CVS commit: src/sys

["Kamil Rytarowski" <kamil%netbsd.org@localhost>]

Module Name:    src
Committed By:   kamil
Date:           Tue Jun 11 23:18:55 UTC 2019

Modified Files:
        src/sys/kern: kern_exec.c kern_proc.c sys_ptrace_common.c
        src/sys/sys: proc.h ptrace.h

Log Message:
Add support for PTRACE_POSIX_SPAWN to report posix_spawn(3) events

posix_spawn(3) is a first class syscall in NetBSD, different to
(V)FORK+EXEC as these operations are executed in one go. This differs to
Linux and FreeBSD, where posix_spawn(3) is implemented with existing kernel
primitives (clone(2), vfork(2), exec(3)) inside libc.

Typically LLDB and GDB software is aware of FORK/VFORK events. As discussed
with the LLDB community, instead of slicing the posix_spawn(3) operation
into phases emulating (V)FORK+EXEC(+VFORK_DONE) and returning intermediate
state to the debugger, that might have abnormal state, introduce new event
type: PTRACE_POSIX_SPAWN.

A debugger implementor can easily map it into existing fork+exec semantics
or treat as a distinct event.

There is no functional change for existing debuggers as there was no
support for reporting posix_spawn(3) events on the kernel side.


To generate a diff of this commit:
cvs rdiff -u -r1.465 -r1.466 src/sys/kern/kern_exec.c
cvs rdiff -u -r1.232 -r1.233 src/sys/kern/kern_proc.c
cvs rdiff -u -r1.54 -r1.55 src/sys/kern/sys_ptrace_common.c
cvs rdiff -u -r1.352 -r1.353 src/sys/sys/proc.h
cvs rdiff -u -r1.64 -r1.65 src/sys/sys/ptrace.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.