From: John Hodge <tpg@mutabah.net>
Date: Mon, 26 Sep 2011 05:07:19 +0000 (+0800)
Subject: Kernel/x86_64 - Debugging iret->CPL3 crash
X-Git-Tag: rel0.11~58
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=58c7107eb0a5ae254c135f2eaa6263751f1ebe67;p=tpg%2Facess2.git

Kernel/x86_64 - Debugging iret->CPL3 crash
---

diff --git a/Kernel/arch/x86_64/desctab.asm b/Kernel/arch/x86_64/desctab.asm
index 694672c7..739b219f 100644
--- a/Kernel/arch/x86_64/desctab.asm
+++ b/Kernel/arch/x86_64/desctab.asm
@@ -374,6 +374,7 @@ SchedulerIRQ:
 	pop gs
 	POP_GPR
 	add rsp, 2*8	; Dummy error code and IRQ num
+;	xchg bx, bx
 	iretq
 
 [extern ci_offsetof_tThread_KernelStack]
@@ -416,6 +417,10 @@ SyscallStub:
 	pop r11
 	pop rcx
 	pop rsp 	; Change back to user stack
+	; TODO: Determine if user is 64 or 32 bit
+
+;	xchg bx, bx	
+	db 0x48	; REX, nasm doesn't have a sysretq opcode
 	sysret
 
 [section .data]
diff --git a/Kernel/arch/x86_64/mm_virt.c b/Kernel/arch/x86_64/mm_virt.c
index a34c6ad2..1640586b 100644
--- a/Kernel/arch/x86_64/mm_virt.c
+++ b/Kernel/arch/x86_64/mm_virt.c
@@ -90,11 +90,11 @@ void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 {
 	// TODO: Implement Copy-on-Write
 	#if 1
-	if( PAGEMAPLVL4(Addr>39) & PF_PRESENT
-	 && PAGEDIRPTR(Addr>>30) & PF_PRESENT
-	 && PAGEDIR(Addr>>21) & PF_PRESENT
-	 && PAGETABLE(Addr>>12) & PF_PRESENT
-	 && PAGETABLE(Addr>>12) & PF_COW )
+	if( PAGEMAPLVL4(Addr>>39) & PF_PRESENT
+	 && PAGEDIRPTR (Addr>>30) & PF_PRESENT
+	 && PAGEDIR    (Addr>>21) & PF_PRESENT
+	 && PAGETABLE  (Addr>>12) & PF_PRESENT
+	 && PAGETABLE  (Addr>>12) & PF_COW )
 	{
 		tPAddr	paddr;
 		if(MM_GetRefCount( PAGETABLE(Addr>>12) & PADDR_MASK ) == 1)