alpha: Use Linux generic sigaction implementation

Alpha rt_sigaction syscall uses a slight different kernel ABI than
generic one:

arch/alpha/kernel/signal.c

 90 SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
 91                 struct sigaction __user *, oact,
 92                 size_t, sigsetsize, void __user *, restorer)

Similar as sparc, the syscall expects a restorer function.  However
different than sparc, alpha defines the restorer as the 5th argument
(sparc defines as the 4th).

This patch removes the arch-specific alpha sigaction implementation,
adapt the Linux generic one to different restore placements (through
STUB macro), and make alpha use the Linux generic kernel_sigaction
definition.

Checked on alpha-linux-gnu and x86_64-linux-gnu (for sanity).

	* sysdeps/unix/sysv/linux/alpha/Makefile: Update comment about
	__syscall_rt_sigaction.
	* sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
	(kernel_sigaction): Use Linux generic defintion.
	(STUB): Define.
	(__syscall_rt_sigreturn, __syscall_sigreturn): Add prototype.
	* sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
	(__syscall_rt_sigaction): Remove implementation.
	(__syscall_sigreturn, __syscall_rt_sigreturn): Define as global and
	hidden.
	* sysdeps/unix/sysv/linux/alpha/sigaction.c: Remove file.
	* sysdeps/unix/sysv/linux/alpha/sysdep.h (INLINE_SYSCALL,
	INTERNAL_SYSCALL): Remove definitions.
	* sysdeps/unix/sysv/linux/sigaction.c: Define STUB to accept both the
	action and signal set size.
	* sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c (STUB): Redefine.
	* sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c (STUB): Likewise.

1 files changed, 9 insertions, 10 deletions

diff --git a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
index 25180ff9c9..679179b563 100644
--- a/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
+++ b/sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h
@@ -1,12 +1,11 @@
-#ifndef _KERNEL_SIGACTION_H
-# define _KERNEL_SIGACTION_H
+#include <sysdeps/unix/sysv/linux/kernel_sigaction.h>
 
-/* This is the sigaction structure from the Linux 3.2 kernel.  */
-struct kernel_sigaction
-{
-  __sighandler_t k_sa_handler;
-  unsigned int sa_flags;
-  sigset_t sa_mask;
-};
+void __syscall_rt_sigreturn (void) attribute_hidden;
+void __syscall_sigreturn (void) attribute_hidden;
 
-#endif
+#define STUB(act, sigsetsize) \
+  (sigsetsize),						\
+  (act) ? ((unsigned long)((act->sa_flags & SA_SIGINFO)	\
+			    ? &__syscall_rt_sigreturn	\
+			    : &__syscall_sigreturn))	\
+	: 0