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-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=778b8d37865a1d6689155c23802724bf11e4bc75;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.

(cherry picked from commit 7759be2593b689cb1eafc0f52ee7f59c639e5d2f)
---

diff --git a/sysdeps/s390/configure b/sysdeps/s390/configure
index fa46e9e351e..e7f576338d8 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 3ed5a8ef87f..5c3479e8cf1 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 5fc85e129fd..ee59b5de14b 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 e6195c6e261..17c0cc3952d 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