Re: sendmmsg: put_user vs __put_user

From: Ulrich Drepper <redacted>
Date: Fri, 30 Mar 2012 09:36:11 -0400

Shouldn't the compat code in the sendmmsg implementation use the same
code as the normal code?  In which case you probably want something
like this:

Compat processes are not able to generate virtual addresses anywhere
near the range where the kernel resides, so the address range
verification done by put_user() is completely superfluous and
therefore not necessary.  The normal exception handling done by the
access is completely sufficient.