1 files changed, 69 insertions, 0 deletions
diff --git a/libpthread/signal/sigaltstack.c b/libpthread/signal/sigaltstack.c
new file mode 100644
index 00000000..8334811a
--- /dev/null
+++ b/libpthread/signal/sigaltstack.c
@@ -0,0 +1,69 @@
+/* sigaltstack.c - Generic sigaltstack implementation.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   Written by Neal H. Walfield <neal@gnu.org>.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 3 of
+   the License, or (at your option) any later version.
+
+   The GNU Hurd 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 this program.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "sig-internal.h"
+#include "pt-internal.h"
+
+int
+sigaltstack (const stack_t *restrict stack, stack_t *restrict old)
+{
+  int err = 0;
+  struct signal_state *ss = &_pthread_self ()->ss;
+
+  pthread_mutex_lock (&ss->lock);
+
+  if (old)
+    *old = ss->stack;
+
+  if (stack)
+    {
+      if (stack->ss_size < MINSIGSTKSZ)
+	{
+	  err = ENOMEM;
+	  goto out;
+	}
+
+      if ((stack->ss_flags & ~(SS_DISABLE)))
+	/* Flags contains a value other than SS_DISABLE.  */
+	{
+	  err = EINVAL;
+	  goto out;
+	}
+
+      if ((ss->stack.ss_flags & SS_ONSTACK))
+	/* Stack in use.  */
+	{
+	  err = EPERM;
+	  goto out;
+	}
+
+      ss->stack = *stack;
+    }
+
+ out:
+  pthread_mutex_unlock (&ss->lock);
+
+  if (err)
+    {
+      errno = err;
+      return -1;
+    }
+  return 0;
+}