Mps: protection for intel darwin. hopefully cross-platform.

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 Change: 161902
 ServerID: perforce.ravenbrook.com

1 files changed, 147 insertions, 0 deletions

diff --git a/mps/code/protix.c b/mps/code/protix.c
new file mode 100644
index 00000000000..48c432a0a28
--- /dev/null
+++ b/mps/code/protix.c
@@ -0,0 +1,147 @@
+/* protix.c: PROTECTION FOR UNIX
+ *
+ *  $Id$
+ *  Copyright (c) 2001,2007 Ravenbrook Limited.  See end of file for license.
+ *
+ *  Somewhat generic across different Unix systems.  Shared between
+ *  Darwin (OS X), OSF/1 (DIGITAL UNIX), and FreeBSD.
+ *
+ *  May not actually work on OSF/1 due to lack of available machines.
+ *
+ *  This file does not contain a signal handler.  That's in protsgix.c
+ *  (for FreeBSD and Darwin on Intel); in protxcpp.c (for Darwin on
+ *  PowerPC).
+ */
+
+
+/* open sesame magic, see standards(5) */
+#define _POSIX_C_SOURCE 199309L
+#define _XOPEN_SOURCE_EXTENDED 1
+
+#include "mpm.h"
+
+#if !defined(MPS_OS_O1) && !defined(MPS_OS_FR) && !defined(MPS_OS_XC)
+#error "protix.c is Unix-specific, currently for MPS_OS_O1 FR or XC"
+#endif
+#ifndef PROTECTION
+#error "protix.c implements protection, but PROTECTION is not set"
+#endif
+
+#include <limits.h>
+#include <stddef.h>
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+SRCID(protix, "$Id$");
+
+/* ProtSet -- set protection
+ *
+ * This is just a thin veneer on top of mprotect(2).
+ */
+
+void ProtSet(Addr base, Addr limit, AccessSet mode)
+{
+  int flags;
+
+  AVER(sizeof(size_t) == sizeof(Addr));
+  AVER(base < limit);
+  AVER(base != 0);
+  AVER(AddrOffset(base, limit) <= INT_MAX);     /* should be redundant */
+
+  /* Convert between MPS AccessSet and UNIX PROT thingies.
+     In this function, AccessREAD means protect against read accesses
+     (disallow them).  PROT_READ means allow read accesses.
+   */
+  switch(mode) {
+  case AccessWRITE | AccessREAD:
+  case AccessREAD:      /* forbids writes as well */
+    flags = PROT_NONE;
+    break;
+  case AccessWRITE:
+    flags = PROT_READ | PROT_EXEC;
+    break;
+  case AccessSetEMPTY:
+    flags = PROT_READ | PROT_WRITE | PROT_EXEC;
+    break;
+  default:
+    NOTREACHED;
+    flags = PROT_NONE;
+  }
+
+  if(mprotect((caddr_t)base, (size_t)AddrOffset(base, limit), flags) != 0)
+    NOTREACHED;
+}
+
+
+/* ProtSync -- synchronize protection settings with hardware
+ *
+ * This does nothing under Solaris.
+ */
+
+void ProtSync(Arena arena)
+{
+  UNUSED(arena);
+  NOOP;
+}
+
+
+/* ProtTramp -- protection trampoline
+ *
+ * The protection trampoline is trivial under Unix, as there is
+ * nothing that needs to be done in the dynamic context of the mutator in
+ * order to catch faults.  (Contrast this with Win32 Structured Exception
+ * Handling.)
+ */
+
+void ProtTramp(void **resultReturn, void *(*f)(void *, size_t),
+               void *p, size_t s)
+{
+  AVER(resultReturn != NULL);
+  AVER(FUNCHECK(f));
+  /* Can't check p and s as they are interpreted by the client */
+
+  *resultReturn = (*f)(p, s);
+}
+
+
+/* C. COPYRIGHT AND LICENSE
+ *
+ * Copyright (C) 2001-2007 Ravenbrook Limited <http://www.ravenbrook.com/>.
+ * All rights reserved.  This is an open source license.  Contact
+ * Ravenbrook for commercial licensing options.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * 3. Redistributions in any form must be accompanied by information on how
+ * to obtain complete source code for this software and any accompanying
+ * software that uses this software.  The source code must either be
+ * included in the distribution or be available for no more than the cost
+ * of distribution plus a nominal fee, and must be freely redistributable
+ * under reasonable conditions.  For an executable file, complete source
+ * code means the source code for all modules it contains. It does not
+ * include source code for modules or files that typically accompany the
+ * major components of the operating system on which the executable file
+ * runs.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */