Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.
Discussed with: bde, das (previous versions)
MFC after: 1 month
CTF data from a module. On subsequent attempts to retrieve CTF data for
a module, return an error if there no CTF data.
This fixes a panic if you try to enable fbt probes on a module with CTF
data twice.
Submitted by: Paul Ambrose (ambrosehua AT gmail DOT com)
MFC after: 3 days