2007-05-04 12:35:14

by Urs Thuermann

Subject: Q: copy_*_user() with size==0

Reading the i386 source of copy_to_user() and reading some instances
of how it's used, it seems valid to pass 0 for the size argument and
that kernel address pointers, i.e. the @from argument in
copy_to_user() and the @to argument in copy_from_user() don't matter
in this case. Is this correct for all arch's? I don't see this
behavior documented anywhere.

urs