* sysdeps/unix/sysv/linux/i386/makecontext.S (__makecontext): Avoid

	clobbering memory at or above uc_stack.ss_sp + uc_stack.ss_size.
	* stdlib/Makefile: Add rules to build and run tst-makecontext2.
	* stdlib/tst-makecontext2.c: New test.

1 files changed, 80 insertions, 0 deletions

diff --git a/stdlib/tst-makecontext2.c b/stdlib/tst-makecontext2.c
new file mode 100644
index 0000000000..903ccf6f87
--- /dev/null
+++ b/stdlib/tst-makecontext2.c
@@ -0,0 +1,80 @@
+/* Copyright (C) 2008 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 <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ucontext.h>
+#include <tst-stack-align.h>
+
+ucontext_t ucp, ucp2;
+char st1[262144] __attribute__((aligned (16)));
+
+void
+cf (int i, int j)
+{
+  if (i != 78 || j != 274)
+    {
+      printf ("i %d j %d\n", i, j);
+      exit (1);
+    }
+  else if (TEST_STACK_ALIGN ())
+    {
+      puts ("insufficiently aligned stack");
+      exit (2);
+    }
+}
+
+int
+do_test (void)
+{
+  for (size_t j = 32; j < 64; j += sizeof (long))
+    {
+      if (getcontext (&ucp) != 0)
+	{
+	  if (errno == ENOSYS)
+	    {
+	      puts ("context handling not supported");
+	      return 0;
+	    }
+
+	  puts ("getcontext failed");
+	  return 1;
+	}
+      ucp.uc_link = &ucp2;
+      ucp.uc_stack.ss_sp = st1;
+      ucp.uc_stack.ss_size = sizeof (st1) - j;
+      memset (&st1[sizeof (st1) - j], 0x55, j);
+      makecontext (&ucp, (void (*) (void)) cf, 2, 78, 274);
+      if (swapcontext (&ucp2, &ucp) != 0)
+	{
+	  puts ("setcontext failed");
+	  return 1;
+	}
+
+      for (size_t i = j; i > 0; i--)
+	if (st1[sizeof (st1) - j + i - 1] != 0x55)
+	  { printf ("fail %zd %zd\n", i, j); break; }
+    }
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"