bpo-36515: Disable unaligned memory access in _sha3 on ARM (pythonGH-25927)

gpshead · web-flow · commit da5c808fb50d · 2021-05-05T13:55:33.000-07:00
Contributed-By: Matthias Klose

Automerge-Triggered-By: GH:tiran
diff --git a/Misc/NEWS.d/next/Library/2021-05-05-11-44-49.bpo-36515.uOSa3q.rst b/Misc/NEWS.d/next/Library/2021-05-05-11-44-49.bpo-36515.uOSa3q.rst
@@ -0,0 +1,2 @@
+The :mod:`hashlib` module no longer does unaligned memory accesses when
+compiled for ARM platforms.
diff --git a/Modules/_sha3/sha3module.c b/Modules/_sha3/sha3module.c
@@ -64,6 +64,11 @@
 #define PLATFORM_BYTE_ORDER IS_BIG_ENDIAN
 #endif
 
+/* Prevent bus errors on platforms requiring aligned accesses such ARM. */
+#if HAVE_ALIGNED_REQUIRED && !defined(NO_MISALIGNED_ACCESSES)
+#define NO_MISALIGNED_ACCESSES
+#endif
+
 /* mangle names */
 #define KeccakF1600_FastLoop_Absorb _PySHA3_KeccakF1600_FastLoop_Absorb
 #define Keccak_HashFinal _PySHA3_Keccak_HashFinal

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+The :mod:`hashlib` module no longer does unaligned memory accesses when
	`2`	`+compiled for ARM platforms.`