1 files changed, 126 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/i386/sigreturn.c b/sysdeps/mach/hurd/i386/sigreturn.c
new file mode 100644
index 0000000000..df8960669f
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/sigreturn.c
@@ -0,0 +1,126 @@
+/* Copyright (C) 1991, 1992, 1994, 1995 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+register int *sp asm ("%esp");
+
+#include <hurd.h>
+#include <hurd/signal.h>
+#include <hurd/threadvar.h>
+#include <hurd/msg.h>
+#include <stdlib.h>
+
+int
+__sigreturn (struct sigcontext *scp)
+{
+  struct hurd_sigstate *ss;
+  mach_port_t *reply_port;
+
+  if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  ss = _hurd_self_sigstate ();
+  __spin_lock (&ss->lock);
+
+  /* Restore the set of blocked signals, and the intr_port slot.  */
+  ss->blocked = scp->sc_mask;
+  ss->intr_port = scp->sc_intr_port;
+
+  /* Check for pending signals that were blocked by the old set.  */
+  if (ss->pending & ~ss->blocked)
+    {
+      /* There are pending signals that just became unblocked.  Wake up the
+	 signal thread to deliver them.  But first, squirrel away SCP where
+	 the signal thread will notice it if it runs another handler, and
+	 arrange to have us called over again in the new reality.  */
+      ss->context = scp;
+      /* Clear the intr_port slot, since we are not in fact doing
+	 an interruptible RPC right now.  If SS->intr_port is not null,
+	 the SCP context is doing an interruptible RPC, but the signal
+	 thread will examine us while we are blocked in the sig_post RPC.  */
+      ss->intr_port = MACH_PORT_NULL;
+      __spin_unlock (&ss->lock);
+      __msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+      /* If a pending signal was handled, sig_post never returned.  */
+      __spin_lock (&ss->lock);
+    }
+
+  if (scp->sc_onstack)
+    {
+      ss->sigaltstack.ss_flags &= ~SA_ONSTACK; /* XXX threadvars */
+      /* XXX cannot unlock until off sigstack */
+      abort ();
+    }
+  else
+    __spin_unlock (&ss->lock);
+
+  /* Destroy the MiG reply port used by the signal handler, and restore the
+     reply port in use by the thread when interrupted.  */
+  reply_port =
+    (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY);
+  if (*reply_port)
+    __mach_port_destroy (__mach_task_self (), *reply_port);
+  *reply_port = scp->sc_reply_port;
+
+  if (scp->sc_fpused)
+    {
+  /* XXX should restore FPU state here XXX roland needs 387 manual */
+  /*    abort (); */
+    }
+
+  {
+    /* There are convenient instructions to pop state off the stack, so we
+       copy the registers onto the user's stack, switch there, pop and
+       return.  */
+
+    int *usp = (int *) scp->sc_uesp;
+
+    *--usp = scp->sc_eip;
+    *--usp = scp->sc_efl;
+    memcpy (usp -= 12, &scp->sc_i386_thread_state, 12 * sizeof (int));
+
+    sp = usp;
+
+#define A(line) asm volatile (#line)
+    /* The members in the sigcontext are arranged in this order
+       so we can pop them easily.  */
+
+    /* Pop the segment registers (except %cs and %ss, done last).  */
+    A (popl %gs);
+    A (popl %fs);
+    A (popl %es);
+    A (popl %ds);
+    /* Pop the general registers.  */
+    A (popa);
+    /* Pop the processor flags.  */
+    A (popf);
+    /* Return to the saved PC.  */
+    A (ret);
+
+    /* Firewall.  */
+    A (hlt);
+#undef A
+  }
+
+  /* NOTREACHED */
+  return -1;
+}
+
+weak_alias (__sigreturn, sigreturn)