On 2023/08/16 20:15, Theo Buehler wrote:
> I found on one sparc64 box that reposync stopped working and it turned
> out that rsync on sparc64 is busted due to xxhash not dealing correctly
> with unaligned access.
>
> Program terminated with signal SIGBUS, Bus error.
> #0 XXH_read64 (ptr=0xfffffe7ed9467bbe) at /usr/local/include/xxhash.h:2996
>
> xxhash.h claims XXH_FORCE_MEMORY_ACCESS=0 to be the default, but that
> doesn't seem to be true (anymore?). I haven't tried to find out why.
default eh, what a lie.
#ifndef XXH_FORCE_MEMORY_ACCESS /* can be defined externally, on command line
for example */
/* prefer __packed__ structures (method 1) for GCC
* < ARMv7 with unaligned access (e.g. Raspbian armhf) still uses byte
shifting, so we use memcpy
* which for some reason does unaligned loads. */
# if defined(__GNUC__) && !(defined(__ARM_ARCH) && __ARM_ARCH < 7 &&
defined(__ARM_FEATURE_UNALIGNED))
# define XXH_FORCE_MEMORY_ACCESS 1
# endif
#endif
> rsync built with the diff below that forces the use of memcpy() to
> avoid unaligned access seems to work fine and xxhash passes regress on
> sparc64 (after removing -Wvla from ${WRKSRC}/Makefile).
>
> Maybe we only want to set this conditionally on the architectures that
> need this for performance reasons. I also haven't looked into what
> consumes xxhash.h.
>
> I'd appreciate if you could take it from here.
I'm ok with your diff, or perhaps we could do this (then rsync just
needs a bump rather than another change)
Index: Makefile
===================================================================
RCS file: /cvs/ports/sysutils/xxhash/Makefile,v
retrieving revision 1.13
diff -u -p -r1.13 Makefile
--- Makefile 23 Jul 2023 04:29:44 -0000 1.13
+++ Makefile 16 Aug 2023 18:37:00 -0000
@@ -3,6 +3,7 @@ COMMENT = extremely fast non-cryptograph
GH_ACCOUNT = Cyan4973
GH_PROJECT = xxHash
GH_TAGNAME = v0.8.2
+REVISION = 0
PKGNAME = ${DISTNAME:L}
SHARED_LIBS = xxhash 0.3 # 0.8.1
Index: patches/patch-xxhash_h
===================================================================
RCS file: patches/patch-xxhash_h
diff -N patches/patch-xxhash_h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-xxhash_h 16 Aug 2023 18:37:00 -0000
@@ -0,0 +1,14 @@
+XXH_FORCE_MEMORY_ACCESS=1 results in unaligned access on sparc64
+
+Index: xxhash.h
+--- xxhash.h.orig
++++ xxhash.h
+@@ -1983,7 +1983,7 @@ XXH3_128bits_reset_withSecretandSeed(XXH_NOESCAPE XXH3
+ /* prefer __packed__ structures (method 1) for GCC
+ * < ARMv7 with unaligned access (e.g. Raspbian armhf) still uses byte
shifting, so we use memcpy
+ * which for some reason does unaligned loads. */
+-# if defined(__GNUC__) && !(defined(__ARM_ARCH) && __ARM_ARCH < 7 &&
defined(__ARM_FEATURE_UNALIGNED))
++# if defined(__GNUC__) && !(defined(__ARM_ARCH) && __ARM_ARCH < 7 &&
defined(__ARM_FEATURE_UNALIGNED)) && !defined(__sparc64__)
+ # define XXH_FORCE_MEMORY_ACCESS 1
+ # endif
+ #endif
