K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2018-06-21T21:12:49.605508Z
K 7
svn:log
V 599
fork: avoid endless wait with PTRACE_FORK and RFSTOPPED.

An RFSTOPPED thread can't clean TDB_STOPATFORK, which is done in the
fork_return() in its context, so parent is stuck forever.  Triggered
when trying to ptrace linux process.  Instead of waiting for the new
thread to clear TDB_STOPATFORK, tag it as traced and reparent to the
debugger in do_fork(), and let it only notify the debugger when run.

Submitted by:	Yanko Yankulov <yanko.yankulov@gmail.com>
Reviewed by:	jhb
MFC after:	1 week
X-MFC-Note:	keep p_dbgwait placeholder intact
Differential revision:	https://reviews.freebsd.org/D15857

END