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Berkeley UPC v2.8.0 Runtime patch 1: X86_64 cmpxchg16b

This patch fixes runtime crashes (SIGSEGV) due to insufficent alignment of arguments to the cmpxchg16b instruction present on many recent x86_64 processors.

If you have seen UPC applications or GASNet tests fail with a Segmentation Violation (SIGSEGV), you may be seeing this bug (though appliction errors can also lead to a SIGSEGV). To see if you may be affected by this bug, you can run the following command in either your Build or Installation directory for Berkeley UPC 2.8.0:

        find . -name gasnet_config.h | xargs grep 'define GASNETI_HAVE_X86_CMPXCHG16B'

If your output contains any matching lines, then you should apply this patch. If your output does not show any matching lines, then you are not affected.

Instructions:

Download the Berkeley UPC 2.8.0 runtime source release tarball from http://upc.lbl.gov.
Extract the source tarball to a directory on your harddrive.
Download and save the Berkeley UPC Runtime v2.8.0 patch 1 patch file to the same directory.

Patch the source files with the following command:

        patch -p0 < berkeley_upc-2.8.0-patch1.txt

You should see output something like this:

        patching file gasnet/gasnet_syncops.h
        patching file gasnet/gasnet_atomic_bits.h
        patching file gasnet/tests/testgasnet.c

Build and install the source distribution as usual.