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From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>,
	"George Dunlap" <george.dunlap@citrix.com>,
	"Ian Jackson" <iwj@xenproject.org>
Subject: [PATCH v2 7/8] x86: move stac()/clac() from {get,put}_unsafe_asm() ...
Date: Wed, 17 Feb 2021 09:22:59 +0100	[thread overview]
Message-ID: <c817e9be-bcdf-3c38-2298-0a3a58773964@suse.com> (raw)
In-Reply-To: <b466a19e-e547-3c7c-e39b-1a4c848a053a@suse.com>

... to {get,put}_unsafe_size(). There's no need to have the macros
expanded once per case label in the latter. This also makes the former
well-formed single statements again. No change in generated code.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/include/asm-x86/uaccess.h
+++ b/xen/include/asm-x86/uaccess.h
@@ -154,7 +154,6 @@ struct __large_struct { unsigned long bu
  * aliasing issues.
  */
 #define put_unsafe_asm(x, addr, GUARD, err, itype, rtype, ltype, errret) \
-	stac();								\
 	__asm__ __volatile__(						\
 		GUARD(							\
 		"	guest_access_mask_ptr %[ptr], %[scr1], %[scr2]\n" \
@@ -169,11 +168,9 @@ struct __large_struct { unsigned long bu
 		: [ret] "+r" (err), [ptr] "=&r" (dummy_)		\
 		  GUARD(, [scr1] "=&r" (dummy_), [scr2] "=&r" (dummy_))	\
 		: [val] ltype (x), "m" (__m(addr)),			\
-		  "[ptr]" (addr), [errno] "i" (errret));		\
-	clac()
+		  "[ptr]" (addr), [errno] "i" (errret))
 
 #define get_unsafe_asm(x, addr, GUARD, err, rtype, ltype, errret)	\
-	stac();								\
 	__asm__ __volatile__(						\
 		GUARD(							\
 		"	guest_access_mask_ptr %[ptr], %[scr1], %[scr2]\n" \
@@ -190,12 +187,12 @@ struct __large_struct { unsigned long bu
 		  [ptr] "=&r" (dummy_)					\
 		  GUARD(, [scr1] "=&r" (dummy_), [scr2] "=&r" (dummy_))	\
 		: "m" (__m(addr)), "[ptr]" (addr),			\
-		  [errno] "i" (errret));				\
-	clac()
+		  [errno] "i" (errret))
 
 #define put_unsafe_size(x, ptr, size, grd, retval, errret)                 \
 do {                                                                       \
     retval = 0;                                                            \
+    stac();                                                                \
     switch ( size )                                                        \
     {                                                                      \
     long dummy_;                                                           \
@@ -213,6 +210,7 @@ do {
         break;                                                             \
     default: __put_user_bad();                                             \
     }                                                                      \
+    clac();                                                                \
 } while ( false )
 
 #define put_guest_size(x, ptr, size, retval, errret) \
@@ -221,6 +219,7 @@ do {
 #define get_unsafe_size(x, ptr, size, grd, retval, errret)                 \
 do {                                                                       \
     retval = 0;                                                            \
+    stac();                                                                \
     switch ( size )                                                        \
     {                                                                      \
     long dummy_;                                                           \
@@ -230,6 +229,7 @@ do {
     case 8: get_unsafe_asm(x, ptr, grd, retval,  "", "=r", errret); break; \
     default: __get_user_bad();                                             \
     }                                                                      \
+    clac();                                                                \
 } while ( false )
 
 #define get_guest_size(x, ptr, size, retval, errret)                       \


  parent reply	other threads:[~2021-02-17  8:23 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-17  8:16 [PATCH v2 0/8] x86/PV: avoid speculation abuse through guest accessors Jan Beulich
2021-02-17  8:19 ` [PATCH v2 1/8] x86: split __{get,put}_user() into "guest" and "unsafe" variants Jan Beulich
2021-02-17  8:20 ` [PATCH v2 2/8] x86: split __copy_{from,to}_user() " Jan Beulich
2021-02-17  8:20 ` [PATCH v2 3/8] x86/PV: harden guest memory accesses against speculative abuse Jan Beulich
2021-02-17  8:21 ` [PATCH v2 4/8] x86: rename {get,put}_user() to {get,put}_guest() Jan Beulich
2021-02-22 15:22   ` Roger Pau Monné
2021-02-17  8:21 ` [PATCH v2 5/8] x86/gdbsx: convert "user" to "guest" accesses Jan Beulich
2021-02-22 15:31   ` Roger Pau Monné
2021-02-22 15:55     ` Jan Beulich
2021-02-22 16:08       ` Roger Pau Monné
2021-02-17  8:22 ` [PATCH v2 6/8] x86: rename copy_{from,to}_user() to copy_{from,to}_guest_pv() Jan Beulich
2021-02-23 11:04   ` Roger Pau Monné
2021-02-23 15:15     ` Jan Beulich
2021-02-17  8:22 ` Jan Beulich [this message]
2021-02-23 11:40   ` [PATCH v2 7/8] x86: move stac()/clac() from {get,put}_unsafe_asm() Roger Pau Monné
2021-02-17  8:23 ` [PATCH v2 8/8] x86/PV: use get_unsafe() instead of copy_from_unsafe() Jan Beulich
2021-02-23 11:59   ` Roger Pau Monné
2021-02-23 15:25     ` Jan Beulich
2021-02-23 15:37       ` Roger Pau Monné
2021-02-23 16:13         ` Jan Beulich
2021-02-23 18:03           ` Roger Pau Monné
2021-02-19 15:50 ` [PATCH v2 0/8] x86/PV: avoid speculation abuse through guest accessors Ian Jackson
2021-02-19 15:56   ` Jan Beulich
2021-02-19 16:13     ` Ian Jackson
2021-02-19 16:16       ` Jan Beulich
2021-02-19 16:30         ` Ian Jackson
2021-02-24 11:13   ` Jan Beulich
2021-02-24 13:08     ` Ian Jackson
2021-02-24 13:18       ` Jan Beulich
2021-02-24 13:26         ` Ian Jackson

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