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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 16:03:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 16:03:23 -0700
commitc0dfadfed87489fa6126ece161a14c2d15dbdc79 (patch)
tree2b1ac3fb464e4d18b57e3d4735cd6b60454cc972
parentba77c568f3160657a5f7905289c07d18c2dfde78 (diff)
parent1ac1efa5f6950f8f126f2c1921bb699ce009ec7d (diff)
Merge tag 'x86-boot-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar: "The main change in this cycle was to add support for ZSTD-compressed kernel and initrd images. ZSTD has a very fast decompressor, yet it compresses better than gzip" * tag 'x86-boot-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: dontdiff: Add zstd compressed files .gitignore: Add ZSTD-compressed files x86: Add support for ZSTD compressed kernel x86: Bump ZO_z_extra_bytes margin for zstd usr: Add support for zstd compressed initramfs init: Add support for zstd compressed kernel lib: Add zstd support to decompress lib: Prepare zstd for preboot environment, improve performance
-rw-r--r--.gitignore1
-rw-r--r--Documentation/dontdiff1
-rw-r--r--Documentation/x86/boot.rst6
-rw-r--r--Makefile3
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/boot/compressed/Makefile6
-rw-r--r--arch/x86/boot/compressed/kaslr.c7
-rw-r--r--arch/x86/boot/compressed/misc.c4
-rw-r--r--arch/x86/boot/header.S8
-rw-r--r--arch/x86/include/asm/boot.h11
-rw-r--r--include/linux/decompress/unzstd.h11
-rw-r--r--init/Kconfig15
-rw-r--r--lib/Kconfig4
-rw-r--r--lib/Makefile1
-rw-r--r--lib/decompress.c5
-rw-r--r--lib/decompress_unzstd.c345
-rw-r--r--lib/zstd/fse_decompress.c9
-rw-r--r--lib/zstd/zstd_internal.h14
-rw-r--r--scripts/Makefile.lib22
-rw-r--r--usr/Kconfig20
-rw-r--r--usr/Makefile1
21 files changed, 469 insertions, 26 deletions
diff --git a/.gitignore b/.gitignore
index d5f4804ed07c..162bd2b67bdf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,6 +44,7 @@
*.tab.[ch]
*.tar
*.xz
+*.zst
Module.symvers
modules.builtin
modules.order
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index ef9519c32c55..e361fc95ca29 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -55,6 +55,7 @@
*.ver
*.xml
*.xz
+*.zst
*_MODULES
*_vga16.c
*~
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index 5325c71ca877..7fafc7ac00d7 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -782,9 +782,9 @@ 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
diff --git a/Makefile b/Makefile
index 24a4c1b97bb0..aef9ca61caf0 100644
--- a/Makefile
+++ b/Makefile
@@ -464,6 +464,7 @@ KLZOP = lzop
LZMA = lzma
LZ4 = lz4c
XZ = xz
+ZSTD = zstd
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
@@ -512,7 +513,7 @@ CLANG_FLAGS :=
export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX YACC AWK INSTALLKERNEL
export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
-export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ
+export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 883da0abf779..4a64395bc35d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -188,6 +188,7 @@ config X86
select HAVE_KERNEL_LZMA
select HAVE_KERNEL_LZO
select HAVE_KERNEL_XZ
+ select HAVE_KERNEL_ZSTD
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
select HAVE_FUNCTION_ERROR_INJECTION
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 5a828fde7a42..c08714ae76ec 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -26,7 +26,7 @@ OBJECT_FILES_NON_STANDARD := y
KCOV_INSTRUMENT := n
targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
- vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
+ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst
KBUILD_CFLAGS := -m$(BITS) -O2
KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
@@ -42,6 +42,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
KBUILD_CFLAGS += -Wno-pointer-sign
KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS += -D__DISABLE_EXPORTS
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
GCOV_PROFILE := n
@@ -145,6 +146,8 @@ $(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
+ $(call if_changed,zstd22)
suffix-$(CONFIG_KERNEL_GZIP) := gz
suffix-$(CONFIG_KERNEL_BZIP2) := bz2
@@ -152,6 +155,7 @@ suffix-$(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 $< > $@
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index d7408af55738..0048269180d5 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -19,13 +19,6 @@
*/
#define BOOT_CTYPE_H
-/*
- * _ctype[] in lib/ctype.c is needed by isspace() of linux/ctype.h.
- * While both lib/ctype.c and lib/cmdline.c will bring EXPORT_SYMBOL
- * which is meaningless and will cause compiling error in some cases.
- */
-#define __DISABLE_EXPORTS
-
#include "misc.h"
#include "error.h"
#include "../string.h"
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 9652d5c2afda..39e592d0e0b4 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -77,6 +77,10 @@ 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 735ad7f21ab0..6dbd7e9f74c9 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -539,8 +539,14 @@ 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 680c320363db..9191280d9ea3 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -24,9 +24,16 @@
# 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)
+/*
+ * Zstd needs to allocate the ZSTD_DCtx in order to decompress the kernel.
+ * The ZSTD_DCtx is ~160KB, so set the heap size to 192KB because it is a
+ * round number and to allow some slack.
+ */
+# define BOOT_HEAP_SIZE 0x30000
+#else
# define BOOT_HEAP_SIZE 0x10000
#endif
diff --git a/include/linux/decompress/unzstd.h b/include/linux/decompress/unzstd.h
new file mode 100644
index 000000000000..56d539ae880f
--- /dev/null
+++ b/include/linux/decompress/unzstd.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 9f7f249dab43..f4bffefdbed5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -191,13 +191,16 @@ config HAVE_KERNEL_LZO
config HAVE_KERNEL_LZ4
bool
+config HAVE_KERNEL_ZSTD
+ bool
+
config HAVE_KERNEL_UNCOMPRESSED
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 || HAVE_KERNEL_UNCOMPRESSED
+ depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED
help
The linux kernel is a kind of self-extracting executable.
Several compression algorithms are available, which differ
@@ -276,6 +279,16 @@ 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. The zstd command
+ line tool is required for compression.
+
config KERNEL_UNCOMPRESSED
bool "None"
depends on HAVE_KERNEL_UNCOMPRESSED
diff --git a/lib/Kconfig b/lib/Kconfig
index df3f3da95990..a5d6f23c4cab 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -342,6 +342,10 @@ 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 b1c42c10073b..2ba9642a3a87 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -170,6 +170,7 @@ 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 857ab1af1ef3..ab3fc90ffc64 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -13,6 +13,7 @@
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/decompress/unlz4.h>
+#include <linux/decompress/unzstd.h>
#include <linux/types.h>
#include <linux/string.h>
@@ -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 000000000000..0ad2c15479ed
--- /dev/null
+++ b/lib/decompress_unzstd.c
@@ -0,0 +1,345 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * 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
+ */
+
+/*
+ * 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.
+ *
+ * When UNZSTD_PREBOOT is defined we declare __decompress(), which is
+ * used for kernel decompression, instead of unzstd().
+ *
+ * Define __DISABLE_EXPORTS in preboot environments to prevent symbols
+ * from xxhash and zstd from being exported by the EXPORT_SYMBOL macro.
+ */
+#ifdef STATIC
+# define UNZSTD_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 <linux/decompress/mm.h>
+#include <linux/kernel.h>
+#include <linux/zstd.h>
+
+/* 128MB is the maximum window size supported by zstd. */
+#define ZSTD_WINDOWSIZE_MAX (1 << ZSTD_WINDOWLOG_MAX)
+/*
+ * Size of the input and output buffers in multi-call mode.
+ * Pick a larger size because it isn't used during kernel decompression,
+ * since that is single pass, and we have to allocate a large buffer for
+ * zstd's window anyway. The larger size speeds up initramfs decompression.
+ */
+#define ZSTD_IOBUF_SIZE (1 << 17)
+
+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 = large_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 = large_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(&params, 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)
+ large_free(in_allocated);
+ if (out_allocated != NULL)
+ large_free(out_allocated);
+ if (wksp != NULL)
+ large_free(wksp);
+ return err;
+}
+
+#ifndef UNZSTD_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/zstd/fse_decompress.c b/lib/zstd/fse_decompress.c
index a84300e5a013..0b353530fb3f 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 <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/string.h> /* 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 1a79fab9e13a..dac753397f86 100644
--- a/lib/zstd/zstd_internal.h
+++ b/lib/zstd/zstd_internal.h
@@ -127,7 +127,14 @@ 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) */
@@ -137,13 +144,16 @@ 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;
- /* Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.
+#if defined(GCC_VERSION) && 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
* doesn't involve pointer/integer overflow.
*/
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 916b2f7f7098..54f7b7eb580b 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -413,6 +413,28 @@ quiet_cmd_xzkern = XZKERN $@
quiet_cmd_xzmisc = XZMISC $@
cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
+# 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.
+#
+# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
+# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
+# single pass, so zstd doesn't need to allocate a window buffer. When streaming
+# decompression is used, like initramfs decompression, zstd22 should likely not
+# be used because it would require zstd to allocate a 128 MB buffer.
+
+quiet_cmd_zstd = ZSTD $@
+ cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@
+
+quiet_cmd_zstd22 = ZSTD22 $@
+ cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
+
# ASM offsets
# ---------------------------------------------------------------------------
diff --git a/usr/Kconfig b/usr/Kconfig
index 96afb03b65f9..2599bc21c1b2 100644
--- a/usr/Kconfig
+++ b/usr/Kconfig
@@ -100,6 +100,15 @@ config RD_LZ4
Support loading of a LZ4 encoded initial ramdisk or cpio buffer
If unsure, say N.
+config RD_ZSTD
+ bool "Support initial ramdisk/ramfs compressed using ZSTD"
+ default y
+ depends on BLK_DEV_INITRD
+ select DECOMPRESS_ZSTD
+ help
+ Support loading of a ZSTD encoded initial ramdisk or cpio buffer.
+ If unsure, say N.
+
choice
prompt "Built-in initramfs compression mode"
depends on INITRAMFS_SOURCE != ""
@@ -196,6 +205,17 @@ config INITRAMFS_COMPRESSION_LZ4
If you choose this, keep in mind that most distros don't provide lz4
by default which could cause a build failure.
+config INITRAMFS_COMPRESSION_ZSTD
+ bool "ZSTD"
+ depends on RD_ZSTD
+ help
+ ZSTD is a compression algorithm targeting intermediate compression
+ with fast decompression speed. It will compress better than GZIP and
+ decompress around the same speed as LZO, but slower than LZ4.
+
+ If you choose this, keep in mind that you may need to install the zstd
+ tool to be able to compress the initram.
+
config INITRAMFS_COMPRESSION_NONE
bool "None"
help
diff --git a/usr/Makefile b/usr/Makefile
index c12e6b15ce72..b1a81a40eab1 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -15,6 +15,7 @@ compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
+compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD) := zstd
obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o