From c8b308910efa1523f24a935e8d1d38ceb316637f Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Wed, 7 Nov 2018 19:03:44 +0100
Subject: [PATCH] Signals to processes in userspace now work again.

Ugh, how am I going to dispatch signals to processes in the kernel?
---
 Kernel/Process.cpp |  4 +++-
 Userland/sh.cpp    | 24 ++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 2468c8814bc..4071203e676 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -789,7 +789,7 @@ void Process::dispatch_signal(byte signal)
 
     if ((ret_cs & 3) == 0) {
         // FIXME: Handle send_signal to process currently in kernel code.
-        kprintf("Boo! dispatch_signal with return to %w:%x\n", ret_cs, ret_eip);
+        kprintf("Boo! dispatch_signal in %s(%u) with return to %w:%x\n", name().characters(), pid(), ret_cs, ret_eip);
         ASSERT_NOT_REACHED();
     }
 
@@ -827,6 +827,8 @@ void Process::dispatch_signal(byte signal)
 
     push_value_on_stack(m_return_from_signal_trampoline.get());
 
+    m_pending_signals &= ~(1 << signal);
+
     dbgprintf("signal: Okay, %s(%u) has been primed\n", name().characters(), pid());
 }
 
diff --git a/Userland/sh.cpp b/Userland/sh.cpp
index 5d8c224b9a4..19870439644 100644
--- a/Userland/sh.cpp
+++ b/Userland/sh.cpp
@@ -33,10 +33,17 @@ static int sh_pwd(int, const char**)
     return 0;
 }
 
+static volatile bool g_got_signal = false;
+
 void did_receive_signal(int signum)
 {
     printf("\nMy word, I've received a signal with number %d\n", signum);
-    //exit(0);
+    g_got_signal = true;
+}
+
+void handle_sigint(int signum)
+{
+    printf("Interrupt received by sh\n");
 }
 
 static int sh_busy(int, const char**)
@@ -48,11 +55,14 @@ static int sh_busy(int, const char**)
     sa.sa_restorer = nullptr;
     int rc = sigaction(SIGUSR1, &sa, nullptr);
     assert(rc == 0);
-    printf("listening for SIGUSR1 while looping in userspace...\n");
+    printf("listening for signal SIGUSR1 while looping in userspace...\n");
     for (;;) {
         for (volatile int i = 0; i < 100000; ++i)
             ;
+        if (g_got_signal)
+            break;
     }
+    g_got_signal = false;
     return 0;
 }
 
@@ -280,6 +290,16 @@ int main(int, char**)
     g->sid = setsid();
     tcsetpgrp(0, getpgrp());
 
+    {
+        struct sigaction sa;
+        sa.sa_handler = handle_sigint;
+        sa.sa_flags = 0;
+        sa.sa_mask = 0;
+        sa.sa_restorer = nullptr;
+        int rc = sigaction(SIGINT, &sa, nullptr);
+        assert(rc == 0);
+    }
+
     int rc = gethostname(g->hostname, sizeof(g->hostname));
     if (rc < 0)
         perror("gethostname");