WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH] linux/x86: avoid casting hypercall arguments to long

To: <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] [PATCH] linux/x86: avoid casting hypercall arguments to long
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Mon, 21 Jan 2008 15:18:38 +0000
Delivery-date: Mon, 21 Jan 2008 07:18:29 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
.., providing a little more type correctness checking and producing
better code on 64-bits. This includes replacing the directly encoded
moves to %r10 and %r8 on x86-64 by (extended) C-language constructs,
allowing the compiler's scheduler more flexibility.

As usual, written and tested on 2.6.24-rc8 and made apply to the 2.6.18
tree without further testing.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

Index: head-2008-01-21/include/asm-i386/mach-xen/asm/hypercall.h
===================================================================
--- head-2008-01-21.orig/include/asm-i386/mach-xen/asm/hypercall.h      
2008-01-21 13:31:43.000000000 +0100
+++ head-2008-01-21/include/asm-i386/mach-xen/asm/hypercall.h   2008-01-21 
13:31:50.000000000 +0100
@@ -67,7 +67,7 @@
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=b" (__ign1)                   \
-               : "1" ((long)(a1))                              \
+               : "1" ((a1)?:0)                                 \
                : "memory" );                                   \
        (type)__res;                                            \
 })
@@ -78,7 +78,7 @@
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=b" (__ign1), "=c" (__ign2)    \
-               : "1" ((long)(a1)), "2" ((long)(a2))            \
+               : "1" ((a1)?:0), "2" ((a2)?:0)                  \
                : "memory" );                                   \
        (type)__res;                                            \
 })
@@ -89,9 +89,8 @@
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   \
-               "=d" (__ign3)                                   \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3))                                \
+                 "=d" (__ign3)                                 \
+               : "1" ((a1)?:0), "2" ((a2)?:0), "3" ((a3)?:0)   \
                : "memory" );                                   \
        (type)__res;                                            \
 })
@@ -102,9 +101,9 @@
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   \
-               "=d" (__ign3), "=S" (__ign4)                    \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3)), "4" ((long)(a4))              \
+                 "=d" (__ign3), "=S" (__ign4)                  \
+               : "1" ((a1)?:0), "2" ((a2)?:0),                 \
+                 "3" ((a3)?:0), "4" ((a4)?:0)                  \
                : "memory" );                                   \
        (type)__res;                                            \
 })
@@ -115,10 +114,9 @@
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   \
-               "=d" (__ign3), "=S" (__ign4), "=D" (__ign5)     \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3)), "4" ((long)(a4)),             \
-               "5" ((long)(a5))                                \
+                 "=d" (__ign3), "=S" (__ign4), "=D" (__ign5)   \
+               : "1" ((a1)?:0), "2" ((a2)?:0),                 \
+                 "3" ((a3)?:0), "4" ((a4)?:0), "5" ((a5)?:0)   \
                : "memory" );                                   \
        (type)__res;                                            \
 })
@@ -226,7 +224,11 @@ static inline int __must_check
 HYPERVISOR_update_descriptor(
        u64 ma, u64 desc)
 {
-       return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
+       unsigned long ma_hi = (unsigned long)(ma>>32);
+       unsigned long ma_lo = (unsigned long)ma;
+       unsigned long desc_hi = (unsigned long)(desc>>32);
+       unsigned long desc_lo = (unsigned long)desc;
+       return _hypercall4(int, update_descriptor, ma_lo, ma_hi, desc_lo, 
desc_hi);
 }
 
 static inline int __must_check
Index: head-2008-01-21/include/asm-x86_64/mach-xen/asm/hypercall.h
===================================================================
--- head-2008-01-21.orig/include/asm-x86_64/mach-xen/asm/hypercall.h    
2008-01-21 13:31:43.000000000 +0100
+++ head-2008-01-21/include/asm-x86_64/mach-xen/asm/hypercall.h 2008-01-21 
13:31:50.000000000 +0100
@@ -56,77 +56,74 @@
 
 #define _hypercall0(type, name)                        \
 ({                                             \
-       long __res;                             \
+       type __res;                             \
        asm volatile (                          \
                HYPERCALL_STR(name)             \
                : "=a" (__res)                  \
                :                               \
                : "memory" );                   \
-       (type)__res;                            \
+       __res;                                  \
 })
 
 #define _hypercall1(type, name, a1)                            \
 ({                                                             \
-       long __res, __ign1;                                     \
+       type __res, __ign1;                                     \
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=D" (__ign1)                   \
-               : "1" ((long)(a1))                              \
+               : "1" ((a1)?:0)                                 \
                : "memory" );                                   \
-       (type)__res;                                            \
+       __res;                                                  \
 })
 
 #define _hypercall2(type, name, a1, a2)                                \
 ({                                                             \
-       long __res, __ign1, __ign2;                             \
+       type __res, __ign1, __ign2;                             \
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=D" (__ign1), "=S" (__ign2)    \
-               : "1" ((long)(a1)), "2" ((long)(a2))            \
+               : "1" ((a1)?:0), "2" ((a2)?:0)                  \
                : "memory" );                                   \
-       (type)__res;                                            \
+       __res;                                                  \
 })
 
 #define _hypercall3(type, name, a1, a2, a3)                    \
 ({                                                             \
-       long __res, __ign1, __ign2, __ign3;                     \
+       type __res, __ign1, __ign2, __ign3;                     \
        asm volatile (                                          \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=D" (__ign1), "=S" (__ign2),   \
-               "=d" (__ign3)                                   \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3))                                \
+                 "=d" (__ign3)                                 \
+               : "1" ((a1)?:0), "2" ((a2)?:0), "3" ((a3)?:0)   \
                : "memory" );                                   \
-       (type)__res;                                            \
+       __res;                                                  \
 })
 
 #define _hypercall4(type, name, a1, a2, a3, a4)                        \
 ({                                                             \
-       long __res, __ign1, __ign2, __ign3;                     \
+       type __res, __ign1, __ign2, __ign3;                     \
+       register typeof((a4)?:0) __arg4 asm("r10") = (a4);      \
        asm volatile (                                          \
-               "movq %7,%%r10; "                               \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=D" (__ign1), "=S" (__ign2),   \
-               "=d" (__ign3)                                   \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3)), "g" ((long)(a4))              \
-               : "memory", "r10" );                            \
-       (type)__res;                                            \
+                 "=d" (__ign3), "+r" (__arg4)                  \
+               : "1" ((a1)?:0), "2" ((a2)?:0), "3" ((a3)?:0)   \
+               : "memory" );                                   \
+       __res;                                                  \
 })
 
 #define _hypercall5(type, name, a1, a2, a3, a4, a5)            \
 ({                                                             \
-       long __res, __ign1, __ign2, __ign3;                     \
+       type __res, __ign1, __ign2, __ign3;                     \
+       register typeof((a4)?:0) __arg4 asm("r10") = (a4);      \
+       register typeof((a5)?:0) __arg5 asm("r8") = (a5);       \
        asm volatile (                                          \
-               "movq %7,%%r10; movq %8,%%r8; "                 \
                HYPERCALL_STR(name)                             \
                : "=a" (__res), "=D" (__ign1), "=S" (__ign2),   \
-               "=d" (__ign3)                                   \
-               : "1" ((long)(a1)), "2" ((long)(a2)),           \
-               "3" ((long)(a3)), "g" ((long)(a4)),             \
-               "g" ((long)(a5))                                \
-               : "memory", "r10", "r8" );                      \
-       (type)__res;                                            \
+                 "=d" (__ign3), "+r" (__arg4), "+r" (__arg5)   \
+               : "1" ((a1)?:0), "2" ((a2)?:0), "3" ((a3)?:0)   \
+               : "memory" );                                   \
+       __res;                                                  \
 })
 
 static inline int __must_check



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>