On Mon, 2010-09-27 at 10:59 -0400, Matt Rixon wrote: Yes, for some 'not so nice' (IMHO) reasons. The syscall name you give to -S is translated to a number and then matched exactly. since syscall #100 on x86_64 might not be the same as syscall #100 on x86_32 if you don't supply a -F arch= you might end up getting chmod on 32bit and socket on 64bit (I'm just making that up as an example) I personally think userspace should handle that for you (instead of just complaining lightly) if you don't enter -F arch= on a biarch system. -Eric