1 files changed, 57 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c b/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c
new file mode 100644
index 0000000000..619785d7e8
--- /dev/null
+++ b/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c
@@ -0,0 +1,57 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+   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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <jmpbuf-offsets.h>
+#include <sysdep.h>
+#include <setjmp.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stackinfo.h>
+
+#ifdef _STACK_GROWS_DOWN
+#define called_from(this, saved) ((this) < (saved))
+#else
+#define called_from(this, saved) ((this) > (saved))
+#endif
+
+extern void ____longjmp_chk (__jmp_buf __env, int __val)
+  __attribute__ ((__noreturn__));
+
+void ____longjmp_chk (__jmp_buf env, int val)
+{
+  void *this_frame = __builtin_frame_address (0);
+  void *saved_frame = JB_FRAME_ADDRESS (env);
+  INTERNAL_SYSCALL_DECL (err);
+  stack_t ss;
+
+  /* If "env" is from a frame that called us, we're all set.  */
+  if (called_from(this_frame, saved_frame))
+    __longjmp (env, val);
+
+  /* If we can't get the current stack state, give up and do the longjmp. */
+  if (INTERNAL_SYSCALL (sigaltstack, err, 2, NULL, &ss) != 0)
+    __longjmp (env, val);
+
+  /* If we we are executing on the alternate stack and within the
+     bounds, do the longjmp.  */
+  if (ss.ss_flags == SS_ONSTACK &&
+      (this_frame >= ss.ss_sp && this_frame < (ss.ss_sp + ss.ss_size)))
+    __longjmp (env, val);
+
+  __fortify_fail ("longjmp causes uninitialized stack frame");
+}