VisionFive2 Linux kernel

4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   1) // SPDX-License-Identifier: GPL-2.0
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   2) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   3) /*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   4)  * Important notes about in-place decompression
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   5)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   6)  * At least on x86, the kernel is decompressed in place: the compressed data
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   7)  * is placed to the end of the output buffer, and the decompressor overwrites
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   8)  * most of the compressed data. There must be enough safety margin to
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700   9)  * guarantee that the write position is always behind the read position.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  10)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  11)  * The safety margin for ZSTD with a 128 KB block size is calculated below.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  12)  * Note that the margin with ZSTD is bigger than with GZIP or XZ!
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  13)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  14)  * The worst case for in-place decompression is that the beginning of
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  15)  * the file is compressed extremely well, and the rest of the file is
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  16)  * uncompressible. Thus, we must look for worst-case expansion when the
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  17)  * compressor is encoding uncompressible data.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  18)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  19)  * The structure of the .zst file in case of a compresed kernel is as follows.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  20)  * Maximum sizes (as bytes) of the fields are in parenthesis.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  21)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  22)  *    Frame Header: (18)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  23)  *    Blocks: (N)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  24)  *    Checksum: (4)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  25)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  26)  * The frame header and checksum overhead is at most 22 bytes.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  27)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  28)  * ZSTD stores the data in blocks. Each block has a header whose size is
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  29)  * a 3 bytes. After the block header, there is up to 128 KB of payload.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  30)  * The maximum uncompressed size of the payload is 128 KB. The minimum
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  31)  * uncompressed size of the payload is never less than the payload size
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  32)  * (excluding the block header).
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  33)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  34)  * The assumption, that the uncompressed size of the payload is never
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  35)  * smaller than the payload itself, is valid only when talking about
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  36)  * the payload as a whole. It is possible that the payload has parts where
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  37)  * the decompressor consumes more input than it produces output. Calculating
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  38)  * the worst case for this would be tricky. Instead of trying to do that,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  39)  * let's simply make sure that the decompressor never overwrites any bytes
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  40)  * of the payload which it is currently reading.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  41)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  42)  * Now we have enough information to calculate the safety margin. We need
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  43)  *   - 22 bytes for the .zst file format headers;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  44)  *   - 3 bytes per every 128 KiB of uncompressed size (one block header per
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  45)  *     block); and
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  46)  *   - 128 KiB (biggest possible zstd block size) to make sure that the
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  47)  *     decompressor never overwrites anything from the block it is currently
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  48)  *     reading.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  49)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  50)  * We get the following formula:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  51)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  52)  *    safety_margin = 22 + uncompressed_size * 3 / 131072 + 131072
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  53)  *                 <= 22 + (uncompressed_size >> 15) + 131072
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  54)  */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  55) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  56) /*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  57)  * Preboot environments #include "path/to/decompress_unzstd.c".
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  58)  * All of the source files we depend on must be #included.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  59)  * zstd's only source dependeny is xxhash, which has no source
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  60)  * dependencies.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  61)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  62)  * When UNZSTD_PREBOOT is defined we declare __decompress(), which is
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  63)  * used for kernel decompression, instead of unzstd().
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  64)  *
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  65)  * Define __DISABLE_EXPORTS in preboot environments to prevent symbols
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  66)  * from xxhash and zstd from being exported by the EXPORT_SYMBOL macro.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  67)  */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  68) #ifdef STATIC
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  69) # define UNZSTD_PREBOOT
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  70) # include "xxhash.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  71) # include "zstd/entropy_common.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  72) # include "zstd/fse_decompress.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  73) # include "zstd/huf_decompress.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  74) # include "zstd/zstd_common.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  75) # include "zstd/decompress.c"
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  76) #endif
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  77) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  78) #include <linux/decompress/mm.h>
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  79) #include <linux/kernel.h>
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  80) #include <linux/zstd.h>
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  81) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  82) /* 128MB is the maximum window size supported by zstd. */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  83) #define ZSTD_WINDOWSIZE_MAX	(1 << ZSTD_WINDOWLOG_MAX)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  84) /*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  85)  * Size of the input and output buffers in multi-call mode.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  86)  * Pick a larger size because it isn't used during kernel decompression,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  87)  * since that is single pass, and we have to allocate a large buffer for
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  88)  * zstd's window anyway. The larger size speeds up initramfs decompression.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  89)  */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  90) #define ZSTD_IOBUF_SIZE		(1 << 17)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  91) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  92) static int INIT handle_zstd_error(size_t ret, void (*error)(char *x))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  93) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  94) 	const int err = ZSTD_getErrorCode(ret);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  95) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  96) 	if (!ZSTD_isError(ret))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  97) 		return 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  98) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700  99) 	switch (err) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 100) 	case ZSTD_error_memory_allocation:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 101) 		error("ZSTD decompressor ran out of memory");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 102) 		break;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 103) 	case ZSTD_error_prefix_unknown:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 104) 		error("Input is not in the ZSTD format (wrong magic bytes)");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 105) 		break;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 106) 	case ZSTD_error_dstSize_tooSmall:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 107) 	case ZSTD_error_corruption_detected:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 108) 	case ZSTD_error_checksum_wrong:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 109) 		error("ZSTD-compressed data is corrupt");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 110) 		break;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 111) 	default:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 112) 		error("ZSTD-compressed data is probably corrupt");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 113) 		break;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 114) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 115) 	return -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 116) }
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 117) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 118) /*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 119)  * Handle the case where we have the entire input and output in one segment.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 120)  * We can allocate less memory (no circular buffer for the sliding window),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 121)  * and avoid some memcpy() calls.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 122)  */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 123) static int INIT decompress_single(const u8 *in_buf, long in_len, u8 *out_buf,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 124) 				  long out_len, long *in_pos,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 125) 				  void (*error)(char *x))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 126) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 127) 	const size_t wksp_size = ZSTD_DCtxWorkspaceBound();
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 128) 	void *wksp = large_malloc(wksp_size);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 129) 	ZSTD_DCtx *dctx = ZSTD_initDCtx(wksp, wksp_size);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 130) 	int err;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 131) 	size_t ret;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 132) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 133) 	if (dctx == NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 134) 		error("Out of memory while allocating ZSTD_DCtx");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 135) 		err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 136) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 137) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 138) 	/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 139) 	 * Find out how large the frame actually is, there may be junk at
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 140) 	 * the end of the frame that ZSTD_decompressDCtx() can't handle.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 141) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 142) 	ret = ZSTD_findFrameCompressedSize(in_buf, in_len);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 143) 	err = handle_zstd_error(ret, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 144) 	if (err)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 145) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 146) 	in_len = (long)ret;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 147) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 148) 	ret = ZSTD_decompressDCtx(dctx, out_buf, out_len, in_buf, in_len);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 149) 	err = handle_zstd_error(ret, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 150) 	if (err)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 151) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 152) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 153) 	if (in_pos != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 154) 		*in_pos = in_len;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 155) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 156) 	err = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 157) out:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 158) 	if (wksp != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 159) 		large_free(wksp);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 160) 	return err;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 161) }
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 162) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 163) static int INIT __unzstd(unsigned char *in_buf, long in_len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 164) 			 long (*fill)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 165) 			 long (*flush)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 166) 			 unsigned char *out_buf, long out_len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 167) 			 long *in_pos,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 168) 			 void (*error)(char *x))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 169) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 170) 	ZSTD_inBuffer in;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 171) 	ZSTD_outBuffer out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 172) 	ZSTD_frameParams params;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 173) 	void *in_allocated = NULL;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 174) 	void *out_allocated = NULL;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 175) 	void *wksp = NULL;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 176) 	size_t wksp_size;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 177) 	ZSTD_DStream *dstream;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 178) 	int err;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 179) 	size_t ret;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 180) 
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 181) 	/*
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 182) 	 * ZSTD decompression code won't be happy if the buffer size is so big
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 183) 	 * that its end address overflows. When the size is not provided, make
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 184) 	 * it as big as possible without having the end address overflow.
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 185) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 186) 	if (out_len == 0)
1c4dd334df3a0 (Paul Cercueil 2020-09-01 16:26:50 +0200 187) 		out_len = UINTPTR_MAX - (uintptr_t)out_buf;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 188) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 189) 	if (fill == NULL && flush == NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 190) 		/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 191) 		 * We can decompress faster and with less memory when we have a
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 192) 		 * single chunk.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 193) 		 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 194) 		return decompress_single(in_buf, in_len, out_buf, out_len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 195) 					 in_pos, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 196) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 197) 	/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 198) 	 * If in_buf is not provided, we must be using fill(), so allocate
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 199) 	 * a large enough buffer. If it is provided, it must be at least
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 200) 	 * ZSTD_IOBUF_SIZE large.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 201) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 202) 	if (in_buf == NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 203) 		in_allocated = large_malloc(ZSTD_IOBUF_SIZE);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 204) 		if (in_allocated == NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 205) 			error("Out of memory while allocating input buffer");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 206) 			err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 207) 			goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 208) 		}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 209) 		in_buf = in_allocated;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 210) 		in_len = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 211) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 212) 	/* Read the first chunk, since we need to decode the frame header. */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 213) 	if (fill != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 214) 		in_len = fill(in_buf, ZSTD_IOBUF_SIZE);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 215) 	if (in_len < 0) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 216) 		error("ZSTD-compressed data is truncated");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 217) 		err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 218) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 219) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 220) 	/* Set the first non-empty input buffer. */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 221) 	in.src = in_buf;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 222) 	in.pos = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 223) 	in.size = in_len;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 224) 	/* Allocate the output buffer if we are using flush(). */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 225) 	if (flush != NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 226) 		out_allocated = large_malloc(ZSTD_IOBUF_SIZE);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 227) 		if (out_allocated == NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 228) 			error("Out of memory while allocating output buffer");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 229) 			err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 230) 			goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 231) 		}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 232) 		out_buf = out_allocated;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 233) 		out_len = ZSTD_IOBUF_SIZE;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 234) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 235) 	/* Set the output buffer. */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 236) 	out.dst = out_buf;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 237) 	out.pos = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 238) 	out.size = out_len;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 239) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 240) 	/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 241) 	 * We need to know the window size to allocate the ZSTD_DStream.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 242) 	 * Since we are streaming, we need to allocate a buffer for the sliding
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 243) 	 * window. The window size varies from 1 KB to ZSTD_WINDOWSIZE_MAX
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 244) 	 * (8 MB), so it is important to use the actual value so as not to
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 245) 	 * waste memory when it is smaller.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 246) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 247) 	ret = ZSTD_getFrameParams(&params, in.src, in.size);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 248) 	err = handle_zstd_error(ret, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 249) 	if (err)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 250) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 251) 	if (ret != 0) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 252) 		error("ZSTD-compressed data has an incomplete frame header");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 253) 		err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 254) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 255) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 256) 	if (params.windowSize > ZSTD_WINDOWSIZE_MAX) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 257) 		error("ZSTD-compressed data has too large a window size");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 258) 		err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 259) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 260) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 261) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 262) 	/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 263) 	 * Allocate the ZSTD_DStream now that we know how much memory is
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 264) 	 * required.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 265) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 266) 	wksp_size = ZSTD_DStreamWorkspaceBound(params.windowSize);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 267) 	wksp = large_malloc(wksp_size);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 268) 	dstream = ZSTD_initDStream(params.windowSize, wksp, wksp_size);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 269) 	if (dstream == NULL) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 270) 		error("Out of memory while allocating ZSTD_DStream");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 271) 		err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 272) 		goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 273) 	}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 274) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 275) 	/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 276) 	 * Decompression loop:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 277) 	 * Read more data if necessary (error if no more data can be read).
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 278) 	 * Call the decompression function, which returns 0 when finished.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 279) 	 * Flush any data produced if using flush().
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 280) 	 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 281) 	if (in_pos != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 282) 		*in_pos = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 283) 	do {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 284) 		/*
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 285) 		 * If we need to reload data, either we have fill() and can
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 286) 		 * try to get more data, or we don't and the input is truncated.
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 287) 		 */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 288) 		if (in.pos == in.size) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 289) 			if (in_pos != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 290) 				*in_pos += in.pos;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 291) 			in_len = fill ? fill(in_buf, ZSTD_IOBUF_SIZE) : -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 292) 			if (in_len < 0) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 293) 				error("ZSTD-compressed data is truncated");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 294) 				err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 295) 				goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 296) 			}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 297) 			in.pos = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 298) 			in.size = in_len;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 299) 		}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 300) 		/* Returns zero when the frame is complete. */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 301) 		ret = ZSTD_decompressStream(dstream, &out, &in);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 302) 		err = handle_zstd_error(ret, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 303) 		if (err)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 304) 			goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 305) 		/* Flush all of the data produced if using flush(). */
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 306) 		if (flush != NULL && out.pos > 0) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 307) 			if (out.pos != flush(out.dst, out.pos)) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 308) 				error("Failed to flush()");
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 309) 				err = -1;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 310) 				goto out;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 311) 			}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 312) 			out.pos = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 313) 		}
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 314) 	} while (ret != 0);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 315) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 316) 	if (in_pos != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 317) 		*in_pos += in.pos;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 318) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 319) 	err = 0;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 320) out:
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 321) 	if (in_allocated != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 322) 		large_free(in_allocated);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 323) 	if (out_allocated != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 324) 		large_free(out_allocated);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 325) 	if (wksp != NULL)
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 326) 		large_free(wksp);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 327) 	return err;
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 328) }
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 329) 
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 330) #ifndef UNZSTD_PREBOOT
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 331) STATIC int INIT unzstd(unsigned char *buf, long len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 332) 		       long (*fill)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 333) 		       long (*flush)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 334) 		       unsigned char *out_buf,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 335) 		       long *pos,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 336) 		       void (*error)(char *x))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 337) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 338) 	return __unzstd(buf, len, fill, flush, out_buf, 0, pos, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 339) }
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 340) #else
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 341) STATIC int INIT __decompress(unsigned char *buf, long len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 342) 			     long (*fill)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 343) 			     long (*flush)(void*, unsigned long),
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 344) 			     unsigned char *out_buf, long out_len,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 345) 			     long *pos,
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 346) 			     void (*error)(char *x))
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 347) {
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 348) 	return __unzstd(buf, len, fill, flush, out_buf, out_len, pos, error);
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 349) }
4963bb2b89884 (Nick Terrell  2020-07-30 12:08:35 -0700 350) #endif