kernel: Actually register interrupt handlers properly

kernel/src/arch/CPU.h

@@ -22,6 +22,9 @@ namespace CPU
     void disable_interrupts();
     void wait_for_interrupt();
 
+    bool save_interrupts();
+    void restore_interrupts(bool saved);
+
     void get_stack_trace(void (*callback)(u64, void*), void* arg);
     void print_stack_trace();
     void get_stack_trace_at(Registers* regs, void (*callback)(u64, void*), void* arg);
@@ -30,6 +33,7 @@ namespace CPU
     u16 get_processor_id();
 
     bool register_interrupt(u8 interrupt, void (*handler)(Registers*, void*), void* context);
+    void sync_interrupts();
 
     void pause();
 }

kernel/src/arch/x86_64/CPU.cpp

@@ -22,6 +22,7 @@ extern "C" void enable_nx();
 
 extern void setup_gdt();
 extern void remap_pic();
+extern void change_pic_masks(u8 pic1_mask, u8 pic2_mask);
 extern void pic_eoi(unsigned char irq);
 extern void pic_eoi(Registers* regs);
 extern void setup_idt();
@@ -268,6 +269,8 @@ namespace CPU
                           .expect_value("Could not create the IO background thread!");
 
         remap_pic();
+
+        sync_interrupts();
     }
 
     void enable_interrupts()
@@ -280,6 +283,20 @@ namespace CPU
         asm volatile("cli");
     }
 
+    bool save_interrupts()
+    {
+        u64 flags;
+        asm volatile("pushfq; pop %0" : "=r"(flags));
+        return flags & 0x200;
+    }
+
+    void restore_interrupts(bool saved)
+    {
+        if (saved) enable_interrupts();
+        else
+            disable_interrupts();
+    }
+
     void wait_for_interrupt()
     {
         asm volatile("hlt");
@@ -387,8 +404,28 @@ namespace CPU
 
         irq_handlers[interrupt] = { handler, context };
 
+        sync_interrupts();
+
         return true;
     }
+
+    void sync_interrupts()
+    {
+        u8 pic1_mask, pic2_mask;
+        pic1_mask = pic2_mask = 0b11111111;
+        for (int i = 0; i < 8; i++)
+        {
+            if (irq_handlers[i].function) pic1_mask &= (u8)(~(1 << i));
+            if (irq_handlers[i + 8].function) pic2_mask &= (u8)(~(1 << i));
+        }
+
+        if (pic2_mask != 0b11111111) pic1_mask &= 0b11111011;
+
+        auto val = CPU::save_interrupts();
+        CPU::disable_interrupts();
+        change_pic_masks(pic1_mask, pic2_mask);
+        CPU::restore_interrupts(val);
+    }
 }
 
 // called by kernel_yield

kernel/src/arch/x86_64/init/IDT.cpp

@@ -84,6 +84,20 @@ INT(20);
 INT(21);
 INT(32);
 INT(33);
+INT(34);
+INT(35);
+INT(36);
+INT(37);
+INT(38);
+INT(39);
+INT(40);
+INT(41);
+INT(42);
+INT(43);
+INT(44);
+INT(45);
+INT(46);
+INT(47);
 INT(66);
 
 void setup_idt()
@@ -112,6 +126,20 @@ void setup_idt()
     TRAP(21);
     IRQ(32);
     IRQ(33);
+    IRQ(34);
+    IRQ(35);
+    IRQ(36);
+    IRQ(37);
+    IRQ(38);
+    IRQ(39);
+    IRQ(40);
+    IRQ(41);
+    IRQ(42);
+    IRQ(43);
+    IRQ(44);
+    IRQ(45);
+    IRQ(46);
+    IRQ(47);
     SYS(66);
 
     static IDTR idtr;

kernel/src/arch/x86_64/init/PIC.cpp

@@ -36,9 +36,18 @@ void remap_pic()
     IO::outb(PIC2_DATA, ICW4_8086);
     io_delay();
 
-    IO::outb(PIC1_DATA, 0b11111100);
+    IO::outb(PIC1_DATA, 0b11111111);
     io_delay();
     IO::outb(PIC2_DATA, 0b11111111);
+    io_delay();
+}
+
+void change_pic_masks(u8 pic1_mask, u8 pic2_mask)
+{
+    IO::outb(PIC1_DATA, pic1_mask);
+    io_delay();
+    IO::outb(PIC2_DATA, pic2_mask);
+    io_delay();
 }
 
 void pic_eoi(unsigned char irq)