i386, x86: Use libc_ifunc macro for time, gettimeofday.

This patch uses the libc_ifunc_hidden macro to create already existing ifunc functions
time and gettimeofday on intel. This way, the libc_hidden_def macro can be used
instead of the libc_ifunc_hidden_def one which was only used here. Thus the
macro is removed from libc-symbols.h.
On i386, the __GI_* symbols do not target the ifunc symbol and thus the
redirection construct has to be applied here.

ChangeLog:

	* sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday):
	Use libc_ifunc_hidden macro. Use libc_hidden_def instead of
	libc_ifunc_hidden_def.
	* sysdeps/unix/sysv/linux/x86/time.c (time): Likewise.
	* sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday):
	Redirect ifunced function in header for using it as type of ifunc'ed
	function. Redefine libc_hidden_def to use fallback non ifunc'ed
	function for __GI_* symbol.
	* sysdeps/unix/sysv/linux/i386/time.c (time): Likewise.
	* include/libc-symbols.h
	(libc_ifunc_hidden_def, libc_ifunc_hidden_def1): Delete macro.

ChangeLog

@@ -1,3 +1,17 @@
+2016-10-07  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	* sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday):
+	Use libc_ifunc_hidden macro. Use libc_hidden_def instead of
+	libc_ifunc_hidden_def.
+	* sysdeps/unix/sysv/linux/x86/time.c (time): Likewise.
+	* sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday):
+	Redirect ifunced function in header for using it as type of ifunc'ed
+	function. Redefine libc_hidden_def to use fallback non ifunc'ed
+	function for __GI_* symbol.
+	* sysdeps/unix/sysv/linux/i386/time.c (time): Likewise.
+	* include/libc-symbols.h
+	(libc_ifunc_hidden_def, libc_ifunc_hidden_def1): Delete macro.
+
 2016-10-07  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
 	[BZ #20478]

include/libc-symbols.h

@@ -869,21 +869,6 @@ for linking")
 #define libm_ifunc(name, expr)				\
   __ifunc (name, name, expr, void, libm_ifunc_init)
 
-#ifdef HAVE_ASM_SET_DIRECTIVE
-# define libc_ifunc_hidden_def1(local, name)				\
-    __asm__ (".globl " #local "\n\t"					\
-	     ".hidden " #local "\n\t"					\
-	     ".set " #local ", " #name);
-#else
-# define libc_ifunc_hidden_def1(local, name)				\
-    __asm__ (".globl " #local "\n\t"					\
-	     ".hidden " #local "\n\t"					\
-	     #local " = " #name);
-#endif
-
-#define libc_ifunc_hidden_def(name) \
-  libc_ifunc_hidden_def1 (__GI_##name, name)
-
 /* Add the compiler optimization to inhibit loop transformation to library
    calls.  This is used to avoid recursive calls in memset and memmove
    default implementations.  */

sysdeps/unix/sysv/linux/i386/gettimeofday.c

@@ -16,14 +16,20 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifdef SHARED
+# define __gettimeofday __redirect___gettimeofday
+#endif
+
 #include <sys/time.h>
 
 #ifdef SHARED
+# undef __gettimeofday
+# define __gettimeofday_type __redirect___gettimeofday
 
-# undef libc_ifunc_hidden_def
+# undef libc_hidden_def
-# define libc_ifunc_hidden_def(name)  \
+# define libc_hidden_def(name) \
-  libc_ifunc_hidden_def1 (__GI_##name, __gettimeofday_syscall)
+  __hidden_ver1 (__gettimeofday_syscall, __GI___gettimeofday, \
-
+	       __gettimeofday_syscall);
 #endif
 
 #include <sysdeps/unix/sysv/linux/x86/gettimeofday.c>

sysdeps/unix/sysv/linux/i386/time.c

@@ -17,10 +17,18 @@
    <http://www.gnu.org/licenses/>.  */
 
 #ifdef SHARED
+# define time __redirect_time
+#endif
 
-# undef libc_ifunc_hidden_def
+#include <time.h>
-# define libc_ifunc_hidden_def(name)  \
+
-  libc_ifunc_hidden_def1 (__GI_##name, __time_syscall)
+#ifdef SHARED
+# undef time
+# define time_type __redirect_time
+
+# undef libc_hidden_def
+# define libc_hidden_def(name)  \
+  __hidden_ver1 (__time_syscall, __GI_time, __time_syscall);
 #endif
 
 #include <sysdeps/unix/sysv/linux/x86/time.c>

sysdeps/unix/sysv/linux/x86/gettimeofday.c

@@ -29,20 +29,20 @@ __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
   return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
 }
 
-void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday");
+# ifndef __gettimeofday_type
+/* The i386 gettimeofday.c includes this file with a defined
+   __gettimeofday_type macro.  For x86_64 we have to define it to __gettimeofday
+   as the internal symbol is the ifunc'ed one.  */
+#  define __gettimeofday_type __gettimeofday
+# endif
 
-void *
+# undef INIT_ARCH
-gettimeofday_ifunc (void)
+# define INIT_ARCH() PREPARE_VERSION_KNOWN (linux26, LINUX_2_6)
-{
+/* If the vDSO is not available we fall back to syscall.  */
-  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+libc_ifunc_hidden (__gettimeofday_type, __gettimeofday,
-
+		   (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26)
-  /* If the vDSO is not available we fall back to syscall.  */
+		    ?: &__gettimeofday_syscall))
-  return (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26)
+libc_hidden_def (__gettimeofday)
-	  ?: (void*) (&__gettimeofday_syscall));
-}
-asm (".type __gettimeofday, %gnu_indirect_function");
-
-libc_ifunc_hidden_def(__gettimeofday)
 
 #else
 

sysdeps/unix/sysv/linux/x86/time.c

@@ -30,20 +30,20 @@ __time_syscall (time_t *t)
   return INTERNAL_SYSCALL (time, err, 1, t);
 }
 
-void *time_ifunc (void) __asm__ ("time");
+# ifndef time_type
-
+/* The i386 time.c includes this file with a defined time_type macro.
-void *
+   For x86_64 we have to define it to time as the internal symbol is the
-time_ifunc (void)
+   ifunc'ed one.  */
-{
+#  define time_type time
-  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+# endif
 
+#undef INIT_ARCH
+#define INIT_ARCH() PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
 /* If the vDSO is not available we fall back on the syscall.  */
-  return _dl_vdso_vsym ("__vdso_time", &linux26)
+libc_ifunc_hidden (time_type, time,
-			?: (void*) &__time_syscall;
+		   (_dl_vdso_vsym ("__vdso_time", &linux26)
-}
+		    ?:  &__time_syscall))
-asm (".type time, %gnu_indirect_function");
+libc_hidden_def (time)
-
-libc_ifunc_hidden_def(time)
 
 #else