From: Stefan Liebler <stli@linux.ibm.com>
Date: Tue, 23 Mar 2021 16:29:26 +0000 (+0100)
Subject: S390: Also check vector support in memmove ifunc-selector [BZ #27511]
X-Git-Tag: glibc-2.34~787
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7759be2593b689cb1eafc0f52ee7f59c639e5d2f;p=thirdparty%2Fglibc.git

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.
---

diff --git a/sysdeps/s390/configure b/sysdeps/s390/configure
index 5f98640d0fc..7eaefbabcfe 100644
--- a/sysdeps/s390/configure
+++ b/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
diff --git a/sysdeps/s390/configure.ac b/sysdeps/s390/configure.ac
index dfe007a774d..e6df6249190 100644
--- a/sysdeps/s390/configure.ac
+++ b/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
diff --git a/sysdeps/s390/memmove.c b/sysdeps/s390/memmove.c
index f88ea79d97a..1a7d3369f21 100644
--- a/sysdeps/s390/memmove.c
+++ b/sysdeps/s390/memmove.c
@@ -43,7 +43,7 @@ extern __typeof (__redirect_memmove) MEMMOVE_ARCH13 attribute_hidden;
 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))
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c
index 4b170e4459d..2ef38b72dda 100644
--- a/sysdeps/s390/multiarch/ifunc-impl-list.c
+++ b/sysdeps/s390/multiarch/ifunc-impl-list.c
@@ -171,7 +171,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
     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