From c58d3fcbd145cc75350a347991f4736e3a914a01 Mon Sep 17 00:00:00 2001
From: "Evgeny Grechnikov (Diamond)" <diamondz@land.ru>
Date: Wed, 28 Mar 2007 14:51:04 +0000
Subject: [PATCH] Normal stack handling for sysenter/syscall; trap gate for int
 0x40

git-svn-id: svn://kolibrios.org@434 a494cfbc-eb01-0410-851d-a64ba20cac60
---
 kernel/trunk/const.inc        |  1 +
 kernel/trunk/core/sched.inc   |  6 +++++
 kernel/trunk/core/sys32.inc   | 25 +++++++++------------
 kernel/trunk/core/syscall.inc | 41 +++++++++++++++++------------------
 kernel/trunk/kernel.asm       |  3 ++-
 5 files changed, 39 insertions(+), 37 deletions(-)

diff --git a/kernel/trunk/const.inc b/kernel/trunk/const.inc
index 10dd2ab28a..4a9ec49d3f 100644
--- a/kernel/trunk/const.inc
+++ b/kernel/trunk/const.inc
@@ -146,6 +146,7 @@ window_data         equ (OS_BASE+0x0000000)
 
 CURRENT_TASK        equ (OS_BASE+0x0003000)
 TASK_COUNT          equ (OS_BASE+0x0003004)
+CURRENT_RING0_ESP   equ (OS_BASE+0x0003008)
 TASK_BASE           equ (OS_BASE+0x0003010)
 TASK_DATA           equ (OS_BASE+0x0003020)
 TASK_EVENT          equ (OS_BASE+0x0003020)
diff --git a/kernel/trunk/core/sched.inc b/kernel/trunk/core/sched.inc
index ebc0091150..6cc8de4793 100644
--- a/kernel/trunk/core/sched.inc
+++ b/kernel/trunk/core/sched.inc
@@ -159,6 +159,12 @@ find_next_task:
 
         mov   [CURRENT_TASK],ebx
         mov   [TASK_BASE],edi
+        push    ebx
+        shl     ebx, 8
+        mov     ebx, [SLOT_BASE + ebx + APPDATA.pl0_stack]
+        add     ebx, RING0_STACK_SIZE
+        mov     [CURRENT_RING0_ESP], ebx
+        pop     ebx
 
         cmp   al, 5
         jne   .noevents
diff --git a/kernel/trunk/core/sys32.inc b/kernel/trunk/core/sys32.inc
index 51ca925ee7..e40cc49f9c 100644
--- a/kernel/trunk/core/sys32.inc
+++ b/kernel/trunk/core/sys32.inc
@@ -42,23 +42,18 @@ build_interrupt_table:
         mov    esi, sys_int
         mov    ecx, 0x40
      @@:
-        mov    eax, [esi]
-        mov    [edi],   ax           ; lower part of offset
-        mov    [edi+2], word os_code ; segment selector
-        shr    eax, 16
-        mov    [edi+4], word 10001110b shl 8 ; interrupt descriptor
-        mov    [edi+6], ax
-        add    esi, 4
-        add    edi, 8
-        dec    ecx
-        jnz    @b
+        lodsd
+        mov     [edi], ax                       ; lower part of offset
+        mov     [edi+2], word os_code           ; segment selector
+        mov     ax, word 10001110b shl 8        ; type: interrupt gate
+        mov     [edi+4], eax
+        add     edi, 8
+        loop    @b
 
         ;mov    edi,8*0x40+idts+8
-        mov    [edi + 0], word (i40 and ((1 shl 16)-1))
-        mov    [edi + 2], word os_code
-        mov    [edi + 4], word 11101110b*256
-        mov    [edi + 6], word (i40 shr 16)
-
+        mov     dword [edi], (i40 and 0xFFFF) or (os_code shl 16)
+        mov     dword [edi+4], (11101111b shl 8) or (i40 and 0xFFFF0000)
+                                                ; type: trap gate
         ret
 
 iglobal
diff --git a/kernel/trunk/core/syscall.inc b/kernel/trunk/core/syscall.inc
index b512d47db8..8d1d6497b6 100644
--- a/kernel/trunk/core/syscall.inc
+++ b/kernel/trunk/core/syscall.inc
@@ -14,6 +14,8 @@ $Revision$
 
 align 32
 i40:
+; diamond, 27.03.2007: handler does not require disabled interrupts
+;                      so interrupts remain enabled when calling int 0x40
       push  ds es
       pushad
       cld
@@ -31,7 +33,7 @@ i40:
         mov     edi, [esp+28]
 
       ; enable interupts  -  a task switch or an IRQ _CAN_ interrupt i40 handler
-      sti
+;      sti
       push  eax
       and   edi,0xff
       call  dword [servetable+edi*4]
@@ -49,10 +51,10 @@ i40:
 ;;                                                            ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-uglobal
-times	100 db ?
-sysenter_stack:
-endg
+;uglobal
+;times	100 db ?
+;sysenter_stack:
+;endg
 
 align 32
 SYSENTER_VAR	equ	0
@@ -65,11 +67,8 @@ sysenter_entry:
      ;   mov     eax, [ss:SLOT_BASE + eax + APPDATA.pl0_stack]
      ;   lea     esp, [eax + RING0_STACK_SIZE]           ; configure ESP
      ;   mov     eax, [ss:sysenter_stack - 4]            ; eax - original eax, from app
+        mov     esp, [ss:CURRENT_RING0_ESP]
 
-        mov     esp, [ss:CURRENT_TASK]
-        shl     esp, 8
-        mov     esp, [ss:SLOT_BASE + esp + APPDATA.pl0_stack]
-        add     esp, RING0_STACK_SIZE           ; configure ESP
 	sti
 	;------------------
 	push	ds es
@@ -106,9 +105,15 @@ sysenter_entry:
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 align 32
 syscall_entry:
+
   ;     cli                 syscall clear IF
-	xchg	ecx, [esp]
-	mov	[SYSENTER_VAR + 4], esp
+        xchg    esp, [ss:CURRENT_RING0_ESP]
+        push    ecx
+        lea     ecx, [esp+4]
+        xchg    ecx, [ss:CURRENT_RING0_ESP]
+        sti
+        push    ecx
+        mov     ecx, [ecx]
 
   ;      mov     [ss:sysenter_stack - 4], eax
   ;      mov     eax, [ss:CURRENT_TASK]
@@ -117,12 +122,6 @@ syscall_entry:
   ;      lea     esp, [eax + RING0_STACK_SIZE]           ; configure ESP
   ;      mov     eax, [ss:sysenter_stack - 4]            ; eax - original eax, from app
 
-        mov     esp, [ss:CURRENT_TASK]
-        shl     esp, 8
-        mov     esp, [ss:SLOT_BASE + esp + APPDATA.pl0_stack]
-        add     esp, RING0_STACK_SIZE             ; configure ESP
-
-	sti
 	;------------------
 	push	ds es
 	pushad
@@ -148,10 +147,10 @@ syscall_entry:
 	pop	es ds
 	;------------------
 
-        cli
-	mov	esp, [SYSENTER_VAR + 4]
-	xchg	ecx, [esp]
-	sysret
+        mov     ecx, [ss:esp+4]
+        pop     esp
+        sysret
+
 iglobal
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; SYSTEM FUNCTIONS TABLE ;;
diff --git a/kernel/trunk/kernel.asm b/kernel/trunk/kernel.asm
index 9358d20bb0..cae0cba44f 100644
--- a/kernel/trunk/kernel.asm
+++ b/kernel/trunk/kernel.asm
@@ -441,7 +441,8 @@ B32:
            mov eax, os_code
            wrmsr
            mov ecx, MSR_SYSENTER_ESP
-           mov eax, sysenter_stack ; Check it
+;           mov eax, sysenter_stack ; Check it
+           xor     eax, eax
            wrmsr
            mov ecx, MSR_SYSENTER_EIP
            mov eax, sysenter_entry