/* Not static to avoid a conflict with the prototype in the Linux headers. */
+void *memmove(void *dest, const void *src, size_t size)
+{
+        uint8_t *d = dest;
+        const uint8_t *s = src;
+        size_t i;
+
+        if (d < s) {
+                for (i = 0; i < size; ++i)
+                        d[i] = s[i];
+        } else if (d > s) {
+                i = size;
+                while (i-- > 0)
+                        d[i] = s[i];
+        }
+
+        return dest;
+}
+#endif
+
+/*
+ * Since we need memmove anyway, would use it as memcpy too.
+ * Commented out for now to avoid breaking things.
+ */
+/*
+#ifndef memcpy
+#       define memcpy memmove
+#endif
+*/
+
+#include "xz/xz_crc32.c"
+#include "xz/xz_dec_stream.c"
+#include "xz/xz_dec_lzma2.c"
+#include "xz/xz_dec_bcj.c"
+
+#endif /* XZ_PREBOOT */
+
+/* Size of the input and output buffers in multi-call mode */
+#define XZ_IOBUF_SIZE 4096
+
+/*
+ * This function implements the API defined in <linux/decompress/generic.h>.
+ *
+ * This wrapper will automatically choose single-call or multi-call mode
+ * of the native XZ decoder API. The single-call mode can be used only when
+ * both input and output buffers are available as a single chunk, i.e. when
+ * fill() and flush() won't be used.
+ */
+STATIC int INIT unxz(unsigned char *in, int in_size,
+                     int (*fill)(void *dest, unsigned int size),
+                     int (*flush)(void *src, unsigned int size),
+                     unsigned char *out, int *in_used,
+                     void (*error)(char *x))
+{
+        struct xz_buf b;
+        struct xz_dec *s;
+        enum xz_ret ret;
+        bool must_free_in = false;
+
+#if XZ_INTERNAL_CRC32
+        xz_crc32_init();
+#endif
+
+        if (in_used != NULL)
+                *in_used = 0;
+
+        if (fill == NULL && flush == NULL)
+                s = xz_dec_init(XZ_SINGLE, 0);
+        else
+                s = xz_dec_init(XZ_DYNALLOC, (uint32_t)-1);
+
+        if (s == NULL)
+                goto error_alloc_state;
+
+        if (flush == NULL) {
+                b.out = out;
+                b.out_size = (size_t)-1;
+        } else {
+                b.out_size = XZ_IOBUF_SIZE;
+                b.out = malloc(XZ_IOBUF_SIZE);
+                if (b.out == NULL)
+                        goto error_alloc_out;
+        }
+
+        if (in == NULL) {
+                must_free_in = true;
+                in = malloc(XZ_IOBUF_SIZE);
+                if (in == NULL)
+                        goto error_alloc_in;
+        }
+
+        b.in = in;
+        b.in_pos = 0;
+        b.in_size = in_size;
+        b.out_pos = 0;
+
+        if (fill == NULL && flush == NULL) {
+                ret = xz_dec_run(s, &b);
+        } else {
+                do {
+                        if (b.in_pos == b.in_size && fill != NULL) {
+                                if (in_used != NULL)
+                                        *in_used += b.in_pos;
+
+                                b.in_pos = 0;
+
+                                in_size = fill(in, XZ_IOBUF_SIZE);
+                                if (in_size < 0) {
+                                        /*
+                                         * This isn't an optimal error code
+                                         * but it probably isn't worth making
+                                         * a new one either.
+                                         */
+                                        ret = XZ_BUF_ERROR;
+                                        break;
+                                }
+
+                                b.in_size = in_size;
+                        }
+
+                        ret = xz_dec_run(s, &b);
+
+                        if (flush != NULL && (b.out_pos == b.out_size
+                                        || (ret != XZ_OK && b.out_pos > 0))) {
+                                /*
+                                 * Setting ret here may hide an error
+                                 * returned by xz_dec_run(), but probably
+                                 * it's not too bad.
+                                 */
+                                if (flush(b.out, b.out_pos) != (int)b.out_pos)
+                                        ret = XZ_BUF_ERROR;
+
+                                b.out_pos = 0;
+                        }
+                } while (ret == XZ_OK);
+
+                if (must_free_in)
+                        free(in);
+
+                if (flush != NULL)
+                        free(b.out);
+        }
+
+        if (in_used != NULL)
+                *in_used += b.in_pos;
+
+        xz_dec_end(s);
+
+        switch (ret) {
+        case XZ_STREAM_END:
+                return 0;
+
+        case XZ_MEM_ERROR:
+                /* This can occur only in multi-call mode. */
+                error("XZ decompressor ran out of memory");
+                break;
+
+        case XZ_FORMAT_ERROR:
+                error("Input is not in the XZ format (wrong magic bytes)");
+                break;
+
+        case XZ_OPTIONS_ERROR:
+                error("Input was encoded with settings that are not "
+                                "supported by this XZ decoder");
+                break;
+
+        case XZ_DATA_ERROR:
+        case XZ_BUF_ERROR:
+                error("XZ-compressed data is corrupt");
+                break;
+
+        default:
+                error("Bug in the XZ decompressor");
+                break;
+        }
+
+        return -1;
+
+error_alloc_in:
+        if (flush != NULL)
+                free(b.out);
+
+error_alloc_out:
+        xz_dec_end(s);
+
+error_alloc_state:
+        error("XZ decompressor ran out of memory");
+        return -1;
+}
+
+/*
+ * This macro is used by architecture-specific files to decompress
+ * the kernel image.
+ */
+#define decompress unxz
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3094318bfea7..b335acb43be2 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -141,11 +141,10 @@ static void ddebug_change(const struct ddebug_query *query,
                         else if (!dp->flags)
                                 dt->num_enabled++;
                         dp->flags = newflags;
-                        if (newflags) {
-                                jump_label_enable(&dp->enabled);
-                        } else {
-                                jump_label_disable(&dp->enabled);
-                        }
+                        if (newflags)
+                                dp->enabled = 1;
+                        else
+                                dp->enabled = 0;
                         if (verbose)
                                 printk(KERN_INFO
                                         "ddebug: changed %s:%d [%s]%s %s\n",
diff --git a/lib/flex_array.c b/lib/flex_array.c
index 77a6fea7481e..c0ea40ba2082 100644
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -23,6 +23,7 @@
 #include <linux/flex_array.h>
 #include <linux/slab.h>
 #include <linux/stddef.h>
+#include <linux/module.h>
 
 struct flex_array_part {
         char elements[FLEX_ARRAY_PART_SIZE];
@@ -103,6 +104,7 @@ struct flex_array *flex_array_alloc(int element_size, unsigned int total,
                                                 FLEX_ARRAY_BASE_BYTES_LEFT);
         return ret;
 }
+EXPORT_SYMBOL(flex_array_alloc);
 
 static int fa_element_to_part_nr(struct flex_array *fa,
                                         unsigned int element_nr)
@@ -126,12 +128,14 @@ void flex_array_free_parts(struct flex_array *fa)
         for (part_nr = 0; part_nr < FLEX_ARRAY_NR_BASE_PTRS; part_nr++)
                 kfree(fa->parts[part_nr]);
 }
+EXPORT_SYMBOL(flex_array_free_parts);
 
 void flex_array_free(struct flex_array *fa)
 {
         flex_array_free_parts(fa);
         kfree(fa);
 }
+EXPORT_SYMBOL(flex_array_free);
 
 static unsigned int index_inside_part(struct flex_array *fa,
                                         unsigned int element_nr)
@@ -196,6 +200,7 @@ int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,
         memcpy(dst, src, fa->element_size);
         return 0;
 }
+EXPORT_SYMBOL(flex_array_put);
 
 /**
  * flex_array_clear - clear element in array at @element_nr
@@ -223,6 +228,7 @@ int flex_array_clear(struct flex_array *fa, unsigned int element_nr)
         memset(dst, FLEX_ARRAY_FREE, fa->element_size);
         return 0;
 }
+EXPORT_SYMBOL(flex_array_clear);
 
 /**
  * flex_array_prealloc - guarantee that array space exists
@@ -259,6 +265,7 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start,
         }
         return 0;
 }
+EXPORT_SYMBOL(flex_array_prealloc);
 
 /**
  * flex_array_get - pull data back out of the array
@@ -288,6 +295,7 @@ void *flex_array_get(struct flex_array *fa, unsigned int element_nr)
         }
         return &part->elements[index_inside_part(fa, element_nr)];
 }
+EXPORT_SYMBOL(flex_array_get);
 
 /**
  * flex_array_get_ptr - pull a ptr back out of the array
@@ -308,6 +316,7 @@ void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr)
 
         return *tmp;
 }
+EXPORT_SYMBOL(flex_array_get_ptr);
 
 static int part_is_free(struct flex_array_part *part)
 {
@@ -348,3 +357,4 @@ int flex_array_shrink(struct flex_array *fa)
         }
         return ret;
 }
+EXPORT_SYMBOL(flex_array_shrink);
diff --git a/lib/hexdump.c b/lib/hexdump.c
index 5d7a4802c562..f5fe6ba7a3ab 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -34,6 +34,22 @@ int hex_to_bin(char ch)
 EXPORT_SYMBOL(hex_to_bin);
 
 /**
+ * hex2bin - convert an ascii hexadecimal string to its binary representation
+ * @dst: binary result
+ * @src: ascii hexadecimal string
+ * @count: result length
+ */
+void hex2bin(u8 *dst, const char *src, size_t count)
+{
+        while (count--) {
+                *dst = hex_to_bin(*src++) << 4;
+                *dst += hex_to_bin(*src++);
+                dst++;
+        }
+}
+EXPORT_SYMBOL(hex2bin);
+
+/**
  * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
  * @buf: data blob to dump
  * @len: number of bytes in the @buf
@@ -138,6 +154,7 @@ nil:
 }
 EXPORT_SYMBOL(hex_dump_to_buffer);
 
+#ifdef CONFIG_PRINTK
 /**
  * print_hex_dump - print a text hex dump to syslog for a binary blob of data
  * @level: kernel log level (e.g. KERN_DEBUG)
@@ -222,3 +239,4 @@ void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
                        buf, len, true);
 }
 EXPORT_SYMBOL(print_hex_dump_bytes);
+#endif
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 5730ecd3eb66..da4e2ad74b68 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -9,6 +9,7 @@
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/io.h>
+#include <linux/module.h>
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
 
@@ -90,3 +91,4 @@ int ioremap_page_range(unsigned long addr,
 
         return err;
 }
+EXPORT_SYMBOL_GPL(ioremap_page_range);
diff --git a/lib/kref.c b/lib/kref.c
index d3d227a08a4b..3efb882b11db 100644
--- a/lib/kref.c
+++ b/lib/kref.c
@@ -62,6 +62,36 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref))
         return 0;
 }
 
+
+/**
+ * kref_sub - subtract a number of refcounts for object.
+ * @kref: object.
+ * @count: Number of recounts to subtract.
+ * @release: pointer to the function that will clean up the object when the
+ *           last reference to the object is released.
+ *           This pointer is required, and it is not acceptable to pass kfree
+ *           in as this function.
+ *
+ * Subtract @count from the refcount, and if 0, call release().
+ * Return 1 if the object was removed, otherwise return 0.  Beware, if this
+ * function returns 0, you still can not count on the kref from remaining in
+ * memory.  Only use the return value if you want to see if the kref is now
+ * gone, not present.
+ */
+int kref_sub(struct kref *kref, unsigned int count,
+             void (*release)(struct kref *kref))
+{
+        WARN_ON(release == NULL);
+        WARN_ON(release == (void (*)(struct kref *))kfree);
+
+        if (atomic_sub_and_test((int) count, &kref->refcount)) {
+                release(kref);
+                return 1;
+        }
+        return 0;
+}
+
 EXPORT_SYMBOL(kref_init);
 EXPORT_SYMBOL(kref_get);
 EXPORT_SYMBOL(kref_put);
+EXPORT_SYMBOL(kref_sub);
diff --git a/lib/nlattr.c b/lib/nlattr.c
index c4706eb98d3d..5021cbc34411 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -15,7 +15,7 @@
 #include <linux/types.h>
 #include <net/netlink.h>
 
-static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
+static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
         [NLA_U8]        = sizeof(u8),
         [NLA_U16]       = sizeof(u16),
         [NLA_U32]       = sizeof(u32),
@@ -23,7 +23,7 @@ static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
         [NLA_NESTED]    = NLA_HDRLEN,
 };
 
-static int validate_nla(struct nlattr *nla, int maxtype,
+static int validate_nla(const struct nlattr *nla, int maxtype,
                         const struct nla_policy *policy)
 {
         const struct nla_policy *pt;
@@ -115,10 +115,10 @@ static int validate_nla(struct nlattr *nla, int maxtype,
  *
  * Returns 0 on success or a negative error code.
  */
-int nla_validate(struct nlattr *head, int len, int maxtype,
+int nla_validate(const struct nlattr *head, int len, int maxtype,
                  const struct nla_policy *policy)
 {
-        struct nlattr *nla;
+        const struct nlattr *nla;
         int rem, err;
 
         nla_for_each_attr(nla, head, len, rem) {
@@ -167,16 +167,16 @@ nla_policy_len(const struct nla_policy *p, int n)
  * @policy: validation policy
  *
  * Parses a stream of attributes and stores a pointer to each attribute in
- * the tb array accessable via the attribute type. Attributes with a type
+ * the tb array accessible via the attribute type. Attributes with a type
  * exceeding maxtype will be silently ignored for backwards compatibility
  * reasons. policy may be set to NULL if no validation is required.
  *
  * Returns 0 on success or a negative error code.
  */
-int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
-              const struct nla_policy *policy)
+int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
+              int len, const struct nla_policy *policy)
 {
-        struct nlattr *nla;
+        const struct nlattr *nla;
         int rem, err;
 
         memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
@@ -191,7 +191,7 @@ int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
                                         goto errout;
                         }
 
-                        tb[type] = nla;
+                        tb[type] = (struct nlattr *)nla;
                 }
         }
 
@@ -212,14 +212,14 @@ errout:
  *
  * Returns the first attribute in the stream matching the specified type.
  */
-struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
+struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
 {
-        struct nlattr *nla;
+        const struct nlattr *nla;
         int rem;
 
         nla_for_each_attr(nla, head, len, rem)
                 if (nla_type(nla) == attrtype)
-                        return nla;
+                        return (struct nlattr *)nla;
 
         return NULL;
 }
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 604678d7d06d..28f2c33c6b53 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -72,18 +72,16 @@ EXPORT_SYMBOL(percpu_counter_set);
 void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
 {
         s64 count;
-        s32 *pcount;
 
         preempt_disable();
-        pcount = this_cpu_ptr(fbc->counters);
-        count = *pcount + amount;
+        count = __this_cpu_read(*fbc->counters) + amount;
         if (count >= batch || count <= -batch) {
                 spin_lock(&fbc->lock);
                 fbc->count += count;
-                *pcount = 0;
+                __this_cpu_write(*fbc->counters, 0);
                 spin_unlock(&fbc->lock);
         } else {
-                *pcount = count;
+                __this_cpu_write(*fbc->counters, count);
         }
         preempt_enable();
 }
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 6f412ab4c24f..7ea2e033d715 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -82,6 +82,16 @@ struct radix_tree_preload {
 };
 static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
 
+static inline void *ptr_to_indirect(void *ptr)
+{
+        return (void *)((unsigned long)ptr | RADIX_TREE_INDIRECT_PTR);
+}
+
+static inline void *indirect_to_ptr(void *ptr)
+{
+        return (void *)((unsigned long)ptr & ~RADIX_TREE_INDIRECT_PTR);
+}
+
 static inline gfp_t root_gfp_mask(struct radix_tree_root *root)
 {
         return root->gfp_mask & __GFP_BITS_MASK;
@@ -265,7 +275,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
                         return -ENOMEM;
 
                 /* Increase the height.  */
-                node->slots[0] = radix_tree_indirect_to_ptr(root->rnode);
+                node->slots[0] = indirect_to_ptr(root->rnode);
 
                 /* Propagate the aggregated tag info into the new root */
                 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
@@ -276,7 +286,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
                 newheight = root->height+1;
                 node->height = newheight;
                 node->count = 1;
-                node = radix_tree_ptr_to_indirect(node);
+                node = ptr_to_indirect(node);
                 rcu_assign_pointer(root->rnode, node);
                 root->height = newheight;
         } while (height > root->height);
@@ -309,7 +319,7 @@ int radix_tree_insert(struct radix_tree_root *root,
                         return error;
         }
 
-        slot = radix_tree_indirect_to_ptr(root->rnode);
+        slot = indirect_to_ptr(root->rnode);
 
         height = root->height;
         shift = (height-1) * RADIX_TREE_MAP_SHIFT;
@@ -325,8 +335,7 @@ int radix_tree_insert(struct radix_tree_root *root,
                                 rcu_assign_pointer(node->slots[offset], slot);
                                 node->count++;
                         } else
-                                rcu_assign_pointer(root->rnode,
-                                        radix_tree_ptr_to_indirect(slot));
+                                rcu_assign_pointer(root->rnode, ptr_to_indirect(slot));
                 }
 
                 /* Go a level down */
@@ -374,7 +383,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
                         return NULL;
                 return is_slot ? (void *)&root->rnode : node;
         }
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         height = node->height;
         if (index > radix_tree_maxindex(height))
@@ -393,7 +402,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
                 height--;
         } while (height > 0);
 
-        return is_slot ? (void *)slot:node;
+        return is_slot ? (void *)slot : indirect_to_ptr(node);
 }
 
 /**
@@ -455,7 +464,7 @@ void *radix_tree_tag_set(struct radix_tree_root *root,
         height = root->height;
         BUG_ON(index > radix_tree_maxindex(height));
 
-        slot = radix_tree_indirect_to_ptr(root->rnode);
+        slot = indirect_to_ptr(root->rnode);
         shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
 
         while (height > 0) {
@@ -509,7 +518,7 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
 
         shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
         pathp->node = NULL;
-        slot = radix_tree_indirect_to_ptr(root->rnode);
+        slot = indirect_to_ptr(root->rnode);
 
         while (height > 0) {
                 int offset;
@@ -579,7 +588,7 @@ int radix_tree_tag_get(struct radix_tree_root *root,
 
         if (!radix_tree_is_indirect_ptr(node))
                 return (index == 0);
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         height = node->height;
         if (index > radix_tree_maxindex(height))
@@ -666,7 +675,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
         }
 
         shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
-        slot = radix_tree_indirect_to_ptr(root->rnode);
+        slot = indirect_to_ptr(root->rnode);
 
         /*
          * we fill the path from (root->height - 2) to 0, leaving the index at
@@ -727,10 +736,11 @@ next:
                 }
         }
         /*
-         * The iftag must have been set somewhere because otherwise
-         * we would return immediated at the beginning of the function
+         * We need not to tag the root tag if there is no tag which is set with
+         * settag within the range from *first_indexp to last_index.
          */
-        root_tag_set(root, settag);
+        if (tagged > 0)
+                root_tag_set(root, settag);
         *first_indexp = index;
 
         return tagged;
@@ -897,7 +907,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
                 results[0] = node;
                 return 1;
         }
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         max_index = radix_tree_maxindex(node->height);
 
@@ -916,7 +926,8 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
                         slot = *(((void ***)results)[ret + i]);
                         if (!slot)
                                 continue;
-                        results[ret + nr_found] = rcu_dereference_raw(slot);
+                        results[ret + nr_found] =
+                                indirect_to_ptr(rcu_dereference_raw(slot));
                         nr_found++;
                 }
                 ret += nr_found;
@@ -965,7 +976,7 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
                 results[0] = (void **)&root->rnode;
                 return 1;
         }
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         max_index = radix_tree_maxindex(node->height);
 
@@ -1090,7 +1101,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
                 results[0] = node;
                 return 1;
         }
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         max_index = radix_tree_maxindex(node->height);
 
@@ -1109,7 +1120,8 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
                         slot = *(((void ***)results)[ret + i]);
                         if (!slot)
                                 continue;
-                        results[ret + nr_found] = rcu_dereference_raw(slot);
+                        results[ret + nr_found] =
+                                indirect_to_ptr(rcu_dereference_raw(slot));
                         nr_found++;
                 }
                 ret += nr_found;
@@ -1159,7 +1171,7 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
                 results[0] = (void **)&root->rnode;
                 return 1;
         }
-        node = radix_tree_indirect_to_ptr(node);
+        node = indirect_to_ptr(node);
 
         max_index = radix_tree_maxindex(node->height);
 
@@ -1195,7 +1207,7 @@ static inline void radix_tree_shrink(struct radix_tree_root *root)
                 void *newptr;
 
                 BUG_ON(!radix_tree_is_indirect_ptr(to_free));
-                to_free = radix_tree_indirect_to_ptr(to_free);
+                to_free = indirect_to_ptr(to_free);
 
                 /*
                  * The candidate node has more than one child, or its child
@@ -1208,16 +1220,39 @@ static inline void radix_tree_shrink(struct radix_tree_root *root)
 
                 /*
                  * We don't need rcu_assign_pointer(), since we are simply
-                 * moving the node from one part of the tree to another. If
-                 * it was safe to dereference the old pointer to it
+                 * moving the node from one part of the tree to another: if it
+                 * was safe to dereference the old pointer to it
                  * (to_free->slots[0]), it will be safe to dereference the new
-                 * one (root->rnode).
+                 * one (root->rnode) as far as dependent read barriers go.
                  */
                 newptr = to_free->slots[0];
                 if (root->height > 1)
-                        newptr = radix_tree_ptr_to_indirect(newptr);
+                        newptr = ptr_to_indirect(newptr);
                 root->rnode = newptr;
                 root->height--;
+
+                /*
+                 * We have a dilemma here. The node's slot[0] must not be
+                 * NULLed in case there are concurrent lookups expecting to
+                 * find the item. However if this was a bottom-level node,
+                 * then it may be subject to the slot pointer being visible
+                 * to callers dereferencing it. If item corresponding to
+                 * slot[0] is subsequently deleted, these callers would expect
+                 * their slot to become empty sooner or later.
+                 *
+                 * For example, lockless pagecache will look up a slot, deref
+                 * the page pointer, and if the page is 0 refcount it means it
+                 * was concurrently deleted from pagecache so try the deref
+                 * again. Fortunately there is already a requirement for logic
+                 * to retry the entire slot lookup -- the indirect pointer
+                 * problem (replacing direct root node with an indirect pointer
+                 * also results in a stale slot). So tag the slot as indirect
+                 * to force callers to retry.
+                 */
+                if (root->height == 0)
+                        *((unsigned long *)&to_free->slots[0]) |=
+                                                RADIX_TREE_INDIRECT_PTR;
+
                 radix_tree_node_free(to_free);
         }
 }
@@ -1254,7 +1289,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
                 root->rnode = NULL;
                 goto out;
         }
-        slot = radix_tree_indirect_to_ptr(slot);
+        slot = indirect_to_ptr(slot);
 
         shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
         pathp->node = NULL;
@@ -1296,8 +1331,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
                         radix_tree_node_free(to_free);
 
                 if (pathp->node->count) {
-                        if (pathp->node ==
-                                        radix_tree_indirect_to_ptr(root->rnode))
+                        if (pathp->node == indirect_to_ptr(root->rnode))
                                 radix_tree_shrink(root);
                         goto out;
                 }
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 4693f79195d3..a16be19a1305 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -315,6 +315,7 @@ void rb_augment_insert(struct rb_node *node, rb_augment_f func, void *data)
 
         rb_augment_path(node, func, data);
 }
+EXPORT_SYMBOL(rb_augment_insert);
 
 /*
  * before removing the node, find the deepest node on the rebalance path
@@ -340,6 +341,7 @@ struct rb_node *rb_augment_erase_begin(struct rb_node *node)
 
         return deepest;
 }
+EXPORT_SYMBOL(rb_augment_erase_begin);
 
 /*
  * after removal, update the tree to account for the removed entry
@@ -350,6 +352,7 @@ void rb_augment_erase_end(struct rb_node *node, rb_augment_f func, void *data)
         if (node)
                 rb_augment_path(node, func, data);
 }
+EXPORT_SYMBOL(rb_augment_erase_end);
 
 /*
  * This function returns the first node (in sort order) of the tree.
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 7c06ee51a29a..c47bbe11b804 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -60,7 +60,7 @@ int swiotlb_force;
 static char *io_tlb_start, *io_tlb_end;
 
 /*
- * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
+ * The number of IO TLB blocks (in groups of 64) between io_tlb_start and
  * io_tlb_end.  This is command line adjustable via setup_io_tlb_npages.
  */
 static unsigned long io_tlb_nslabs;
diff --git a/lib/textsearch.c b/lib/textsearch.c
index d608331b3e47..e0cc0146ae62 100644
--- a/lib/textsearch.c
+++ b/lib/textsearch.c
@@ -13,7 +13,7 @@
  *
  * INTRODUCTION
  *
- *   The textsearch infrastructure provides text searching facitilies for
+ *   The textsearch infrastructure provides text searching facilities for
  *   both linear and non-linear data. Individual search algorithms are
  *   implemented in modules and chosen by the user.
  *
@@ -43,7 +43,7 @@
  *       to the algorithm to store persistent variables.
  *   (4) Core eventually resets the search offset and forwards the find()
  *       request to the algorithm.
- *   (5) Algorithm calls get_next_block() provided by the user continously
+ *   (5) Algorithm calls get_next_block() provided by the user continuously
  *       to fetch the data to be searched in block by block.
  *   (6) Algorithm invokes finish() after the last call to get_next_block
  *       to clean up any leftovers from get_next_block. (Optional)
@@ -58,15 +58,15 @@
  *   the pattern to look for and flags. As a flag, you can set TS_IGNORECASE
  *   to perform case insensitive matching. But it might slow down
  *   performance of algorithm, so you should use it at own your risk.
- *   The returned configuration may then be used for an arbitary
+ *   The returned configuration may then be used for an arbitrary
  *   amount of times and even in parallel as long as a separate struct
  *   ts_state variable is provided to every instance.
  *
  *   The actual search is performed by either calling textsearch_find_-
  *   continuous() for linear data or by providing an own get_next_block()
  *   implementation and calling textsearch_find(). Both functions return
- *   the position of the first occurrence of the patern or UINT_MAX if
- *   no match was found. Subsequent occurences can be found by calling
+ *   the position of the first occurrence of the pattern or UINT_MAX if
+ *   no match was found. Subsequent occurrences can be found by calling
  *   textsearch_next() regardless of the linearity of the data.
  *
  *   Once you're done using a configuration it must be given back via
diff --git a/lib/timerqueue.c b/lib/timerqueue.c
new file mode 100644
index 000000000000..e3a1050e6820
--- /dev/null
+++ b/lib/timerqueue.c
@@ -0,0 +1,107 @@
+/*
+ *  Generic Timer-queue
+ *
+ *  Manages a simple queue of timers, ordered by expiration time.
+ *  Uses rbtrees for quick list adds and expiration.
+ *
+ *  NOTE: All of the following functions need to be serialized
+ *  to avoid races. No locking is done by this libary code.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/timerqueue.h>
+#include <linux/rbtree.h>
+#include <linux/module.h>
+
+/**
+ * timerqueue_add - Adds timer to timerqueue.
+ *
+ * @head: head of timerqueue
+ * @node: timer node to be added
+ *
+ * Adds the timer node to the timerqueue, sorted by the
+ * node's expires value.
+ */
+void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
+{
+        struct rb_node **p = &head->head.rb_node;
+        struct rb_node *parent = NULL;
+        struct timerqueue_node  *ptr;
+
+        /* Make sure we don't add nodes that are already added */
+        WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node));
+
+        while (*p) {
+                parent = *p;
+                ptr = rb_entry(parent, struct timerqueue_node, node);
+                if (node->expires.tv64 < ptr->expires.tv64)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+        rb_link_node(&node->node, parent, p);
+        rb_insert_color(&node->node, &head->head);
+
+        if (!head->next || node->expires.tv64 < head->next->expires.tv64)
+                head->next = node;
+}
+EXPORT_SYMBOL_GPL(timerqueue_add);
+
+/**
+ * timerqueue_del - Removes a timer from the timerqueue.
+ *
+ * @head: head of timerqueue
+ * @node: timer node to be removed
+ *
+ * Removes the timer node from the timerqueue.
+ */
+void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
+{
+        WARN_ON_ONCE(RB_EMPTY_NODE(&node->node));
+
+        /* update next pointer */
+        if (head->next == node) {
+                struct rb_node *rbn = rb_next(&node->node);
+
+                head->next = rbn ?
+                        rb_entry(rbn, struct timerqueue_node, node) : NULL;
+        }
+        rb_erase(&node->node, &head->head);
+        RB_CLEAR_NODE(&node->node);
+}
+EXPORT_SYMBOL_GPL(timerqueue_del);
+
+/**
+ * timerqueue_iterate_next - Returns the timer after the provided timer
+ *
+ * @node: Pointer to a timer.
+ *
+ * Provides the timer that is after the given node. This is used, when
+ * necessary, to iterate through the list of timers in a timer list
+ * without modifying the list.
+ */
+struct timerqueue_node *timerqueue_iterate_next(struct timerqueue_node *node)
+{
+        struct rb_node *next;
+
+        if (!node)
+                return NULL;
+        next = rb_next(&node->node);
+        if (!next)
+                return NULL;
+        return container_of(next, struct timerqueue_node, node);
+}
+EXPORT_SYMBOL_GPL(timerqueue_iterate_next);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c150d3dafff4..d3023df8477f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -936,6 +936,8 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
         return string(buf, end, uuid, spec);
 }
 
+int kptr_restrict = 1;
+
 /*
  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
  * by an extra set of alphanumeric characters that are extended format
@@ -979,6 +981,7 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
  *       Implements a "recursive vsnprintf".
  *       Do not use this feature without some mechanism to verify the
  *       correctness of the format string and va_list arguments.
+ * - 'K' For a kernel pointer that should be hidden from unprivileged users
  *
  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  * function pointers are really function descriptors, which contain a
@@ -1035,6 +1038,25 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
                 return buf + vsnprintf(buf, end - buf,
                                        ((struct va_format *)ptr)->fmt,
                                        *(((struct va_format *)ptr)->va));
+        case 'K':
+                /*
+                 * %pK cannot be used in IRQ context because its test
+                 * for CAP_SYSLOG would be meaningless.
+                 */
+                if (in_irq() || in_serving_softirq() || in_nmi()) {
+                        if (spec.field_width == -1)
+                                spec.field_width = 2 * sizeof(void *);
+                        return string(buf, end, "pK-error", spec);
+                } else if ((kptr_restrict == 0) ||
+                         (kptr_restrict == 1 &&
+                          has_capability_noaudit(current, CAP_SYSLOG)))
+                        break;
+
+                if (spec.field_width == -1) {
+                        spec.field_width = 2 * sizeof(void *);
+                        spec.flags |= ZEROPAD;
+                }
+                return number(buf, end, 0, spec);
         }
         spec.flags |= SMALL;
         if (spec.field_width == -1) {
@@ -1451,7 +1473,7 @@ EXPORT_SYMBOL(vsnprintf);
  * @args: Arguments for the format string
  *
  * The return value is the number of characters which have been written into
- * the @buf not including the trailing '\0'. If @size is <= 0 the function
+ * the @buf not including the trailing '\0'. If @size is == 0 the function
  * returns 0.
  *
  * Call this function if you are already dealing with a va_list.
@@ -1465,7 +1487,11 @@ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 
         i = vsnprintf(buf, size, fmt, args);
 
-        return (i >= size) ? (size - 1) : i;
+        if (likely(i < size))
+                return i;
+        if (size != 0)
+                return size - 1;
+        return 0;
 }
 EXPORT_SYMBOL(vscnprintf);
 
@@ -1513,14 +1539,10 @@ int scnprintf(char *buf, size_t size, const char *fmt, ...)
         int i;
 
         va_start(args, fmt);
-        i = vsnprintf(buf, size, fmt, args);
+        i = vscnprintf(buf, size, fmt, args);
         va_end(args);
 
-        if (likely(i < size))
-                return i;
-        if (size != 0)
-                return size - 1;
-        return 0;
+        return i;
 }
 EXPORT_SYMBOL(scnprintf);
 
diff --git a/lib/xz/Kconfig b/lib/xz/Kconfig
new file mode 100644
index 000000000000..60a6088d0e5e
--- /dev/null
+++ b/lib/xz/Kconfig
@@ -0,0 +1,59 @@
+config XZ_DEC
+        tristate "XZ decompression support"
+        select CRC32
+        help
+          LZMA2 compression algorithm and BCJ filters are supported using
+          the .xz file format as the container. For integrity checking,
+          CRC32 is supported. See Documentation/xz.txt for more information.
+
+config XZ_DEC_X86
+        bool "x86 BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_POWERPC
+        bool "PowerPC BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_IA64
+        bool "IA-64 BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_ARM
+        bool "ARM BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_ARMTHUMB
+        bool "ARM-Thumb BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_SPARC
+        bool "SPARC BCJ filter decoder" if EXPERT
+        default y
+        depends on XZ_DEC
+        select XZ_DEC_BCJ
+
+config XZ_DEC_BCJ
+        bool
+        default n
+
+config XZ_DEC_TEST
+        tristate "XZ decompressor tester"
+        default n
+        depends on XZ_DEC
+        help
+          This allows passing .xz files to the in-kernel XZ decoder via
+          a character special file. It calculates CRC32 of the decompressed
+          data and writes diagnostics to the system log.
+
+          Unless you are developing the XZ decoder, you don't need this
+          and should say N.
diff --git a/lib/xz/Makefile b/lib/xz/Makefile
new file mode 100644
index 000000000000..a7fa7693f0f3
--- /dev/null
+++ b/lib/xz/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_XZ_DEC) += xz_dec.o
+xz_dec-y := xz_dec_syms.o xz_dec_stream.o xz_dec_lzma2.o
+xz_dec-$(CONFIG_XZ_DEC_BCJ) += xz_dec_bcj.o
+
+obj-$(CONFIG_XZ_DEC_TEST) += xz_dec_test.o
diff --git a/lib/xz/xz_crc32.c b/lib/xz/xz_crc32.c
new file mode 100644
index 000000000000..34532d14fd4c
--- /dev/null
+++ b/lib/xz/xz_crc32.c
@@ -0,0 +1,59 @@
+/*
+ * CRC32 using the polynomial from IEEE-802.3
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.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.
+ */
+
+/*
+ * This is not the fastest implementation, but it is pretty compact.
+ * The fastest versions of xz_crc32() on modern CPUs without hardware
+ * accelerated CRC instruction are 3-5 times as fast as this version,
+ * but they are bigger and use more memory for the lookup table.
+ */
+
+#include "xz_private.h"
+
+/*
+ * STATIC_RW_DATA is used in the pre-boot environment on some architectures.
+ * See <linux/decompress/mm.h> for details.
+ */
+#ifndef STATIC_RW_DATA
+#       define STATIC_RW_DATA static
+#endif
+
+STATIC_RW_DATA uint32_t xz_crc32_table[256];
+
+XZ_EXTERN void xz_crc32_init(void)
+{
+        const uint32_t poly = 0xEDB88320;
+
+        uint32_t i;
+        uint32_t j;
+        uint32_t r;
+
+        for (i = 0; i < 256; ++i) {
+                r = i;
+                for (j = 0; j < 8; ++j)
+                        r = (r >> 1) ^ (poly & ~((r & 1) - 1));
+
+                xz_crc32_table[i] = r;
+        }
+
+        return;
+}
+
+XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
+{
+        crc = ~crc;
+
+        while (size != 0) {
+                crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
+                --size;
+        }
+
+        return ~crc;
+}
diff --git a/lib/xz/xz_dec_bcj.c b/lib/xz/xz_dec_bcj.c
new file mode 100644
index 000000000000..e51e2558ca9d
--- /dev/null
+++ b/lib/xz/xz_dec_bcj.c
@@ -0,0 +1,561 @@
+/*
+ * Branch/Call/Jump (BCJ) filter decoders
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.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.
+ */
+
+#include "xz_private.h"
+
+/*
+ * The rest of the file is inside this ifdef. It makes things a little more
+ * convenient when building without support for any BCJ filters.
+ */
+#ifdef XZ_DEC_BCJ
+
+struct xz_dec_bcj {
+        /* Type of the BCJ filter being used */
+        enum {
+                BCJ_X86 = 4,        /* x86 or x86-64 */
+                BCJ_POWERPC = 5,    /* Big endian only */
+                BCJ_IA64 = 6,       /* Big or little endian */
+                BCJ_ARM = 7,        /* Little endian only */
+                BCJ_ARMTHUMB = 8,   /* Little endian only */
+                BCJ_SPARC = 9       /* Big or little endian */
+        } type;
+
+        /*
+         * Return value of the next filter in the chain. We need to preserve
+         * this information across calls, because we must not call the next
+         * filter anymore once it has returned XZ_STREAM_END.
+         */
+        enum xz_ret ret;
+
+        /* True if we are operating in single-call mode. */
+        bool single_call;
+
+        /*
+         * Absolute position relative to the beginning of the uncompressed
+         * data (in a single .xz Block). We care only about the lowest 32
+         * bits so this doesn't need to be uint64_t even with big files.
+         */
+        uint32_t pos;
+
+        /* x86 filter state */
+        uint32_t x86_prev_mask;
+
+        /* Temporary space to hold the variables from struct xz_buf */
+        uint8_t *out;
+        size_t out_pos;
+        size_t out_size;
+
+        struct {
+                /* Amount of already filtered data in the beginning of buf */
+                size_t filtered;
+
+                /* Total amount of data currently stored in buf  */
+                size_t size;
+
+                /*
+                 * Buffer to hold a mix of filtered and unfiltered data. This
+                 * needs to be big enough to hold Alignment + 2 * Look-ahead:
+                 *
+                 * Type         Alignment   Look-ahead
+                 * x86              1           4
+                 * PowerPC          4           0
+                 * IA-64           16           0
+                 * ARM              4           0
+                 * ARM-Thumb        2           2
+                 * SPARC            4           0
+                 */
+                uint8_t buf[16];
+        } temp;
+};
+
+#ifdef XZ_DEC_X86
+/*
+ * This is used to test the most significant byte of a memory address
+ * in an x86 instruction.
+ */
+static inline int bcj_x86_test_msbyte(uint8_t b)
+{
+        return b == 0x00 || b == 0xFF;
+}
+
+static size_t bcj_x86(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        static const bool mask_to_allowed_status[8]
+                = { true, true, true, false, true, false, false, false };
+
+        static const uint8_t mask_to_bit_num[8] = { 0, 1, 2, 2, 3, 3, 3, 3 };
+
+        size_t i;
+        size_t prev_pos = (size_t)-1;
+        uint32_t prev_mask = s->x86_prev_mask;
+        uint32_t src;
+        uint32_t dest;
+        uint32_t j;
+        uint8_t b;
+
+        if (size <= 4)
+                return 0;
+
+        size -= 4;
+        for (i = 0; i < size; ++i) {
+                if ((buf[i] & 0xFE) != 0xE8)
+                        continue;
+
+                prev_pos = i - prev_pos;
+                if (prev_pos > 3) {
+                        prev_mask = 0;
+                } else {
+                        prev_mask = (prev_mask << (prev_pos - 1)) & 7;
+                        if (prev_mask != 0) {
+                                b = buf[i + 4 - mask_to_bit_num[prev_mask]];
+                                if (!mask_to_allowed_status[prev_mask]
+                                                || bcj_x86_test_msbyte(b)) {
+                                        prev_pos = i;
+                                        prev_mask = (prev_mask << 1) | 1;
+                                        continue;
+                                }
+                        }
+                }
+
+                prev_pos = i;
+
+                if (bcj_x86_test_msbyte(buf[i + 4])) {
+                        src = get_unaligned_le32(buf + i + 1);
+                        while (true) {
+                                dest = src - (s->pos + (uint32_t)i + 5);
+                                if (prev_mask == 0)
+                                        break;
+
+                                j = mask_to_bit_num[prev_mask] * 8;
+                                b = (uint8_t)(dest >> (24 - j));
+                                if (!bcj_x86_test_msbyte(b))
+                                        break;
+
+                                src = dest ^ (((uint32_t)1 << (32 - j)) - 1);
+                        }
+
+                        dest &= 0x01FFFFFF;
+                        dest |= (uint32_t)0 - (dest & 0x01000000);
+                        put_unaligned_le32(dest, buf + i + 1);
+                        i += 4;
+                } else {
+                        prev_mask = (prev_mask << 1) | 1;
+                }
+        }
+
+        prev_pos = i - prev_pos;
+        s->x86_prev_mask = prev_pos > 3 ? 0 : prev_mask << (prev_pos - 1);
+        return i;
+}
+#endif
+
+#ifdef XZ_DEC_POWERPC
+static size_t bcj_powerpc(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        size_t i;
+        uint32_t instr;
+
+        for (i = 0; i + 4 <= size; i += 4) {
+                instr = get_unaligned_be32(buf + i);
+                if ((instr & 0xFC000003) == 0x48000001) {
+                        instr &= 0x03FFFFFC;
+                        instr -= s->pos + (uint32_t)i;
+                        instr &= 0x03FFFFFC;
+                        instr |= 0x48000001;
+                        put_unaligned_be32(instr, buf + i);
+                }
+        }
+
+        return i;
+}
+#endif
+
+#ifdef XZ_DEC_IA64
+static size_t bcj_ia64(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        static const uint8_t branch_table[32] = {
+                0, 0, 0, 0, 0, 0, 0, 0,
+                0, 0, 0, 0, 0, 0, 0, 0,
+                4, 4, 6, 6, 0, 0, 7, 7,
+                4, 4, 0, 0, 4, 4, 0, 0
+        };
+
+        /*
+         * The local variables take a little bit stack space, but it's less
+         * than what LZMA2 decoder takes, so it doesn't make sense to reduce
+         * stack usage here without doing that for the LZMA2 decoder too.
+         */
+
+        /* Loop counters */
+        size_t i;
+        size_t j;
+
+        /* Instruction slot (0, 1, or 2) in the 128-bit instruction word */
+        uint32_t slot;
+
+        /* Bitwise offset of the instruction indicated by slot */
+        uint32_t bit_pos;
+
+        /* bit_pos split into byte and bit parts */
+        uint32_t byte_pos;
+        uint32_t bit_res;
+
+        /* Address part of an instruction */
+        uint32_t addr;
+
+        /* Mask used to detect which instructions to convert */
+        uint32_t mask;
+
+        /* 41-bit instruction stored somewhere in the lowest 48 bits */
+        uint64_t instr;
+
+        /* Instruction normalized with bit_res for easier manipulation */
+        uint64_t norm;
+
+        for (i = 0; i + 16 <= size; i += 16) {
+                mask = branch_table[buf[i] & 0x1F];
+                for (slot = 0, bit_pos = 5; slot < 3; ++slot, bit_pos += 41) {
+                        if (((mask >> slot) & 1) == 0)
+                                continue;
+
+                        byte_pos = bit_pos >> 3;
+                        bit_res = bit_pos & 7;
+                        instr = 0;
+                        for (j = 0; j < 6; ++j)
+                                instr |= (uint64_t)(buf[i + j + byte_pos])
+                                                << (8 * j);
+
+                        norm = instr >> bit_res;
+
+                        if (((norm >> 37) & 0x0F) == 0x05
+                                        && ((norm >> 9) & 0x07) == 0) {
+                                addr = (norm >> 13) & 0x0FFFFF;
+                                addr |= ((uint32_t)(norm >> 36) & 1) << 20;
+                                addr <<= 4;
+                                addr -= s->pos + (uint32_t)i;
+                                addr >>= 4;
+
+                                norm &= ~((uint64_t)0x8FFFFF << 13);
+                                norm |= (uint64_t)(addr & 0x0FFFFF) << 13;
+                                norm |= (uint64_t)(addr & 0x100000)
+                                                << (36 - 20);
+
+                                instr &= (1 << bit_res) - 1;
+                                instr |= norm << bit_res;
+
+                                for (j = 0; j < 6; j++)
+                                        buf[i + j + byte_pos]
+                                                = (uint8_t)(instr >> (8 * j));
+                        }
+                }
+        }
+
+        return i;
+}
+#endif
+
+#ifdef XZ_DEC_ARM
+static size_t bcj_arm(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        size_t i;
+        uint32_t addr;
+
+        for (i = 0; i + 4 <= size; i += 4) {
+                if (buf[i + 3] == 0xEB) {
+                        addr = (uint32_t)buf[i] | ((uint32_t)buf[i + 1] << 8)
+                                        | ((uint32_t)buf[i + 2] << 16);
+                        addr <<= 2;
+                        addr -= s->pos + (uint32_t)i + 8;
+                        addr >>= 2;
+                        buf[i] = (uint8_t)addr;
+                        buf[i + 1] = (uint8_t)(addr >> 8);
+                        buf[i + 2] = (uint8_t)(addr >> 16);
+                }
+        }
+
+        return i;
+}
+#endif
+
+#ifdef XZ_DEC_ARMTHUMB
+static size_t bcj_armthumb(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        size_t i;
+        uint32_t addr;
+
+        for (i = 0; i + 4 <= size; i += 2) {
+                if ((buf[i + 1] & 0xF8) == 0xF0
+                                && (buf[i + 3] & 0xF8) == 0xF8) {
+                        addr = (((uint32_t)buf[i + 1] & 0x07) << 19)
+                                        | ((uint32_t)buf[i] << 11)
+                                        | (((uint32_t)buf[i + 3] & 0x07) << 8)
+                                        | (uint32_t)buf[i + 2];
+                        addr <<= 1;
+                        addr -= s->pos + (uint32_t)i + 4;
+                        addr >>= 1;
+                        buf[i + 1] = (uint8_t)(0xF0 | ((addr >> 19) & 0x07));
+                        buf[i] = (uint8_t)(addr >> 11);
+                        buf[i + 3] = (uint8_t)(0xF8 | ((addr >> 8) & 0x07));
+                        buf[i + 2] = (uint8_t)addr;
+                        i += 2;
+                }
+        }
+
+        return i;
+}
+#endif
+
+#ifdef XZ_DEC_SPARC
+static size_t bcj_sparc(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
+{
+        size_t i;
+        uint32_t instr;
+
+        for (i = 0; i + 4 <= size; i += 4) {
+                instr = get_unaligned_be32(buf + i);
+                if ((instr >> 22) == 0x100 || (instr >> 22) == 0x1FF) {
+                        instr <<= 2;
+                        instr -= s->pos + (uint32_t)i;
+                        instr >>= 2;
+                        instr = ((uint32_t)0x40000000 - (instr & 0x400000))
+                                        | 0x40000000 | (instr & 0x3FFFFF);
+                        put_unaligned_be32(instr, buf + i);
+                }
+        }
+
+        return i;
+}
+#endif
+
+/*
+ * Apply the selected BCJ filter. Update *pos and s->pos to match the amount
+ * of data that got filtered.
+ *
+ * NOTE: This is implemented as a switch statement to avoid using function
+ * pointers, which could be problematic in the kernel boot code, which must
+ * avoid pointers to static data (at least on x86).
+ */
+static void bcj_apply(struct xz_dec_bcj *s,
+                      uint8_t *buf, size_t *pos, size_t size)
+{
+        size_t filtered;
+
+        buf += *pos;
+        size -= *pos;
+
+        switch (s->type) {
+#ifdef XZ_DEC_X86
+        case BCJ_X86:
+                filtered = bcj_x86(s, buf, size);
+                break;
+#endif
+#ifdef XZ_DEC_POWERPC
+        case BCJ_POWERPC:
+                filtered = bcj_powerpc(s, buf, size);
+                break;
+#endif
+#ifdef XZ_DEC_IA64
+        case BCJ_IA64:
+                filtered = bcj_ia64(s, buf, size);
+                break;
+#endif
+#ifdef XZ_DEC_ARM
+        case BCJ_ARM:
+                filtered = bcj_arm(s, buf, size);
+                break;
+#endif
+#ifdef XZ_DEC_ARMTHUMB
+        case BCJ_ARMTHUMB:
+                filtered = bcj_armthumb(s, buf, size);
+                break;
+#endif
+#ifdef XZ_DEC_SPARC
+        case BCJ_SPARC:
+                filtered = bcj_sparc(s, buf, size);
+                break;
+#endif
+        default:
+                /* Never reached but silence compiler warnings. */
+                filtered = 0;
+                break;
+        }
+
+        *pos += filtered;
+        s->pos += filtered;
+}
+
+/*
+ * Flush pending filtered data from temp to the output buffer.
+ * Move the remaining mixture of possibly filtered and unfiltered
+ * data to the beginning of temp.
+ */
+static void bcj_flush(struct xz_dec_bcj *s, struct xz_buf *b)
+{
+        size_t copy_size;
+
+        copy_size = min_t(size_t, s->temp.filtered, b->out_size - b->out_pos);
+        memcpy(b->out + b->out_pos, s->temp.buf, copy_size);
+        b->out_pos += copy_size;
+
+        s->temp.filtered -= copy_size;
+        s->temp.size -= copy_size;
+        memmove(s->temp.buf, s->temp.buf + copy_size, s->temp.size);
+}
+
+/*
+ * The BCJ filter functions are primitive in sense that they process the
+ * data in chunks of 1-16 bytes. To hide this issue, this function does
+ * some buffering.
+ */
+XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
+                                     struct xz_dec_lzma2 *lzma2,
+                                     struct xz_buf *b)
+{
+        size_t out_start;
+
+        /*
+         * Flush pending already filtered data to the output buffer. Return
+         * immediatelly if we couldn't flush everything, or if the next
+         * filter in the chain had already returned XZ_STREAM_END.
+         */
+        if (s->temp.filtered > 0) {
+                bcj_flush(s, b);
+                if (s->temp.filtered > 0)
+                        return XZ_OK;
+
+                if (s->ret == XZ_STREAM_END)
+                        return XZ_STREAM_END;
+        }
+
+        /*
+         * If we have more output space than what is currently pending in
+         * temp, copy the unfiltered data from temp to the output buffer
+         * and try to fill the output buffer by decoding more data from the
+         * next filter in the chain. Apply the BCJ filter on the new data
+         * in the output buffer. If everything cannot be filtered, copy it
+         * to temp and rewind the output buffer position accordingly.
+         */
+        if (s->temp.size < b->out_size - b->out_pos) {
+                out_start = b->out_pos;
+                memcpy(b->out + b->out_pos, s->temp.buf, s->temp.size);
+                b->out_pos += s->temp.size;
+
+                s->ret = xz_dec_lzma2_run(lzma2, b);
+                if (s->ret != XZ_STREAM_END
+                                && (s->ret != XZ_OK || s->single_call))
+                        return s->ret;
+
+                bcj_apply(s, b->out, &out_start, b->out_pos);
+
+                /*
+                 * As an exception, if the next filter returned XZ_STREAM_END,
+                 * we can do that too, since the last few bytes that remain
+                 * unfiltered are meant to remain unfiltered.
+                 */
+                if (s->ret == XZ_STREAM_END)
+                        return XZ_STREAM_END;
+
+                s->temp.size = b->out_pos - out_start;
+                b->out_pos -= s->temp.size;
+                memcpy(s->temp.buf, b->out + b->out_pos, s->temp.size);
+        }
+
+        /*
+         * If we have unfiltered data in temp, try to fill by decoding more
+         * data from the next filter. Apply the BCJ filter on temp. Then we
+         * hopefully can fill the actual output buffer by copying filtered
+         * data from temp. A mix of filtered and unfiltered data may be left
+         * in temp; it will be taken care on the next call to this function.
+         */
+        if (s->temp.size > 0) {
+                /* Make b->out{,_pos,_size} temporarily point to s->temp. */
+                s->out = b->out;
+                s->out_pos = b->out_pos;
+                s->out_size = b->out_size;
+                b->out = s->temp.buf;
+                b->out_pos = s->temp.size;
+                b->out_size = sizeof(s->temp.buf);
+
+                s->ret = xz_dec_lzma2_run(lzma2, b);
+
+                s->temp.size = b->out_pos;
+                b->out = s->out;
+                b->out_pos = s->out_pos;
+                b->out_size = s->out_size;
+
+                if (s->ret != XZ_OK && s->ret != XZ_STREAM_END)
+                        return s->ret;
+
+                bcj_apply(s, s->temp.buf, &s->temp.filtered, s->temp.size);
+
+                /*
+                 * If the next filter returned XZ_STREAM_END, we mark that
+                 * everything is filtered, since the last unfiltered bytes
+                 * of the stream are meant to be left as is.
+                 */
+                if (s->ret == XZ_STREAM_END)
+                        s->temp.filtered = s->temp.size;
+
+                bcj_flush(s, b);
+                if (s->temp.filtered > 0)
+                        return XZ_OK;
+        }
+
+        return s->ret;
+}
+
+XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call)
+{
+        struct xz_dec_bcj *s = kmalloc(sizeof(*s), GFP_KERNEL);
+        if (s != NULL)
+                s->single_call = single_call;
+
+        return s;
+}
+
+XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id)
+{
+        switch (id) {
+#ifdef XZ_DEC_X86
+        case BCJ_X86:
+#endif
+#ifdef XZ_DEC_POWERPC
+        case BCJ_POWERPC:
+#endif
+#ifdef XZ_DEC_IA64
+        case BCJ_IA64:
+#endif
+#ifdef XZ_DEC_ARM
+        case BCJ_ARM:
+#endif
+#ifdef XZ_DEC_ARMTHUMB
+        case BCJ_ARMTHUMB:
+#endif
+#ifdef XZ_DEC_SPARC
+        case BCJ_SPARC:
+#endif
+                break;
+
+        default:
+                /* Unsupported Filter ID */
+                return XZ_OPTIONS_ERROR;
+        }
+
+        s->type = id;
+        s->ret = XZ_OK;
+        s->pos = 0;
+        s->x86_prev_mask = 0;
+        s->temp.filtered = 0;
+        s->temp.size = 0;
+
+        return XZ_OK;
+}
+
+#endif
diff --git a/lib/xz/xz_dec_lzma2.c b/lib/xz/xz_dec_lzma2.c
new file mode 100644
index 000000000000..ea5fa4fe9d67
--- /dev/null
+++ b/lib/xz/xz_dec_lzma2.c
@@ -0,0 +1,1171 @@
+/*
+ * LZMA2 decoder
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.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.
+ */
+
+#include "xz_private.h"
+#include "xz_lzma2.h"
+
+/*
+ * Range decoder initialization eats the first five bytes of each LZMA chunk.
+ */
+#define RC_INIT_BYTES 5
+
+/*
+ * Minimum number of usable input buffer to safely decode one LZMA symbol.
+ * The worst case is that we decode 22 bits using probabilities and 26
+ * direct bits. This may decode at maximum of 20 bytes of input. However,
+ * lzma_main() does an extra normalization before returning, thus we
+ * need to put 21 here.
+ */
+#define LZMA_IN_REQUIRED 21
+
+/*
+ * Dictionary (history buffer)
+ *
+ * These are always true:
+ *    start <= pos <= full <= end
+ *    pos <= limit <= end
+ *
+ * In multi-call mode, also these are true:
+ *    end == size
+ *    size <= size_max
+ *    allocated <= size
+ *
+ * Most of these variables are size_t to support single-call mode,
+ * in which the dictionary variables address the actual output
+ * buffer directly.
+ */
+struct dictionary {
+        /* Beginning of the history buffer */
+        uint8_t *buf;
+
+        /* Old position in buf (before decoding more data) */
+        size_t start;
+
+        /* Position in buf */
+        size_t pos;
+
+        /*
+         * How full dictionary is. This is used to detect corrupt input that
+         * would read beyond the beginning of the uncompressed stream.
+         */
+        size_t full;
+
+        /* Write limit; we don't write to buf[limit] or later bytes. */
+        size_t limit;
+
+        /*
+         * End of the dictionary buffer. In multi-call mode, this is
+         * the same as the dictionary size. In single-call mode, this
+         * indicates the size of the output buffer.
+         */
+        size_t end;
+
+        /*
+         * Size of the dictionary as specified in Block Header. This is used
+         * together with "full" to detect corrupt input that would make us
+         * read beyond the beginning of the uncompressed stream.
+         */
+        uint32_t size;
+
+        /*
+         * Maximum allowed dictionary size in multi-call mode.
+         * This is ignored in single-call mode.
+         */
+        uint32_t size_max;
+
+        /*
+         * Amount of memory currently allocated for the dictionary.
+         * This is used only with XZ_DYNALLOC. (With XZ_PREALLOC,
+         * size_max is always the same as the allocated size.)
+         */
+        uint32_t allocated;
+
+        /* Operation mode */
+        enum xz_mode mode;
+};
+
+/* Range decoder */
+struct rc_dec {
+        uint32_t range;
+        uint32_t code;
+
+        /*
+         * Number of initializing bytes remaining to be read
+         * by rc_read_init().
+         */
+        uint32_t init_bytes_left;
+
+        /*
+         * Buffer from which we read our input. It can be either
+         * temp.buf or the caller-provided input buffer.
+         */
+        const uint8_t *in;
+        size_t in_pos;
+        size_t in_limit;
+};
+
+/* Probabilities for a length decoder. */
+struct lzma_len_dec {
+        /* Probability of match length being at least 10 */
+        uint16_t choice;
+
+        /* Probability of match length being at least 18 */
+        uint16_t choice2;
+
+        /* Probabilities for match lengths 2-9 */
+        uint16_t low[POS_STATES_MAX][LEN_LOW_SYMBOLS];
+
+        /* Probabilities for match lengths 10-17 */
+        uint16_t mid[POS_STATES_MAX][LEN_MID_SYMBOLS];
+
+        /* Probabilities for match lengths 18-273 */
+        uint16_t high[LEN_HIGH_SYMBOLS];
+};
+
+struct lzma_dec {
+        /* Distances of latest four matches */
+        uint32_t rep0;
+        uint32_t rep1;
+        uint32_t rep2;
+        uint32_t rep3;
+
+        /* Types of the most recently seen LZMA symbols */
+        enum lzma_state state;
+
+        /*
+         * Length of a match. This is updated so that dict_repeat can
+         * be called again to finish repeating the whole match.
+         */
+        uint32_t len;
+
+        /*
+         * LZMA properties or related bit masks (number of literal
+         * context bits, a mask dervied from the number of literal
+         * position bits, and a mask dervied from the number
+         * position bits)
+         */
+        uint32_t lc;
+        uint32_t literal_pos_mask; /* (1 << lp) - 1 */
+        uint32_t pos_mask;         /* (1 << pb) - 1 */
+
+        /* If 1, it's a match. Otherwise it's a single 8-bit literal. */
+        uint16_t is_match[STATES][POS_STATES_MAX];
+
+        /* If 1, it's a repeated match. The distance is one of rep0 .. rep3. */
+        uint16_t is_rep[STATES];
+
+        /*
+         * If 0, distance of a repeated match is rep0.
+         * Otherwise check is_rep1.
+         */
+        uint16_t is_rep0[STATES];
+
+        /*
+         * If 0, distance of a repeated match is rep1.
+         * Otherwise check is_rep2.
+         */
+        uint16_t is_rep1[STATES];
+
+        /* If 0, distance of a repeated match is rep2. Otherwise it is rep3. */
+        uint16_t is_rep2[STATES];
+
+        /*
+         * If 1, the repeated match has length of one byte. Otherwise
+         * the length is decoded from rep_len_decoder.
+         */
+        uint16_t is_rep0_long[STATES][POS_STATES_MAX];
+
+        /*
+         * Probability tree for the highest two bits of the match
+         * distance. There is a separate probability tree for match
+         * lengths of 2 (i.e. MATCH_LEN_MIN), 3, 4, and [5, 273].
+         */
+        uint16_t dist_slot[DIST_STATES][DIST_SLOTS];
+
+        /*
+         * Probility trees for additional bits for match distance
+         * when the distance is in the range [4, 127].
+         */
+        uint16_t dist_special[FULL_DISTANCES - DIST_MODEL_END];
+
+        /*
+         * Probability tree for the lowest four bits of a match
+         * distance that is equal to or greater than 128.
+         */
+        uint16_t dist_align[ALIGN_SIZE];
+
+        /* Length of a normal match */
+        struct lzma_len_dec match_len_dec;
+
+        /* Length of a repeated match */
+        struct lzma_len_dec rep_len_dec;
+
+        /* Probabilities of literals */
+        uint16_t literal[LITERAL_CODERS_MAX][LITERAL_CODER_SIZE];
+};
+
+struct lzma2_dec {
+        /* Position in xz_dec_lzma2_run(). */
+        enum lzma2_seq {
+                SEQ_CONTROL,
+                SEQ_UNCOMPRESSED_1,
+                SEQ_UNCOMPRESSED_2,
+                SEQ_COMPRESSED_0,
+                SEQ_COMPRESSED_1,
+                SEQ_PROPERTIES,
+                SEQ_LZMA_PREPARE,
+                SEQ_LZMA_RUN,
+                SEQ_COPY
+        } sequence;
+
+        /* Next position after decoding the compressed size of the chunk. */
+        enum lzma2_seq next_sequence;
+
+        /* Uncompressed size of LZMA chunk (2 MiB at maximum) */
+        uint32_t uncompressed;
+
+        /*
+         * Compressed size of LZMA chunk or compressed/uncompressed
+         * size of uncompressed chunk (64 KiB at maximum)
+         */
+        uint32_t compressed;
+
+        /*
+         * True if dictionary reset is needed. This is false before
+         * the first chunk (LZMA or uncompressed).
+         */
+        bool need_dict_reset;
+
+        /*
+         * True if new LZMA properties are needed. This is false
+         * before the first LZMA chunk.
+         */
+        bool need_props;
+};
+
+struct xz_dec_lzma2 {
+        /*
+         * The order below is important on x86 to reduce code size and
+         * it shouldn't hurt on other platforms. Everything up to and
+         * including lzma.pos_mask are in the first 128 bytes on x86-32,
+         * which allows using smaller instructions to access those
+         * variables. On x86-64, fewer variables fit into the first 128
+         * bytes, but this is still the best order without sacrificing
+         * the readability by splitting the structures.
+         */
+        struct rc_dec rc;
+        struct dictionary dict;
+        struct lzma2_dec lzma2;
+        struct lzma_dec lzma;
+
+        /*
+         * Temporary buffer which holds small number of input bytes between
+         * decoder calls. See lzma2_lzma() for details.
+         */
+        struct {
+                uint32_t size;
+                uint8_t buf[3 * LZMA_IN_REQUIRED];
+        } temp;
+};
+
+/**************
+ * Dictionary *
+ **************/
+
+/*
+ * Reset the dictionary state. When in single-call mode, set up the beginning
+ * of the dictionary to point to the actual output buffer.
+ */
+static void dict_reset(struct dictionary *dict, struct xz_buf *b)
+{
+        if (DEC_IS_SINGLE(dict->mode)) {
+                dict->buf = b->out + b->out_pos;
+                dict->end = b->out_size - b->out_pos;
+        }
+
+        dict->start = 0;
+        dict->pos = 0;
+        dict->limit = 0;
+        dict->full = 0;
+}
+
+/* Set dictionary write limit */
+static void dict_limit(struct dictionary *dict, size_t out_max)
+{
+        if (dict->end - dict->pos <= out_max)
+                dict->limit = dict->end;
+        else
+                dict->limit = dict->pos + out_max;
+}
+
+/* Return true if at least one byte can be written into the dictionary. */
+static inline bool dict_has_space(const struct dictionary *dict)
+{
+        return dict->pos < dict->limit;
+}
+
+/*
+ * Get a byte from the dictionary at the given distance. The distance is
+ * assumed to valid, or as a special case, zero when the dictionary is
+ * still empty. This special case is needed for single-call decoding to
+ * avoid writing a '\0' to the end of the destination buffer.
+ */
+static inline uint32_t dict_get(const struct dictionary *dict, uint32_t dist)
+{
+        size_t offset = dict->pos - dist - 1;
+
+        if (dist >= dict->pos)
+                offset += dict->end;
+
+        return dict->full > 0 ? dict->buf[offset] : 0;
+}
+
+/*
+ * Put one byte into the dictionary. It is assumed that there is space for it.
+ */
+static inline void dict_put(struct dictionary *dict, uint8_t byte)
+{
+        dict->buf[dict->pos++] = byte;
+
+        if (dict->full < dict->pos)
+                dict->full = dict->pos;
+}
+
+/*
+ * Repeat given number of bytes from the given distance. If the distance is
+ * invalid, false is returned. On success, true is returned and *len is
+ * updated to indicate how many bytes were left to be repeated.
+ */
+static bool dict_repeat(struct dictionary *dict, uint32_t *len, uint32_t dist)
+{
+        size_t back;
+        uint32_t left;
+
+        if (dist >= dict->full || dist >= dict->size)
+                return false;
+
+        left = min_t(size_t, dict->limit - dict->pos, *len);
+        *len -= left;
+
+        back = dict->pos - dist - 1;
+        if (dist >= dict->pos)
+                back += dict->end;
+
+        do {
+                dict->buf[dict->pos++] = dict->buf[back++];
+                if (back == dict->end)
+                        back = 0;
+        } while (--left > 0);
+
+        if (dict->full < dict->pos)
+                dict->full = dict->pos;
+
+        return true;
+}
+
+/* Copy uncompressed data as is from input to dictionary and output buffers. */
+static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
+                              uint32_t *left)
+{
+        size_t copy_size;
+
+        while (*left > 0 && b->in_pos < b->in_size
+                        && b->out_pos < b->out_size) {
+                copy_size = min(b->in_size - b->in_pos,
+                                b->out_size - b->out_pos);
+                if (copy_size > dict->end - dict->pos)
+                        copy_size = dict->end - dict->pos;
+                if (copy_size > *left)
+                        copy_size = *left;
+
+                *left -= copy_size;
+
+                memcpy(dict->buf + dict->pos, b->in + b->in_pos, copy_size);
+                dict->pos += copy_size;
+
+                if (dict->full < dict->pos)
+                        dict->full = dict->pos;
+
+                if (DEC_IS_MULTI(dict->mode)) {
+                        if (dict->pos == dict->end)
+                                dict->pos = 0;
+
+                        memcpy(b->out + b->out_pos, b->in + b->in_pos,
+                                        copy_size);
+                }
+
+                dict->start = dict->pos;
+
+                b->out_pos += copy_size;
+                b->in_pos += copy_size;
+        }
+}
+
+/*
+ * 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()
+ * before decoding data into the dictionary.
+ */
+static uint32_t dict_flush(struct dictionary *dict, struct xz_buf *b)
+{
+        size_t copy_size = dict->pos - dict->start;
+
+        if (DEC_IS_MULTI(dict->mode)) {
+                if (dict->pos == dict->end)
+                        dict->pos = 0;
+
+                memcpy(b->out + b->out_pos, dict->buf + dict->start,
+                                copy_size);
+        }
+
+        dict->start = dict->pos;
+        b->out_pos += copy_size;
+        return copy_size;
+}
+
+/*****************
+ * Range decoder *
+ *****************/
+
+/* Reset the range decoder. */
+static void rc_reset(struct rc_dec *rc)
+{
+        rc->range = (uint32_t)-1;
+        rc->code = 0;
+        rc->init_bytes_left = RC_INIT_BYTES;
+}
+
+/*
+ * Read the first five initial bytes into rc->code if they haven't been
+ * read already. (Yes, the first byte gets completely ignored.)
+ */
+static bool rc_read_init(struct rc_dec *rc, struct xz_buf *b)
+{
+        while (rc->init_bytes_left > 0) {
+                if (b->in_pos == b->in_size)
+                        return false;
+
+                rc->code = (rc->code << 8) + b->in[b->in_pos++];
+                --rc->init_bytes_left;
+        }
+
+        return true;
+}
+
+/* Return true if there may not be enough input for the next decoding loop. */
+static inline bool rc_limit_exceeded(const struct rc_dec *rc)
+{
+        return rc->in_pos > rc->in_limit;
+}
+
+/*
+ * Return true if it is possible (from point of view of range decoder) that
+ * we have reached the end of the LZMA chunk.
+ */
+static inline bool rc_is_finished(const struct rc_dec *rc)
+{
+        return rc->code == 0;
+}
+
+/* Read the next input byte if needed. */
+static __always_inline void rc_normalize(struct rc_dec *rc)
+{
+        if (rc->range < RC_TOP_VALUE) {
+                rc->range <<= RC_SHIFT_BITS;
+                rc->code = (rc->code << RC_SHIFT_BITS) + rc->in[rc->in_pos++];
+        }
+}
+
+/*
+ * 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-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,
+ * and it generates 10-20 % faster code than GCC 3.x from this file anyway.)
+ */
+static __always_inline int rc_bit(struct rc_dec *rc, uint16_t *prob)
+{
+        uint32_t bound;
+        int bit;
+
+        rc_normalize(rc);
+        bound = (rc->range >> RC_BIT_MODEL_TOTAL_BITS) * *prob;
+        if (rc->code < bound) {
+                rc->range = bound;
+                *prob += (RC_BIT_MODEL_TOTAL - *prob) >> RC_MOVE_BITS;
+                bit = 0;
+        } else {
+                rc->range -= bound;
+                rc->code -= bound;
+                *prob -= *prob >> RC_MOVE_BITS;
+                bit = 1;
+        }
+
+        return bit;
+}
+
+/* Decode a bittree starting from the most significant bit. */
+static __always_inline uint32_t rc_bittree(struct rc_dec *rc,
+                                           uint16_t *probs, uint32_t limit)
+{
+        uint32_t symbol = 1;
+
+        do {
+                if (rc_bit(rc, &probs[symbol]))
+                        symbol = (symbol << 1) + 1;
+                else
+                        symbol <<= 1;
+        } while (symbol < limit);
+
+        return symbol;
+}
+
+/* Decode a bittree starting from the least significant bit. */
+static __always_inline void rc_bittree_reverse(struct rc_dec *rc,
+                                               uint16_t *probs,
+                                               uint32_t *dest, uint32_t limit)
+{
+        uint32_t symbol = 1;
+        uint32_t i = 0;
+
+        do {
+                if (rc_bit(rc, &probs[symbol])) {
+                        symbol = (symbol << 1) + 1;
+                        *dest += 1 << i;
+                } else {
+                        symbol <<= 1;
+                }
+        } while (++i < limit);
+}
+
+/* Decode direct bits (fixed fifty-fifty probability) */
+static inline void rc_direct(struct rc_dec *rc, uint32_t *dest, uint32_t limit)
+{
+        uint32_t mask;
+
+        do {
+                rc_normalize(rc);
+                rc->range >>= 1;
+                rc->code -= rc->range;
+                mask = (uint32_t)0 - (rc->code >> 31);
+                rc->code += rc->range & mask;
+                *dest = (*dest << 1) + (mask + 1);
+        } while (--limit > 0);
+}
+
+/********
+ * LZMA *
+ ********/
+
+/* Get pointer to literal coder probability array. */
+static uint16_t *lzma_literal_probs(struct xz_dec_lzma2 *s)
+{
+        uint32_t prev_byte = dict_get(&s->dict, 0);
+        uint32_t low = prev_byte >> (8 - s->lzma.lc);
+        uint32_t high = (s->dict.pos & s->lzma.literal_pos_mask) << s->lzma.lc;
+        return s->lzma.literal[low + high];
+}
+
+/* Decode a literal (one 8-bit byte) */
+static void lzma_literal(struct xz_dec_lzma2 *s)
+{
+        uint16_t *probs;
+        uint32_t symbol;
+        uint32_t match_byte;
+        uint32_t match_bit;
+        uint32_t offset;
+        uint32_t i;
+
+        probs = lzma_literal_probs(s);
+
+        if (lzma_state_is_literal(s->lzma.state)) {
+                symbol = rc_bittree(&s->rc, probs, 0x100);
+        } else {
+                symbol = 1;
+                match_byte = dict_get(&s->dict, s->lzma.rep0) << 1;
+                offset = 0x100;
+
+                do {
+                        match_bit = match_byte & offset;
+                        match_byte <<= 1;
+                        i = offset + match_bit + symbol;
+
+                        if (rc_bit(&s->rc, &probs[i])) {
+                                symbol = (symbol << 1) + 1;
+                                offset &= match_bit;
+                        } else {
+                                symbol <<= 1;
+                                offset &= ~match_bit;
+                        }
+                } while (symbol < 0x100);
+        }
+
+        dict_put(&s->dict, (uint8_t)symbol);
+        lzma_state_literal(&s->lzma.state);
+}
+
+/* Decode the length of the match into s->lzma.len. */
+static void lzma_len(struct xz_dec_lzma2 *s, struct lzma_len_dec *l,
+                     uint32_t pos_state)
+{
+        uint16_t *probs;
+        uint32_t limit;
+
+        if (!rc_bit(&s->rc, &l->choice)) {
+                probs = l->low[pos_state];
+                limit = LEN_LOW_SYMBOLS;
+                s->lzma.len = MATCH_LEN_MIN;
+        } else {
+                if (!rc_bit(&s->rc, &l->choice2)) {
+                        probs = l->mid[pos_state];
+                        limit = LEN_MID_SYMBOLS;
+                        s->lzma.len = MATCH_LEN_MIN + LEN_LOW_SYMBOLS;
+                } else {
+                        probs = l->high;
+                        limit = LEN_HIGH_SYMBOLS;
+                        s->lzma.len = MATCH_LEN_MIN + LEN_LOW_SYMBOLS
+                                        + LEN_MID_SYMBOLS;
+                }
+        }
+
+        s->lzma.len += rc_bittree(&s->rc, probs, limit) - limit;
+}
+
+/* Decode a match. The distance will be stored in s->lzma.rep0. */
+static void lzma_match(struct xz_dec_lzma2 *s, uint32_t pos_state)
+{
+        uint16_t *probs;
+        uint32_t dist_slot;
+        uint32_t limit;
+
+        lzma_state_match(&s->lzma.state);
+
+        s->lzma.rep3 = s->lzma.rep2;
+        s->lzma.rep2 = s->lzma.rep1;
+        s->lzma.rep1 = s->lzma.rep0;
+
+        lzma_len(s, &s->lzma.match_len_dec, pos_state);
+
+        probs = s->lzma.dist_slot[lzma_get_dist_state(s->lzma.len)];
+        dist_slot = rc_bittree(&s->rc, probs, DIST_SLOTS) - DIST_SLOTS;
+
+        if (dist_slot < DIST_MODEL_START) {
+                s->lzma.rep0 = dist_slot;
+        } else {
+                limit = (dist_slot >> 1) - 1;
+                s->lzma.rep0 = 2 + (dist_slot & 1);
+
+                if (dist_slot < DIST_MODEL_END) {
+                        s->lzma.rep0 <<= limit;
+                        probs = s->lzma.dist_special + s->lzma.rep0
+                                        - dist_slot - 1;
+                        rc_bittree_reverse(&s->rc, probs,
+                                        &s->lzma.rep0, limit);
+                } else {
+                        rc_direct(&s->rc, &s->lzma.rep0, limit - ALIGN_BITS);
+                        s->lzma.rep0 <<= ALIGN_BITS;
+                        rc_bittree_reverse(&s->rc, s->lzma.dist_align,
+                                        &s->lzma.rep0, ALIGN_BITS);
+                }
+        }
+}
+
+/*
+ * Decode a repeated match. The distance is one of the four most recently
+ * seen matches. The distance will be stored in s->lzma.rep0.
+ */
+static void lzma_rep_match(struct xz_dec_lzma2 *s, uint32_t pos_state)
+{
+        uint32_t tmp;
+
+        if (!rc_bit(&s->rc, &s->lzma.is_rep0[s->lzma.state])) {
+                if (!rc_bit(&s->rc, &s->lzma.is_rep0_long[
+                                s->lzma.state][pos_state])) {
+                        lzma_state_short_rep(&s->lzma.state);
+                        s->lzma.len = 1;
+                        return;
+                }
+        } else {
+                if (!rc_bit(&s->rc, &s->lzma.is_rep1[s->lzma.state])) {
+                        tmp = s->lzma.rep1;
+                } else {
+                        if (!rc_bit(&s->rc, &s->lzma.is_rep2[s->lzma.state])) {
+                                tmp = s->lzma.rep2;
+                        } else {
+                                tmp = s->lzma.rep3;
+                                s->lzma.rep3 = s->lzma.rep2;
+                        }
+
+                        s->lzma.rep2 = s->lzma.rep1;
+                }
+
+                s->lzma.rep1 = s->lzma.rep0;
+                s->lzma.rep0 = tmp;
+        }
+
+        lzma_state_long_rep(&s->lzma.state);
+        lzma_len(s, &s->lzma.rep_len_dec, pos_state);
+}
+
+/* LZMA decoder core */
+static bool lzma_main(struct xz_dec_lzma2 *s)
+{
+        uint32_t pos_state;
+
+        /*
+         * If the dictionary was reached during the previous call, try to
+         * finish the possibly pending repeat in the dictionary.
+         */
+        if (dict_has_space(&s->dict) && s->lzma.len > 0)
+                dict_repeat(&s->dict, &s->lzma.len, s->lzma.rep0);
+
+        /*
+         * Decode more LZMA symbols. One iteration may consume up to
+         * LZMA_IN_REQUIRED - 1 bytes.
+         */
+        while (dict_has_space(&s->dict) && !rc_limit_exceeded(&s->rc)) {
+                pos_state = s->dict.pos & s->lzma.pos_mask;
+
+                if (!rc_bit(&s->rc, &s->lzma.is_match[
+                                s->lzma.state][pos_state])) {
+                        lzma_literal(s);
+                } else {
+                        if (rc_bit(&s->rc, &s->lzma.is_rep[s->lzma.state]))
+                                lzma_rep_match(s, pos_state);
+                        else
+                                lzma_match(s, pos_state);
+
+                        if (!dict_repeat(&s->dict, &s->lzma.len, s->lzma.rep0))
+                                return false;
+                }
+        }
+
+        /*
+         * Having the range decoder always normalized when we are outside
+         * this function makes it easier to correctly handle end of the chunk.
+         */
+        rc_normalize(&s->rc);
+
+        return true;
+}
+
+/*
+ * 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)
+{
+        uint16_t *probs;
+        size_t i;
+
+        s->lzma.state = STATE_LIT_LIT;
+        s->lzma.rep0 = 0;
+        s->lzma.rep1 = 0;
+        s->lzma.rep2 = 0;
+        s->lzma.rep3 = 0;
+
+        /*
+         * All probabilities are initialized to the same value. This hack
+         * makes the code smaller by avoiding a separate loop for each
+         * probability array.
+         *
+         * This could be optimized so that only that part of literal
+         * probabilities that are actually required. In the common case
+         * we would write 12 KiB less.
+         */
+        probs = s->lzma.is_match[0];
+        for (i = 0; i < PROBS_TOTAL; ++i)
+                probs[i] = RC_BIT_MODEL_TOTAL / 2;
+
+        rc_reset(&s->rc);
+}
+
+/*
+ * Decode and validate LZMA properties (lc/lp/pb) and calculate the bit masks
+ * from the decoded lp and pb values. On success, the LZMA decoder state is
+ * reset and true is returned.
+ */
+static bool lzma_props(struct xz_dec_lzma2 *s, uint8_t props)
+{
+        if (props > (4 * 5 + 4) * 9 + 8)
+                return false;
+
+        s->lzma.pos_mask = 0;
+        while (props >= 9 * 5) {
+                props -= 9 * 5;
+                ++s->lzma.pos_mask;
+        }
+
+        s->lzma.pos_mask = (1 << s->lzma.pos_mask) - 1;
+
+        s->lzma.literal_pos_mask = 0;
+        while (props >= 9) {
+                props -= 9;
+                ++s->lzma.literal_pos_mask;
+        }
+
+        s->lzma.lc = props;
+
+        if (s->lzma.lc + s->lzma.literal_pos_mask > 4)
+                return false;
+
+        s->lzma.literal_pos_mask = (1 << s->lzma.literal_pos_mask) - 1;
+
+        lzma_reset(s);
+
+        return true;
+}
+
+/*********
+ * LZMA2 *
+ *********/
+
+/*
+ * The LZMA decoder assumes that if the input limit (s->rc.in_limit) hasn't
+ * been exceeded, it is safe to read up to LZMA_IN_REQUIRED bytes. This
+ * wrapper function takes care of making the LZMA decoder's assumption safe.
+ *
+ * As long as there is plenty of input left to be decoded in the current LZMA
+ * chunk, we decode directly from the caller-supplied input buffer until
+ * there's LZMA_IN_REQUIRED bytes left. Those remaining bytes are copied into
+ * s->temp.buf, which (hopefully) gets filled on the next call to this
+ * function. We decode a few bytes from the temporary buffer so that we can
+ * continue decoding from the caller-supplied input buffer again.
+ */
+static bool lzma2_lzma(struct xz_dec_lzma2 *s, struct xz_buf *b)
+{
+        size_t in_avail;
+        uint32_t tmp;
+
+        in_avail = b->in_size - b->in_pos;
+        if (s->temp.size > 0 || s->lzma2.compressed == 0) {
+                tmp = 2 * LZMA_IN_REQUIRED - s->temp.size;
+                if (tmp > s->lzma2.compressed - s->temp.size)
+                        tmp = s->lzma2.compressed - s->temp.size;
+                if (tmp > in_avail)
+                        tmp = in_avail;
+
+                memcpy(s->temp.buf + s->temp.size, b->in + b->in_pos, tmp);
+
+                if (s->temp.size + tmp == s->lzma2.compressed) {
+                        memzero(s->temp.buf + s->temp.size + tmp,
+                                        sizeof(s->temp.buf)
+                                                - s->temp.size - tmp);
+                        s->rc.in_limit = s->temp.size + tmp;
+                } else if (s->temp.size + tmp < LZMA_IN_REQUIRED) {
+                        s->temp.size += tmp;
+                        b->in_pos += tmp;
+                        return true;
+                } else {
+                        s->rc.in_limit = s->temp.size + tmp - LZMA_IN_REQUIRED;
+                }
+
+                s->rc.in = s->temp.buf;
+                s->rc.in_pos = 0;
+
+                if (!lzma_main(s) || s->rc.in_pos > s->temp.size + tmp)
+                        return false;
+
+                s->lzma2.compressed -= s->rc.in_pos;
+
+                if (s->rc.in_pos < s->temp.size) {
+                        s->temp.size -= s->rc.in_pos;
+                        memmove(s->temp.buf, s->temp.buf + s->rc.in_pos,
+                                        s->temp.size);
+                        return true;
+                }
+
+                b->in_pos += s->rc.in_pos - s->temp.size;
+                s->temp.size = 0;
+        }
+
+        in_avail = b->in_size - b->in_pos;
+        if (in_avail >= LZMA_IN_REQUIRED) {
+                s->rc.in = b->in;
+                s->rc.in_pos = b->in_pos;
+
+                if (in_avail >= s->lzma2.compressed + LZMA_IN_REQUIRED)
+                        s->rc.in_limit = b->in_pos + s->lzma2.compressed;
+                else
+                        s->rc.in_limit = b->in_size - LZMA_IN_REQUIRED;
+
+                if (!lzma_main(s))
+                        return false;
+
+                in_avail = s->rc.in_pos - b->in_pos;
+                if (in_avail > s->lzma2.compressed)
+                        return false;
+
+                s->lzma2.compressed -= in_avail;
+                b->in_pos = s->rc.in_pos;
+        }
+
+        in_avail = b->in_size - b->in_pos;
+        if (in_avail < LZMA_IN_REQUIRED) {
+                if (in_avail > s->lzma2.compressed)
+                        in_avail = s->lzma2.compressed;
+
+                memcpy(s->temp.buf, b->in + b->in_pos, in_avail);
+                s->temp.size = in_avail;
+                b->in_pos += in_avail;
+        }
+
+        return true;
+}
+
+/*
+ * Take care of the LZMA2 control layer, and forward the job of actual LZMA
+ * decoding or copying of uncompressed chunks to other functions.
+ */
+XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
+                                       struct xz_buf *b)
+{
+        uint32_t tmp;
+
+        while (b->in_pos < b->in_size || s->lzma2.sequence == SEQ_LZMA_RUN) {
+                switch (s->lzma2.sequence) {
+                case SEQ_CONTROL:
+                        /*
+                         * LZMA2 control byte
+                         *
+                         * Exact values:
+                         *   0x00   End marker
+                         *   0x01   Dictionary reset followed by
+                         *          an uncompressed chunk
+                         *   0x02   Uncompressed chunk (no dictionary reset)
+                         *
+                         * Highest three bits (s->control & 0xE0):
+                         *   0xE0   Dictionary reset, new properties and state
+                         *          reset, followed by LZMA compressed chunk
+                         *   0xC0   New properties and state reset, followed
+                         *          by LZMA compressed chunk (no dictionary
+                         *          reset)
+                         *   0xA0   State reset using old properties,
+                         *          followed by LZMA compressed chunk (no
+                         *          dictionary reset)
+                         *   0x80   LZMA chunk (no dictionary or state reset)
+                         *
+                         * For LZMA compressed chunks, the lowest five bits
+                         * (s->control & 1F) are the highest bits of the
+                         * uncompressed size (bits 16-20).
+                         *
+                         * A new LZMA2 stream must begin with a dictionary
+                         * reset. The first LZMA chunk must set new
+                         * properties and reset the LZMA state.
+                         *
+                         * Values that don't match anything described above
+                         * are invalid and we return XZ_DATA_ERROR.
+                         */
+                        tmp = b->in[b->in_pos++];
+
+                        if (tmp >= 0xE0 || tmp == 0x01) {
+                                s->lzma2.need_props = true;
+                                s->lzma2.need_dict_reset = false;
+                                dict_reset(&s->dict, b);
+                        } else if (s->lzma2.need_dict_reset) {
+                                return XZ_DATA_ERROR;
+                        }
+
+                        if (tmp >= 0x80) {
+                                s->lzma2.uncompressed = (tmp & 0x1F) << 16;
+                                s->lzma2.sequence = SEQ_UNCOMPRESSED_1;
+
+                                if (tmp >= 0xC0) {
+                                        /*
+                                         * When there are new properties,
+                                         * state reset is done at
+                                         * SEQ_PROPERTIES.
+                                         */
+                                        s->lzma2.need_props = false;
+                                        s->lzma2.next_sequence
+                                                        = SEQ_PROPERTIES;
+
+                                } else if (s->lzma2.need_props) {
+                                        return XZ_DATA_ERROR;
+
+                                } else {
+                                        s->lzma2.next_sequence
+                                                        = SEQ_LZMA_PREPARE;
+                                        if (tmp >= 0xA0)
+                                                lzma_reset(s);
+                                }
+                        } else {
+                                if (tmp == 0x00)
+                                        return XZ_STREAM_END;
+
+                                if (tmp > 0x02)
+                                        return XZ_DATA_ERROR;
+
+                                s->lzma2.sequence = SEQ_COMPRESSED_0;
+                                s->lzma2.next_sequence = SEQ_COPY;
+                        }
+
+                        break;
+
+                case SEQ_UNCOMPRESSED_1:
+                        s->lzma2.uncompressed
+                                        += (uint32_t)b->in[b->in_pos++] << 8;
+                        s->lzma2.sequence = SEQ_UNCOMPRESSED_2;
+                        break;
+
+                case SEQ_UNCOMPRESSED_2:
+                        s->lzma2.uncompressed
+                                        += (uint32_t)b->in[b->in_pos++] + 1;
+                        s->lzma2.sequence = SEQ_COMPRESSED_0;
+                        break;
+
+                case SEQ_COMPRESSED_0:
+                        s->lzma2.compressed
+                                        = (uint32_t)b->in[b->in_pos++] << 8;
+                        s->lzma2.sequence = SEQ_COMPRESSED_1;
+                        break;
+
+                case SEQ_COMPRESSED_1:
+                        s->lzma2.compressed
+                                        += (uint32_t)b->in[b->in_pos++] + 1;
+                        s->lzma2.sequence = s->lzma2.next_sequence;
+                        break;
+
+                case SEQ_PROPERTIES:
+                        if (!lzma_props(s, b->in[b->in_pos++]))
+                                return XZ_DATA_ERROR;
+
+                        s->lzma2.sequence = SEQ_LZMA_PREPARE;
+
+                case SEQ_LZMA_PREPARE:
+                        if (s->lzma2.compressed < RC_INIT_BYTES)
+                                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;
+
+                case SEQ_LZMA_RUN:
+                        /*
+                         * Set dictionary limit to indicate how much we want
+                         * to be encoded at maximum. Decode new data into the
+                         * dictionary. Flush the new data from dictionary to
+                         * b->out. Check if we finished decoding this chunk.
+                         * In case the dictionary got full but we didn't fill
+                         * the output buffer yet, we may run this loop
+                         * multiple times without changing s->lzma2.sequence.
+                         */
+                        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.compressed > 0 || s->lzma.len > 0
+                                                || !rc_is_finished(&s->rc))
+                                        return XZ_DATA_ERROR;
+
+                                rc_reset(&s->rc);
+                                s->lzma2.sequence = SEQ_CONTROL;
+
+                        } else if (b->out_pos == b->out_size
+                                        || (b->in_pos == b->in_size
+                                                && s->temp.size
+                                                < s->lzma2.compressed)) {
+                                return XZ_OK;
+                        }
+
+                        break;
+
+                case SEQ_COPY:
+                        dict_uncompressed(&s->dict, b, &s->lzma2.compressed);
+                        if (s->lzma2.compressed > 0)
+                                return XZ_OK;
+
+                        s->lzma2.sequence = SEQ_CONTROL;
+                        break;
+                }
+        }
+
+        return XZ_OK;
+}
+
+XZ_EXTERN struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode,
+                                                   uint32_t dict_max)
+{
+        struct xz_dec_lzma2 *s = kmalloc(sizeof(*s), GFP_KERNEL);
+        if (s == NULL)
+                return NULL;
+
+        s->dict.mode = mode;
+        s->dict.size_max = dict_max;
+
+        if (DEC_IS_PREALLOC(mode)) {
+                s->dict.buf = vmalloc(dict_max);
+                if (s->dict.buf == NULL) {
+                        kfree(s);
+                        return NULL;
+                }
+        } else if (DEC_IS_DYNALLOC(mode)) {
+                s->dict.buf = NULL;
+                s->dict.allocated = 0;
+        }
+
+        return s;
+}
+
+XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props)
+{
+        /* This limits dictionary size to 3 GiB to keep parsing simpler. */
+        if (props > 39)
+                return XZ_OPTIONS_ERROR;
+
+        s->dict.size = 2 + (props & 1);
+        s->dict.size <<= (props >> 1) + 11;
+
+        if (DEC_IS_MULTI(s->dict.mode)) {
+                if (s->dict.size > s->dict.size_max)
+                        return XZ_MEMLIMIT_ERROR;
+
+                s->dict.end = s->dict.size;
+
+                if (DEC_IS_DYNALLOC(s->dict.mode)) {
+                        if (s->dict.allocated < s->dict.size) {
+                                vfree(s->dict.buf);
+                                s->dict.buf = vmalloc(s->dict.size);
+                                if (s->dict.buf == NULL) {
+                                        s->dict.allocated = 0;
+                                        return XZ_MEM_ERROR;
+                                }
+                        }
+                }
+        }
+
+        s->lzma.len = 0;
+
+        s->lzma2.sequence = SEQ_CONTROL;
+        s->lzma2.need_dict_reset = true;
+
+        s->temp.size = 0;
+
+        return XZ_OK;
+}
+
+XZ_EXTERN void xz_dec_lzma2_end(struct xz_dec_lzma2 *s)
+{
+        if (DEC_IS_MULTI(s->dict.mode))
+                vfree(s->dict.buf);
+
+        kfree(s);
+}
diff --git a/lib/xz/xz_dec_stream.c b/lib/xz/xz_dec_stream.c
new file mode 100644
index 000000000000..ac809b1e64f7
--- /dev/null
+++ b/lib/xz/xz_dec_stream.c
@@ -0,0 +1,821 @@
+/*
+ * .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"
+
+/* 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;
+
+        /* CRC32 value in Block or Index */
+        uint32_t crc32;
+
+        /* 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 if presence of the CRC32
+ * 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->crc32 = xz_crc32(b->out + s->out_start,
+                                b->out_pos - s->out_start, s->crc32);
+
+        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;
+#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->crc32 = xz_crc32(b->in + s->in_start, in_used, s->crc32);
+}
+
+/*
+ * 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 input bytes match the value of s->crc32.
+ * s->pos must be zero when starting to validate the first byte.
+ */
+static enum xz_ret crc32_validate(struct xz_dec *s, struct xz_buf *b)
+{
+        do {
+                if (b->in_pos == b->in_size)
+                        return XZ_OK;
+
+                if (((s->crc32 >> s->pos) & 0xFF) != b->in[b->in_pos++])
+                        return XZ_DATA_ERROR;
+
+                s->pos += 8;
+
+        } while (s->pos < 32);
+
+        s->crc32 = 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 only none (Check ID = 0) and
+         * CRC32 (Check ID = 1). 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)
+                return XZ_UNSUPPORTED_CHECK;
+#else
+        if (s->check_type > XZ_CHECK_CRC32)
+                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 = crc32_validate(s, b);
+                                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 = crc32_validate(s, b);
+                        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->crc32 = 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);
+        }
+}
diff --git a/lib/xz/xz_dec_syms.c b/lib/xz/xz_dec_syms.c
new file mode 100644
index 000000000000..32eb3c03aede
--- /dev/null
+++ b/lib/xz/xz_dec_syms.c
@@ -0,0 +1,26 @@
+/*
+ * XZ decoder module information
+ *
+ * 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 <linux/module.h>
+#include <linux/xz.h>
+
+EXPORT_SYMBOL(xz_dec_init);
+EXPORT_SYMBOL(xz_dec_reset);
+EXPORT_SYMBOL(xz_dec_run);
+EXPORT_SYMBOL(xz_dec_end);
+
+MODULE_DESCRIPTION("XZ decompressor");
+MODULE_VERSION("1.0");
+MODULE_AUTHOR("Lasse Collin <lasse.collin@tukaani.org> and Igor Pavlov");
+
+/*
+ * This code is in the public domain, but in Linux it's simplest to just
+ * say it's GPL and consider the authors as the copyright holders.
+ */
+MODULE_LICENSE("GPL");
diff --git a/lib/xz/xz_dec_test.c b/lib/xz/xz_dec_test.c
new file mode 100644
index 000000000000..da28a19d6c98
--- /dev/null
+++ b/lib/xz/xz_dec_test.c
@@ -0,0 +1,220 @@
+/*
+ * XZ decoder tester
+ *
+ * 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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/crc32.h>
+#include <linux/xz.h>
+
+/* Maximum supported dictionary size */
+#define DICT_MAX (1 << 20)
+
+/* Device name to pass to register_chrdev(). */
+#define DEVICE_NAME "xz_dec_test"
+
+/* Dynamically allocated device major number */
+static int device_major;
+
+/*
+ * We reuse the same decoder state, and thus can decode only one
+ * file at a time.
+ */
+static bool device_is_open;
+
+/* XZ decoder state */
+static struct xz_dec *state;
+
+/*
+ * Return value of xz_dec_run(). We need to avoid calling xz_dec_run() after
+ * it has returned XZ_STREAM_END, so we make this static.
+ */
+static enum xz_ret ret;
+
+/*
+ * Input and output buffers. The input buffer is used as a temporary safe
+ * place for the data coming from the userspace.
+ */
+static uint8_t buffer_in[1024];
+static uint8_t buffer_out[1024];
+
+/*
+ * Structure to pass the input and output buffers to the XZ decoder.
+ * A few of the fields are never modified so we initialize them here.
+ */
+static struct xz_buf buffers = {
+        .in = buffer_in,
+        .out = buffer_out,
+        .out_size = sizeof(buffer_out)
+};
+
+/*
+ * CRC32 of uncompressed data. This is used to give the user a simple way
+ * to check that the decoder produces correct output.
+ */
+static uint32_t crc;
+
+static int xz_dec_test_open(struct inode *i, struct file *f)
+{
+        if (device_is_open)
+                return -EBUSY;
+
+        device_is_open = true;
+
+        xz_dec_reset(state);
+        ret = XZ_OK;
+        crc = 0xFFFFFFFF;
+
+        buffers.in_pos = 0;
+        buffers.in_size = 0;
+        buffers.out_pos = 0;
+
+        printk(KERN_INFO DEVICE_NAME ": opened\n");
+        return 0;
+}
+
+static int xz_dec_test_release(struct inode *i, struct file *f)
+{
+        device_is_open = false;
+
+        if (ret == XZ_OK)
+                printk(KERN_INFO DEVICE_NAME ": input was truncated\n");
+
+        printk(KERN_INFO DEVICE_NAME ": closed\n");
+        return 0;
+}
+
+/*
+ * Decode the data given to us from the userspace. CRC32 of the uncompressed
+ * data is calculated and is printed at the end of successful decoding. The
+ * uncompressed data isn't stored anywhere for further use.
+ *
+ * The .xz file must have exactly one Stream and no Stream Padding. The data
+ * after the first Stream is considered to be garbage.
+ */
+static ssize_t xz_dec_test_write(struct file *file, const char __user *buf,
+                                 size_t size, loff_t *pos)
+{
+        size_t remaining;
+
+        if (ret != XZ_OK) {
+                if (size > 0)
+                        printk(KERN_INFO DEVICE_NAME ": %zu bytes of "
+                                        "garbage at the end of the file\n",
+                                        size);
+
+                return -ENOSPC;
+        }
+
+        printk(KERN_INFO DEVICE_NAME ": decoding %zu bytes of input\n",
+                        size);
+
+        remaining = size;
+        while ((remaining > 0 || buffers.out_pos == buffers.out_size)
+                        && ret == XZ_OK) {
+                if (buffers.in_pos == buffers.in_size) {
+                        buffers.in_pos = 0;
+                        buffers.in_size = min(remaining, sizeof(buffer_in));
+                        if (copy_from_user(buffer_in, buf, buffers.in_size))
+                                return -EFAULT;
+
+                        buf += buffers.in_size;
+                        remaining -= buffers.in_size;
+                }
+
+                buffers.out_pos = 0;
+                ret = xz_dec_run(state, &buffers);
+                crc = crc32(crc, buffer_out, buffers.out_pos);
+        }
+
+        switch (ret) {
+        case XZ_OK:
+                printk(KERN_INFO DEVICE_NAME ": XZ_OK\n");
+                return size;
+
+        case XZ_STREAM_END:
+                printk(KERN_INFO DEVICE_NAME ": XZ_STREAM_END, "
+                                "CRC32 = 0x%08X\n", ~crc);
+                return size - remaining - (buffers.in_size - buffers.in_pos);
+
+        case XZ_MEMLIMIT_ERROR:
+                printk(KERN_INFO DEVICE_NAME ": XZ_MEMLIMIT_ERROR\n");
+                break;
+
+        case XZ_FORMAT_ERROR:
+                printk(KERN_INFO DEVICE_NAME ": XZ_FORMAT_ERROR\n");
+                break;
+
+        case XZ_OPTIONS_ERROR:
+                printk(KERN_INFO DEVICE_NAME ": XZ_OPTIONS_ERROR\n");
+                break;
+
+        case XZ_DATA_ERROR:
+                printk(KERN_INFO DEVICE_NAME ": XZ_DATA_ERROR\n");
+                break;
+
+        case XZ_BUF_ERROR:
+                printk(KERN_INFO DEVICE_NAME ": XZ_BUF_ERROR\n");
+                break;
+
+        default:
+                printk(KERN_INFO DEVICE_NAME ": Bug detected!\n");
+                break;
+        }
+
+        return -EIO;
+}
+
+/* Allocate the XZ decoder state and register the character device. */
+static int __init xz_dec_test_init(void)
+{
+        static const struct file_operations fileops = {
+                .owner = THIS_MODULE,
+                .open = &xz_dec_test_open,
+                .release = &xz_dec_test_release,
+                .write = &xz_dec_test_write
+        };
+
+        state = xz_dec_init(XZ_PREALLOC, DICT_MAX);
+        if (state == NULL)
+                return -ENOMEM;
+
+        device_major = register_chrdev(0, DEVICE_NAME, &fileops);
+        if (device_major < 0) {
+                xz_dec_end(state);
+                return device_major;
+        }
+
+        printk(KERN_INFO DEVICE_NAME ": module loaded\n");
+        printk(KERN_INFO DEVICE_NAME ": Create a device node with "
+                        "'mknod " DEVICE_NAME " c %d 0' and write .xz files "
+                        "to it.\n", device_major);
+        return 0;
+}
+
+static void __exit xz_dec_test_exit(void)
+{
+        unregister_chrdev(device_major, DEVICE_NAME);
+        xz_dec_end(state);
+        printk(KERN_INFO DEVICE_NAME ": module unloaded\n");
+}
+
+module_init(xz_dec_test_init);
+module_exit(xz_dec_test_exit);
+
+MODULE_DESCRIPTION("XZ decompressor tester");
+MODULE_VERSION("1.0");
+MODULE_AUTHOR("Lasse Collin <lasse.collin@tukaani.org>");
+
+/*
+ * This code is in the public domain, but in Linux it's simplest to just
+ * say it's GPL and consider the authors as the copyright holders.
+ */
+MODULE_LICENSE("GPL");
diff --git a/lib/xz/xz_lzma2.h b/lib/xz/xz_lzma2.h
new file mode 100644
index 000000000000..071d67bee9f5
--- /dev/null
+++ b/lib/xz/xz_lzma2.h
@@ -0,0 +1,204 @@
+/*
+ * LZMA2 definitions
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.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.
+ */
+
+#ifndef XZ_LZMA2_H
+#define XZ_LZMA2_H
+
+/* Range coder constants */
+#define RC_SHIFT_BITS 8
+#define RC_TOP_BITS 24
+#define RC_TOP_VALUE (1 << RC_TOP_BITS)
+#define RC_BIT_MODEL_TOTAL_BITS 11
+#define RC_BIT_MODEL_TOTAL (1 << RC_BIT_MODEL_TOTAL_BITS)
+#define RC_MOVE_BITS 5
+
+/*
+ * Maximum number of position states. A position state is the lowest pb
+ * number of bits of the current uncompressed offset. In some places there
+ * are different sets of probabilities for different position states.
+ */
+#define POS_STATES_MAX (1 << 4)
+
+/*
+ * This enum is used to track which LZMA symbols have occurred most recently
+ * and in which order. This information is used to predict the next symbol.
+ *
+ * Symbols:
+ *  - Literal: One 8-bit byte
+ *  - Match: Repeat a chunk of data at some distance
+ *  - Long repeat: Multi-byte match at a recently seen distance
+ *  - Short repeat: One-byte repeat at a recently seen distance
+ *
+ * The symbol names are in from STATE_oldest_older_previous. REP means
+ * either short or long repeated match, and NONLIT means any non-literal.
+ */
+enum lzma_state {
+        STATE_LIT_LIT,
+        STATE_MATCH_LIT_LIT,
+        STATE_REP_LIT_LIT,
+        STATE_SHORTREP_LIT_LIT,
+        STATE_MATCH_LIT,
+        STATE_REP_LIT,
+        STATE_SHORTREP_LIT,
+        STATE_LIT_MATCH,
+        STATE_LIT_LONGREP,
+        STATE_LIT_SHORTREP,
+        STATE_NONLIT_MATCH,
+        STATE_NONLIT_REP
+};
+
+/* Total number of states */
+#define STATES 12
+
+/* The lowest 7 states indicate that the previous state was a literal. */
+#define LIT_STATES 7
+
+/* Indicate that the latest symbol was a literal. */
+static inline void lzma_state_literal(enum lzma_state *state)
+{
+        if (*state <= STATE_SHORTREP_LIT_LIT)
+                *state = STATE_LIT_LIT;
+        else if (*state <= STATE_LIT_SHORTREP)
+                *state -= 3;
+        else
+                *state -= 6;
+}
+
+/* Indicate that the latest symbol was a match. */
+static inline void lzma_state_match(enum lzma_state *state)
+{
+        *state = *state < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH;
+}
+
+/* Indicate that the latest state was a long repeated match. */
+static inline void lzma_state_long_rep(enum lzma_state *state)
+{
+        *state = *state < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP;
+}
+
+/* Indicate that the latest symbol was a short match. */
+static inline void lzma_state_short_rep(enum lzma_state *state)
+{
+        *state = *state < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP;
+}
+
+/* Test if the previous symbol was a literal. */
+static inline bool lzma_state_is_literal(enum lzma_state state)
+{
+        return state < LIT_STATES;
+}
+
+/* Each literal coder is divided in three sections:
+ *   - 0x001-0x0FF: Without match byte
+ *   - 0x101-0x1FF: With match byte; match bit is 0
+ *   - 0x201-0x2FF: With match byte; match bit is 1
+ *
+ * Match byte is used when the previous LZMA symbol was something else than
+ * a literal (that is, it was some kind of match).
+ */
+#define LITERAL_CODER_SIZE 0x300
+
+/* Maximum number of literal coders */
+#define LITERAL_CODERS_MAX (1 << 4)
+
+/* Minimum length of a match is two bytes. */
+#define MATCH_LEN_MIN 2
+
+/* Match length is encoded with 4, 5, or 10 bits.
+ *
+ * Length   Bits
+ *  2-9      4 = Choice=0 + 3 bits
+ * 10-17     5 = Choice=1 + Choice2=0 + 3 bits
+ * 18-273   10 = Choice=1 + Choice2=1 + 8 bits
+ */
+#define LEN_LOW_BITS 3
+#define LEN_LOW_SYMBOLS (1 << LEN_LOW_BITS)
+#define LEN_MID_BITS 3
+#define LEN_MID_SYMBOLS (1 << LEN_MID_BITS)
+#define LEN_HIGH_BITS 8
+#define LEN_HIGH_SYMBOLS (1 << LEN_HIGH_BITS)
+#define LEN_SYMBOLS (LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS + LEN_HIGH_SYMBOLS)
+
+/*
+ * Maximum length of a match is 273 which is a result of the encoding
+ * described above.
+ */
+#define MATCH_LEN_MAX (MATCH_LEN_MIN + LEN_SYMBOLS - 1)
+
+/*
+ * Different sets of probabilities are used for match distances that have
+ * very short match length: Lengths of 2, 3, and 4 bytes have a separate
+ * set of probabilities for each length. The matches with longer length
+ * use a shared set of probabilities.
+ */
+#define DIST_STATES 4
+
+/*
+ * Get the index of the appropriate probability array for decoding
+ * the distance slot.
+ */
+static inline uint32_t lzma_get_dist_state(uint32_t len)
+{
+        return len < DIST_STATES + MATCH_LEN_MIN
+                        ? len - MATCH_LEN_MIN : DIST_STATES - 1;
+}
+
+/*
+ * The highest two bits of a 32-bit match distance are encoded using six bits.
+ * This six-bit value is called a distance slot. This way encoding a 32-bit
+ * value takes 6-36 bits, larger values taking more bits.
+ */
+#define DIST_SLOT_BITS 6
+#define DIST_SLOTS (1 << DIST_SLOT_BITS)
+
+/* Match distances up to 127 are fully encoded using probabilities. Since
+ * the highest two bits (distance slot) are always encoded using six bits,
+ * the distances 0-3 don't need any additional bits to encode, since the
+ * distance slot itself is the same as the actual distance. DIST_MODEL_START
+ * indicates the first distance slot where at least one additional bit is
+ * needed.
+ */
+#define DIST_MODEL_START 4
+
+/*
+ * Match distances greater than 127 are encoded in three pieces:
+ *   - distance slot: the highest two bits
+ *   - direct bits: 2-26 bits below the highest two bits
+ *   - alignment bits: four lowest bits
+ *
+ * Direct bits don't use any probabilities.
+ *
+ * The distance slot value of 14 is for distances 128-191.
+ */
+#define DIST_MODEL_END 14
+
+/* Distance slots that indicate a distance <= 127. */
+#define FULL_DISTANCES_BITS (DIST_MODEL_END / 2)
+#define FULL_DISTANCES (1 << FULL_DISTANCES_BITS)
+
+/*
+ * For match distances greater than 127, only the highest two bits and the
+ * lowest four bits (alignment) is encoded using probabilities.
+ */
+#define ALIGN_BITS 4
+#define ALIGN_SIZE (1 << ALIGN_BITS)
+#define ALIGN_MASK (ALIGN_SIZE - 1)
+
+/* Total number of all probability variables */
+#define PROBS_TOTAL (1846 + LITERAL_CODERS_MAX * LITERAL_CODER_SIZE)
+
+/*
+ * LZMA remembers the four most recent match distances. Reusing these
+ * distances tends to take less space than re-encoding the actual
+ * distance value.
+ */
+#define REPS 4
+
+#endif
diff --git a/lib/xz/xz_private.h b/lib/xz/xz_private.h
new file mode 100644
index 000000000000..a65633e06962
--- /dev/null
+++ b/lib/xz/xz_private.h
@@ -0,0 +1,156 @@
+/*
+ * Private includes and definitions
+ *
+ * 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.
+ */
+
+#ifndef XZ_PRIVATE_H
+#define XZ_PRIVATE_H
+
+#ifdef __KERNEL__
+#       include <linux/xz.h>
+#       include <asm/byteorder.h>
+#       include <asm/unaligned.h>
+        /* XZ_PREBOOT may be defined only via decompress_unxz.c. */
+#       ifndef XZ_PREBOOT
+#               include <linux/slab.h>
+#               include <linux/vmalloc.h>
+#               include <linux/string.h>
+#               ifdef CONFIG_XZ_DEC_X86
+#                       define XZ_DEC_X86
+#               endif
+#               ifdef CONFIG_XZ_DEC_POWERPC
+#                       define XZ_DEC_POWERPC
+#               endif
+#               ifdef CONFIG_XZ_DEC_IA64
+#                       define XZ_DEC_IA64
+#               endif
+#               ifdef CONFIG_XZ_DEC_ARM
+#                       define XZ_DEC_ARM
+#               endif
+#               ifdef CONFIG_XZ_DEC_ARMTHUMB
+#                       define XZ_DEC_ARMTHUMB
+#               endif
+#               ifdef CONFIG_XZ_DEC_SPARC
+#                       define XZ_DEC_SPARC
+#               endif
+#               define memeq(a, b, size) (memcmp(a, b, size) == 0)
+#               define memzero(buf, size) memset(buf, 0, size)
+#       endif
+#       define get_le32(p) le32_to_cpup((const uint32_t *)(p))
+#else
+        /*
+         * For userspace builds, use a separate header to define the required
+         * macros and functions. This makes it easier to adapt the code into
+         * different environments and avoids clutter in the Linux kernel tree.
+         */
+#       include "xz_config.h"
+#endif
+
+/* If no specific decoding mode is requested, enable support for all modes. */
+#if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
+                && !defined(XZ_DEC_DYNALLOC)
+#       define XZ_DEC_SINGLE
+#       define XZ_DEC_PREALLOC
+#       define XZ_DEC_DYNALLOC
+#endif
+
+/*
+ * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
+ * of the supported modes are enabled, these macros will evaluate to true or
+ * false at compile time and thus allow the compiler to omit unneeded code.
+ */
+#ifdef XZ_DEC_SINGLE
+#       define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
+#else
+#       define DEC_IS_SINGLE(mode) (false)
+#endif
+
+#ifdef XZ_DEC_PREALLOC
+#       define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
+#else
+#       define DEC_IS_PREALLOC(mode) (false)
+#endif
+
+#ifdef XZ_DEC_DYNALLOC
+#       define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
+#else
+#       define DEC_IS_DYNALLOC(mode) (false)
+#endif
+
+#if !defined(XZ_DEC_SINGLE)
+#       define DEC_IS_MULTI(mode) (true)
+#elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
+#       define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
+#else
+#       define DEC_IS_MULTI(mode) (false)
+#endif
+
+/*
+ * If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
+ * XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
+ */
+#ifndef XZ_DEC_BCJ
+#       if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
+                        || defined(XZ_DEC_IA64) || defined(XZ_DEC_ARM) \
+                        || defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
+                        || defined(XZ_DEC_SPARC)
+#               define XZ_DEC_BCJ
+#       endif
+#endif
+
+/*
+ * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
+ * before calling xz_dec_lzma2_run().
+ */
+XZ_EXTERN struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode,
+                                                   uint32_t dict_max);
+
+/*
+ * Decode the LZMA2 properties (one byte) and reset the decoder. Return
+ * XZ_OK on success, XZ_MEMLIMIT_ERROR if the preallocated dictionary is not
+ * big enough, and XZ_OPTIONS_ERROR if props indicates something that this
+ * decoder doesn't support.
+ */
+XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s,
+                                         uint8_t props);
+
+/* Decode raw LZMA2 stream from b->in to b->out. */
+XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
+                                       struct xz_buf *b);
+
+/* Free the memory allocated for the LZMA2 decoder. */
+XZ_EXTERN void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
+
+#ifdef XZ_DEC_BCJ
+/*
+ * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
+ * calling xz_dec_bcj_run().
+ */
+XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
+
+/*
+ * Decode the Filter ID of a BCJ filter. This implementation doesn't
+ * support custom start offsets, so no decoding of Filter Properties
+ * is needed. Returns XZ_OK if the given Filter ID is supported.
+ * Otherwise XZ_OPTIONS_ERROR is returned.
+ */
+XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
+
+/*
+ * Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
+ * a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
+ * must be called directly.
+ */
+XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
+                                     struct xz_dec_lzma2 *lzma2,
+                                     struct xz_buf *b);
+
+/* Free the memory allocated for the BCJ filters. */
+#define xz_dec_bcj_end(s) kfree(s)
+#endif
+
+#endif
diff --git a/lib/xz/xz_stream.h b/lib/xz/xz_stream.h
new file mode 100644
index 000000000000..66cb5a7055ec
--- /dev/null
+++ b/lib/xz/xz_stream.h
@@ -0,0 +1,62 @@
+/*
+ * Definitions for handling the .xz file format
+ *
+ * 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.
+ */
+
+#ifndef XZ_STREAM_H
+#define XZ_STREAM_H
+
+#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
+#       include <linux/crc32.h>
+#       undef crc32
+#       define xz_crc32(buf, size, crc) \
+                (~crc32_le(~(uint32_t)(crc), buf, size))
+#endif
+
+/*
+ * See the .xz file format specification at
+ * http://tukaani.org/xz/xz-file-format.txt
+ * to understand the container format.
+ */
+
+#define STREAM_HEADER_SIZE 12
+
+#define HEADER_MAGIC "\3757zXZ"
+#define HEADER_MAGIC_SIZE 6
+
+#define FOOTER_MAGIC "YZ"
+#define FOOTER_MAGIC_SIZE 2
+
+/*
+ * Variable-length integer can hold a 63-bit unsigned integer or a special
+ * value indicating that the value is unknown.
+ *
+ * Experimental: vli_type can be defined to uint32_t to save a few bytes
+ * in code size (no effect on speed). Doing so limits the uncompressed and
+ * compressed size of the file to less than 256 MiB and may also weaken
+ * error detection slightly.
+ */
+typedef uint64_t vli_type;
+
+#define VLI_MAX ((vli_type)-1 / 2)
+#define VLI_UNKNOWN ((vli_type)-1)
+
+/* Maximum encoded size of a VLI */
+#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
+
+/* Integrity Check types */
+enum xz_check {
+        XZ_CHECK_NONE = 0,
+        XZ_CHECK_CRC32 = 1,
+        XZ_CHECK_CRC64 = 4,
+        XZ_CHECK_SHA256 = 10
+};
+
+/* Maximum possible Check ID */
+#define XZ_CHECK_MAX 15
+
+#endif