1 // SPDX-License-Identifier: GPL 2.0+ OR BSD-3-Clause
2 /*
3 * Copyright 2015 Google Inc.
4 */
5
6 #include <common.h>
7 #include <compiler.h>
8 #include <image.h>
9 #include <lz4.h>
10 #include <linux/kernel.h>
11 #include <linux/types.h>
12 #include <asm/unaligned.h>
13
LZ4_readLE16(const void * src)14 static u16 LZ4_readLE16(const void *src)
15 {
16 return get_unaligned_le16(src);
17 }
LZ4_copy4(void * dst,const void * src)18 static void LZ4_copy4(void *dst, const void *src)
19 {
20 put_unaligned(get_unaligned((const u32 *)src), (u32 *)dst);
21 }
LZ4_copy8(void * dst,const void * src)22 static void LZ4_copy8(void *dst, const void *src)
23 {
24 put_unaligned(get_unaligned((const u64 *)src), (u64 *)dst);
25 }
26
27 typedef uint8_t BYTE;
28 typedef uint16_t U16;
29 typedef uint32_t U32;
30 typedef int32_t S32;
31 typedef uint64_t U64;
32
33 #define FORCE_INLINE static inline __attribute__((always_inline))
34
35 /* lz4.c is unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
36 #include "lz4.c" /* #include for inlining, do not link! */
37
38 #define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
39
ulz4fn(const void * src,size_t srcn,void * dst,size_t * dstn)40 int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
41 {
42 const void *end = dst + *dstn;
43 const void *in = src;
44 void *out = dst;
45 int has_block_checksum;
46 int ret;
47 *dstn = 0;
48
49 { /* With in-place decompression the header may become invalid later. */
50 u32 magic;
51 u8 flags, version, independent_blocks, has_content_size;
52 u8 block_desc;
53
54 if (srcn < sizeof(u32) + 3*sizeof(u8))
55 return -EINVAL; /* input overrun */
56
57 magic = get_unaligned_le32(in);
58 in += sizeof(u32);
59 flags = *(u8 *)in;
60 in += sizeof(u8);
61 block_desc = *(u8 *)in;
62 in += sizeof(u8);
63
64 version = (flags >> 6) & 0x3;
65 independent_blocks = (flags >> 5) & 0x1;
66 has_block_checksum = (flags >> 4) & 0x1;
67 has_content_size = (flags >> 3) & 0x1;
68
69 /* We assume there's always only a single, standard frame. */
70 if (magic != LZ4F_MAGIC || version != 1)
71 return -EPROTONOSUPPORT; /* unknown format */
72 if ((flags & 0x03) || (block_desc & 0x8f))
73 return -EINVAL; /* reserved bits must be zero */
74 if (!independent_blocks)
75 return -EPROTONOSUPPORT; /* we can't support this yet */
76
77 if (has_content_size) {
78 if (srcn < sizeof(u32) + 3*sizeof(u8) + sizeof(u64))
79 return -EINVAL; /* input overrun */
80 in += sizeof(u64);
81 }
82 /* Header checksum byte */
83 in += sizeof(u8);
84 }
85
86 while (1) {
87 u32 block_header, block_size;
88
89 block_header = get_unaligned_le32(in);
90 in += sizeof(u32);
91 block_size = block_header & ~LZ4F_BLOCKUNCOMPRESSED_FLAG;
92
93 if (in - src + block_size > srcn) {
94 ret = -EINVAL; /* input overrun */
95 break;
96 }
97
98 if (!block_size) {
99 ret = 0; /* decompression successful */
100 break;
101 }
102
103 if (block_header & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
104 size_t size = min((ptrdiff_t)block_size, end - out);
105 memcpy(out, in, size);
106 out += size;
107 if (size < block_size) {
108 ret = -ENOBUFS; /* output overrun */
109 break;
110 }
111 } else {
112 /* constant folding essential, do not touch params! */
113 ret = LZ4_decompress_generic(in, out, block_size,
114 end - out, endOnInputSize,
115 full, 0, noDict, out, NULL, 0);
116 if (ret < 0) {
117 ret = -EPROTO; /* decompression error */
118 break;
119 }
120 out += ret;
121 }
122
123 in += block_size;
124 if (has_block_checksum)
125 in += sizeof(u32);
126 }
127
128 *dstn = out - dst;
129 return ret;
130 }
131