File s390-memmove-ifunc-selector-arch13.patch of Package glibc.25649

From 0c92f409a7b078a50eb7e63ff57eb1e7ef57f90d Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.ibm.com>
Date: Tue, 23 Mar 2021 17:29:26 +0100
Subject: [PATCH] S390: Also check vector support in memmove ifunc-selector [BZ
 #27511]

The arch13 memmove variant is currently selected by the ifunc selector
if the Miscellaneous-Instruction-Extensions Facility 3 facility bit
is present, but the function is also using vector instructions.
If the vector support is not present, one is receiving an operation
exception.

Therefore this patch also checks for vector support in the ifunc
selector and in ifunc-impl-list.c.

Just to be sure, the configure check is now also testing an arch13
vector instruction and an arch13 Miscellaneous-Instruction-Extensions
Facility 3 instruction.

(cherry picked from commit 7759be2593b689cb1eafc0f52ee7f59c639e5d2f)
---
 sysdeps/s390/configure                   | 8 ++++++--
 sysdeps/s390/configure.ac                | 8 ++++++--
 sysdeps/s390/memmove.c                   | 2 +-
 sysdeps/s390/multiarch/ifunc-impl-list.c | 3 ++-
 4 files changed, 15 insertions(+), 6 deletions(-)

Index: glibc-2.31/sysdeps/s390/configure
===================================================================
--- glibc-2.31.orig/sysdeps/s390/configure
+++ glibc-2.31/sysdeps/s390/configure
@@ -123,7 +123,9 @@ void testinsn (char *buf)
     __asm__ (".machine \"arch13\" \n\t"
 	     ".machinemode \"zarch_nohighgprs\" \n\t"
 	     "lghi %%r0,16 \n\t"
-	     "mvcrl 0(%0),32(%0)" : : "a" (buf) : "memory", "r0");
+	     "mvcrl 0(%0),32(%0) \n\t"
+	     "vstrs %%v20,%%v20,%%v20,%%v20,0,2"
+	     : : "a" (buf) : "memory", "r0");
 }
 EOF
 if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS --shared conftest.c
@@ -271,7 +273,9 @@ else
 void testinsn (char *buf)
 {
     __asm__ ("lghi %%r0,16 \n\t"
-	     "mvcrl 0(%0),32(%0)" : : "a" (buf) : "memory", "r0");
+	     "mvcrl 0(%0),32(%0) \n\t"
+	     "vstrs %%v20,%%v20,%%v20,%%v20,0,2"
+	     : : "a" (buf) : "memory", "r0");
 }
 EOF
 if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS --shared conftest.c
Index: glibc-2.31/sysdeps/s390/configure.ac
===================================================================
--- glibc-2.31.orig/sysdeps/s390/configure.ac
+++ glibc-2.31/sysdeps/s390/configure.ac
@@ -88,7 +88,9 @@ void testinsn (char *buf)
     __asm__ (".machine \"arch13\" \n\t"
 	     ".machinemode \"zarch_nohighgprs\" \n\t"
 	     "lghi %%r0,16 \n\t"
-	     "mvcrl 0(%0),32(%0)" : : "a" (buf) : "memory", "r0");
+	     "mvcrl 0(%0),32(%0) \n\t"
+	     "vstrs %%v20,%%v20,%%v20,%%v20,0,2"
+	     : : "a" (buf) : "memory", "r0");
 }
 EOF
 dnl test, if assembler supports S390 arch13 instructions
@@ -195,7 +197,9 @@ cat > conftest.c <<\EOF
 void testinsn (char *buf)
 {
     __asm__ ("lghi %%r0,16 \n\t"
-	     "mvcrl 0(%0),32(%0)" : : "a" (buf) : "memory", "r0");
+	     "mvcrl 0(%0),32(%0) \n\t"
+	     "vstrs %%v20,%%v20,%%v20,%%v20,0,2"
+	     : : "a" (buf) : "memory", "r0");
 }
 EOF
 dnl test, if assembler supports S390 arch13 zarch instructions as default
Index: glibc-2.31/sysdeps/s390/memmove.c
===================================================================
--- glibc-2.31.orig/sysdeps/s390/memmove.c
+++ glibc-2.31/sysdeps/s390/memmove.c
@@ -43,7 +43,7 @@ extern __typeof (__redirect_memmove) MEM
 s390_libc_ifunc_expr (__redirect_memmove, memmove,
 		      ({
 			s390_libc_ifunc_expr_stfle_init ();
-			(HAVE_MEMMOVE_ARCH13
+			(HAVE_MEMMOVE_ARCH13 && (hwcap & HWCAP_S390_VXRS_EXT2)
 			 && S390_IS_ARCH13_MIE3 (stfle_bits))
 			  ? MEMMOVE_ARCH13
 			  : (HAVE_MEMMOVE_Z13 && (hwcap & HWCAP_S390_VX))
Index: glibc-2.31/sysdeps/s390/multiarch/ifunc-impl-list.c
===================================================================
--- glibc-2.31.orig/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ glibc-2.31/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -171,7 +171,8 @@ __libc_ifunc_impl_list (const char *name
     IFUNC_IMPL (i, name, memmove,
 # if HAVE_MEMMOVE_ARCH13
 		IFUNC_IMPL_ADD (array, i, memmove,
-				S390_IS_ARCH13_MIE3 (stfle_bits),
+				((dl_hwcap & HWCAP_S390_VXRS_EXT2)
+				 && S390_IS_ARCH13_MIE3 (stfle_bits)),
 				MEMMOVE_ARCH13)
 # endif
 # if HAVE_MEMMOVE_Z13