change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/lib/lzo/lzo1x_decompress_safe.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  *  LZO1X Decompressor from LZO
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  *
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@@ -31,7 +32,7 @@
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  * depending on the base count. Since the base count is taken from a u8
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  * and a few bits, it is safe to assume that it will always be lower than
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  * or equal to 2*255, thus we can always prevent any overflow by accepting
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- * two less 255 steps. See Documentation/lzo.txt for more information.
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+ * two less 255 steps. See Documentation/staging/lzo.rst for more information.
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  */
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 #define MAX_255_COUNT      ((((size_t)~0) / 255) - 2)
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@@ -46,11 +47,21 @@
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 	const unsigned char * const ip_end = in + in_len;
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 	unsigned char * const op_end = out + *out_len;
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+	unsigned char bitstream_version;
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+
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 	op = out;
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 	ip = in;
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 	if (unlikely(in_len < 3))
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 		goto input_overrun;
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+
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+	if (likely(in_len >= 5) && likely(*ip == 17)) {
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+		bitstream_version = ip[1];
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+		ip += 2;
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+	} else {
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+		bitstream_version = 0;
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+	}
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+
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 	if (*ip > 17) {
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 		t = *ip++ - 17;
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 		if (t < 4) {
..
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@@ -154,32 +165,49 @@
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 			m_pos -= next >> 2;
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 			next &= 3;
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 		} else {
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-			m_pos = op;
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-			m_pos -= (t & 8) << 11;
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-			t = (t & 7) + (3 - 1);
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-			if (unlikely(t == 2)) {
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-				size_t offset;
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-				const unsigned char *ip_last = ip;
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-
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-				while (unlikely(*ip == 0)) {
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-					ip++;
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-					NEED_IP(1);
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-				}
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-				offset = ip - ip_last;
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-				if (unlikely(offset > MAX_255_COUNT))
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-					return LZO_E_ERROR;
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-
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-				offset = (offset << 8) - offset;
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-				t += offset + 7 + *ip++;
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-				NEED_IP(2);
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-			}
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+			NEED_IP(2);
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 			next = get_unaligned_le16(ip);
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-			ip += 2;
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-			m_pos -= next >> 2;
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-			next &= 3;
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-			if (m_pos == op)
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-				goto eof_found;
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-			m_pos -= 0x4000;
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+			if (((next & 0xfffc) == 0xfffc) &&
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+			    ((t & 0xf8) == 0x18) &&
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+			    likely(bitstream_version)) {
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+				NEED_IP(3);
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+				t &= 7;
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+				t |= ip[2] << 3;
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+				t += MIN_ZERO_RUN_LENGTH;
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+				NEED_OP(t);
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+				memset(op, 0, t);
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+				op += t;
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+				next &= 3;
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+				ip += 3;
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+				goto match_next;
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+			} else {
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+				m_pos = op;
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+				m_pos -= (t & 8) << 11;
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+				t = (t & 7) + (3 - 1);
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+				if (unlikely(t == 2)) {
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+					size_t offset;
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+					const unsigned char *ip_last = ip;
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+
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+					while (unlikely(*ip == 0)) {
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+						ip++;
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+						NEED_IP(1);
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+					}
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+					offset = ip - ip_last;
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+					if (unlikely(offset > MAX_255_COUNT))
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+						return LZO_E_ERROR;
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+
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+					offset = (offset << 8) - offset;
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+					t += offset + 7 + *ip++;
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+					NEED_IP(2);
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+					next = get_unaligned_le16(ip);
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+				}
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+				ip += 2;
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+				m_pos -= next >> 2;
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+				next &= 3;
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+				if (m_pos == op)
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+					goto eof_found;
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+				m_pos -= 0x4000;
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+			}
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 		}
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 		TEST_LB(m_pos);
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 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)