Flash sound issues with 64-bit linux

A glibc change committed one year ago (Improve 64bit memcpy/memmove for Atom, Core 2 and Core i7), which already resulted in some flamewars discussions (involving Linus Torvalds vs. Ulrich Drepper), broke some applications which used memcpy when they should have used memmove (only the latter handles overlapping memory areas).

Many applications have probably been fixed, but Adobe never took their 64-bit linux flash player very serious. So if your flash player has a very strange sound output, you can try to preload a wrapper libary which replaces memcpy with memmove.

Debian includes such wrapper in the 64-bit libc6 package (for details read /usr/share/doc/libc6/NEWS.Debian.gz), just check whether you have the file /usr/lib/x86_64-linux-gnu/libc/memcpy-preload.so.

If you do, just run something like this:

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$ cat >> /etc/ld.so.preload
/usr/lib/x86_64-linux-gnu/libc/memcpy-preload.so
<ctrl-d>

And all (64 bit) applications on your system will use memmove – and this fixed the sound issues for me :)

Another way to fix it is to use “nspluginwrapper” and the 32-bit flash player.