Indeed, setting the resume signal explicitly on the thread on stop was not the right thing to do. You don't want to clear the thread's resume signal out in Thread::ShouldStop because somebody might be trying to resume the thread with a hand-provided signal, and you wouldn't want to interrupt that. But the thread itself should let the StopInfo carry the stop signal information.
Jim On Mar 21, 2014, at 11:35 AM, Andrew MacPherson <[email protected]> wrote: > Actually it looks like those calls may be redundant now as it's being handled > by StopInfo. This patch gets attach resume/interrupt working for me on Linux. > > > On Fri, Mar 21, 2014 at 7:21 PM, Andrew MacPherson <[email protected]> > wrote: > Thanks Jim, LinuxSignals.cpp had SIGSTOP marked as suppress = false unlike > UnixSignals.cpp which had it correctly marked suppress = true. With that > fixed though the SIGSTOP is still getting set due to the call to > SetResumeSignal() in POSIXThread::SignalDeliveredNotify() it looks like. > Should this code also be using the signals table to decide whether to > suppress it? > > Thanks again. > > > > On Fri, Mar 21, 2014 at 6:58 PM, <[email protected]> wrote: > Sorry, that's StopInfoSignal::WillResume. > > Jim > > On Mar 21, 2014, at 10:54 AM, [email protected] wrote: > > > Somebody is not paying attention to the "process handle" settings. > > Normally SIGSTOP is set not to pass: > > > > (lldb) process handle SIGSTOP > > NAME PASS STOP NOTIFY > > ========== ===== ===== ====== > > SIGSTOP false true true > > > > This check should be done in Process::WillResume: > > > > virtual void > > WillResume (lldb::StateType resume_state) > > { > > ThreadSP thread_sp (m_thread_wp.lock()); > > if (thread_sp) > > { > > if > > (thread_sp->GetProcess()->GetUnixSignals().GetShouldSuppress(m_value) == > > false) > > thread_sp->SetResumeSignal(m_value); > > } > > } > > > > I wonder why this isn't happening in your case? > > > > Jim > > > > > > On Mar 21, 2014, at 10:46 AM, Andrew MacPherson <[email protected]> > > wrote: > > > >> Currently when attaching to a running process on Linux, a SIGSTOP signal > >> is (incorrectly I think) injected into the inferior on resume. This can be > >> reproduced by simply launching any process and then in a separate terminal > >> doing: > >> > >> sudo lldb -p <pid> > >> c > >> process interrupt > >> c > >> > >> On the second continue the SIGSTOP that was used to stop the process is > >> injected into the inferior by being passed to PTRACE_CONT, resulting in > >> the process going into a stop state outside the control of LLDB. The > >> SIGSTOP comes from the SetResumeSignal() call in POSIXThread and StopInfo. > >> > >> I can't think of any reason why a SIGSTOP should ever be injected into the > >> inferior so as a test I simply prevented it from ever happening: > >> > >> diff --git a/source/Plugins/Process/Linux/ProcessMonitor.cpp > >> b/source/Plugins/Process/Linux/ProcessMonitor.cpp > >> index 3dec6de..3079379 100644 > >> --- a/source/Plugins/Process/Linux/ProcessMonitor.cpp > >> +++ b/source/Plugins/Process/Linux/ProcessMonitor.cpp > >> @@ -2209,6 +2209,9 @@ ProcessMonitor::Resume(lldb::tid_t tid, uint32_t > >> signo) > >> bool result; > >> Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet > >> (POSIX_LOG_PROCESS)); > >> > >> + if (signo == SIGSTOP) > >> + signo = eResumeSignalNone; > >> + > >> if (log) > >> log->Printf ("ProcessMonitor::%s() resuming thread = %" PRIu64 " > >> with signal %s", __FUNCTION__, tid, > >> > >> m_process->GetUnixSignals().GetSignalAsCString (signo)); > >> > >> This resolves the issue and doesn't cause any other problems that I can > >> find but almost certainly isn't the proper fix. My main concern is that > >> all of the resume signal code is shared with other OSes which I'm guessing > >> treat this differently. > >> > >> Any thoughts as to what the proper fix here might be? > >> > >> Thanks, > >> Andrew > >> _______________________________________________ > >> lldb-dev mailing list > >> [email protected] > >> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev > > > > _______________________________________________ > > lldb-dev mailing list > > [email protected] > > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev > > > > <SIGSTOP-resume.patch> _______________________________________________ lldb-dev mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
