sch: Try to address segment selector corruption

kernel/arch/x86_64/system/apic.c

@@ -91,8 +91,8 @@ void lapic_init(usize cpu_id)
 	// Set timer init counter to -1
 	lapic_write(0x380, 0xFFFFFFFF);
 
-	// See how many ticks pass in 100 microseconds.
-	clock_wait(100 * 10000);
+	// See how many ticks pass in 10 milliseconds.
+	clock_wait(10 * 1000000);
 
 	// Stop the APIC timer
 	lapic_write(0x320, 0x10000);

kernel/arch/x86_64/system/arch.s

@@ -5,7 +5,7 @@
 
 /* Swaps GSBASE if CPL == KERNEL */
 .macro swapgs_if_necessary
-	cmpw	$0x8,	0x8(%rsp)
+	cmpw	$0x8,	0x18(%rsp)
 	je		1f
 	swapgs
 1:
@@ -88,19 +88,20 @@ interrupt_internal:
 	call	isr_handler			/* Call interrupt handler */
 	mov		%rax,	%rsp		/* interrupt_handler returns a pointer to the new context. */
 	pop_all_regs
-	add		$0x10,	%rsp		/* Skip Context.error and Context.isr fields. */
 	swapgs_if_necessary			/* Change GS back to user mode if we came from user mode. */
+	add		$0x8,	%rsp		/* Skip Context.isr field. */
+	add		$0x8,	%rsp		/* Skip Context.error field. */
 	iretq
 
 /* Define 256 interrupt stubs using the macro above. */
 .rept 256
 .align 0x10
 interrupt_\+:
-	swapgs_if_necessary			/* Change GS to kernel mode if we're coming from user mode. */
 .if !(\+ == 8 || (\+ >= 10 && \+ <= 14) || \+ == 17 || \+ == 21 || \+ == 29 || \+ == 30)
 	pushq	$0					/* If this is an interrupt that doesn't push an error code, push one ourselves. */
 .endif
 	pushq	$\+					/* Push the ISR to the stack. */
+	swapgs_if_necessary			/* Change GS to kernel mode if we're coming from user mode. */
 	jmp		interrupt_internal
 .endr
 

kernel/arch/x86_64/system/gdt.c

@@ -10,6 +10,7 @@
 void gdt_init(Gdt* gdt_table, TaskStateSegment* tss)
 {
 	// clang-format off
+	asm_interrupt_disable();
 
 	// Kernel Code
 	GDT_ENCODE(gdt_table->kernel_code,
@@ -49,10 +50,12 @@ void gdt_init(Gdt* gdt_table, TaskStateSegment* tss)
 		0);
 
 	// clang-format on
+	asm_interrupt_enable();
 }
 
 void gdt_load(Gdt* gdt_table)
 {
+	asm_interrupt_disable();
 	GdtRegister gdtr = {
 		.limit = sizeof(Gdt) - 1,
 		.base = gdt_table,
@@ -61,4 +64,5 @@ void gdt_load(Gdt* gdt_table)
 	asm_gdt_set(gdtr);
 	tss_reload();
 	asm_flush_segment_regs(offsetof(Gdt, kernel_code), offsetof(Gdt, kernel_data));
+	asm_interrupt_enable();
 }

kernel/system/sch/core.c

@@ -248,6 +248,10 @@ Context* sch_reschedule(Context* context)
 	cur->thread = running;
 	sch_arch_update(cur, running);
 
+	//! TODO: Nasty workaround. Need to figure out what's corrupting CS and SS values on interrupt entry.
+	if (running->registers.ss == 0x20)
+		running->registers.ss = 0x23;
+
 	// Load new page map.
 	vm_set_page_map(running->parent->page_map);
 	return &running->registers;