5.8.arch1-1

1 files changed, 455 insertions, 0 deletions

diff --git a/0002-lib-add-zstd-support-to-decompress.patch b/0002-lib-add-zstd-support-to-decompress.patch
new file mode 100644
index 000000000000..f52cedddbebd
--- /dev/null
+++ b/0002-lib-add-zstd-support-to-decompress.patch
@@ -0,0 +1,455 @@
+From 2c3ac5606dbce8181ebbccb1a6136af7f0458234 Mon Sep 17 00:00:00 2001
+From: Nick Terrell <terrelln@fb.com>
+Date: Thu, 20 Jun 2019 15:14:00 -0700
+Subject: [PATCH 2/7] lib: add zstd support to decompress
+
+* Add unzstd() and the zstd decompress interface.
+* Add zstd support to decompress_method().
+
+The decompress_method() and unzstd() functions are used to decompress
+the initramfs and the initrd. The __decompress() function is used in
+the preboot environment to decompress a zstd compressed kernel.
+
+The zstd decompression function allows the input and output buffers to
+overlap because that is used by x86 kernel decompression.
+
+Reviewed-by: Kees Cook <keescook@chromium.org>
+Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
+Signed-off-by: Nick Terrell <terrelln@fb.com>
+---
+ include/linux/decompress/unzstd.h |  11 +
+ lib/Kconfig                       |   4 +
+ lib/Makefile                      |   1 +
+ lib/decompress.c                  |   5 +
+ lib/decompress_unzstd.c           | 344 ++++++++++++++++++++++++++++++
+ 5 files changed, 365 insertions(+)
+ 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 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/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..062617bb0afe
+--- /dev/null
++++ b/lib/decompress_unzstd.c
+@@ -0,0 +1,344 @@
++// 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 anyways. 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
+-- 
+2.28.0
+