Use ifuncs for time and gettimeofday on x86-64

1 files changed, 47 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/x86_64/time.c b/sysdeps/unix/sysv/linux/x86_64/time.c
new file mode 100644
index 0000000000..698d56156c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/time.c
@@ -0,0 +1,47 @@
+/* Copyright (C) 2001,02, 2003, 2011 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <dl-vdso.h>
+
+
+#define VSYSCALL_ADDR_vtime	0xffffffffff600400
+
+
+#ifdef SHARED
+void *time_ifunc (void) __asm__ ("time");
+
+void *
+time_ifunc (void)
+{
+  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
+
+  /* If the vDSO is not available we fall back on the old vsyscall.  */
+  return _dl_vdso_vsym ("time", &linux26) ?: (void *) VSYSCALL_ADDR_vtime;
+}
+__asm (".type time, %gnu_indirect_function");
+#else
+# include <time.h>
+
+time_t
+time (time_t *t)
+{
+  return ((time_t (*) (time_t *)) VSYSCALL_ADDR_vtime) (t);
+}
+#endif
+
+strong_alias (time, __GI_time)