PT_SETKSTACK. These requests allow the tracing process to access the
dirty registers of the traced process that are on the kernel stack.
Note that there's currently no way to access the rnat register for
those dirty registers that are not (yet) covered by a nat collection
point. The interface for this is still being slept on.
Also note that implied by these requests is the division of work:
The tracing process has to keep track of where registers are spilled
and is responsible to figure out where the NaT bit of the stacked
registers are at any time during the execution of the traced process.
The kernel provides the interfaces but will not abstract the fact
that the register stack can be split. This model does not follow
the approach taken in Linux where PT_PEEK and PT_POKE deals with
this automagically.
are a really nasty interface that should have been killed long ago
when 'ptrace(PT_[SG]ETREGS' etc came along. The entity that they
operate on (struct user) will not be around much longer since it
is part-per-process and part-per-thread in a post-KSE world.
gdb does not actually use this except for the obscure 'info udot'
command which does a hexdump of as much of the child's 'struct user'
as it can get. It carries its own #defines so it doesn't break
compiles.
not work on any real hardware (or fully work on any simulator). Much more
needs to happen before this is actually functional but its nice to see
the FreeBSD copyright message appear in the ia64 simulator.
