Add x86 32 bit vDSO time function support

Linux 3.15 adds support for clock_gettime, gettimeofday, and time vDSO
(commit id 37c975545ec63320789962bf307f000f08fabd48).  This patch adds
GLIBC supports to use such symbol when they are avaiable.

Along with x86 vDSO support, this patch cleanup x86_64 code by moving
all common code to x86 common folder.  Only init-first.c is different
between implementations.

ChangeLog

@@ -1,3 +1,30 @@
+2015-01-12  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+	    Stefani Seibold  <stefani@seibold.net>
+
+	* sysdeps/unix/sysv/linux/x86_64/Makefile [$(subdir) = elf]
+	(sysdep_routines): Add dl-vdso here, ...
+	* sysdeps/unix/sysv/linux/x86/Makefile [$(subdir) = elf]
+	(sysdep_routines): ... not here.
+	* sysdeps/unix/sysv/linux/i386/gettimeofday.c: New file: set syscall
+	fallback when vDSO is not presented.
+	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_clock_gettime):
+	Define with libc_hidden_proto/libc_hidden_data_def definitions.
+	(_libc_vdso_platform_setup): Rename to __vdso_platform_setup.
+	* sysdeps/unix/sysv/linux/i386/init-first.c: New file: likewise.
+	* sysdeps/unix/sysv/linux/i386/time.c: New file: likewise.
+	* sysdeps/unix/sysv/linux/x86_64/bits/libc-vdso.h: Moved to ...
+	* sysdeps/unix/sysv/linux/x86/libc-vdso.h: ... here.
+	* sysdeps/unix/sysv/linux/x86_64/clock_gettime.c: Move to ...
+	* sysdeps/unix/sysv/linux/x86/clock_gettime.c: ... here.
+	* sysdeps/unix/sysv/linux/x86_64/gettimeofday.c: Move to ...
+	* sysdeps/unix/sysv/linux/x86/gettimeofday.c: ... here.  Also added
+	fallback configurable symbol when vDSO is not available.
+	* sysdeps/unix/sysv/linux/x86_64/time.c: Move to ...
+	* sysdeps/unix/sysv/linux/x86/time.c: ... here.  Also refactored to
+	be able to redefine fallback symbol when vDSO is not available.
+	* sysdeps/unix/sysv/linux/x86_64/timespec_get.c: Move to ...
+	* sysdeps/unix/sysv/linux/x86/timespec_get.c: ... here.
+
 2015-01-12  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
 	* sysdeps/powerpc/nptl/tls.h (tcbhead_t): Add tm_capable field.

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

@@ -0,0 +1,39 @@
+/* gettimeofday - get the time.  Linux/i386 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/time.h>
+
+#ifdef SHARED
+
+# include <dl-vdso.h>
+# include <errno.h>
+
+/* If the vDSO is not available we fall back on the syscall.  */
+static int
+__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
+{
+  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+}
+# define GETTIMEOFAY_FALLBACK (void*) (&__gettimeofday_syscall)
+# undef libc_ifunc_hidden_def
+# define libc_ifunc_hidden_def(name)  \
+  libc_ifunc_hidden_def1 (__GI_##name, __gettimeofday_syscall)
+
+#endif
+
+#include <sysdeps/unix/sysv/linux/x86/gettimeofday.c>

sysdeps/unix/sysv/linux/i386/init-first.c

@@ -0,0 +1,52 @@
+/* Initialization code run first thing by the ELF startup code.  Linux/i386.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifdef SHARED
+# include <time.h>
+# include <sysdep.h>
+# include <dl-vdso.h>
+# include <libc-vdso.h>
+
+long int (*__vdso_clock_gettime) (clockid_t, struct timespec *)
+  __attribute__ ((nocommon));
+libc_hidden_proto (__vdso_clock_gettime)
+libc_hidden_data_def (__vdso_clock_gettime)
+
+static long int
+clock_gettime_syscall (clockid_t id, struct timespec *tp)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  return INTERNAL_SYSCALL (clock_gettime, err, 2, id, tp);
+}
+
+static inline void
+__vdso_platform_setup (void)
+{
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+
+  void *p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
+  if (p == NULL)
+    p = clock_gettime_syscall;
+  PTR_MANGLE (p);
+  __vdso_clock_gettime = p;
+}
+
+# define VDSO_SETUP __vdso_platform_setup
+#endif
+
+#include <csu/init-first.c>

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

@@ -0,0 +1,37 @@
+/* time -- Get number of seconds since Epoch.  Linux/i386 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifdef SHARED
+
+# include <dl-vdso.h>
+# include <errno.h>
+
+/* If the vDSO is not available we fall back on the old vsyscall.  */
+static time_t
+__time_syscall (time_t *t)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  return INTERNAL_SYSCALL (time, err, 1, t);
+}
+# define TIME_FALLBACK  (void*) &__time_syscall
+# undef libc_ifunc_hidden_def
+# define libc_ifunc_hidden_def(name)  \
+  libc_ifunc_hidden_def1 (__GI_##name, __time_syscall)
+#endif
+
+#include <sysdeps/unix/sysv/linux/x86/time.c>

sysdeps/unix/sysv/linux/x86/Makefile

@@ -19,3 +19,7 @@ libpthread-sysdep_routines += init-arch
 libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
 			      elision-trylock
 endif
+
+ifeq ($(subdir),elf)
+sysdep_routines += dl-vdso
+endif

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

@@ -0,0 +1,34 @@
+/* Get the current value of a clock.  Linux/x86 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libc-vdso.h>
+
+#ifdef SHARED
+# define SYSCALL_GETTIME(id, tp) \
+  ({ long int (*f) (clockid_t, struct timespec *) = __vdso_clock_gettime; \
+  long int v_ret;							  \
+  PTR_DEMANGLE (f);							  \
+  v_ret = (*f) (id, tp);						  \
+  if (INTERNAL_SYSCALL_ERROR_P (v_ret, )) {				  \
+    __set_errno (INTERNAL_SYSCALL_ERRNO (v_ret, ));			  \
+    v_ret = -1;								  \
+  }									  \
+  v_ret; })
+#endif
+
+#include <sysdeps/unix/sysv/linux/clock_gettime.c>

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

@@ -0,0 +1,54 @@
+/* gettimeofday - get the time.  Linux/x86 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/time.h>
+
+#ifdef SHARED
+
+# include <dl-vdso.h>
+
+void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday");
+
+void *
+gettimeofday_ifunc (void)
+{
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+
+  /* If the vDSO is not available we fall back on the old vsyscall.  */
+  return (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26)
+	  ?: GETTIMEOFAY_FALLBACK);
+}
+asm (".type __gettimeofday, %gnu_indirect_function");
+
+libc_ifunc_hidden_def(__gettimeofday)
+
+#else
+
+# include <sysdep.h>
+# include <errno.h>
+
+int
+__gettimeofday (struct timeval *tv, struct timezone *tz)
+{
+  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+}
+libc_hidden_def (__gettimeofday)
+
+#endif
+weak_alias (__gettimeofday, gettimeofday)
+libc_hidden_weak (gettimeofday)

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

@@ -0,0 +1,49 @@
+/* time -- Get number of seconds since Epoch.  Linux/x86 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+
+#ifdef SHARED
+
+#include <dl-vdso.h>
+
+void *time_ifunc (void) __asm__ ("time");
+
+void *
+time_ifunc (void)
+{
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
+
+  return _dl_vdso_vsym ("__vdso_time", &linux26) ?: TIME_FALLBACK;
+}
+asm (".type time, %gnu_indirect_function");
+
+libc_ifunc_hidden_def(time)
+
+#else
+
+# include <sysdep.h>
+
+time_t
+time (time_t *t)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  return INTERNAL_SYSCALL (time, err, 1, t);
+}
+
+#endif

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

@@ -0,0 +1,29 @@
+/* timespec_get -- returns the calendar time based on a given time base.
+   Linux/x86 version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libc-vdso.h>
+
+#ifdef SHARED
+# define INTERNAL_GETTIME(id, tp) \
+  ({ long int (*f) (clockid_t, struct timespec *) = __vdso_clock_gettime; \
+  PTR_DEMANGLE (f);							  \
+  (*f) (id, tp); })
+#endif
+
+#include <sysdeps/unix/sysv/linux/timespec_get.c>

sysdeps/unix/sysv/linux/x86_64/Makefile

@@ -13,7 +13,3 @@ endif
 ifeq ($(subdir),misc)
 gen-as-const-headers += sigaltstack-offsets.sym
 endif
-
-ifeq ($(subdir),elf)
-sysdep_routines += dl-vdso
-endif