Consolidate vDSO macros and usage

This patch consolidate the Linux vDSO define and usage across all ports
that uses it.  The common vDSO definitions and calling through
{INLINE/INTERNAL}_VSYSCALL macros are moved to a common header
sysdep-vdso.h and vDSO name declaration and prototype is defined
using a common macro.

Also PTR_{MANGLE,DEMANGLE} is added to ports that does not use them
for vDSO calls (aarch64, powerpc, s390, and tile) and thus it will
reflect in code changes.  For ports that already implement pointer
mangling/demangling in vDSO system (i386, x32, x86_64) this patch
is mainly a code refactor.

Checked on x32, x86_64, x32, ppc64le, and aarch64.

1 files changed, 98 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/sysdep-vdso.h b/sysdeps/unix/sysv/linux/sysdep-vdso.h
new file mode 100644
index 0000000000..43e74b9e7c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sysdep-vdso.h
@@ -0,0 +1,98 @@
+/* vDSO common definition for Linux.
+   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/>.  */
+
+#ifndef SYSDEP_VDSO_LINUX_H
+# define SYSDEP_VDSO_LINUX_H
+
+#define VDSO_SYMBOL(__name) __vdso_##__name
+
+#ifndef INTERNAL_VSYSCALL_CALL
+# define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...)		      \
+     funcptr (args)
+#endif
+
+#ifdef SHARED
+
+# ifdef HAVE_VSYSCALL
+
+#  include <libc-vdso.h>
+
+#  define INLINE_VSYSCALL(name, nr, args...)				      \
+  ({									      \
+    __label__ out;							      \
+    __label__ iserr;							      \
+    INTERNAL_SYSCALL_DECL (sc_err);					      \
+    long int sc_ret;							      \
+									      \
+    __typeof (__vdso_##name) vdsop = __vdso_##name;			      \
+    PTR_DEMANGLE (vdsop);						      \
+    if (vdsop != NULL)							      \
+      {									      \
+	sc_ret = INTERNAL_VSYSCALL_CALL (vdsop, sc_err, nr, ##args);	      \
+	if (!INTERNAL_SYSCALL_ERROR_P (sc_ret, sc_err))			      \
+	  goto out;							      \
+	if (INTERNAL_SYSCALL_ERRNO (sc_ret, sc_err) != ENOSYS)		      \
+	  goto iserr;							      \
+      }									      \
+									      \
+    sc_ret = INTERNAL_SYSCALL (name, sc_err, nr, ##args);		      \
+    if (INTERNAL_SYSCALL_ERROR_P (sc_ret, sc_err))			      \
+      {									      \
+      iserr:								      \
+        __set_errno (INTERNAL_SYSCALL_ERRNO (sc_ret, sc_err));		      \
+        sc_ret = -1L;							      \
+      }									      \
+  out:									      \
+    sc_ret;								      \
+  })
+
+#  define INTERNAL_VSYSCALL(name, err, nr, args...)			      \
+  ({									      \
+    __label__ out;							      \
+    long v_ret;								      \
+									      \
+    __typeof (__vdso_##name) vdsop = __vdso_##name;			      \
+    PTR_DEMANGLE (vdsop);						      \
+    if (vdsop != NULL)							      \
+      {									      \
+	v_ret = INTERNAL_VSYSCALL_CALL (vdsop, err, nr, ##args);	      \
+	if (!INTERNAL_SYSCALL_ERROR_P (v_ret, err)			      \
+	    || INTERNAL_SYSCALL_ERRNO (v_ret, err) != ENOSYS)		      \
+	  goto out;							      \
+      }									      \
+    v_ret = INTERNAL_SYSCALL (name, err, nr, ##args);			      \
+  out:									      \
+    v_ret;								      \
+  })
+# else
+#  define INLINE_VSYSCALL(name, nr, args...) \
+    INLINE_SYSCALL (name, nr, ##args)
+#  define INTERNAL_VSYSCALL(name, err, nr, args...) \
+    INTERNAL_SYSCALL (name, err, nr, ##args)
+# endif /* HAVE_VSYSCALL  */
+
+# else /* SHARED  */
+
+#  define INLINE_VSYSCALL(name, nr, args...) \
+    INLINE_SYSCALL (name, nr, ##args)
+#  define INTERNAL_VSYSCALL(name, err, nr, args...) \
+    INTERNAL_SYSCALL (name, err, nr, ##args)
+
+#endif /* SHARED  */
+
+#endif /* SYSDEP_VDSO_LINUX_H  */