lib/lzo/lzo1x_decompress_safe.c

Source file repositories/reference/linux-study-clean/lib/lzo/lzo1x_decompress_safe.c

File Facts

System
Linux kernel
Corpus path
lib/lzo/lzo1x_decompress_safe.c
Extension
.c
Size
6482 bytes
Lines
297
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

if (t < 4) {
			next = t;
			goto match_next;
		}
		goto copy_literal_run;
	}

	for (;;) {
		t = *ip++;
		if (t < 16) {
			if (likely(state == 0)) {
				if (unlikely(t == 0)) {
					size_t offset;
					const unsigned char *ip_last = ip;

					while (unlikely(*ip == 0)) {
						ip++;
						NEED_IP(1);
					}
					offset = ip - ip_last;
					if (unlikely(offset > MAX_255_COUNT))
						return LZO_E_ERROR;

					offset = (offset << 8) - offset;
					t += offset + 15 + *ip++;
				}
				t += 3;
copy_literal_run:
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
				if (likely(HAVE_IP(t + 15) && HAVE_OP(t + 15))) {
					const unsigned char *ie = ip + t;
					unsigned char *oe = op + t;
					do {
						COPY8(op, ip);
						op += 8;
						ip += 8;
						COPY8(op, ip);
						op += 8;
						ip += 8;
					} while (ip < ie);
					ip = ie;
					op = oe;
				} else
#endif
				{
					NEED_OP(t);
					NEED_IP(t + 3);
					do {
						*op++ = *ip++;
					} while (--t > 0);
				}
				state = 4;
				continue;
			} else if (state != 4) {
				next = t & 3;
				m_pos = op - 1;
				m_pos -= t >> 2;
				m_pos -= *ip++ << 2;
				TEST_LB(m_pos);
				NEED_OP(2);
				op[0] = m_pos[0];
				op[1] = m_pos[1];
				op += 2;
				goto match_next;
			} else {
				next = t & 3;
				m_pos = op - (1 + M2_MAX_OFFSET);
				m_pos -= t >> 2;
				m_pos -= *ip++ << 2;
				t = 3;
			}
		} else if (t >= 64) {
			next = t & 3;
			m_pos = op - 1;
			m_pos -= (t >> 2) & 7;
			m_pos -= *ip++ << 3;
			t = (t >> 5) - 1 + (3 - 1);
		} else if (t >= 32) {
			t = (t & 31) + (3 - 1);
			if (unlikely(t == 2)) {
				size_t offset;
				const unsigned char *ip_last = ip;

				while (unlikely(*ip == 0)) {
					ip++;
					NEED_IP(1);
				}
				offset = ip - ip_last;
				if (unlikely(offset > MAX_255_COUNT))
					return LZO_E_ERROR;

Annotation

Implementation Notes