[Xen-changelog] Fix XCHG instruction emulation.

[BitKeeper Bot <riel@xxxxxxxxxxx>]

ChangeSet 1.1350, 2005/03/22 20:04:01+00:00, kaf24@xxxxxxxxxxxxxxxxxxxx

        Fix XCHG instruction emulation.
        Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>



 tools/tests/test_x86_emulator.c |   37 +++++++++++++++++++++++++++++++++++--
 xen/arch/x86/x86_emulate.c      |    8 ++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)


diff -Nru a/tools/tests/test_x86_emulator.c b/tools/tests/test_x86_emulator.c
--- a/tools/tests/test_x86_emulator.c   2005-03-22 16:03:17 -05:00
+++ b/tools/tests/test_x86_emulator.c   2005-03-22 16:03:17 -05:00
@@ -134,9 +134,42 @@
         goto fail;
     printf("okay\n");
 
+    printf("%-40s", "Testing lock cmpxchgb %%cl,(%%eax)...");
+    instr[0] = 0xf0; instr[1] = 0x0f; instr[2] = 0xb0; instr[3] = 0x08;
+    regs.eflags = 0x200;
+    regs.eip    = (unsigned long)&instr[0];
+    regs.eax    = 0xAABBCC77UL;
+    regs.ecx    = 0xFF;
+    cr2         = (unsigned long)&res;
+    rc = x86_emulate_memop(&regs, cr2, &emulops, 4);    
+    if ( (rc != 0) || 
+         (res != 0x923456AA) || 
+         ((regs.eflags&0x240) != 0x200) ||
+         (regs.eax != 0xAABBCCAA) ||
+         (regs.ecx != 0xFF) ||
+         (regs.eip != (unsigned long)&instr[4]) )
+        goto fail;
+    printf("okay\n");
+
+    printf("%-40s", "Testing xchgl %%ecx,(%%eax)...");
+    instr[0] = 0x87; instr[1] = 0x08;
+    regs.eflags = 0x200;
+    regs.eip    = (unsigned long)&instr[0];
+    regs.ecx    = 0x12345678;
+    cr2         = (unsigned long)&res;
+    rc = x86_emulate_memop(&regs, cr2, &emulops, 4);    
+    if ( (rc != 0) || 
+         (res != 0x12345678) || 
+         (regs.eflags != 0x200) ||
+         (regs.ecx != 0x923456AA) ||
+         (regs.eip != (unsigned long)&instr[2]) )
+        goto fail;
+    printf("okay\n");
+
     printf("%-40s", "Testing lock cmpxchgl %%ecx,(%%eax)...");
     instr[0] = 0xf0; instr[1] = 0x0f; instr[2] = 0xb1; instr[3] = 0x08;
     regs.eflags = 0x200;
+    res         = 0x923456AA;
     regs.eip    = (unsigned long)&instr[0];
     regs.eax    = 0x923456AAUL;
     regs.ecx    = 0xDDEEFF00L;
@@ -186,7 +219,7 @@
         goto fail;
     printf("okay\n");
 
-    printf("%-40s", "Testing cmpxchg (%edi) [succeeding]...");
+    printf("%-40s", "Testing cmpxchg8b (%edi) [succeeding]...");
     instr[0] = 0x0f; instr[1] = 0xc7; instr[2] = 0x0f;
     regs.eflags = 0x200;
     regs.eax    = cmpxchg8b_res[0];
@@ -205,7 +238,7 @@
         goto fail;
     printf("okay\n");
 
-    printf("%-40s", "Testing cmpxchg (%edi) [failing]...");
+    printf("%-40s", "Testing cmpxchg8b (%edi) [failing]...");
     instr[0] = 0x0f; instr[1] = 0xc7; instr[2] = 0x0f;
     regs.eip    = (unsigned long)&instr[0];
     regs.edi    = (unsigned long)cmpxchg8b_res;
diff -Nru a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c
--- a/xen/arch/x86/x86_emulate.c        2005-03-22 16:03:17 -05:00
+++ b/xen/arch/x86/x86_emulate.c        2005-03-22 16:03:17 -05:00
@@ -672,6 +672,14 @@
         dst.val ^= src.val;
         src.val ^= dst.val;
         lock_prefix = 1;
+        /* Write back the source (temporary register location). */
+        switch ( dst.bytes )
+        {
+        case 1: *(u8  *)src.ptr = (u8)src.val; break;
+        case 2: *(u16 *)src.ptr = (u16)src.val; break;
+        case 4: *src.ptr = (u32)src.val; break; /* 64b mode: zero-extend */
+        case 8: *src.ptr = src.val; break;
+        }
         break;
     case 0xa0 ... 0xa1: /* mov */
         dst.ptr = (unsigned long *)&_regs.eax;


-------------------------------------------------------
This SF.net email is sponsored by: 2005 Windows Mobile Application Contest
Submit applications for Windows Mobile(tm)-based Pocket PCs or Smartphones
for the chance to win $25,000 and application distribution. Enter today at
http://ads.osdn.com/?ad_id=6882&alloc_id=15148&op=click
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-changelog