From 1d7795e22c90bf718c68b43aeecded849af829dc Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Sun, 30 Jul 2023 14:17:39 +0300
Subject: [PATCH] Kernel: Hardware exceptions  now sends signals to userspace

---
 kernel/arch/x86_64/IDT.cpp | 31 +++++++++++++++++++++++++++----
 userspace/Shell/main.cpp   |  5 +++++
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/kernel/arch/x86_64/IDT.cpp b/kernel/arch/x86_64/IDT.cpp
index 37c2f7b7..78acea54 100644
--- a/kernel/arch/x86_64/IDT.cpp
+++ b/kernel/arch/x86_64/IDT.cpp
@@ -163,10 +163,33 @@ namespace IDT
 
 		if (tid && Kernel::Thread::current().is_userspace() && !Kernel::Thread::current().is_in_syscall())
 		{
-			auto message = BAN::String::formatted("{}, aborting\n", isr_exceptions[isr]);
-			(void)Kernel::Process::current().sys_write(STDERR_FILENO, message.data(), message.size());
-			asm volatile("sti");
-			Kernel::Process::current().exit(1);
+			// TODO: Confirm and fix the exception to signal mappings
+
+			int signal = 0;
+			switch (isr)
+			{
+			case ISR::DeviceNotAvailable:
+			case ISR::DivisionError:
+			case ISR::SIMDFloatingPointException:
+			case ISR::x87FloatingPointException:
+				signal = SIGFPE;
+				break;
+			case ISR::AlignmentCheck:
+				signal = SIGBUS;
+				break;
+			case ISR::InvalidOpcode:
+				signal = SIGILL;
+				break;
+			case ISR::PageFault:
+				signal = SIGSEGV;
+				break;			
+			default:
+				dwarnln("Unhandled exception");
+				signal = SIGABRT;
+				break;
+			}
+
+			Kernel::Thread::current().handle_signal(-signal);
 		}
 		else
 		{
diff --git a/userspace/Shell/main.cpp b/userspace/Shell/main.cpp
index 7e890a47..8af6561a 100644
--- a/userspace/Shell/main.cpp
+++ b/userspace/Shell/main.cpp
@@ -260,6 +260,11 @@ int execute_command(BAN::Vector<BAN::String>& args)
 		while (*current)
 			printf("%s\n", *current++);
 	}
+	else if (args.front() == "page-fault-test"sv)
+	{
+		volatile int* ptr = nullptr;
+		*ptr = 0;
+	}
 	else if (args.front() == "kill-test"sv)
 	{
 		pid_t pid = fork();