1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/sigaction.c b/sysdeps/unix/sysv/linux/x86_64/sigaction.c
new file mode 100644
index 0000000000..5aa8b9f43b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/sigaction.c
@@ -0,0 +1,99 @@
+/* POSIX.1 `sigaction' call for Linux/x86-64.
+   Copyright (C) 2001 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 <sysdep.h>
+#include <errno.h>
+#include <stddef.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+#include <kernel-features.h>
+
+/* The difference here is that the sigaction structure used in the
+   kernel is not the same as we use in the libc.  Therefore we must
+   translate it here.  */
+#include <kernel_sigaction.h>
+
+/* We do not globally define the SA_RESTORER flag so do it here.  */
+#define SA_RESTORER 0x04000000
+
+extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *__unbounded,
+				   struct kernel_sigaction *__unbounded, size_t);
+
+static void restore_rt (void) asm ("__restore_rt");
+
+
+/* If ACT is not NULL, change the action for SIG to *ACT.
+   If OACT is not NULL, put the old action for SIG in *OACT.  */
+int
+__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
+{
+  int result;
+  struct kernel_sigaction kact, koact;
+
+  if (act)
+    {
+      kact.k_sa_handler = act->sa_handler;
+      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
+      kact.sa_flags = act->sa_flags | SA_RESTORER;
+
+      kact.sa_restorer = &restore_rt;
+    }
+
+  /* XXX The size argument hopefully will have to be changed to the
+     real size of the user-level sigset_t.  */
+  result = INLINE_SYSCALL (rt_sigaction, 4,
+			   sig, act ? __ptrvalue (&kact) : NULL,
+			   oact ? __ptrvalue (&koact) : NULL, _NSIG / 8);
+  if (oact && result >= 0)
+    {
+      oact->sa_handler = koact.k_sa_handler;
+      memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
+      oact->sa_flags = koact.sa_flags;
+      oact->sa_restorer = koact.sa_restorer;
+    }
+  return result;
+}
+
+weak_alias (__libc_sigaction, __sigaction)
+weak_alias (__libc_sigaction, sigaction)
+
+/* NOTE: Please think twice before making any changes to the bits of
+   code below.  GDB needs some intimate knowledge about it to
+   recognize them as signal trampolines, and make backtraces through
+   signal handlers work right.  Important are both the names
+   (__restore_rt) and the exact instruction sequence.
+   If you ever feel the need to make any changes, please notify the
+   appropriate GDB maintainer.  */
+
+#define RESTORE(name, syscall) RESTORE2 (name, syscall)
+#define RESTORE2(name, syscall) \
+asm						\
+  (						\
+   ".align 16\n"				\
+   "__" #name ":\n"				\
+   "	movq $" #syscall ", %rax\n"		\
+   "	syscall\n"				\
+   );
+
+/* The return code for realtime-signals.  */
+RESTORE (restore_rt, __NR_rt_sigreturn)