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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - lib/lzo/lzo1x_decompress_safe.c
2 * LZO1X Decompressor from LZO
4 * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
6 * The full LZO package can be found at:
7 * http://www.oberhumer.com/opensource/lzo/
9 * Changed for Linux kernel use by:
10 * Nitin Gupta <nitingupta910@gmail.com>
11 * Richard Purdie <rpurdie@openedhand.com>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
18 #include <asm/unaligned.h>
19 #include <linux/lzo.h>
22 #define HAVE_IP(x) ((size_t)(ip_end - ip) >= (size_t)(x))
23 #define HAVE_OP(x) ((size_t)(op_end - op) >= (size_t)(x))
24 #define NEED_IP(x) if (!HAVE_IP(x)) goto input_overrun
25 #define NEED_OP(x) if (!HAVE_OP(x)) goto output_overrun
26 #define TEST_LB(m_pos) if ((m_pos) < out) goto lookbehind_overrun
28 int lzo1x_decompress_safe(const unsigned char *in
, size_t in_len
,
29 unsigned char *out
, size_t *out_len
)
32 const unsigned char *ip
;
35 const unsigned char *m_pos
;
36 const unsigned char * const ip_end
= in
+ in_len
;
37 unsigned char * const op_end
= out
+ *out_len
;
42 if (unlikely(in_len
< 3))
50 goto copy_literal_run
;
56 if (likely(state
== 0)) {
57 if (unlikely(t
== 0)) {
58 while (unlikely(*ip
== 0)) {
67 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
68 if (likely(HAVE_IP(t
+ 15) && HAVE_OP(t
+ 15))) {
69 const unsigned char *ie
= ip
+ t
;
70 unsigned char *oe
= op
+ t
;
92 } else if (state
!= 4) {
105 m_pos
= op
- (1 + M2_MAX_OFFSET
);
110 } else if (t
>= 64) {
113 m_pos
-= (t
>> 2) & 7;
115 t
= (t
>> 5) - 1 + (3 - 1);
116 } else if (t
>= 32) {
117 t
= (t
& 31) + (3 - 1);
118 if (unlikely(t
== 2)) {
119 while (unlikely(*ip
== 0)) {
128 next
= get_unaligned_le16(ip
);
134 m_pos
-= (t
& 8) << 11;
135 t
= (t
& 7) + (3 - 1);
136 if (unlikely(t
== 2)) {
137 while (unlikely(*ip
== 0)) {
145 next
= get_unaligned_le16(ip
);
154 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
155 if (op
- m_pos
>= 8) {
156 unsigned char *oe
= op
+ t
;
157 if (likely(HAVE_OP(t
+ 15))) {
183 unsigned char *oe
= op
+ t
;
196 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
197 if (likely(HAVE_IP(6) && HAVE_OP(4))) {
215 return (t
!= 3 ? LZO_E_ERROR
:
216 ip
== ip_end
? LZO_E_OK
:
217 ip
< ip_end
? LZO_E_INPUT_NOT_CONSUMED
: LZO_E_INPUT_OVERRUN
);
221 return LZO_E_INPUT_OVERRUN
;
225 return LZO_E_OUTPUT_OVERRUN
;
229 return LZO_E_LOOKBEHIND_OVERRUN
;
232 EXPORT_SYMBOL_GPL(lzo1x_decompress_safe
);
234 MODULE_LICENSE("GPL");
235 MODULE_DESCRIPTION("LZO1X Decompressor");