x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER

[linux-2.6-microblaze.git] / arch / x86 / entry / entry_64_compat.S

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 381a6de..541fdaf 100644 (file)
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -57,15 +57,6 @@ SYM_CODE_START(entry_SYSENTER_compat)
 
        movq    PER_CPU_VAR(cpu_current_top_of_stack), %rsp
 
-       /*
-        * User tracing code (ptrace or signal handlers) might assume that
-        * the saved RAX contains a 32-bit number when we're invoking a 32-bit
-        * syscall.  Just in case the high bits are nonzero, zero-extend
-        * the syscall number.  (This could almost certainly be deleted
-        * with no ill effects.)
-        */
-       movl    %eax, %eax
-
        /* Construct struct pt_regs on stack */
        pushq   $__USER32_DS            /* pt_regs->ss */
        pushq   $0                      /* pt_regs->sp = 0 (placeholder) */
@@ -80,6 +71,16 @@ SYM_CODE_START(entry_SYSENTER_compat)
        pushq   $__USER32_CS            /* pt_regs->cs */
        pushq   $0                      /* pt_regs->ip = 0 (placeholder) */
 SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)
+
+       /*
+        * User tracing code (ptrace or signal handlers) might assume that
+        * the saved RAX contains a 32-bit number when we're invoking a 32-bit
+        * syscall.  Just in case the high bits are nonzero, zero-extend
+        * the syscall number.  (This could almost certainly be deleted
+        * with no ill effects.)
+        */
+       movl    %eax, %eax
+
        pushq   %rax                    /* pt_regs->orig_ax */
        pushq   %rdi                    /* pt_regs->di */
        pushq   %rsi                    /* pt_regs->si */