https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83279
--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> --- "sendfile() will transfer at most 0x7ffff000 (2,147,479,552) bytes, returning the number of bytes actually transferred. (This is true on both 32-bit and 64-bit systems.)" Oops.
