Make assembly language versions of OPENSSL_cleanse() accept zero length

parameter. Backport from HEAD, orginal by appro.

crypto/alphacpuid.s

@@ -90,6 +90,7 @@ OPENSSL_rdtsc:
 OPENSSL_cleanse:
 	.frame	$30,0,$26
 	.prologue 0
+	beq	$17,.Ldone
 	and	$16,7,$0
 	bic	$17,7,$at
 	beq	$at,.Little

crypto/ia64cpuid.S

@@ -130,9 +130,11 @@ OPENSSL_wipe_cpu:
 .global	OPENSSL_cleanse#
 .proc	OPENSSL_cleanse#
 OPENSSL_cleanse:
+{ .mib;	cmp.eq		p6,p0=0,r33	    // len==0
 #if defined(_HPUX_SOURCE) && !defined(_LP64)
-{ .mmi;	addp4		r32=0,r32	};;
+	addp4		r32=0,r32
 #endif
+(p6)	br.ret.spnt	b0		};;
 { .mib;	and		r2=7,r32
 	cmp.leu		p6,p0=15,r33	    // len>=15
 (p6)	br.cond.dptk	.Lot		};;

crypto/perlasm/ppc-xlate.pl

@@ -101,6 +101,13 @@ my $bnelr = sub {
 	"	.long	".sprintf "0x%x",19<<26|$bo<<21|2<<16|16<<1 :
 	"	bclr	$bo,2";
 };
+my $beqlr = sub {
+    my $f = shift;
+    my $bo = $f=~/-/ ? 12+2 : 12;	# optional "not to be taken" hint
+    ($flavour =~ /linux/) ?		# GNU as doesn't allow most recent hints
+	"	.long	".sprintf "0x%X",19<<26|$bo<<21|2<<16|16<<1 :
+	"	bclr	$bo,2";
+};
 # GNU assembler can't handle extrdi rA,rS,16,48, or when sum of last two
 # arguments is 64, with "operand out of range" error.
 my $extrdi = sub {

crypto/ppccpuid.pl

@@ -67,6 +67,8 @@ Loop:	lwarx	r5,0,r3
 	$CMPLI	r4,7
 	li	r0,0
 	bge	Lot
+	$CMPLI	r4,0
+	beqlr-
 Little:	mtctr	r4
 	stb	r0,0(r3)
 	addi	r3,r3,1

crypto/s390xcpuid.S

@@ -62,6 +62,8 @@ OPENSSL_cleanse:
 	lghi	%r0,0
 	clgr	%r3,%r4
 	jh	.Lot
+	clgr	%r3,%r0
+	bcr	8,%r14
 .Little:
 	stc	%r0,0(%r2)
 	la	%r2,1(%r2)

crypto/sparccpuid.S

@@ -242,6 +242,10 @@ OPENSSL_cleanse:
 #else
 	bgu	.Lot
 #endif
+	cmp	%o1,0
+	bne	.Little
+	nop
+	retl
 	nop
 
 .Little:

crypto/x86_64cpuid.pl

@@ -145,12 +145,14 @@ OPENSSL_cleanse:
 	xor	%rax,%rax
 	cmp	\$15,$arg2
 	jae	.Lot
+	cmp	\$0,$arg2
+	je	.Lret
 .Little:
 	mov	%al,($arg1)
 	sub	\$1,$arg2
 	lea	1($arg1),$arg1
 	jnz	.Little
-	ret
+.Lret:	ret
 .align	16
 .Lot:
 	test	\$7,$arg1

crypto/x86cpuid.pl

@@ -279,11 +279,14 @@ for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
 	&xor	("eax","eax");
 	&cmp	("ecx",7);
 	&jae	(&label("lot"));
+	&cmp	("ecx",0);
+	&je	(&label("ret"));
 &set_label("little");
 	&mov	(&BP(0,"edx"),"al");
 	&sub	("ecx",1);
 	&lea	("edx",&DWP(1,"edx"));
 	&jnz	(&label("little"));
+&set_label("ret");
 	&ret	();
 
 &set_label("lot",16);