PERFORCE change 32144 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=32144

Change 32144 by marcel at marcel_nfs on 2003/05/30 19:12:58

	Some nitpicking changes:
	
	o  Be less eager in restoring registers from the trapframe
	   when exec'ing a ia32 process. Only restore the ia32
	   general registers that constitute ia32 state.
	o  Clear the ia32 state registers if they don't contain
	   important data at startup. This reduces the chance of
	   leaking NaT bits into the ia32 process.
	o  The SDM states that the best way to call ia32 code is
	   to flush the RSE in the cycle immediately prior to the
	   br.ia. Do it that way, even though it's not strictly
	   necessary.
	o  Make sure we set ar.k6 and ar.k7 prior to changing sp
	   and ar.bspstore. We used to change ar.bspstore before
	   we set ar.k6, creating a small hole in which interrupts
	   could cause corruption.

Affected files ...

.. //depot/projects/ia64/sys/ia64/ia64/syscall.s#9 edit

Differences ...

==== //depot/projects/ia64/sys/ia64/ia64/syscall.s#9 (text+ko) ====

@@ -101,13 +101,20 @@
 	;;
 }
 gw_ret_ia32:
-	mov		ar.rnat=r0
-	mov		ar.rsc=0xc
-	mov		ar.pfs=r0
+{	.mfb
+	flushrs
+	nop		0
+	nop		0
 	;;
+}
+{	.mfb
+	nop		0
+	nop		0
 	br.ia.sptk	b6
 	;;
+}
 
+
 ENTRY(break_sigtramp, 0)
 {	.mib
 	mov		ar.rsc=0
@@ -509,33 +516,24 @@
 {	.mmi
 	mov		r30=ar.bspstore
 	;;
-	mov		ar.bspstore=r21
+	mov		ar.unat=r17
 	dep		r30=0,r30,0,9
 	;;
 }
 {	.mmi
 	mov		ar.k6=r30
-	mov		ar.unat=r17
-	mov		r11=r26
+	mov		ar.bspstore=r21
+	mov		r11=r0
 	;;
 }
-
-	ld8		r16=[r14],16
-	ld8		r17=[r15],16
+{	.mmi
+	ld8		r16=[r14],64
+	ld8		r17=[r15],80
+	mov		r13=r0
 	;;
-	ld8		r18=[r14],16
-	ld8		r19=[r15],16
-	;;
-	ld8		r20=[r14],16
-	ld8		r21=[r15],16
-	;;
-	ld8		r22=[r14],16
-	ld8		r23=[r15],16
-	;;
-	ld8		r24=[r14],16
-	ld8		r25=[r15],16
-	;;
-	ld8		r26=[r14],16
+}
+ 
+	ld8		r24=[r14],32
 	ld8		r27=[r15],16
 	;;
 	ld8		r28=[r14],16
@@ -544,18 +542,27 @@
 	ld8		r30=[r14],40
 	ld8		r31=[r15],40
 	;;
-	ld8		r2=[r14],16
-	ld8		r3=[r15],8
+
+{	.mmi
+	ld8		r2=[r14]
+	ld8		r3=[r15]
+	mov		r14=r0
 	;;
+}
+{	.mmi
 	mov		ar.csd=r2
 	mov		ar.ssd=r3
+	mov		r15=r0
 	;;
+}
+
 	mov		r2=ar.k5
-	mov		psr.l=r11
+	mov		psr.l=r26
 	;;
 	srlz.d
 	add		r2=gw_ret_ia32-ia64_gateway_page,r2
 	;;
+	mov		ar.rsc=0x0
 	mov		b7=r2
 	br.ret.sptk	b7
 	;;