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).
llvm-svn: 182153
diff --git a/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp b/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
index f7f7d8c..bfb710d 100644
--- a/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
+++ b/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
@@ -1208,7 +1208,13 @@
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 @@
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 @@
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 @@
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);