[PATCH] crypto: xor - move __crypto_xor into lib/
From: Eric Biggers
Date: Sat Jul 09 2022 - 17:55:42 EST
From: Eric Biggers <ebiggers@xxxxxxxxxx>
CRYPTO_LIB_CHACHA depends on CRYPTO for __crypto_xor, defined in
crypto/algapi.c. This is a layering violation because the dependencies
should only go in the other direction (crypto/ => lib/crypto/). Also
the correct dependency would be CRYPTO_ALGAPI, not CRYPTO. Fix this by
moving __crypto_xor into lib/xor.c, alongside lib/memneq.c where
__crypto_memneq was recently moved.
Note that CRYPTO_LIB_CHACHA_GENERIC selected XOR_BLOCKS, which is
unrelated and unnecessary. It was perhaps thought that XOR_BLOCKS was
needed for __crypto_xor, but that's not the case.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
crypto/Kconfig | 1 +
crypto/algapi.c | 71 --------------------------------------
lib/Kconfig | 3 ++
lib/Makefile | 1 +
lib/crypto/Kconfig | 3 +-
lib/xor.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 91 insertions(+), 73 deletions(-)
create mode 100644 lib/xor.c
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 59489a300cd100..9145fdfa8a5bbd 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -40,6 +40,7 @@ config CRYPTO_ALGAPI
This option provides the API for cryptographic algorithms.
config CRYPTO_ALGAPI2
+ select LIB_XOR
tristate
config CRYPTO_AEAD
diff --git a/crypto/algapi.c b/crypto/algapi.c
index d1c99288af3e0d..5c69ff8e8fa5c1 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -997,77 +997,6 @@ void crypto_inc(u8 *a, unsigned int size)
}
EXPORT_SYMBOL_GPL(crypto_inc);
-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)src1) |
- ((unsigned long)dst ^ (unsigned long)src2)) &
- (size - 1);
-
- relalign = d ? 1 << __ffs(d) : size;
-
- /*
- * If we care about alignment, process as many bytes as
- * needed to advance dst and src to values whose alignments
- * equal their relative alignment. This will allow us to
- * process the remainder of the input using optimal strides.
- */
- 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);
-
unsigned int crypto_alg_extsize(struct crypto_alg *alg)
{
return alg->cra_ctxsize +
diff --git a/lib/Kconfig b/lib/Kconfig
index eaaad4d85bf24b..4d2b09487442ea 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -123,6 +123,9 @@ source "lib/crypto/Kconfig"
config LIB_MEMNEQ
bool
+config LIB_XOR
+ bool
+
config CRC_CCITT
tristate "CRC-CCITT functions"
help
diff --git a/lib/Makefile b/lib/Makefile
index f99bf61f8bbc67..ceeb3f913f1b57 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -252,6 +252,7 @@ obj-$(CONFIG_SIGNATURE) += digsig.o
lib-$(CONFIG_CLZ_TAB) += clz_tab.o
lib-$(CONFIG_LIB_MEMNEQ) += memneq.o
+lib-$(CONFIG_LIB_XOR) += xor.o
obj-$(CONFIG_GENERIC_STRNCPY_FROM_USER) += strncpy_from_user.o
obj-$(CONFIG_GENERIC_STRNLEN_USER) += strnlen_user.o
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 2082af43d51fbe..8432e0e2a9ee0d 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -33,7 +33,7 @@ config CRYPTO_ARCH_HAVE_LIB_CHACHA
config CRYPTO_LIB_CHACHA_GENERIC
tristate
- select XOR_BLOCKS
+ select LIB_XOR
help
This symbol can be depended upon by arch implementations of the
ChaCha library interface that require the generic code as a
@@ -43,7 +43,6 @@ config CRYPTO_LIB_CHACHA_GENERIC
config CRYPTO_LIB_CHACHA
tristate "ChaCha library interface"
- depends on CRYPTO
depends on CRYPTO_ARCH_HAVE_LIB_CHACHA || !CRYPTO_ARCH_HAVE_LIB_CHACHA
select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
help
diff --git a/lib/xor.c b/lib/xor.c
new file mode 100644
index 00000000000000..5f8f7765a48d5f
--- /dev/null
+++ b/lib/xor.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * The __crypto_xor library function
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
+ */
+
+#include <crypto/algapi.h>
+#include <asm/unaligned.h>
+
+/*
+ * XOR @len bytes from @src1 and @src2 together, writing the result to @dst
+ * (which may alias one of the sources). Don't call this directly; call
+ * crypto_xor() or crypto_xor_cpy() instead.
+ */
+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)src1) |
+ ((unsigned long)dst ^ (unsigned long)src2)) &
+ (size - 1);
+
+ relalign = d ? 1 << __ffs(d) : size;
+
+ /*
+ * If we care about alignment, process as many bytes as
+ * needed to advance dst and src to values whose alignments
+ * equal their relative alignment. This will allow us to
+ * process the remainder of the input using optimal strides.
+ */
+ 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);
base-commit: 79e6e2f3f3ff345947075341781e900e4f70db81
--
2.37.0