aboutsummaryrefslogtreecommitdiff
path: root/fs/ntfs3/lib/decompress_common.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/ntfs3/lib/decompress_common.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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(). ...
Diffstat (limited to 'fs/ntfs3/lib/decompress_common.c')
-rw-r--r--fs/ntfs3/lib/decompress_common.c319
1 files changed, 319 insertions, 0 deletions
diff --git a/fs/ntfs3/lib/decompress_common.c b/fs/ntfs3/lib/decompress_common.c
new file mode 100644
index 000000000..e96652240
--- /dev/null
+++ b/fs/ntfs3/lib/decompress_common.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * decompress_common.c - Code shared by the XPRESS and LZX decompressors
+ *
+ * Copyright (C) 2015 Eric Biggers
+ */
+
+#include "decompress_common.h"
+
+/*
+ * make_huffman_decode_table() -
+ *
+ * Build a decoding table for a canonical prefix code, or "Huffman code".
+ *
+ * This is an internal function, not part of the library API!
+ *
+ * This takes as input the length of the codeword for each symbol in the
+ * alphabet and produces as output a table that can be used for fast
+ * decoding of prefix-encoded symbols using read_huffsym().
+ *
+ * Strictly speaking, a canonical prefix code might not be a Huffman
+ * code. But this algorithm will work either way; and in fact, since
+ * Huffman codes are defined in terms of symbol frequencies, there is no
+ * way for the decompressor to know whether the code is a true Huffman
+ * code or not until all symbols have been decoded.
+ *
+ * Because the prefix code is assumed to be "canonical", it can be
+ * reconstructed directly from the codeword lengths. A prefix code is
+ * canonical if and only if a longer codeword never lexicographically
+ * precedes a shorter codeword, and the lexicographic ordering of
+ * codewords of the same length is the same as the lexicographic ordering
+ * of the corresponding symbols. Consequently, we can sort the symbols
+ * primarily by codeword length and secondarily by symbol value, then
+ * reconstruct the prefix code by generating codewords lexicographically
+ * in that order.
+ *
+ * This function does not, however, generate the prefix code explicitly.
+ * Instead, it directly builds a table for decoding symbols using the
+ * code. The basic idea is this: given the next 'max_codeword_len' bits
+ * in the input, we can look up the decoded symbol by indexing a table
+ * containing 2**max_codeword_len entries. A codeword with length
+ * 'max_codeword_len' will have exactly one entry in this table, whereas
+ * a codeword shorter than 'max_codeword_len' will have multiple entries
+ * in this table. Precisely, a codeword of length n will be represented
+ * by 2**(max_codeword_len - n) entries in this table. The 0-based index
+ * of each such entry will contain the corresponding codeword as a prefix
+ * when zero-padded on the left to 'max_codeword_len' binary digits.
+ *
+ * That's the basic idea, but we implement two optimizations regarding
+ * the format of the decode table itself:
+ *
+ * - For many compression formats, the maximum codeword length is too
+ * long for it to be efficient to build the full decoding table
+ * whenever a new prefix code is used. Instead, we can build the table
+ * using only 2**table_bits entries, where 'table_bits' is some number
+ * less than or equal to 'max_codeword_len'. Then, only codewords of
+ * length 'table_bits' and shorter can be directly looked up. For
+ * longer codewords, the direct lookup instead produces the root of a
+ * binary tree. Using this tree, the decoder can do traditional
+ * bit-by-bit decoding of the remainder of the codeword. Child nodes
+ * are allocated in extra entries at the end of the table; leaf nodes
+ * contain symbols. Note that the long-codeword case is, in general,
+ * not performance critical, since in Huffman codes the most frequently
+ * used symbols are assigned the shortest codeword lengths.
+ *
+ * - When we decode a symbol using a direct lookup of the table, we still
+ * need to know its length so that the bitstream can be advanced by the
+ * appropriate number of bits. The simple solution is to simply retain
+ * the 'lens' array and use the decoded symbol as an index into it.
+ * However, this requires two separate array accesses in the fast path.
+ * The optimization is to store the length directly in the decode
+ * table. We use the bottom 11 bits for the symbol and the top 5 bits
+ * for the length. In addition, to combine this optimization with the
+ * previous one, we introduce a special case where the top 2 bits of
+ * the length are both set if the entry is actually the root of a
+ * binary tree.
+ *
+ * @decode_table:
+ * The array in which to create the decoding table. This must have
+ * a length of at least ((2**table_bits) + 2 * num_syms) entries.
+ *
+ * @num_syms:
+ * The number of symbols in the alphabet; also, the length of the
+ * 'lens' array. Must be less than or equal to 2048.
+ *
+ * @table_bits:
+ * The order of the decode table size, as explained above. Must be
+ * less than or equal to 13.
+ *
+ * @lens:
+ * An array of length @num_syms, indexable by symbol, that gives the
+ * length of the codeword, in bits, for that symbol. The length can
+ * be 0, which means that the symbol does not have a codeword
+ * assigned.
+ *
+ * @max_codeword_len:
+ * The longest codeword length allowed in the compression format.
+ * All entries in 'lens' must be less than or equal to this value.
+ * This must be less than or equal to 23.
+ *
+ * @working_space
+ * A temporary array of length '2 * (max_codeword_len + 1) +
+ * num_syms'.
+ *
+ * Returns 0 on success, or -1 if the lengths do not form a valid prefix
+ * code.
+ */
+int make_huffman_decode_table(u16 decode_table[], const u32 num_syms,
+ const u32 table_bits, const u8 lens[],
+ const u32 max_codeword_len,
+ u16 working_space[])
+{
+ const u32 table_num_entries = 1 << table_bits;
+ u16 * const len_counts = &working_space[0];
+ u16 * const offsets = &working_space[1 * (max_codeword_len + 1)];
+ u16 * const sorted_syms = &working_space[2 * (max_codeword_len + 1)];
+ int left;
+ void *decode_table_ptr;
+ u32 sym_idx;
+ u32 codeword_len;
+ u32 stores_per_loop;
+ u32 decode_table_pos;
+ u32 len;
+ u32 sym;
+
+ /* Count how many symbols have each possible codeword length.
+ * Note that a length of 0 indicates the corresponding symbol is not
+ * used in the code and therefore does not have a codeword.
+ */
+ for (len = 0; len <= max_codeword_len; len++)
+ len_counts[len] = 0;
+ for (sym = 0; sym < num_syms; sym++)
+ len_counts[lens[sym]]++;
+
+ /* We can assume all lengths are <= max_codeword_len, but we
+ * cannot assume they form a valid prefix code. A codeword of
+ * length n should require a proportion of the codespace equaling
+ * (1/2)^n. The code is valid if and only if the codespace is
+ * exactly filled by the lengths, by this measure.
+ */
+ left = 1;
+ for (len = 1; len <= max_codeword_len; len++) {
+ left <<= 1;
+ left -= len_counts[len];
+ if (left < 0) {
+ /* The lengths overflow the codespace; that is, the code
+ * is over-subscribed.
+ */
+ return -1;
+ }
+ }
+
+ if (left) {
+ /* The lengths do not fill the codespace; that is, they form an
+ * incomplete set.
+ */
+ if (left == (1 << max_codeword_len)) {
+ /* The code is completely empty. This is arguably
+ * invalid, but in fact it is valid in LZX and XPRESS,
+ * so we must allow it. By definition, no symbols can
+ * be decoded with an empty code. Consequently, we
+ * technically don't even need to fill in the decode
+ * table. However, to avoid accessing uninitialized
+ * memory if the algorithm nevertheless attempts to
+ * decode symbols using such a code, we zero out the
+ * decode table.
+ */
+ memset(decode_table, 0,
+ table_num_entries * sizeof(decode_table[0]));
+ return 0;
+ }
+ return -1;
+ }
+
+ /* Sort the symbols primarily by length and secondarily by symbol order.
+ */
+
+ /* Initialize 'offsets' so that offsets[len] for 1 <= len <=
+ * max_codeword_len is the number of codewords shorter than 'len' bits.
+ */
+ offsets[1] = 0;
+ for (len = 1; len < max_codeword_len; len++)
+ offsets[len + 1] = offsets[len] + len_counts[len];
+
+ /* Use the 'offsets' array to sort the symbols. Note that we do not
+ * include symbols that are not used in the code. Consequently, fewer
+ * than 'num_syms' entries in 'sorted_syms' may be filled.
+ */
+ for (sym = 0; sym < num_syms; sym++)
+ if (lens[sym])
+ sorted_syms[offsets[lens[sym]]++] = sym;
+
+ /* Fill entries for codewords with length <= table_bits
+ * --- that is, those short enough for a direct mapping.
+ *
+ * The table will start with entries for the shortest codeword(s), which
+ * have the most entries. From there, the number of entries per
+ * codeword will decrease.
+ */
+ decode_table_ptr = decode_table;
+ sym_idx = 0;
+ codeword_len = 1;
+ stores_per_loop = (1 << (table_bits - codeword_len));
+ for (; stores_per_loop != 0; codeword_len++, stores_per_loop >>= 1) {
+ u32 end_sym_idx = sym_idx + len_counts[codeword_len];
+
+ for (; sym_idx < end_sym_idx; sym_idx++) {
+ u16 entry;
+ u16 *p;
+ u32 n;
+
+ entry = ((u32)codeword_len << 11) | sorted_syms[sym_idx];
+ p = (u16 *)decode_table_ptr;
+ n = stores_per_loop;
+
+ do {
+ *p++ = entry;
+ } while (--n);
+
+ decode_table_ptr = p;
+ }
+ }
+
+ /* If we've filled in the entire table, we are done. Otherwise,
+ * there are codewords longer than table_bits for which we must
+ * generate binary trees.
+ */
+ decode_table_pos = (u16 *)decode_table_ptr - decode_table;
+ if (decode_table_pos != table_num_entries) {
+ u32 j;
+ u32 next_free_tree_slot;
+ u32 cur_codeword;
+
+ /* First, zero out the remaining entries. This is
+ * necessary so that these entries appear as
+ * "unallocated" in the next part. Each of these entries
+ * will eventually be filled with the representation of
+ * the root node of a binary tree.
+ */
+ j = decode_table_pos;
+ do {
+ decode_table[j] = 0;
+ } while (++j != table_num_entries);
+
+ /* We allocate child nodes starting at the end of the
+ * direct lookup table. Note that there should be
+ * 2*num_syms extra entries for this purpose, although
+ * fewer than this may actually be needed.
+ */
+ next_free_tree_slot = table_num_entries;
+
+ /* Iterate through each codeword with length greater than
+ * 'table_bits', primarily in order of codeword length
+ * and secondarily in order of symbol.
+ */
+ for (cur_codeword = decode_table_pos << 1;
+ codeword_len <= max_codeword_len;
+ codeword_len++, cur_codeword <<= 1) {
+ u32 end_sym_idx = sym_idx + len_counts[codeword_len];
+
+ for (; sym_idx < end_sym_idx; sym_idx++, cur_codeword++) {
+ /* 'sorted_sym' is the symbol represented by the
+ * codeword.
+ */
+ u32 sorted_sym = sorted_syms[sym_idx];
+ u32 extra_bits = codeword_len - table_bits;
+ u32 node_idx = cur_codeword >> extra_bits;
+
+ /* Go through each bit of the current codeword
+ * beyond the prefix of length @table_bits and
+ * walk the appropriate binary tree, allocating
+ * any slots that have not yet been allocated.
+ *
+ * Note that the 'pointer' entry to the binary
+ * tree, which is stored in the direct lookup
+ * portion of the table, is represented
+ * identically to other internal (non-leaf)
+ * nodes of the binary tree; it can be thought
+ * of as simply the root of the tree. The
+ * representation of these internal nodes is
+ * simply the index of the left child combined
+ * with the special bits 0xC000 to distinguish
+ * the entry from direct mapping and leaf node
+ * entries.
+ */
+ do {
+ /* At least one bit remains in the
+ * codeword, but the current node is an
+ * unallocated leaf. Change it to an
+ * internal node.
+ */
+ if (decode_table[node_idx] == 0) {
+ decode_table[node_idx] =
+ next_free_tree_slot | 0xC000;
+ decode_table[next_free_tree_slot++] = 0;
+ decode_table[next_free_tree_slot++] = 0;
+ }
+
+ /* Go to the left child if the next bit
+ * in the codeword is 0; otherwise go to
+ * the right child.
+ */
+ node_idx = decode_table[node_idx] & 0x3FFF;
+ --extra_bits;
+ node_idx += (cur_codeword >> extra_bits) & 1;
+ } while (extra_bits != 0);
+
+ /* We've traversed the tree using the entire
+ * codeword, and we're now at the entry where
+ * the actual symbol will be stored. This is
+ * distinguished from internal nodes by not
+ * having its high two bits set.
+ */
+ decode_table[node_idx] = sorted_sym;
+ }
+ }
+ }
+ return 0;
+}