This patch (with .rpms for x86_64 and i686) enables glibc optionally
to detect, diagnose, and work around overlap in memcpy/mempcpy:
http://bitwagon.com/glibc-memlap/glibc-memlap.html
The option to check is controlled by an environment variable
MEMCPY_CHECK_ which influences choices made by __init_cpu_features
and the STT_GNU_IFUNC mechanism for choosing alternate implementations
at runtime.
This does not work where the memcpy is inlined (which glibc can do in
several cases).
Kevin Kofler