From ecfe121a8ca8526276a013ed78c6575b3f3abb13 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Mon, 28 Mar 2016 17:37:37 +0200
Subject: [PATCH] Add assertions to Signal::DispatchHandler callers.

---
 kernel/scheduler.cpp            |  1 +
 kernel/signal.cpp               |  3 +++
 kernel/x86-family/interrupt.cpp | 13 ++++++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/kernel/scheduler.cpp b/kernel/scheduler.cpp
index 088d0ce7..e46229c6 100644
--- a/kernel/scheduler.cpp
+++ b/kernel/scheduler.cpp
@@ -322,6 +322,7 @@ static void RealSwitch(struct interrupt_context* intctx, bool yielded)
 		{
 			// We're already this thread, so run the signal handler.
 			Interrupt::Enable();
+			assert(Interrupt::IsEnabled());
 			Signal::DispatchHandler(intctx, NULL);
 		}
 		else
diff --git a/kernel/signal.cpp b/kernel/signal.cpp
index fb1b83b6..58a6481d 100644
--- a/kernel/signal.cpp
+++ b/kernel/signal.cpp
@@ -818,6 +818,7 @@ void Thread::HandleSigreturn(struct interrupt_context* intctx)
 
 	lock.Reset();
 
+	assert(Interrupt::IsEnabled());
 	HandleSignal(intctx);
 }
 
@@ -825,11 +826,13 @@ namespace Signal {
 
 void DispatchHandler(struct interrupt_context* intctx, void* /*user*/)
 {
+	assert(Interrupt::IsEnabled());
 	return CurrentThread()->HandleSignal(intctx);
 }
 
 void ReturnHandler(struct interrupt_context* intctx, void* /*user*/)
 {
+	assert(Interrupt::IsEnabled());
 	return CurrentThread()->HandleSigreturn(intctx);
 }
 
diff --git a/kernel/x86-family/interrupt.cpp b/kernel/x86-family/interrupt.cpp
index 6b3903cf..cc241290 100644
--- a/kernel/x86-family/interrupt.cpp
+++ b/kernel/x86-family/interrupt.cpp
@@ -132,6 +132,13 @@ static struct interrupt_handler Signal__DispatchHandler_handler;
 static struct interrupt_handler Signal__ReturnHandler_handler;
 static struct interrupt_handler Scheduler__ThreadExitCPU_handler;
 
+// Temporarily to see if this is the source of the assertion failure.
+void DispatchHandlerWrap(struct interrupt_context* intctx, void* user)
+{
+	assert(Interrupt::IsEnabled());
+	return Signal::DispatchHandler(intctx, user);
+}
+
 void RegisterHandler(unsigned int index, struct interrupt_handler* handler)
 {
 	assert(index < NUM_INTERRUPTS);
@@ -239,7 +246,7 @@ void Init()
 
 	Scheduler__InterruptYieldCPU_handler.handler = Scheduler::InterruptYieldCPU;
 	RegisterHandler(129, &Scheduler__InterruptYieldCPU_handler);
-	Signal__DispatchHandler_handler.handler = Signal::DispatchHandler;
+	Signal__DispatchHandler_handler.handler = DispatchHandlerWrap;
 	RegisterHandler(130, &Signal__DispatchHandler_handler);
 	Signal__ReturnHandler_handler.handler = Signal::ReturnHandler;
 	RegisterHandler(131, &Signal__ReturnHandler_handler);
@@ -295,7 +302,10 @@ void UserCrashHandler(struct interrupt_context* intctx)
 			CurrentThread()->DeliverSignalUnlocked(SIGSEGV);
 		kthread_mutex_unlock(&CurrentProcess()->signal_lock);
 		if ( handled )
+		{
+			assert(Interrupt::IsEnabled());
 			return Signal::DispatchHandler(intctx, NULL);
+		}
 	}
 
 	// Issue a diagnostic message to the kernel log concerning the crash.
@@ -310,6 +320,7 @@ void UserCrashHandler(struct interrupt_context* intctx)
 	CurrentProcess()->ExitThroughSignal(SIGSEGV);
 
 	// Deliver signals to this thread so it can exit correctly.
+	assert(Interrupt::IsEnabled());
 	Signal::DispatchHandler(intctx, NULL);
 }