From 28c82567a0415c58198ee7f591517c4d3c7a4f3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Tue, 6 Mar 2018 10:28:35 +0100
Subject: [PATCH] Process page fault handler

---
 src/kernel/proc/process.c |  6 ++++++
 src/kernel/proc/procmm.c  | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/kernel/proc/process.c b/src/kernel/proc/process.c
index 9e6b4ca..3d9acd4 100644
--- a/src/kernel/proc/process.c
+++ b/src/kernel/proc/process.c
@@ -21,10 +21,16 @@ struct process *sched_proc = 0;
 struct process *_proc = 0;
 
 void procmm_init(struct process *p);
+registers *proc_pagefault(registers *r);
 
 uint64_t next_pid = 1;
 struct process *new_process(void (*function)(void))
 {
+  if(next_pid == 1)
+  {
+    bind_interrupt(14, proc_pagefault);
+  }
+
   struct process *proc = P2V(pmm_calloc());
   proc->pid = next_pid++;
   proc->stack_ptr = incptr(proc, PAGE_SIZE - sizeof(struct swtch_stack));
diff --git a/src/kernel/proc/procmm.c b/src/kernel/proc/procmm.c
index 0c8c9f3..c30ebdc 100644
--- a/src/kernel/proc/procmm.c
+++ b/src/kernel/proc/procmm.c
@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include <debug.h>
 #include <memory.h>
+#include <cpu.h>
 
 void procmm_init(struct process *p)
 {
@@ -22,3 +23,18 @@ uint64_t procmm_brk(struct process *p, void *addr)
   }
   return p->brk;
 }
+
+registers *proc_pagefault(registers *r)
+{
+  if(!(r->rflags & (3<<12)))
+  {
+    debug_error("Page fault in kernel!\n");
+    debug("Interrupt number: %d Error code: %d\n", r->int_no, r->err_code);
+    debug_print_registers(r);
+    PANIC("Page fault in kernel\n");
+  }
+
+  PANIC("Page fault in process\n");
+
+  return r;
+}