svn commit: r350017 - in head: lib/libc/sys sys/kern sys/sys tests/sys/kern

[Kyle Evans]

On Mon, Jul 15, 2019 at 4:48 PM John Baldwin <jhb at freebsd.org> wrote:
>
> Author: jhb
> Date: Mon Jul 15 21:48:02 2019
> New Revision: 350017
> URL: https://svnweb.freebsd.org/changeset/base/350017
>
> Log:
>   Add ptrace op PT_GET_SC_RET.
>
>   This ptrace operation returns a structure containing the error and
>   return values from the current system call.  It is only valid when a
>   thread is stopped during a system call exit (PL_FLAG_SCX is set).
>
>   The sr_error member holds the error value from the system call.  Note
>   that this error value is the native FreeBSD error value that has _not_
>   been translated to an ABI-specific error value similar to the values
>   logged to ktrace.
>
>   If sr_error is zero, then the return values of the system call will be
>   set in sr_retval[0] and sr_retval[1].
>
>   Reviewed by:  kib
>   MFC after:    1 month
>   Sponsored by: DARPA
>   Differential Revision:        https://reviews.freebsd.org/D20901
>
> Modified:
>   head/lib/libc/sys/ptrace.2
>   head/sys/kern/sys_process.c
>   head/sys/sys/ptrace.h
>   head/tests/sys/kern/ptrace_test.c
>

Hey John,

Any objection to MFC'ing this to stable/12 at least? I've found this
to be almost-required in the ptrace user I've been working on
lately... I certainly ripped out plenty of hair before realizing that
it wasn't detecting error returns properly.

Thanks,

Kyle Evans