Commit 6ed251ef authored by Bill Wendling's avatar Bill Wendling
Browse files

Merging r182153: 

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r182153 | mkopec | 2013-05-17 12:27:47 -0700 (Fri, 17 May 2013) | 5 lines

ProcessMonitor improvements for Linux.
-Remove tracing of fork/vfork until we add support for tracing inferiors' children on Linux.
-Add trace exec option for ptrace so that we don't receive legacy SIGTRAP signals on execve calls.
-Add handling of SIGCHLD sent by kernel (for now, deliver the signal to the inferior).

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llvm-svn: 182517
parent 33a47c22

lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp

+28 −3
Original line number Diff line number Diff line
@@ -1208,7 +1208,13 @@ ProcessMonitor::Launch(LaunchArgs *args) 
    ptrace_opts |= PTRACE_O_TRACEEXIT;



    // Have the tracer trace threads which spawn in the inferior process.

    ptrace_opts |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACECLONE;

    // TODO: if we want to support tracing the inferiors' child, add the

    // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)

    ptrace_opts |= PTRACE_O_TRACECLONE;



    // Have the tracer notify us before execve returns

    // (needed to disable legacy SIGTRAP generation)

    ptrace_opts |= PTRACE_O_TRACEEXEC;



    if (PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) < 0)

    {
@@ -1390,8 +1396,11 @@ ProcessMonitor::MonitorSIGTRAP(ProcessMonitor *monitor, 
        assert(false && "Unexpected SIGTRAP code!");

        break;



    case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):

    case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):

    // TODO: these two cases are required if we want to support tracing

    // of the inferiors' children

    // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):

    // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):



    case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):

    {

        unsigned long tid = 0;
@@ -1401,6 +1410,11 @@ ProcessMonitor::MonitorSIGTRAP(ProcessMonitor *monitor, 
        break;

    }



    case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):

        // Don't follow the child by default and resume

        monitor->Resume(pid, SIGCONT);

        break;



    case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):

    {

        // The inferior process is about to exit.  Maintain the process in a
@@ -1478,6 +1492,17 @@ ProcessMonitor::MonitorSignal(ProcessMonitor *monitor, 
        return ProcessMessage::Crash(pid, reason, signo, fault_addr);

    }



    if (signo == SIGCHLD) {

        assert(monitor);

        // TODO: Implement tracing of inferiors' children

        // If we fail to deliver the signal then create a message with the signal

        if (!monitor->Resume(pid, signo)) {

            assert(0 && "SIGCHLD delivery failed");

            message = ProcessMessage::Signal(pid, signo);

        }

        return message;

    }



    // Everything else is "normal" and does not require any special action on

    // our part.

    return ProcessMessage::Signal(pid, signo);