Assert that tracer parent can PT_ATTACH to its child.
This test is for all members of the wait(2) family.
Currently it is marked as an explicit failure PR kern/51621.
I faced the following issues (noted and discussed in the bug report):
- PT_ATTACH seems to work, but waiting for stopped status and signal from the
child results in getting SIGTRAP, not SIGSTOP like in Linux and FreeBSD. This
might be by design, I'm unsure. However, so far I was getting SIGSTOP from a
tracer process that was not the parent. SIGSTOP vs SIGTRAP logic also
complicates the things up as tracer must check whether is a parent for tracee
or not - this shouldn't be needed.
- PT_CONTINUE seems to have no effect at all, the child hangs. This operation
works on Linux and FreeBSD and in the end, test passes correctly.
- Debugging this with gdb(1) results in receiving SIGABRT from the GNU
debugger (in the moment of raising/receiving SIGTRAP). This is making the
things harder in general.
Sponsored by <The NetBSD Foundation>.
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