1 files changed, 39 insertions, 0 deletions
diff --git a/arch/x86_64/pagefault.c b/arch/x86_64/pagefault.c
new file mode 100644
index 0000000..5bba20b
--- /dev/null
+++ b/arch/x86_64/pagefault.c
@@ -0,0 +1,39 @@
+#include "arch/x86_64/idt.h"
+#include "arch/processor.h"
+#include "memory.h"
+#include "print.h"
+#include "jove.h"
+
+#include <stdbool.h>
+
+int_state_t*
+_pagefault_handler(int_state_t *state)
+{
+    extern uint64_t __isr_err;
+
+    uintptr_t fault_addr = 0;
+    __asm__ volatile("movq %%cr2, %0": "=r"(fault_addr));
+
+    if(fault_addr < USERLAND_MEMORY_LIMIT) {
+        // Check if there is an entry in the exception return table.
+        processor_t *proc = processor_current();
+        if(proc->ert_i > 0) {
+            state->ip = (uintptr_t)_exrtab_pop();
+            return state;
+        }
+    }
+
+    bool present = __isr_err & 1;
+    bool write = __isr_err & 2;
+    bool user = __isr_err & 4;
+
+    klogf("Page fault at %016X\n", fault_addr);
+    klogf("%s %s from a %s address\n", 
+            user ? "user" : "kernel",
+            write ? "wrote" : "read",
+            present ? "present" : "non-present");
+
+    int_state_print(state);
+    kpanic("Unhandled page fault\n");
+    return state;
+}