lib/crypto/utils.c

Source file repositories/reference/linux-study-clean/lib/crypto/utils.c

File Facts

System
Linux kernel
Corpus path
lib/crypto/utils.c
Extension
.c
Size
2329 bytes
Lines
91
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

while (((unsigned long)dst & (relalign - 1)) && len > 0) {
			*dst++ = *src1++ ^ *src2++;
			len--;
		}
	}

	while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) {
		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
			u64 l = get_unaligned((u64 *)src1) ^
				get_unaligned((u64 *)src2);
			put_unaligned(l, (u64 *)dst);
		} else {
			*(u64 *)dst = *(u64 *)src1 ^ *(u64 *)src2;
		}
		dst += 8;
		src1 += 8;
		src2 += 8;
		len -= 8;
	}

	while (len >= 4 && !(relalign & 3)) {
		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
			u32 l = get_unaligned((u32 *)src1) ^
				get_unaligned((u32 *)src2);
			put_unaligned(l, (u32 *)dst);
		} else {
			*(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2;
		}
		dst += 4;
		src1 += 4;
		src2 += 4;
		len -= 4;
	}

	while (len >= 2 && !(relalign & 1)) {
		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
			u16 l = get_unaligned((u16 *)src1) ^
				get_unaligned((u16 *)src2);
			put_unaligned(l, (u16 *)dst);
		} else {
			*(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2;
		}
		dst += 2;
		src1 += 2;
		src2 += 2;
		len -= 2;
	}

	while (len--)
		*dst++ = *src1++ ^ *src2++;
}
EXPORT_SYMBOL_GPL(__crypto_xor);

MODULE_DESCRIPTION("Crypto library utility functions");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes