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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-07-24 11:28:03 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2017-08-04 09:27:05 +0800
commita7c391f04fe3259fb0417d71fec78ae28f25780e (patch)
treeae138006abd68d231231dbea641ea1cb46e43dff /crypto
parent9a42e4eed3fcd7ba8dff6622384cd08bfe5ef707 (diff)
download96b-common-a7c391f04fe3259fb0417d71fec78ae28f25780e.tar.gz
crypto: algapi - use separate dst and src operands for __crypto_xor()
In preparation of introducing crypto_xor_cpy(), which will use separate operands for input and output, modify the __crypto_xor() implementation, which it will share with the existing crypto_xor(), which provides the actual functionality when not using the inline version. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/algapi.c25
1 files changed, 15 insertions, 10 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);