Re: [Qemu-devel] Final call for help: x86: enter instruction bug: PATCH

[Stefan Kisdaroczi <kisda@hispeed.ch>]

[-- Attachment #1: Type: text/plain, Size: 290 bytes --]

Hi,

I have attached a patch which fixes the emulation of the i386 enter
instruction. My Test-App is using the enter levels 1-3 is now working
identical under qemu and a real i386 (checked registers and stack
contens with debugger, 16-Bit Mode).

Please review. Thank you.

greetings
kisda

[-- Attachment #2: qemu-i386-gen_enter.patch --]
[-- Type: text/x-patch, Size: 3023 bytes --]

diff -uNrp qemu.orig/target-i386/exec.h qemu/target-i386/exec.h
--- qemu.orig/target-i386/exec.h	2004-11-14 13:43:20.000000000 +0100
+++ qemu/target-i386/exec.h	2004-11-14 13:47:31.000000000 +0100
@@ -167,6 +167,7 @@ void helper_divl_EAX_T0(uint32_t eip);
 void helper_idivl_EAX_T0(uint32_t eip);
 void helper_cmpxchg8b(void);
 void helper_cpuid(void);
+void helper_enter_level(uint8_t *dst_ptr, int level, int data32);
 void helper_sysenter(void);
 void helper_sysexit(void);
 void helper_rdtsc(void);
diff -uNrp qemu.orig/target-i386/helper.c qemu/target-i386/helper.c
--- qemu.orig/target-i386/helper.c	2004-11-14 13:43:20.000000000 +0100
+++ qemu/target-i386/helper.c	2004-11-14 13:47:31.000000000 +0100
@@ -1068,6 +1068,27 @@ void helper_cpuid(void)
     }
 }
 
+void helper_enter_level( uint8_t *dst_ptr, int level, int data32 )
+{
+  int ofs = 0;
+  uint8_t *src_ptr = env->segs[R_SS].base + EBP;
+
+  if (data32) {
+    /* 32 bit */
+    while (--level) {
+      ofs -= 4;
+      stl( dst_ptr + ofs, ldl( src_ptr + ofs ) );
+    }
+  }
+  else {
+    /* 16 bit */
+    while (--level) {
+      ofs -= 2;
+      stw( dst_ptr + ofs, lduw( src_ptr + ofs ) );
+    }
+  }
+}
+
 void helper_lldt_T0(void)
 {
     int selector;
diff -uNrp qemu.orig/target-i386/op.c qemu/target-i386/op.c
--- qemu.orig/target-i386/op.c	2004-11-14 13:43:20.000000000 +0100
+++ qemu/target-i386/op.c	2004-11-14 13:47:31.000000000 +0100
@@ -695,6 +695,11 @@ void OPPROTO op_cpuid(void)
     helper_cpuid();
 }
 
+void OPPROTO op_enter_level(void)
+{
+    helper_enter_level((uint8_t *)A0, PARAM1, PARAM2);
+}
+
 void OPPROTO op_sysenter(void)
 {
     helper_sysenter();
diff -uNrp qemu.orig/target-i386/translate.c qemu/target-i386/translate.c
--- qemu.orig/target-i386/translate.c	2004-11-14 13:43:20.000000000 +0100
+++ qemu/target-i386/translate.c	2004-11-14 13:51:57.000000000 +0100
@@ -1694,11 +1694,10 @@ static void gen_popa(DisasContext *s)
 /* XXX: check this */
 static void gen_enter(DisasContext *s, int esp_addend, int level)
 {
-    int ot, level1, addend, opsize;
+    int ot, opsize;
 
     ot = s->dflag + OT_WORD;
     level &= 0x1f;
-    level1 = level;
     opsize = 2 << s->dflag;
 
     gen_op_movl_A0_ESP();
@@ -1712,19 +1711,13 @@ static void gen_enter(DisasContext *s, i
     gen_op_mov_TN_reg[OT_LONG][0][R_EBP]();
     gen_op_st_T0_A0[ot + s->mem_index]();
     if (level) {
-        while (level--) {
-            gen_op_addl_A0_im(-opsize);
-            gen_op_addl_T0_im(-opsize);
-            gen_op_st_T0_A0[ot + s->mem_index]();
-        }
-        gen_op_addl_A0_im(-opsize);
+        if (level > 1)
+            gen_op_enter_level( level, s->dflag );
+        gen_op_addl_A0_im(-opsize * level);
         gen_op_st_T1_A0[ot + s->mem_index]();
     }
     gen_op_mov_reg_T1[ot][R_EBP]();
-    addend = -esp_addend;
-    if (level1)
-        addend -= opsize * (level1 + 1);
-    gen_op_addl_T1_im(addend);
+    gen_op_addl_T1_im( -esp_addend + (-opsize * level) );
     gen_op_mov_reg_T1[ot][R_ESP]();
 }