Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 670 insertions, 0 deletions

diff --git a/fs/ntfs3/lib/lzx_decompress.c b/fs/ntfs3/lib/lzx_decompress.c
new file mode 100644
index 000000000..6b16f0707
--- /dev/null
+++ b/fs/ntfs3/lib/lzx_decompress.c
@@ -0,0 +1,670 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * lzx_decompress.c - A decompressor for the LZX compression format, which can
+ * be used in "System Compressed" files.  This is based on the code from wimlib.
+ * This code only supports a window size (dictionary size) of 32768 bytes, since
+ * this is the only size used in System Compression.
+ *
+ * Copyright (C) 2015 Eric Biggers
+ */
+
+#include "decompress_common.h"
+#include "lib.h"
+
+/* Number of literal byte values  */
+#define LZX_NUM_CHARS			256
+
+/* The smallest and largest allowed match lengths  */
+#define LZX_MIN_MATCH_LEN		2
+#define LZX_MAX_MATCH_LEN		257
+
+/* Number of distinct match lengths that can be represented  */
+#define LZX_NUM_LENS			(LZX_MAX_MATCH_LEN - LZX_MIN_MATCH_LEN + 1)
+
+/* Number of match lengths for which no length symbol is required  */
+#define LZX_NUM_PRIMARY_LENS		7
+#define LZX_NUM_LEN_HEADERS		(LZX_NUM_PRIMARY_LENS + 1)
+
+/* Valid values of the 3-bit block type field  */
+#define LZX_BLOCKTYPE_VERBATIM		1
+#define LZX_BLOCKTYPE_ALIGNED		2
+#define LZX_BLOCKTYPE_UNCOMPRESSED	3
+
+/* Number of offset slots for a window size of 32768  */
+#define LZX_NUM_OFFSET_SLOTS		30
+
+/* Number of symbols in the main code for a window size of 32768  */
+#define LZX_MAINCODE_NUM_SYMBOLS	\
+	(LZX_NUM_CHARS + (LZX_NUM_OFFSET_SLOTS * LZX_NUM_LEN_HEADERS))
+
+/* Number of symbols in the length code  */
+#define LZX_LENCODE_NUM_SYMBOLS		(LZX_NUM_LENS - LZX_NUM_PRIMARY_LENS)
+
+/* Number of symbols in the precode  */
+#define LZX_PRECODE_NUM_SYMBOLS		20
+
+/* Number of bits in which each precode codeword length is represented  */
+#define LZX_PRECODE_ELEMENT_SIZE	4
+
+/* Number of low-order bits of each match offset that are entropy-encoded in
+ * aligned offset blocks
+ */
+#define LZX_NUM_ALIGNED_OFFSET_BITS	3
+
+/* Number of symbols in the aligned offset code  */
+#define LZX_ALIGNEDCODE_NUM_SYMBOLS	(1 << LZX_NUM_ALIGNED_OFFSET_BITS)
+
+/* Mask for the match offset bits that are entropy-encoded in aligned offset
+ * blocks
+ */
+#define LZX_ALIGNED_OFFSET_BITMASK	((1 << LZX_NUM_ALIGNED_OFFSET_BITS) - 1)
+
+/* Number of bits in which each aligned offset codeword length is represented  */
+#define LZX_ALIGNEDCODE_ELEMENT_SIZE	3
+
+/* Maximum lengths (in bits) of the codewords in each Huffman code  */
+#define LZX_MAX_MAIN_CODEWORD_LEN	16
+#define LZX_MAX_LEN_CODEWORD_LEN	16
+#define LZX_MAX_PRE_CODEWORD_LEN	((1 << LZX_PRECODE_ELEMENT_SIZE) - 1)
+#define LZX_MAX_ALIGNED_CODEWORD_LEN	((1 << LZX_ALIGNEDCODE_ELEMENT_SIZE) - 1)
+
+/* The default "filesize" value used in pre/post-processing.  In the LZX format
+ * used in cabinet files this value must be given to the decompressor, whereas
+ * in the LZX format used in WIM files and system-compressed files this value is
+ * fixed at 12000000.
+ */
+#define LZX_DEFAULT_FILESIZE		12000000
+
+/* Assumed block size when the encoded block size begins with a 0 bit.  */
+#define LZX_DEFAULT_BLOCK_SIZE		32768
+
+/* Number of offsets in the recent (or "repeat") offsets queue.  */
+#define LZX_NUM_RECENT_OFFSETS		3
+
+/* These values are chosen for fast decompression.  */
+#define LZX_MAINCODE_TABLEBITS		11
+#define LZX_LENCODE_TABLEBITS		10
+#define LZX_PRECODE_TABLEBITS		6
+#define LZX_ALIGNEDCODE_TABLEBITS	7
+
+#define LZX_READ_LENS_MAX_OVERRUN	50
+
+/* Mapping: offset slot => first match offset that uses that offset slot.
+ */
+static const u32 lzx_offset_slot_base[LZX_NUM_OFFSET_SLOTS + 1] = {
+	0,	1,	2,	3,	4,	/* 0  --- 4  */
+	6,	8,	12,	16,	24,	/* 5  --- 9  */
+	32,	48,	64,	96,	128,	/* 10 --- 14 */
+	192,	256,	384,	512,	768,	/* 15 --- 19 */
+	1024,	1536,	2048,	3072,	4096,   /* 20 --- 24 */
+	6144,	8192,	12288,	16384,	24576,	/* 25 --- 29 */
+	32768,					/* extra     */
+};
+
+/* Mapping: offset slot => how many extra bits must be read and added to the
+ * corresponding offset slot base to decode the match offset.
+ */
+static const u8 lzx_extra_offset_bits[LZX_NUM_OFFSET_SLOTS] = {
+	0,	0,	0,	0,	1,
+	1,	2,	2,	3,	3,
+	4,	4,	5,	5,	6,
+	6,	7,	7,	8,	8,
+	9,	9,	10,	10,	11,
+	11,	12,	12,	13,	13,
+};
+
+/* Reusable heap-allocated memory for LZX decompression  */
+struct lzx_decompressor {
+
+	/* Huffman decoding tables, and arrays that map symbols to codeword
+	 * lengths
+	 */
+
+	u16 maincode_decode_table[(1 << LZX_MAINCODE_TABLEBITS) +
+					(LZX_MAINCODE_NUM_SYMBOLS * 2)];
+	u8 maincode_lens[LZX_MAINCODE_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN];
+
+
+	u16 lencode_decode_table[(1 << LZX_LENCODE_TABLEBITS) +
+					(LZX_LENCODE_NUM_SYMBOLS * 2)];
+	u8 lencode_lens[LZX_LENCODE_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN];
+
+
+	u16 alignedcode_decode_table[(1 << LZX_ALIGNEDCODE_TABLEBITS) +
+					(LZX_ALIGNEDCODE_NUM_SYMBOLS * 2)];
+	u8 alignedcode_lens[LZX_ALIGNEDCODE_NUM_SYMBOLS];
+
+	u16 precode_decode_table[(1 << LZX_PRECODE_TABLEBITS) +
+				 (LZX_PRECODE_NUM_SYMBOLS * 2)];
+	u8 precode_lens[LZX_PRECODE_NUM_SYMBOLS];
+
+	/* Temporary space for make_huffman_decode_table()  */
+	u16 working_space[2 * (1 + LZX_MAX_MAIN_CODEWORD_LEN) +
+			  LZX_MAINCODE_NUM_SYMBOLS];
+};
+
+static void undo_e8_translation(void *target, s32 input_pos)
+{
+	s32 abs_offset, rel_offset;
+
+	abs_offset = get_unaligned_le32(target);
+	if (abs_offset >= 0) {
+		if (abs_offset < LZX_DEFAULT_FILESIZE) {
+			/* "good translation" */
+			rel_offset = abs_offset - input_pos;
+			put_unaligned_le32(rel_offset, target);
+		}
+	} else {
+		if (abs_offset >= -input_pos) {
+			/* "compensating translation" */
+			rel_offset = abs_offset + LZX_DEFAULT_FILESIZE;
+			put_unaligned_le32(rel_offset, target);
+		}
+	}
+}
+
+/*
+ * Undo the 'E8' preprocessing used in LZX.  Before compression, the
+ * uncompressed data was preprocessed by changing the targets of suspected x86
+ * CALL instructions from relative offsets to absolute offsets.  After
+ * match/literal decoding, the decompressor must undo the translation.
+ */
+static void lzx_postprocess(u8 *data, u32 size)
+{
+	/*
+	 * A worthwhile optimization is to push the end-of-buffer check into the
+	 * relatively rare E8 case.  This is possible if we replace the last six
+	 * bytes of data with E8 bytes; then we are guaranteed to hit an E8 byte
+	 * before reaching end-of-buffer.  In addition, this scheme guarantees
+	 * that no translation can begin following an E8 byte in the last 10
+	 * bytes because a 4-byte offset containing E8 as its high byte is a
+	 * large negative number that is not valid for translation.  That is
+	 * exactly what we need.
+	 */
+	u8 *tail;
+	u8 saved_bytes[6];
+	u8 *p;
+
+	if (size <= 10)
+		return;
+
+	tail = &data[size - 6];
+	memcpy(saved_bytes, tail, 6);
+	memset(tail, 0xE8, 6);
+	p = data;
+	for (;;) {
+		while (*p != 0xE8)
+			p++;
+		if (p >= tail)
+			break;
+		undo_e8_translation(p + 1, p - data);
+		p += 5;
+	}
+	memcpy(tail, saved_bytes, 6);
+}
+
+/* Read a Huffman-encoded symbol using the precode.  */
+static forceinline u32 read_presym(const struct lzx_decompressor *d,
+					struct input_bitstream *is)
+{
+	return read_huffsym(is, d->precode_decode_table,
+			    LZX_PRECODE_TABLEBITS, LZX_MAX_PRE_CODEWORD_LEN);
+}
+
+/* Read a Huffman-encoded symbol using the main code.  */
+static forceinline u32 read_mainsym(const struct lzx_decompressor *d,
+					 struct input_bitstream *is)
+{
+	return read_huffsym(is, d->maincode_decode_table,
+			    LZX_MAINCODE_TABLEBITS, LZX_MAX_MAIN_CODEWORD_LEN);
+}
+
+/* Read a Huffman-encoded symbol using the length code.  */
+static forceinline u32 read_lensym(const struct lzx_decompressor *d,
+					struct input_bitstream *is)
+{
+	return read_huffsym(is, d->lencode_decode_table,
+			    LZX_LENCODE_TABLEBITS, LZX_MAX_LEN_CODEWORD_LEN);
+}
+
+/* Read a Huffman-encoded symbol using the aligned offset code.  */
+static forceinline u32 read_alignedsym(const struct lzx_decompressor *d,
+					    struct input_bitstream *is)
+{
+	return read_huffsym(is, d->alignedcode_decode_table,
+			    LZX_ALIGNEDCODE_TABLEBITS,
+			    LZX_MAX_ALIGNED_CODEWORD_LEN);
+}
+
+/*
+ * Read the precode from the compressed input bitstream, then use it to decode
+ * @num_lens codeword length values.
+ *
+ * @is:		The input bitstream.
+ *
+ * @lens:	An array that contains the length values from the previous time
+ *		the codeword lengths for this Huffman code were read, or all 0's
+ *		if this is the first time.  This array must have at least
+ *		(@num_lens + LZX_READ_LENS_MAX_OVERRUN) entries.
+ *
+ * @num_lens:	Number of length values to decode.
+ *
+ * Returns 0 on success, or -1 if the data was invalid.
+ */
+static int lzx_read_codeword_lens(struct lzx_decompressor *d,
+				  struct input_bitstream *is,
+				  u8 *lens, u32 num_lens)
+{
+	u8 *len_ptr = lens;
+	u8 *lens_end = lens + num_lens;
+	int i;
+
+	/* Read the lengths of the precode codewords.  These are given
+	 * explicitly.
+	 */
+	for (i = 0; i < LZX_PRECODE_NUM_SYMBOLS; i++) {
+		d->precode_lens[i] =
+			bitstream_read_bits(is, LZX_PRECODE_ELEMENT_SIZE);
+	}
+
+	/* Make the decoding table for the precode.  */
+	if (make_huffman_decode_table(d->precode_decode_table,
+				      LZX_PRECODE_NUM_SYMBOLS,
+				      LZX_PRECODE_TABLEBITS,
+				      d->precode_lens,
+				      LZX_MAX_PRE_CODEWORD_LEN,
+				      d->working_space))
+		return -1;
+
+	/* Decode the codeword lengths.  */
+	do {
+		u32 presym;
+		u8 len;
+
+		/* Read the next precode symbol.  */
+		presym = read_presym(d, is);
+		if (presym < 17) {
+			/* Difference from old length  */
+			len = *len_ptr - presym;
+			if ((s8)len < 0)
+				len += 17;
+			*len_ptr++ = len;
+		} else {
+			/* Special RLE values  */
+
+			u32 run_len;
+
+			if (presym == 17) {
+				/* Run of 0's  */
+				run_len = 4 + bitstream_read_bits(is, 4);
+				len = 0;
+			} else if (presym == 18) {
+				/* Longer run of 0's  */
+				run_len = 20 + bitstream_read_bits(is, 5);
+				len = 0;
+			} else {
+				/* Run of identical lengths  */
+				run_len = 4 + bitstream_read_bits(is, 1);
+				presym = read_presym(d, is);
+				if (presym > 17)
+					return -1;
+				len = *len_ptr - presym;
+				if ((s8)len < 0)
+					len += 17;
+			}
+
+			do {
+				*len_ptr++ = len;
+			} while (--run_len);
+			/* Worst case overrun is when presym == 18,
+			 * run_len == 20 + 31, and only 1 length was remaining.
+			 * So LZX_READ_LENS_MAX_OVERRUN == 50.
+			 *
+			 * Overrun while reading the first half of maincode_lens
+			 * can corrupt the previous values in the second half.
+			 * This doesn't really matter because the resulting
+			 * lengths will still be in range, and data that
+			 * generates overruns is invalid anyway.
+			 */
+		}
+	} while (len_ptr < lens_end);
+
+	return 0;
+}
+
+/*
+ * Read the header of an LZX block and save the block type and (uncompressed)
+ * size in *block_type_ret and *block_size_ret, respectively.
+ *
+ * If the block is compressed, also update the Huffman decode @tables with the
+ * new Huffman codes.  If the block is uncompressed, also update the match
+ * offset @queue with the new match offsets.
+ *
+ * Return 0 on success, or -1 if the data was invalid.
+ */
+static int lzx_read_block_header(struct lzx_decompressor *d,
+				 struct input_bitstream *is,
+				 int *block_type_ret,
+				 u32 *block_size_ret,
+				 u32 recent_offsets[])
+{
+	int block_type;
+	u32 block_size;
+	int i;
+
+	bitstream_ensure_bits(is, 4);
+
+	/* The first three bits tell us what kind of block it is, and should be
+	 * one of the LZX_BLOCKTYPE_* values.
+	 */
+	block_type = bitstream_pop_bits(is, 3);
+
+	/* Read the block size.  */
+	if (bitstream_pop_bits(is, 1)) {
+		block_size = LZX_DEFAULT_BLOCK_SIZE;
+	} else {
+		block_size = 0;
+		block_size |= bitstream_read_bits(is, 8);
+		block_size <<= 8;
+		block_size |= bitstream_read_bits(is, 8);
+	}
+
+	switch (block_type) {
+
+	case LZX_BLOCKTYPE_ALIGNED:
+
+		/* Read the aligned offset code and prepare its decode table.
+		 */
+
+		for (i = 0; i < LZX_ALIGNEDCODE_NUM_SYMBOLS; i++) {
+			d->alignedcode_lens[i] =
+				bitstream_read_bits(is,
+						    LZX_ALIGNEDCODE_ELEMENT_SIZE);
+		}
+
+		if (make_huffman_decode_table(d->alignedcode_decode_table,
+					      LZX_ALIGNEDCODE_NUM_SYMBOLS,
+					      LZX_ALIGNEDCODE_TABLEBITS,
+					      d->alignedcode_lens,
+					      LZX_MAX_ALIGNED_CODEWORD_LEN,
+					      d->working_space))
+			return -1;
+
+		/* Fall though, since the rest of the header for aligned offset
+		 * blocks is the same as that for verbatim blocks.
+		 */
+		fallthrough;
+
+	case LZX_BLOCKTYPE_VERBATIM:
+
+		/* Read the main code and prepare its decode table.
+		 *
+		 * Note that the codeword lengths in the main code are encoded
+		 * in two parts: one part for literal symbols, and one part for
+		 * match symbols.
+		 */
+
+		if (lzx_read_codeword_lens(d, is, d->maincode_lens,
+					   LZX_NUM_CHARS))
+			return -1;
+
+		if (lzx_read_codeword_lens(d, is,
+					   d->maincode_lens + LZX_NUM_CHARS,
+					   LZX_MAINCODE_NUM_SYMBOLS - LZX_NUM_CHARS))
+			return -1;
+
+		if (make_huffman_decode_table(d->maincode_decode_table,
+					      LZX_MAINCODE_NUM_SYMBOLS,
+					      LZX_MAINCODE_TABLEBITS,
+					      d->maincode_lens,
+					      LZX_MAX_MAIN_CODEWORD_LEN,
+					      d->working_space))
+			return -1;
+
+		/* Read the length code and prepare its decode table.  */
+
+		if (lzx_read_codeword_lens(d, is, d->lencode_lens,
+					   LZX_LENCODE_NUM_SYMBOLS))
+			return -1;
+
+		if (make_huffman_decode_table(d->lencode_decode_table,
+					      LZX_LENCODE_NUM_SYMBOLS,
+					      LZX_LENCODE_TABLEBITS,
+					      d->lencode_lens,
+					      LZX_MAX_LEN_CODEWORD_LEN,
+					      d->working_space))
+			return -1;
+
+		break;
+
+	case LZX_BLOCKTYPE_UNCOMPRESSED:
+
+		/* Before reading the three recent offsets from the uncompressed
+		 * block header, the stream must be aligned on a 16-bit
+		 * boundary.  But if the stream is *already* aligned, then the
+		 * next 16 bits must be discarded.
+		 */
+		bitstream_ensure_bits(is, 1);
+		bitstream_align(is);
+
+		recent_offsets[0] = bitstream_read_u32(is);
+		recent_offsets[1] = bitstream_read_u32(is);
+		recent_offsets[2] = bitstream_read_u32(is);
+
+		/* Offsets of 0 are invalid.  */
+		if (recent_offsets[0] == 0 || recent_offsets[1] == 0 ||
+		    recent_offsets[2] == 0)
+			return -1;
+		break;
+
+	default:
+		/* Unrecognized block type.  */
+		return -1;
+	}
+
+	*block_type_ret = block_type;
+	*block_size_ret = block_size;
+	return 0;
+}
+
+/* Decompress a block of LZX-compressed data.  */
+static int lzx_decompress_block(const struct lzx_decompressor *d,
+				struct input_bitstream *is,
+				int block_type, u32 block_size,
+				u8 * const out_begin, u8 *out_next,
+				u32 recent_offsets[])
+{
+	u8 * const block_end = out_next + block_size;
+	u32 ones_if_aligned = 0U - (block_type == LZX_BLOCKTYPE_ALIGNED);
+
+	do {
+		u32 mainsym;
+		u32 match_len;
+		u32 match_offset;
+		u32 offset_slot;
+		u32 num_extra_bits;
+
+		mainsym = read_mainsym(d, is);
+		if (mainsym < LZX_NUM_CHARS) {
+			/* Literal  */
+			*out_next++ = mainsym;
+			continue;
+		}
+
+		/* Match  */
+
+		/* Decode the length header and offset slot.  */
+		mainsym -= LZX_NUM_CHARS;
+		match_len = mainsym % LZX_NUM_LEN_HEADERS;
+		offset_slot = mainsym / LZX_NUM_LEN_HEADERS;
+
+		/* If needed, read a length symbol to decode the full length. */
+		if (match_len == LZX_NUM_PRIMARY_LENS)
+			match_len += read_lensym(d, is);
+		match_len += LZX_MIN_MATCH_LEN;
+
+		if (offset_slot < LZX_NUM_RECENT_OFFSETS) {
+			/* Repeat offset  */
+
+			/* Note: This isn't a real LRU queue, since using the R2
+			 * offset doesn't bump the R1 offset down to R2.  This
+			 * quirk allows all 3 recent offsets to be handled by
+			 * the same code.  (For R0, the swap is a no-op.)
+			 */
+			match_offset = recent_offsets[offset_slot];
+			recent_offsets[offset_slot] = recent_offsets[0];
+			recent_offsets[0] = match_offset;
+		} else {
+			/* Explicit offset  */
+
+			/* Look up the number of extra bits that need to be read
+			 * to decode offsets with this offset slot.
+			 */
+			num_extra_bits = lzx_extra_offset_bits[offset_slot];
+
+			/* Start with the offset slot base value.  */
+			match_offset = lzx_offset_slot_base[offset_slot];
+
+			/* In aligned offset blocks, the low-order 3 bits of
+			 * each offset are encoded using the aligned offset
+			 * code.  Otherwise, all the extra bits are literal.
+			 */
+
+			if ((num_extra_bits & ones_if_aligned) >= LZX_NUM_ALIGNED_OFFSET_BITS) {
+				match_offset +=
+					bitstream_read_bits(is, num_extra_bits -
+								LZX_NUM_ALIGNED_OFFSET_BITS)
+							<< LZX_NUM_ALIGNED_OFFSET_BITS;
+				match_offset += read_alignedsym(d, is);
+			} else {
+				match_offset += bitstream_read_bits(is, num_extra_bits);
+			}
+
+			/* Adjust the offset.  */
+			match_offset -= (LZX_NUM_RECENT_OFFSETS - 1);
+
+			/* Update the recent offsets.  */
+			recent_offsets[2] = recent_offsets[1];
+			recent_offsets[1] = recent_offsets[0];
+			recent_offsets[0] = match_offset;
+		}
+
+		/* Validate the match, then copy it to the current position.  */
+
+		if (match_len > (size_t)(block_end - out_next))
+			return -1;
+
+		if (match_offset > (size_t)(out_next - out_begin))
+			return -1;
+
+		out_next = lz_copy(out_next, match_len, match_offset,
+				   block_end, LZX_MIN_MATCH_LEN);
+
+	} while (out_next != block_end);
+
+	return 0;
+}
+
+/*
+ * lzx_allocate_decompressor - Allocate an LZX decompressor
+ *
+ * Return the pointer to the decompressor on success, or return NULL and set
+ * errno on failure.
+ */
+struct lzx_decompressor *lzx_allocate_decompressor(void)
+{
+	return kmalloc(sizeof(struct lzx_decompressor), GFP_NOFS);
+}
+
+/*
+ * lzx_decompress - Decompress a buffer of LZX-compressed data
+ *
+ * @decompressor:      A decompressor allocated with lzx_allocate_decompressor()
+ * @compressed_data:	The buffer of data to decompress
+ * @compressed_size:	Number of bytes of compressed data
+ * @uncompressed_data:	The buffer in which to store the decompressed data
+ * @uncompressed_size:	The number of bytes the data decompresses into
+ *
+ * Return 0 on success, or return -1 and set errno on failure.
+ */
+int lzx_decompress(struct lzx_decompressor *decompressor,
+		   const void *compressed_data, size_t compressed_size,
+		   void *uncompressed_data, size_t uncompressed_size)
+{
+	struct lzx_decompressor *d = decompressor;
+	u8 * const out_begin = uncompressed_data;
+	u8 *out_next = out_begin;
+	u8 * const out_end = out_begin + uncompressed_size;
+	struct input_bitstream is;
+	u32 recent_offsets[LZX_NUM_RECENT_OFFSETS] = {1, 1, 1};
+	int e8_status = 0;
+
+	init_input_bitstream(&is, compressed_data, compressed_size);
+
+	/* Codeword lengths begin as all 0's for delta encoding purposes.  */
+	memset(d->maincode_lens, 0, LZX_MAINCODE_NUM_SYMBOLS);
+	memset(d->lencode_lens, 0, LZX_LENCODE_NUM_SYMBOLS);
+
+	/* Decompress blocks until we have all the uncompressed data.  */
+
+	while (out_next != out_end) {
+		int block_type;
+		u32 block_size;
+
+		if (lzx_read_block_header(d, &is, &block_type, &block_size,
+					  recent_offsets))
+			goto invalid;
+
+		if (block_size < 1 || block_size > (size_t)(out_end - out_next))
+			goto invalid;
+
+		if (block_type != LZX_BLOCKTYPE_UNCOMPRESSED) {
+
+			/* Compressed block  */
+
+			if (lzx_decompress_block(d,
+						 &is,
+						 block_type,
+						 block_size,
+						 out_begin,
+						 out_next,
+						 recent_offsets))
+				goto invalid;
+
+			e8_status |= d->maincode_lens[0xe8];
+			out_next += block_size;
+		} else {
+			/* Uncompressed block  */
+
+			out_next = bitstream_read_bytes(&is, out_next,
+							block_size);
+			if (!out_next)
+				goto invalid;
+
+			if (block_size & 1)
+				bitstream_read_byte(&is);
+
+			e8_status = 1;
+		}
+	}
+
+	/* Postprocess the data unless it cannot possibly contain 0xe8 bytes. */
+	if (e8_status)
+		lzx_postprocess(uncompressed_data, uncompressed_size);
+
+	return 0;
+
+invalid:
+	return -1;
+}
+
+/*
+ * lzx_free_decompressor - Free an LZX decompressor
+ *
+ * @decompressor:       A decompressor that was allocated with
+ *			lzx_allocate_decompressor(), or NULL.
+ */
+void lzx_free_decompressor(struct lzx_decompressor *decompressor)
+{
+	kfree(decompressor);
+}