# --- T2-COPYRIGHT-NOTE-BEGIN --- # This copyright note is auto-generated by scripts/Create-CopyPatch. # # T2 SDE: architecture/mips64/package/.../zstd.patch # Copyright (C) 2017 - 2020 The T2 SDE Project # # More information can be found in the files COPYING and README. # # This patch file is dual-licensed. It is available under the license the # patched project is licensed under, as long as it is an OpenSource license # as defined at http://www.opensource.org/ (e.g. BSD, X11) or 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. # --- T2-COPYRIGHT-NOTE-END --- Add support for extracting ZSTD-compressed kernel images, as well as ZSTD-compressed ramdisk images in the kernel boot process. When neither `fill' nor `flush' are used, the decompression function requires a constant amount of memory (192 KB is sufficient). When either is used the decompression function requires memory proportional to the window size used during compression, which is limited to 8 MB. The maximum memory usage is just over 8 MB. Fix up lib/zstd and lib/xxhash.c for the preboot environment. They avoid declaring themselves as modules. A memcpy() call needs to be a __builtin_memcpy() for performance. The gcc-7.1 bug in ZSTD_wildcopy() was fixed in gcc-7.2, so it can be gated, since it hurts performance. Signed-off-by: Nick Terrell --- v1 -> v2: - Fix performance bug in zstd decompression - Gate gcc bug workaround to buggy versions include/linux/decompress/unzstd.h | 26 +++ init/Kconfig | 14 +- lib/Kconfig | 4 + lib/Makefile | 1 + lib/decompress.c | 5 + lib/decompress_unzstd.c | 341 ++++++++++++++++++++++++++++++++++++++ lib/xxhash.c | 21 ++- lib/zstd/decompress.c | 2 + lib/zstd/fse_decompress.c | 9 +- lib/zstd/zstd_internal.h | 10 +- scripts/Makefile.lib | 15 ++ usr/Kconfig | 22 +++ 12 files changed, 451 insertions(+), 19 deletions(-) create mode 100644 include/linux/decompress/unzstd.h create mode 100644 lib/decompress_unzstd.c diff --git a/include/linux/decompress/unzstd.h b/include/linux/decompress/unzstd.h new file mode 100644 index 0000000..6f3022c --- /dev/null +++ b/include/linux/decompress/unzstd.h @@ -0,0 +1,26 @@ +/* + * Copyright (C) 2017 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * 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, see . + */ + +#ifndef LINUX_DECOMPRESS_UNZSTD_H +#define LINUX_DECOMPRESS_UNZSTD_H + +int unzstd(unsigned char *inbuf, long len, + long (*fill)(void*, unsigned long), + long (*flush)(void*, unsigned long), + unsigned char *output, + long *pos, + void (*error_fn)(char *x)); +#endif diff --git a/init/Kconfig b/init/Kconfig index e37f4b2..4dc2c30 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -127,10 +127,13 @@ config HAVE_KERNEL_LZO config HAVE_KERNEL_LZ4 bool +config HAVE_KERNEL_ZSTD + bool + choice prompt "Kernel compression mode" default KERNEL_GZIP - depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 + depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD help The linux kernel is a kind of self-extracting executable. Several compression algorithms are available, which differ @@ -209,6 +212,15 @@ config KERNEL_LZ4 is about 8% bigger than LZO. But the decompression speed is faster than LZO. +config KERNEL_ZSTD + bool "ZSTD" + depends on HAVE_KERNEL_ZSTD + help + ZSTD is a compression algorithm targeting intermediate compression + with fast decompression speed. It will compress better than GZIP and + decompress around the same speed as LZO, but slower than LZ4. You + will need at least 192 KB RAM or more for booting. + endchoice config DEFAULT_HOSTNAME diff --git a/lib/Kconfig b/lib/Kconfig index e960894..c98b633 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -281,6 +281,10 @@ config DECOMPRESS_LZ4 select LZ4_DECOMPRESS tristate +config DECOMPRESS_ZSTD + select ZSTD_DECOMPRESS + tristate + # # Generic allocator support is selected if needed # diff --git a/lib/Makefile b/lib/Makefile index a90d4fc..c65fd07 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -131,6 +131,7 @@ lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o lib-$(CONFIG_DECOMPRESS_XZ) += decompress_unxz.o lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o lib-$(CONFIG_DECOMPRESS_LZ4) += decompress_unlz4.o +lib-$(CONFIG_DECOMPRESS_ZSTD) += decompress_unzstd.o obj-$(CONFIG_TEXTSEARCH) += textsearch.o obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o diff --git a/lib/decompress.c b/lib/decompress.c index 857ab1a..ab3fc90 100644 --- a/lib/decompress.c +++ b/lib/decompress.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -37,6 +38,9 @@ #ifndef CONFIG_DECOMPRESS_LZ4 # define unlz4 NULL #endif +#ifndef CONFIG_DECOMPRESS_ZSTD +# define unzstd NULL +#endif struct compress_format { unsigned char magic[2]; @@ -52,6 +56,7 @@ static const struct compress_format compressed_formats[] __initconst = { { {0xfd, 0x37}, "xz", unxz }, { {0x89, 0x4c}, "lzo", unlzo }, { {0x02, 0x21}, "lz4", unlz4 }, + { {0x28, 0xb5}, "zstd", unzstd }, { {0, 0}, NULL, NULL } }; diff --git a/lib/decompress_unzstd.c b/lib/decompress_unzstd.c new file mode 100644 index 0000000..84315dc --- /dev/null +++ b/lib/decompress_unzstd.c @@ -0,0 +1,341 @@ +/* + * Copyright (C) 2017 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * 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, see . + */ + +/* + * 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 ZSTD with a 128 KB block size is calculated below. + * Note that the margin with ZSTD is bigger than with GZIP or XZ! + * + * 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 .zst file in case of a compresed kernel is as follows. + * Maximum sizes (as bytes) of the fields are in parenthesis. + * + * Frame Header: (18) + * Blocks: (N) + * Checksum: (4) + * + * The frame header and checksum overhead is at most 22 bytes. + * + * ZSTD stores the data in blocks. Each block has a header whose size is + * a 3 bytes. After the block header, there is up to 128 KB of payload. + * The maximum uncompressed size of the payload is 128 KB. The minimum + * uncompressed size of the payload is never less than the payload size + * (excluding the block header). + * + * 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 + * - 22 bytes for the .zst file format headers; + * - 3 bytes per every 128 KiB of uncompressed size (one block header per + * block); and + * - 128 KiB (biggest possible zstd block size) to make sure that the + * decompressor never overwrites anything from the block it is currently + * reading. + * + * We get the following formula: + * + * safety_margin = 22 + uncompressed_size * 3 / 131072 + 131072 + * <= 22 + (uncompressed_size >> 15) + 131072 + */ + +#ifdef STATIC + /* Preboot environments #include "path/to/decompress_unzstd.c". + * All of the source files we depend on must be #included. + * zstd's only source dependeny is xxhash, which has no source + * dependencies. + * + * zstd and xxhash both avoid declaring themselves as modules + * when PREBOOT is defined. + */ +# define PREBOOT +# include "xxhash.c" +# include "zstd/entropy_common.c" +# include "zstd/fse_decompress.c" +# include "zstd/huf_decompress.c" +# include "zstd/zstd_common.c" +# include "zstd/decompress.c" +#endif + +#include +#include +#include + +/* 8 MB maximum window size */ +#define ZSTD_WINDOWSIZE_MAX (1 << 23) +/* Size of the input and output buffers in multi-call mdoe */ +#define ZSTD_IOBUF_SIZE 4096 + +static int INIT handle_zstd_error(size_t ret, void (*error)(char *x)) +{ + const int err = ZSTD_getErrorCode(ret); + + if (!ZSTD_isError(ret)) + return 0; + + switch (err) { + case ZSTD_error_memory_allocation: + error("ZSTD decompressor ran out of memory"); + break; + case ZSTD_error_prefix_unknown: + error("Input is not in the ZSTD format (wrong magic bytes)"); + break; + case ZSTD_error_dstSize_tooSmall: + case ZSTD_error_corruption_detected: + case ZSTD_error_checksum_wrong: + error("ZSTD-compressed data is corrupt"); + break; + default: + error("ZSTD-compressed data is probably corrupt"); + break; + } + return -1; +} + +/* Handle the case where we have the entire input and output in one segment. + * We can allocate less memory (no circular buffer for the sliding window), + * and avoid some memcpy() calls. + */ +static int INIT decompress_single(const u8 *in_buf, long in_len, u8 *out_buf, + long out_len, long *in_pos, + void (*error)(char *x)) +{ + const size_t wksp_size = ZSTD_DCtxWorkspaceBound(); + void *wksp = large_malloc(wksp_size); + ZSTD_DCtx *dctx = ZSTD_initDCtx(wksp, wksp_size); + int err; + size_t ret; + + if (dctx == NULL) { + error("Out of memory while allocating ZSTD_DCtx"); + err = -1; + goto out; + } + /* Find out how large the frame actually is, there may be junk at + * the end of the frame that ZSTD_decompressDCtx() can't handle. + */ + ret = ZSTD_findFrameCompressedSize(in_buf, in_len); + err = handle_zstd_error(ret, error); + if (err) + goto out; + in_len = (long)ret; + + ret = ZSTD_decompressDCtx(dctx, out_buf, out_len, in_buf, in_len); + err = handle_zstd_error(ret, error); + if (err) + goto out; + + if (in_pos != NULL) + *in_pos = in_len; + + err = 0; +out: + if (wksp != NULL) + large_free(wksp); + return err; +} + +static int INIT __unzstd(unsigned char *in_buf, long in_len, + long (*fill)(void*, unsigned long), + long (*flush)(void*, unsigned long), + unsigned char *out_buf, long out_len, + long *in_pos, + void (*error)(char *x)) +{ + ZSTD_inBuffer in; + ZSTD_outBuffer out; + ZSTD_frameParams params; + void *in_allocated = NULL; + void *out_allocated = NULL; + void *wksp = NULL; + size_t wksp_size; + ZSTD_DStream *dstream; + int err; + size_t ret; + + if (out_len == 0) + out_len = LONG_MAX; /* no limit */ + + if (fill == NULL && flush == NULL) + /* We can decompress faster and with less memory when we have a + * single chunk. + */ + return decompress_single(in_buf, in_len, out_buf, out_len, + in_pos, error); + + /* If in_buf is not provided, we must be using fill(), so allocate + * a large enough buffer. If it is provided, it must be at least + * ZSTD_IOBUF_SIZE large. + */ + if (in_buf == NULL) { + in_allocated = malloc(ZSTD_IOBUF_SIZE); + if (in_allocated == NULL) { + error("Out of memory while allocating input buffer"); + err = -1; + goto out; + } + in_buf = in_allocated; + in_len = 0; + } + /* Read the first chunk, since we need to decode the frame header */ + if (fill != NULL) + in_len = fill(in_buf, ZSTD_IOBUF_SIZE); + if (in_len < 0) { + error("ZSTD-compressed data is truncated"); + err = -1; + goto out; + } + /* Set the first non-empty input buffer */ + in.src = in_buf; + in.pos = 0; + in.size = in_len; + /* Allocate the output buffer if we are using flush(). */ + if (flush != NULL) { + out_allocated = malloc(ZSTD_IOBUF_SIZE); + if (out_allocated == NULL) { + error("Out of memory while allocating output buffer"); + err = -1; + goto out; + } + out_buf = out_allocated; + out_len = ZSTD_IOBUF_SIZE; + } + /* Set the output buffer */ + out.dst = out_buf; + out.pos = 0; + out.size = out_len; + + /* We need to know the window size to allocate the ZSTD_DStream. + * Since we are streaming, we need to allocate a buffer for the sliding + * window. The window size varies from 1 KB to ZSTD_WINDOWSIZE_MAX + * (8 MB), so it is important to use the actual value so as not to + * waste memory when it is smaller. + */ + ret = ZSTD_getFrameParams(¶ms, in.src, in.size); + err = handle_zstd_error(ret, error); + if (err) + goto out; + if (ret != 0) { + error("ZSTD-compressed data has an incomplete frame header"); + err = -1; + goto out; + } + if (params.windowSize > ZSTD_WINDOWSIZE_MAX) { + error("ZSTD-compressed data has too large a window size"); + err = -1; + goto out; + } + + /* Allocate the ZSTD_DStream now that we know how much memory is + * required. + */ + wksp_size = ZSTD_DStreamWorkspaceBound(params.windowSize); + wksp = large_malloc(wksp_size); + dstream = ZSTD_initDStream(params.windowSize, wksp, wksp_size); + if (dstream == NULL) { + error("Out of memory while allocating ZSTD_DStream"); + err = -1; + goto out; + } + /* Decompression loop: + * Read more data if necessary (error if no more data can be read). + * Call the decompression function, which returns 0 when finished. + * Flush any data produced if using flush(). + */ + if (in_pos != NULL) + *in_pos = 0; + do { + /* If we need to reload data, either we have fill() and can + * try to get more data, or we don't and the input is truncated. + */ + if (in.pos == in.size) { + if (in_pos != NULL) + *in_pos += in.pos; + in_len = fill ? fill(in_buf, ZSTD_IOBUF_SIZE) : -1; + if (in_len < 0) { + error("ZSTD-compressed data is truncated"); + err = -1; + goto out; + } + in.pos = 0; + in.size = in_len; + } + /* Returns zero when the frame is complete */ + ret = ZSTD_decompressStream(dstream, &out, &in); + err = handle_zstd_error(ret, error); + if (err) + goto out; + /* Flush all of the data produced if using flush() */ + if (flush != NULL && out.pos > 0) { + if (out.pos != flush(out.dst, out.pos)) { + error("Failed to flush()"); + err = -1; + goto out; + } + out.pos = 0; + } + } while (ret != 0); + + if (in_pos != NULL) + *in_pos += in.pos; + + err = 0; +out: + if (in_allocated != NULL) + free(in_allocated); + if (out_allocated != NULL) + free(out_allocated); + if (wksp != NULL) + large_free(wksp); + return err; +} + +#ifndef PREBOOT +STATIC int INIT unzstd(unsigned char *buf, long len, + long (*fill)(void*, unsigned long), + long (*flush)(void*, unsigned long), + unsigned char *out_buf, + long *pos, + void (*error)(char *x)) +{ + return __unzstd(buf, len, fill, flush, out_buf, 0, pos, error); +} +#else +STATIC int INIT __decompress(unsigned char *buf, long len, + long (*fill)(void*, unsigned long), + long (*flush)(void*, unsigned long), + unsigned char *out_buf, long out_len, + long *pos, + void (*error)(char *x)) +{ + return __unzstd(buf, len, fill, flush, out_buf, out_len, pos, error); +} +#endif diff --git a/lib/xxhash.c b/lib/xxhash.c index aa61e2a..7f1d3cb 100644 --- a/lib/xxhash.c +++ b/lib/xxhash.c @@ -80,13 +80,11 @@ void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src) { memcpy(dst, src, sizeof(*dst)); } -EXPORT_SYMBOL(xxh32_copy_state); void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src) { memcpy(dst, src, sizeof(*dst)); } -EXPORT_SYMBOL(xxh64_copy_state); /*-*************************** * Simple Hash Functions @@ -151,7 +149,6 @@ uint32_t xxh32(const void *input, const size_t len, const uint32_t seed) return h32; } -EXPORT_SYMBOL(xxh32); static uint64_t xxh64_round(uint64_t acc, const uint64_t input) { @@ -234,7 +231,6 @@ uint64_t xxh64(const void *input, const size_t len, const uint64_t seed) return h64; } -EXPORT_SYMBOL(xxh64); /*-************************************************** * Advanced Hash Functions @@ -251,7 +247,6 @@ void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed) state.v4 = seed - PRIME32_1; memcpy(statePtr, &state, sizeof(state)); } -EXPORT_SYMBOL(xxh32_reset); void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed) { @@ -265,7 +260,6 @@ void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed) state.v4 = seed - PRIME64_1; memcpy(statePtr, &state, sizeof(state)); } -EXPORT_SYMBOL(xxh64_reset); int xxh32_update(struct xxh32_state *state, const void *input, const size_t len) { @@ -334,7 +328,6 @@ int xxh32_update(struct xxh32_state *state, const void *input, const size_t len) return 0; } -EXPORT_SYMBOL(xxh32_update); uint32_t xxh32_digest(const struct xxh32_state *state) { @@ -372,7 +365,6 @@ uint32_t xxh32_digest(const struct xxh32_state *state) return h32; } -EXPORT_SYMBOL(xxh32_digest); int xxh64_update(struct xxh64_state *state, const void *input, const size_t len) { @@ -439,7 +431,6 @@ int xxh64_update(struct xxh64_state *state, const void *input, const size_t len) return 0; } -EXPORT_SYMBOL(xxh64_update); uint64_t xxh64_digest(const struct xxh64_state *state) { @@ -494,7 +485,19 @@ uint64_t xxh64_digest(const struct xxh64_state *state) return h64; } + +#ifndef PREBOOT +EXPORT_SYMBOL(xxh32_copy_state); +EXPORT_SYMBOL(xxh64_copy_state); +EXPORT_SYMBOL(xxh32); +EXPORT_SYMBOL(xxh64); +EXPORT_SYMBOL(xxh32_reset); +EXPORT_SYMBOL(xxh64_reset); +EXPORT_SYMBOL(xxh32_update); +EXPORT_SYMBOL(xxh32_digest); +EXPORT_SYMBOL(xxh64_update); EXPORT_SYMBOL(xxh64_digest); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("xxHash"); +#endif diff --git a/lib/zstd/decompress.c b/lib/zstd/decompress.c index b178467..b7b6599 100644 --- a/lib/zstd/decompress.c +++ b/lib/zstd/decompress.c @@ -2487,6 +2487,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream *zds, ZSTD_outBuffer *output, ZSTD_inB } } +#ifndef PREBOOT EXPORT_SYMBOL(ZSTD_DCtxWorkspaceBound); EXPORT_SYMBOL(ZSTD_initDCtx); EXPORT_SYMBOL(ZSTD_decompressDCtx); @@ -2526,3 +2527,4 @@ EXPORT_SYMBOL(ZSTD_insertBlock); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("Zstd Decompressor"); +#endif diff --git a/lib/zstd/fse_decompress.c b/lib/zstd/fse_decompress.c index a84300e..0b35353 100644 --- a/lib/zstd/fse_decompress.c +++ b/lib/zstd/fse_decompress.c @@ -47,6 +47,7 @@ ****************************************************************/ #include "bitstream.h" #include "fse.h" +#include "zstd_internal.h" #include #include #include /* memcpy, memset */ @@ -60,14 +61,6 @@ enum { FSE_static_assert = 1 / (int)(!!(c)) }; \ } /* use only *after* variable declarations */ -/* check and forward error code */ -#define CHECK_F(f) \ - { \ - size_t const e = f; \ - if (FSE_isError(e)) \ - return e; \ - } - /* ************************************************************** * Templates ****************************************************************/ diff --git a/lib/zstd/zstd_internal.h b/lib/zstd/zstd_internal.h index 1a79fab..40026c0 100644 --- a/lib/zstd/zstd_internal.h +++ b/lib/zstd/zstd_internal.h @@ -127,7 +127,13 @@ static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG; * Shared functions to include for inlining *********************************************/ ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) { - memcpy(dst, src, 8); + /* zstd relies heavily on gcc being able to analyze and inline this + * memcpy() call, since it is called in a tight loop. Preboot mode + * is compiled in freestanding mode, which stops gcc from analyzing + * memcpy(). Use __builtin_memcpy() to tell gcc to analyze this as a + * regular memcpy(). + */ + __builtin_memcpy(dst, src, 8); } /*! ZSTD_wildcopy() : * custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */ @@ -137,6 +143,7 @@ ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length) const BYTE* ip = (const BYTE*)src; BYTE* op = (BYTE*)dst; BYTE* const oend = op + length; +#if GCC_VERSION >= 70000 && GCC_VERSION < 70200 /* Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388. * Avoid the bad case where the loop only runs once by handling the * special case separately. This doesn't trigger the bug because it @@ -144,6 +151,7 @@ ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length) */ if (length <= 8) return ZSTD_copy8(dst, src); +#endif do { ZSTD_copy8(op, ip); op += 8; diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index a6f538b..f012d62 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -416,6 +416,21 @@ cmd_xzmisc = (cat $(filter-out FORCE,$^) | \ xz --check=crc32 --lzma2=dict=1MiB) > $@ || \ (rm -f $@ ; false) +# ZSTD +# --------------------------------------------------------------------------- +# Appends the uncompressed size of the data using size_append. The .zst +# format has the size information available at the beginning of the file too, +# but it's in a more complex format and it's good to avoid changing the part +# of the boot code that reads the uncompressed size. +# Note that the bytes added by size_append will make the zstd tool think that +# the file is corrupt. This is expected. + +quiet_cmd_zstd = ZSTD $@ +cmd_zstd = (cat $(filter-out FORCE,$^) | \ + zstd -19 && \ + $(call size_append, $(filter-out FORCE,$^))) > $@ || \ + (rm -f $@ ; false) + # ASM offsets # --------------------------------------------------------------------------- diff --git a/usr/Kconfig b/usr/Kconfig index 43658b8..5ff529b 100644 --- a/usr/Kconfig +++ b/usr/Kconfig @@ -106,6 +106,15 @@ config RD_LZ4 Support loading of a LZ4 encoded initial ramdisk or cpio buffer If unsure, say N. +config RD_ZSTD + bool "Support initial ramdisk/ramfs compressed using ZSTD" + default y + depends on BLK_DEV_INITRD + select DECOMPRESS_ZSTD + help + Support loading of a ZSTD encoded initial ramdisk or cpio buffer. + If unsure, say N. + choice prompt "Built-in initramfs compression mode" depends on INITRAMFS_SOURCE!="" @@ -214,6 +223,17 @@ config INITRAMFS_COMPRESSION_LZ4 If you choose this, keep in mind that most distros don't provide lz4 by default which could cause a build failure. +config INITRAMFS_COMPRESSION_ZSTD + bool "ZSTD" + depends on RD_ZSTD + help + ZSTD is a compression algorithm targeting intermediate compression + with fast decompression speed. It will compress better than GZIP and + decompress around the same speed as LZO, but slower than LZ4. + + If you choose this, keep in mind that you may need to install the zstd + tool to be able to compress the initram. + endchoice config INITRAMFS_COMPRESSION @@ -226,10 +246,12 @@ config INITRAMFS_COMPRESSION default ".xz" if INITRAMFS_COMPRESSION_XZ default ".lzo" if INITRAMFS_COMPRESSION_LZO default ".lz4" if INITRAMFS_COMPRESSION_LZ4 + default ".zst" if INITRAMFS_COMPRESSION_ZSTD default ".gz" if RD_GZIP default ".lz4" if RD_LZ4 default ".lzo" if RD_LZO default ".xz" if RD_XZ default ".lzma" if RD_LZMA default ".bz2" if RD_BZIP2 + default ".zst" if RD_ZSTD default "" -- 2.9.5 Integrates the ZSTD decompression code to the x86 pre-boot code. Zstandard requires slightly more memory during the kernel decompression on x86 (192 KB vs 64 KB), and the memory usage is independent of the window size. Zstandard requires memory proportional to the window size used during compression for decompressing the ramdisk image, since streaming mode is used. Newer versions of zstd (1.3.2+) list the window size of a file with `zstd -lv '. The absolute maximum amount of memory required is just over 8 MB. Signed-off-by: Nick Terrell --- Documentation/x86/boot.txt | 6 +++--- arch/x86/Kconfig | 1 + arch/x86/boot/compressed/Makefile | 5 ++++- arch/x86/boot/compressed/misc.c | 4 ++++ arch/x86/boot/header.S | 8 +++++++- arch/x86/include/asm/boot.h | 6 ++++-- 6 files changed, 23 insertions(+), 7 deletions(-) diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt index 5e9b826..7f5d1f9 100644 --- a/Documentation/x86/boot.txt +++ b/Documentation/x86/boot.txt @@ -666,9 +666,9 @@ Protocol: 2.08+ uncompressed data should be determined using the standard magic numbers. The currently supported compression formats are gzip (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA - (magic number 5D 00), XZ (magic number FD 37), and LZ4 (magic number - 02 21). The uncompressed payload is currently always ELF (magic - number 7F 45 4C 46). + (magic number 5D 00), XZ (magic number FD 37), LZ4 (magic number + 02 21) and ZSTD (magic number 28 B5). The uncompressed payload is + currently always ELF (magic number 7F 45 4C 46). Field name: payload_length Type: read diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0fa71a7..75515b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -155,6 +155,7 @@ config X86 select HAVE_KERNEL_LZMA select HAVE_KERNEL_LZO select HAVE_KERNEL_XZ + select HAVE_KERNEL_ZSTD select HAVE_KPROBES select HAVE_KPROBES_ON_FTRACE select HAVE_FUNCTION_ERROR_INJECTION diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index f25e153..779b1ed 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -24,7 +24,7 @@ OBJECT_FILES_NON_STANDARD := y KCOV_INSTRUMENT := n targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ - vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 + vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ -O2 KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) @@ -137,6 +137,8 @@ $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE $(call if_changed,lzo) $(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE $(call if_changed,lz4) +$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE + $(call if_changed,zstd) suffix-$(CONFIG_KERNEL_GZIP) := gz suffix-$(CONFIG_KERNEL_BZIP2) := bz2 @@ -144,6 +146,7 @@ suffix-$(CONFIG_KERNEL_LZMA) := lzma suffix-$(CONFIG_KERNEL_XZ) := xz suffix-$(CONFIG_KERNEL_LZO) := lzo suffix-$(CONFIG_KERNEL_LZ4) := lz4 +suffix-$(CONFIG_KERNEL_ZSTD) := zst quiet_cmd_mkpiggy = MKPIGGY $@ cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false ) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 98761a1..e0fbf26 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -75,6 +75,10 @@ static int lines, cols; #ifdef CONFIG_KERNEL_LZ4 #include "../../../../lib/decompress_unlz4.c" #endif + +#ifdef CONFIG_KERNEL_ZSTD +#include "../../../../lib/decompress_unzstd.c" +#endif /* * NOTE: When adding a new decompressor, please update the analysis in * ../header.S. diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index 850b876..221c181 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -526,8 +526,14 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr # the size-dependent part now grows so fast. # # extra_bytes = (uncompressed_size >> 8) + 65536 +# +# ZSTD compressed data grows by at most 3 bytes per 128K, and only has a 22 +# byte fixed overhead but has a maximum block size of 128K, so it needs a +# larger margin. +# +# extra_bytes = (uncompressed_size >> 8) + 131072 -#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 65536) +#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 131072) #if ZO_z_output_len > ZO_z_input_len # define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \ ZO_z_input_len) diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h index 680c320..d6dd43d 100644 --- a/arch/x86/include/asm/boot.h +++ b/arch/x86/include/asm/boot.h @@ -24,9 +24,11 @@ # error "Invalid value for CONFIG_PHYSICAL_ALIGN" #endif -#ifdef CONFIG_KERNEL_BZIP2 +#if defined(CONFIG_KERNEL_BZIP2) # define BOOT_HEAP_SIZE 0x400000 -#else /* !CONFIG_KERNEL_BZIP2 */ +#elif defined(CONFIG_KERNEL_ZSTD) +# define BOOT_HEAP_SIZE 0x30000 +#else # define BOOT_HEAP_SIZE 0x10000 #endif -- 2.9.5