In preparation of updating crypto_xor() [which is what the crypto API exposes to other subsystems] to use separate operands for input and output, first modify the __crypto_xor() implementation that provides the actual functionality when not using the inline version. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- crypto/algapi.c | 25 ++++++++++++-------- include/crypto/algapi.h | 4 ++-- 2 files changed, 17 insertions(+), 12 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index e4cc7615a139..aa699ff6c876 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -975,13 +975,15 @@ void crypto_inc(u8 *a, unsigned int size) } EXPORT_SYMBOL_GPL(crypto_inc); -void __crypto_xor(u8 *dst, const u8 *src, unsigned int len) +void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len) { int relalign = 0; if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { int size = sizeof(unsigned long); - int d = ((unsigned long)dst ^ (unsigned long)src) & (size - 1); + int d = (((unsigned long)dst ^ (unsigned long)src1) | + ((unsigned long)dst ^ (unsigned long)src2)) & + (size - 1); relalign = d ? 1 << __ffs(d) : size; @@ -992,34 +994,37 @@ void __crypto_xor(u8 *dst, const u8 *src, unsigned int len) * process the remainder of the input using optimal strides. */ while (((unsigned long)dst & (relalign - 1)) && len > 0) { - *dst++ ^= *src++; + *dst++ = *src1++ ^ *src2++; len--; } } while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) { - *(u64 *)dst ^= *(u64 *)src; + *(u64 *)dst = *(u64 *)src1 ^ *(u64 *)src2; dst += 8; - src += 8; + src1 += 8; + src2 += 8; len -= 8; } while (len >= 4 && !(relalign & 3)) { - *(u32 *)dst ^= *(u32 *)src; + *(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2; dst += 4; - src += 4; + src1 += 4; + src2 += 4; len -= 4; } while (len >= 2 && !(relalign & 1)) { - *(u16 *)dst ^= *(u16 *)src; + *(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2; dst += 2; - src += 2; + src1 += 2; + src2 += 2; len -= 2; } while (len--) - *dst++ ^= *src++; + *dst++ = *src1++ ^ *src2++; } EXPORT_SYMBOL_GPL(__crypto_xor); diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h index 436c4c2683c7..fd547f946bf8 100644 --- a/include/crypto/algapi.h +++ b/include/crypto/algapi.h @@ -192,7 +192,7 @@ static inline unsigned int crypto_queue_len(struct crypto_queue *queue) } void crypto_inc(u8 *a, unsigned int size); -void __crypto_xor(u8 *dst, const u8 *src, unsigned int size); +void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size); static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size) { @@ -207,7 +207,7 @@ static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size) size -= sizeof(unsigned long); } } else { - __crypto_xor(dst, src, size); + __crypto_xor(dst, dst, src, size); } } -- 2.9.3 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel