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Diffstat (limited to 'app-backup/tarsnap/files/tarsnap-1.0.40-strict-aliasing-fix.patch')
-rw-r--r--app-backup/tarsnap/files/tarsnap-1.0.40-strict-aliasing-fix.patch158
1 files changed, 158 insertions, 0 deletions
diff --git a/app-backup/tarsnap/files/tarsnap-1.0.40-strict-aliasing-fix.patch b/app-backup/tarsnap/files/tarsnap-1.0.40-strict-aliasing-fix.patch
new file mode 100644
index 000000000000..d168d99222e8
--- /dev/null
+++ b/app-backup/tarsnap/files/tarsnap-1.0.40-strict-aliasing-fix.patch
@@ -0,0 +1,158 @@
+https://github.com/Tarsnap/tarsnap/commit/ca40c06f290fb8298dc2e583303d45b58878f37b
+https://github.com/Tarsnap/tarsnap/commit/4af6d8350ab53d0f1f3104ce3d9072c2d5f9ef7a
+
+From 4af6d8350ab53d0f1f3104ce3d9072c2d5f9ef7a Mon Sep 17 00:00:00 2001
+From: Graham Percival <gperciva@tarsnap.com>
+Date: Fri, 1 Apr 2022 16:58:43 -0700
+Subject: [PATCH] scrypt: Fix strict aliasing
+
+The original scrypt code treated its data as blobs of bytes, accessing
+them in whatever manner was convenient from time to time:
+
+* as 32-bit words or vectors thereof for the purpose of the Salsa20/8 core
+* in machine-word-sized chunks (aka. size_t) for block copy and xor operations
+* as 32-bit words for the Integerify function.
+
+This worked fine at the time, but newer compilers apply strict aliasing rules
+which allow them to assume that e.g. data accessed as a uint32_t is not the
+same as data accessed as a size_t, resulting in miscompilation.
+
+Note that in recent versions of scrypt (after 2015-07-18; versions 1.2.0 and
+later) such miscompilation should be detected by the built-in runtime testing.
+
+To avoid aliasing problems, the generic scrypt code now operates on uint32_t
+throughout while the SSE2-enabled scrypt code operates on __m128i throughout.
+
+Experimentally, we found that memcpy() speeds up blkcpy() in the plain C
+case, but slowed it down in the _sse2.c case (probably because memcpy
+can make use of vector instructions internally, but cannot assume that
+it will always have a multiple of 16 bytes, as we do).
+--- a/lib/crypto/crypto_scrypt_smix.c
++++ b/lib/crypto/crypto_scrypt_smix.c
+@@ -27,39 +27,32 @@
+ * online backup system.
+ */
+ #include <stdint.h>
++#include <string.h>
+
+ #include "sysendian.h"
+
+ #include "crypto_scrypt_smix.h"
+
+-static void blkcpy(void *, const void *, size_t);
+-static void blkxor(void *, const void *, size_t);
++static void blkcpy(uint32_t *, const uint32_t *, size_t);
++static void blkxor(uint32_t *, const uint32_t *, size_t);
+ static void salsa20_8(uint32_t[16]);
+ static void blockmix_salsa8(const uint32_t *, uint32_t *, uint32_t *, size_t);
+-static uint64_t integerify(const void *, size_t);
++static uint64_t integerify(const uint32_t *, size_t);
+
+ static void
+-blkcpy(void * dest, const void * src, size_t len)
++blkcpy(uint32_t * dest, const uint32_t * src, size_t len)
+ {
+- size_t * D = dest;
+- const size_t * S = src;
+- size_t L = len / sizeof(size_t);
+- size_t i;
+
+- for (i = 0; i < L; i++)
+- D[i] = S[i];
++ memcpy(dest, src, len);
+ }
+
+ static void
+-blkxor(void * dest, const void * src, size_t len)
++blkxor(uint32_t * dest, const uint32_t * src, size_t len)
+ {
+- size_t * D = dest;
+- const size_t * S = src;
+- size_t L = len / sizeof(size_t);
+ size_t i;
+
+- for (i = 0; i < L; i++)
+- D[i] ^= S[i];
++ for (i = 0; i < len / 4; i++)
++ dest[i] ^= src[i];
+ }
+
+ /**
+@@ -145,9 +138,9 @@ blockmix_salsa8(const uint32_t * Bin, uint32_t * Bout, uint32_t * X, size_t r)
+ * Return the result of parsing B_{2r-1} as a little-endian integer.
+ */
+ static uint64_t
+-integerify(const void * B, size_t r)
++integerify(const uint32_t * B, size_t r)
+ {
+- const uint32_t * X = (const void *)((uintptr_t)(B) + (2 * r - 1) * 64);
++ const uint32_t * X = B + (2 * r - 1) * 16;
+
+ return (((uint64_t)(X[1]) << 32) + X[0]);
+ }
+--- a/lib/crypto/crypto_scrypt_smix_sse2.c
++++ b/lib/crypto/crypto_scrypt_smix_sse2.c
+@@ -36,34 +36,30 @@
+
+ #include "crypto_scrypt_smix_sse2.h"
+
+-static void blkcpy(void *, const void *, size_t);
+-static void blkxor(void *, const void *, size_t);
++static void blkcpy(__m128i *, const __m128i *, size_t);
++static void blkxor(__m128i *, const __m128i *, size_t);
+ static void salsa20_8(__m128i[4]);
+ static void blockmix_salsa8(const __m128i *, __m128i *, __m128i *, size_t);
+-static uint64_t integerify(const void *, size_t);
++static uint64_t integerify(const __m128i *, size_t);
+
+ static void
+-blkcpy(void * dest, const void * src, size_t len)
++blkcpy(__m128i * dest, const __m128i * src, size_t len)
+ {
+- __m128i * D = dest;
+- const __m128i * S = src;
+ size_t L = len / 16;
+ size_t i;
+
+ for (i = 0; i < L; i++)
+- D[i] = S[i];
++ dest[i] = src[i];
+ }
+
+ static void
+-blkxor(void * dest, const void * src, size_t len)
++blkxor(__m128i * dest, const __m128i * src, size_t len)
+ {
+- __m128i * D = dest;
+- const __m128i * S = src;
+ size_t L = len / 16;
+ size_t i;
+
+ for (i = 0; i < L; i++)
+- D[i] = _mm_xor_si128(D[i], S[i]);
++ dest[i] = _mm_xor_si128(dest[i], src[i]);
+ }
+
+ /**
+@@ -168,11 +164,18 @@ blockmix_salsa8(const __m128i * Bin, __m128i * Bout, __m128i * X, size_t r)
+ * Note that B's layout is permuted compared to the generic implementation.
+ */
+ static uint64_t
+-integerify(const void * B, size_t r)
++integerify(const __m128i * B, size_t r)
+ {
+- const uint32_t * X = (const void *)((uintptr_t)(B) + (2 * r - 1) * 64);
++ const __m128i * X = B + (2*r - 1) * 4;
++ uint32_t X0, X13;
+
+- return (((uint64_t)(X[13]) << 32) + X[0]);
++ /* Get the first 32-bit element in X[0]. */
++ X0 = (uint32_t)_mm_cvtsi128_si32(X[0]);
++
++ /* Get the second 32-bit element in X[3]. */
++ X13 = (uint32_t)_mm_cvtsi128_si32(_mm_srli_si128(X[3], 4));
++
++ return (((uint64_t)(X13) << 32) + X0);
+ }
+
+ /**