K 10
svn:author
V 4
zont
K 8
svn:date
V 27
2012-09-12T13:06:57.209330Z
K 7
svn:log
V 889
- Fix detaching under some circumstances.

  When truss is detaching from very active process it is possible to
  hang on waitpid(2) in restore_proc() forever, because
  ptrace(PT_SYSCALL) must be called before detaching, to allow the
  debugging process to continue execution.  Also when truss called with
  '-c' argument, it does not print anything after detach, because it
  immediately exits from restore_proc().

  To fix these two problems make detaching deferred, but then it is
  impossible to detach from a process which does not do any system call.
  To fix this issue use sigaction(2) instead of signal(3) to disable
  SA_RESTART flag for waitpid(2) that makes it non-restartable.  Remove
  global variable child_pid, because now detaching is handled in context
  where child's pid is known.

Reported by:	mjg
Tested by:	mjg, swills
Approved by:	kib (mentor)
MFC after:	2 weeks

END