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Diffstat (limited to 'lib/lzo/lzo1x_compress.c')
-rw-r--r--lib/lzo/lzo1x_compress.c221
1 files changed, 196 insertions, 25 deletions
diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index 236eb21167b5..01586af2347f 100644
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* LZO1X Compressor from LZO
*
@@ -13,14 +14,26 @@
#include <linux/module.h>
#include <linux/kernel.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
#include <linux/lzo.h>
#include "lzodefs.h"
-static noinline size_t
-lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
- unsigned char *out, size_t *out_len,
- size_t ti, void *wrkmem)
+#undef LZO_UNSAFE
+
+#ifndef LZO_SAFE
+#define LZO_UNSAFE 1
+#define LZO_SAFE(name) name
+#define HAVE_OP(x) 1
+#endif
+
+#define NEED_OP(x) if (unlikely(!HAVE_OP(x))) goto output_overrun
+
+static noinline int
+LZO_SAFE(lzo1x_1_do_compress)(const unsigned char *in, size_t in_len,
+ unsigned char **out, unsigned char *op_end,
+ size_t *tp, void *wrkmem,
+ signed char *state_offset,
+ const unsigned char bitstream_version)
{
const unsigned char *ip;
unsigned char *op;
@@ -28,53 +41,119 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
const unsigned char * const ip_end = in + in_len - 20;
const unsigned char *ii;
lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
+ size_t ti = *tp;
- op = out;
+ op = *out;
ip = in;
ii = ip;
ip += ti < 4 ? 4 - ti : 0;
for (;;) {
- const unsigned char *m_pos;
+ const unsigned char *m_pos = NULL;
size_t t, m_len, m_off;
u32 dv;
+ u32 run_length = 0;
literal:
ip += 1 + ((ip - ii) >> 5);
next:
if (unlikely(ip >= ip_end))
break;
dv = get_unaligned_le32(ip);
- t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
- m_pos = in + dict[t];
- dict[t] = (lzo_dict_t) (ip - in);
- if (unlikely(dv != get_unaligned_le32(m_pos)))
- goto literal;
+
+ if (dv == 0 && bitstream_version) {
+ const unsigned char *ir = ip + 4;
+ const unsigned char *limit = min(ip_end, ip + MAX_ZERO_RUN_LENGTH + 1);
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \
+ defined(LZO_FAST_64BIT_MEMORY_ACCESS)
+ u64 dv64;
+
+ for (; (ir + 32) <= limit; ir += 32) {
+ dv64 = get_unaligned((u64 *)ir);
+ dv64 |= get_unaligned((u64 *)ir + 1);
+ dv64 |= get_unaligned((u64 *)ir + 2);
+ dv64 |= get_unaligned((u64 *)ir + 3);
+ if (dv64)
+ break;
+ }
+ for (; (ir + 8) <= limit; ir += 8) {
+ dv64 = get_unaligned((u64 *)ir);
+ if (dv64) {
+# if defined(__LITTLE_ENDIAN)
+ ir += __builtin_ctzll(dv64) >> 3;
+# elif defined(__BIG_ENDIAN)
+ ir += __builtin_clzll(dv64) >> 3;
+# else
+# error "missing endian definition"
+# endif
+ break;
+ }
+ }
+#else
+ while ((ir < (const unsigned char *)
+ ALIGN((uintptr_t)ir, 4)) &&
+ (ir < limit) && (*ir == 0))
+ ir++;
+ if (IS_ALIGNED((uintptr_t)ir, 4)) {
+ for (; (ir + 4) <= limit; ir += 4) {
+ dv = *((u32 *)ir);
+ if (dv) {
+# if defined(__LITTLE_ENDIAN)
+ ir += __builtin_ctz(dv) >> 3;
+# elif defined(__BIG_ENDIAN)
+ ir += __builtin_clz(dv) >> 3;
+# else
+# error "missing endian definition"
+# endif
+ break;
+ }
+ }
+ }
+#endif
+ while (likely(ir < limit) && unlikely(*ir == 0))
+ ir++;
+ run_length = ir - ip;
+ if (run_length > MAX_ZERO_RUN_LENGTH)
+ run_length = MAX_ZERO_RUN_LENGTH;
+ } else {
+ t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
+ m_pos = in + dict[t];
+ dict[t] = (lzo_dict_t) (ip - in);
+ if (unlikely(dv != get_unaligned_le32(m_pos)))
+ goto literal;
+ }
ii -= ti;
ti = 0;
t = ip - ii;
if (t != 0) {
if (t <= 3) {
- op[-2] |= t;
+ op[*state_offset] |= t;
+ NEED_OP(4);
COPY4(op, ii);
op += t;
} else if (t <= 16) {
+ NEED_OP(17);
*op++ = (t - 3);
COPY8(op, ii);
COPY8(op + 8, ii + 8);
op += t;
} else {
if (t <= 18) {
+ NEED_OP(1);
*op++ = (t - 3);
} else {
size_t tt = t - 18;
+ NEED_OP(1);
*op++ = 0;
while (unlikely(tt > 255)) {
tt -= 255;
+ NEED_OP(1);
*op++ = 0;
}
+ NEED_OP(1);
*op++ = tt;
}
+ NEED_OP(t);
do {
COPY8(op, ii);
COPY8(op + 8, ii + 8);
@@ -88,6 +167,18 @@ next:
}
}
+ if (unlikely(run_length)) {
+ ip += run_length;
+ run_length -= MIN_ZERO_RUN_LENGTH;
+ NEED_OP(4);
+ put_unaligned_le32((run_length << 21) | 0xfffc18
+ | (run_length & 0x7), op);
+ op += 4;
+ run_length = 0;
+ *state_offset = -3;
+ goto finished_writing_instruction;
+ }
+
m_len = 4;
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
@@ -170,13 +261,14 @@ m_len_done:
m_off = ip - m_pos;
ip += m_len;
- ii = ip;
if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
m_off -= 1;
+ NEED_OP(2);
*op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
*op++ = (m_off >> 3);
} else if (m_off <= M3_MAX_OFFSET) {
m_off -= 1;
+ NEED_OP(1);
if (m_len <= M3_MAX_LEN)
*op++ = (M3_MARKER | (m_len - 2));
else {
@@ -184,54 +276,103 @@ m_len_done:
*op++ = M3_MARKER | 0;
while (unlikely(m_len > 255)) {
m_len -= 255;
+ NEED_OP(1);
*op++ = 0;
}
+ NEED_OP(1);
*op++ = (m_len);
}
+ NEED_OP(2);
*op++ = (m_off << 2);
*op++ = (m_off >> 6);
} else {
m_off -= 0x4000;
+ NEED_OP(1);
if (m_len <= M4_MAX_LEN)
*op++ = (M4_MARKER | ((m_off >> 11) & 8)
| (m_len - 2));
else {
+ if (unlikely(((m_off & 0x403f) == 0x403f)
+ && (m_len >= 261)
+ && (m_len <= 264))
+ && likely(bitstream_version)) {
+ // Under lzo-rle, block copies
+ // for 261 <= length <= 264 and
+ // (distance & 0x80f3) == 0x80f3
+ // can result in ambiguous
+ // output. Adjust length
+ // to 260 to prevent ambiguity.
+ ip -= m_len - 260;
+ m_len = 260;
+ }
m_len -= M4_MAX_LEN;
*op++ = (M4_MARKER | ((m_off >> 11) & 8));
while (unlikely(m_len > 255)) {
+ NEED_OP(1);
m_len -= 255;
*op++ = 0;
}
+ NEED_OP(1);
*op++ = (m_len);
}
+ NEED_OP(2);
*op++ = (m_off << 2);
*op++ = (m_off >> 6);
}
+ *state_offset = -2;
+finished_writing_instruction:
+ ii = ip;
goto next;
}
- *out_len = op - out;
- return in_end - (ii - ti);
+ *out = op;
+ *tp = in_end - (ii - ti);
+ return LZO_E_OK;
+
+output_overrun:
+ return LZO_E_OUTPUT_OVERRUN;
}
-int lzo1x_1_compress(const unsigned char *in, size_t in_len,
- unsigned char *out, size_t *out_len,
- void *wrkmem)
+static int LZO_SAFE(lzogeneric1x_1_compress)(
+ const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len,
+ void *wrkmem, const unsigned char bitstream_version)
{
+ unsigned char * const op_end = out + *out_len;
const unsigned char *ip = in;
unsigned char *op = out;
+ unsigned char *data_start;
size_t l = in_len;
size_t t = 0;
+ signed char state_offset = -2;
+ unsigned int m4_max_offset;
+
+ // LZO v0 will never write 17 as first byte (except for zero-length
+ // input), so this is used to version the bitstream
+ if (bitstream_version > 0) {
+ *op++ = 17;
+ *op++ = bitstream_version;
+ m4_max_offset = M4_MAX_OFFSET_V1;
+ } else {
+ m4_max_offset = M4_MAX_OFFSET_V0;
+ }
+
+ data_start = op;
while (l > 20) {
- size_t ll = l <= (M4_MAX_OFFSET + 1) ? l : (M4_MAX_OFFSET + 1);
+ size_t ll = min_t(size_t, l, m4_max_offset + 1);
uintptr_t ll_end = (uintptr_t) ip + ll;
+ int err;
+
if ((ll_end + ((t + ll) >> 5)) <= ll_end)
break;
BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
- t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem);
+ err = LZO_SAFE(lzo1x_1_do_compress)(
+ ip, ll, &op, op_end, &t, wrkmem,
+ &state_offset, bitstream_version);
+ if (err != LZO_E_OK)
+ return err;
ip += ll;
- op += *out_len;
l -= ll;
}
t += l;
@@ -239,21 +380,27 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len,
if (t > 0) {
const unsigned char *ii = in + in_len - t;
- if (op == out && t <= 238) {
+ if (op == data_start && t <= 238) {
+ NEED_OP(1);
*op++ = (17 + t);
} else if (t <= 3) {
- op[-2] |= t;
+ op[state_offset] |= t;
} else if (t <= 18) {
+ NEED_OP(1);
*op++ = (t - 3);
} else {
size_t tt = t - 18;
+ NEED_OP(1);
*op++ = 0;
while (tt > 255) {
tt -= 255;
+ NEED_OP(1);
*op++ = 0;
}
+ NEED_OP(1);
*op++ = tt;
}
+ NEED_OP(t);
if (t >= 16) do {
COPY8(op, ii);
COPY8(op + 8, ii + 8);
@@ -266,14 +413,38 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len,
} while (--t > 0);
}
+ NEED_OP(3);
*op++ = M4_MARKER | 1;
*op++ = 0;
*op++ = 0;
*out_len = op - out;
return LZO_E_OK;
+
+output_overrun:
+ return LZO_E_OUTPUT_OVERRUN;
+}
+
+int LZO_SAFE(lzo1x_1_compress)(const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len,
+ void *wrkmem)
+{
+ return LZO_SAFE(lzogeneric1x_1_compress)(
+ in, in_len, out, out_len, wrkmem, 0);
+}
+
+int LZO_SAFE(lzorle1x_1_compress)(const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len,
+ void *wrkmem)
+{
+ return LZO_SAFE(lzogeneric1x_1_compress)(
+ in, in_len, out, out_len, wrkmem, LZO_VERSION);
}
-EXPORT_SYMBOL_GPL(lzo1x_1_compress);
+EXPORT_SYMBOL_GPL(LZO_SAFE(lzo1x_1_compress));
+EXPORT_SYMBOL_GPL(LZO_SAFE(lzorle1x_1_compress));
+
+#ifndef LZO_UNSAFE
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZO1X-1 Compressor");
+#endif
generated by cgit (git 2.34.1) at 2025-12-24 22:13:02 +0000