S390: Use new s390_libc_ifunc_expr macro in s390 8bit-generic.c.

This patch adds s390_libc_ifunc_expr macro which uses the __ifunc base macro
in include/libc-symbols.h and lets the user define a generic expression to
choose the correct ifunc variant.  Furthermore as the base macro is used,
the ifunc resolver functions are now also using inhibit_stack_protector.
S390 needs its own version due to the hwcap argument of the ifunc resolver.

This new macro is now used in iconv code in 8bit-generic.c instead of using
gcc attribute ifunc directly.

ChangeLog:

	* sysdeps/s390/multiarch/ifunc-resolve.h
	(s390_libc_ifunc_expr_init, s390_libc_ifunc_expr): New Define.
	* sysdeps/s390/multiarch/8bit-generic.c
	(__to_generic, __from_generic): Use s390_libc_ifunc_expr to
	define ifunc resolvers.

3 files changed, 25 insertions, 29 deletions

diff --git a/ChangeLog b/ChangeLog
index dedd753d5f..12bf100cfa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-04-21  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	* sysdeps/s390/multiarch/ifunc-resolve.h
+	(s390_libc_ifunc_expr_init, s390_libc_ifunc_expr): New Define.
+	* sysdeps/s390/multiarch/8bit-generic.c
+	(__to_generic, __from_generic): Use s390_libc_ifunc_expr to
+	define ifunc resolvers.
+
 2017-04-21  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #20424]
diff --git a/sysdeps/s390/multiarch/8bit-generic.c b/sysdeps/s390/multiarch/8bit-generic.c
index 99f63e4b0b..49f0ed8ae5 100644
--- a/sysdeps/s390/multiarch/8bit-generic.c
+++ b/sysdeps/s390/multiarch/8bit-generic.c
@@ -40,8 +40,7 @@
    to translate between multiple generic characters and "1 byte UCS4"
    characters at once. The vector instructions are used to convert between
    the "1 byte UCS4" and UCS4.  */
-# include <unistd.h>
-# include <dl-procinfo.h>
+# include <ifunc-resolve.h>
 
 # undef FROM_LOOP
 # undef TO_LOOP
@@ -372,33 +371,17 @@
 
 
 /* Generate ifunc'ed loop function.  */
-__typeof(__from_generic_c)
-__attribute__ ((ifunc ("__from_generic_resolver")))
-__from_generic;
+s390_libc_ifunc_expr (__from_generic_c, __from_generic,
+		      (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
+		       && hwcap & HWCAP_S390_VX)
+		      ? __from_generic_vx
+		      : __from_generic_c);
 
-static void *
-__from_generic_resolver (unsigned long int dl_hwcap)
-{
-  if (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
-      && dl_hwcap & HWCAP_S390_VX)
-    return &__from_generic_vx;
-  else
-    return &__from_generic_c;
-}
-
-__typeof(__to_generic_c)
-__attribute__ ((ifunc ("__to_generic_resolver")))
-__to_generic;
-
-static void *
-__to_generic_resolver (unsigned long int dl_hwcap)
-{
-  if (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
-      && dl_hwcap & HWCAP_S390_VX)
-    return &__to_generic_vx;
-  else
-    return &__to_generic_c;
-}
+s390_libc_ifunc_expr (__to_generic_c, __to_generic,
+		      (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
+		       && hwcap & HWCAP_S390_VX)
+		      ? __to_generic_vx
+		      : __to_generic_c);
 
 strong_alias (__to_generic_c_single, __to_generic_single)
 
@@ -410,6 +393,6 @@ strong_alias (__to_generic_c_single, __to_generic_single)
 
 #else
 /* Generate this module without ifunc if build environment lacks vector
-   support. Instead the common 8bit-generic.c is used.  */
+   support.  Instead the common 8bit-generic.c is used.  */
 # include "iconvdata/8bit-generic.c"
 #endif /* !defined HAVE_S390_VX_ASM_SUPPORT */
diff --git a/sysdeps/s390/multiarch/ifunc-resolve.h b/sysdeps/s390/multiarch/ifunc-resolve.h
index c04822d55a..adbd08a6ee 100644
--- a/sysdeps/s390/multiarch/ifunc-resolve.h
+++ b/sysdeps/s390/multiarch/ifunc-resolve.h
@@ -83,3 +83,8 @@
 	   ? RESOLVERFUNC##_vx						\
 	   : RESOLVERFUNC##_c,						\
 	   unsigned long int dl_hwcap, s390_vx_libc_ifunc_init);
+
+#define s390_libc_ifunc_expr_init()
+#define s390_libc_ifunc_expr(TYPE_FUNC, FUNC, EXPR)		\
+  __ifunc (TYPE_FUNC, FUNC, EXPR, unsigned long int hwcap,	\
+	   s390_libc_ifunc_expr_init);