svn commit: r359047 - in head: lib/libsysdecode sys/fs/procfs sys/sys

[John Baldwin]

On 3/17/20 11:44 AM, John Baldwin wrote:
> Author: jhb
> Date: Tue Mar 17 18:44:03 2020
> New Revision: 359047
> URL: https://svnweb.freebsd.org/changeset/base/359047
> 
> Log:
>   Mark procfs-based process debugging as deprecated for FreeBSD 13.
>   
>   Attempting to use ioctls on /proc/<pid>/mem to control a process will
>   trigger warnings on the console.  The <sys/pioctl.h> include file will
>   also now emit a compile-time warning when used from userland.
>   
>   Reviewed by:	emaste
>   MFC after:	1 week
>   Relnotes:	yes
>   Differential Revision:	https://reviews.freebsd.org/D23822

Missed:

PR: 244383 (exp-run)

I also didn't quite say why.  My original reason for why is that I have
some debugging changes in flight to try to fix spurious EINTR's that
break the GDB test suite (and we also have an open bug about spurious
errors for gcore and truss).  mjg@ wants to do this to remove overhead
from the syscall path.  Both of these reasons stem from the fact that
procfs debugging is not just a layer on top of ptrace but sits beside it
requiring duplicate checks in code, etc.  They reuse some, but not all,
of the same infrastructure.  At this point, ptrace() now provides a superset
of functionality relative to procfs, and that is only going to continue
going forward as only ptrace() based debugging has seen active work in
the past several years.

-- 
John Baldwin