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-rw-r--r--REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c b/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c
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+++ b/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c
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+/* _longjmp_unwind -- Clean up stack frames unwound by longjmp.  Hurd version.
+   Copyright (C) 1995-2017 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <jmpbuf-unwind.h>
+#include <hurd/userlink.h>
+#include <hurd/signal.h>
+#include <hurd/sigpreempt.h>
+#include <assert.h>
+#include <stdint.h>
+
+
+#ifndef _JMPBUF_UNWINDS
+#error "<jmpbuf-unwind.h> fails to define _JMPBUF_UNWINDS"
+#endif
+
+static inline uintptr_t
+demangle_ptr (uintptr_t x)
+{
+# ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (x);
+# endif
+  return x;
+}
+
+/* This function is called by `longjmp' (with its arguments) to restore
+   active resources to a sane state before the frames code using them are
+   jumped out of.  */
+
+void
+_longjmp_unwind (jmp_buf env, int val)
+{
+  struct hurd_sigstate *ss = _hurd_self_sigstate ();
+  struct hurd_userlink *link;
+
+  /* All access to SS->active_resources must take place inside a critical
+     section where signal handlers cannot run.  */
+  __spin_lock (&ss->lock);
+  assert (! __spin_lock_locked (&ss->critical_section_lock));
+  __spin_lock (&ss->critical_section_lock);
+
+  /* Remove local signal preemptors being unwound past.  */
+  while (ss->preemptors &&
+	 _JMPBUF_UNWINDS (env[0].__jmpbuf, ss->preemptors, demangle_ptr))
+    ss->preemptors = ss->preemptors->next;
+
+  __spin_unlock (&ss->lock);
+
+  /* Iterate over the current thread's list of active resources.
+     Process the head portion of the list whose links reside
+     in stack frames being unwound by this jump.  */
+
+  for (link = ss->active_resources;
+       link && _JMPBUF_UNWINDS (env[0].__jmpbuf, link, demangle_ptr);
+       link = link->thread.next)
+    /* Remove this link from the resource's users list,
+       since the frame using the resource is being unwound.
+       This call returns nonzero if that was the last user.  */
+    if (_hurd_userlink_unlink (link))
+      /* One of the frames being unwound by the longjmp was the last user
+	 of its resource.  Call the cleanup function to deallocate it.  */
+      (*link->cleanup) (link->cleanup_data, env, val);
+
+  _hurd_critical_section_unlock (ss);
+}