service_runtime/nacl_config.h

   1 /*
   2  * Copyright 2008, Google Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  *     * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * NaCl Simple/secure ELF loader (NaCl SEL).
  34  */
  35 #ifndef NATIVE_CLIENT_SERVICE_RUNTIME_NACL_CONFIG_H_
  36 #define NATIVE_CLIENT_SERVICE_RUNTIME_NACL_CONFIG_H_
  37
  38 /*
  39  * this value must be consistent with NaCl compiler flags
  40  * -falign-functions -falign-labels -and nacl-align.
  41  */
  42 #if defined(NACL_BLOCK_SHIFT)
  43 # define NACL_INSTR_BLOCK_SHIFT       (NACL_BLOCK_SHIFT)
  44 #else
  45 # error "NACL_BLOCK_SHIFT should be defined by CFLAGS"
  46 #endif
  47 #define NACL_INSTR_BLOCK_SIZE         (1 << NACL_INSTR_BLOCK_SHIFT)
  48
  49 /* this must be a multiple of the system page size */
  50 #define NACL_PAGESHIFT                12
  51 #define NACL_PAGESIZE                 (1U << NACL_PAGESHIFT)
  52
  53 #define NACL_MAP_PAGESHIFT            12
  54 #define NACL_MAP_PAGESIZE             (1U << NACL_MAP_PAGESHIFT)
  55
  56 #if NACL_MAP_PAGESHIFT < NACL_PAGESHIFT
  57 # error "NACL_MAP_PAGESHIFT smaller than NACL_PAGESHIFT"
  58 #endif
  59
  60 /* NACL_MAP_PAGESIFT >= NACL_PAGESHIFT must hold */
  61 #define NACL_PAGES_PER_MAP            (1 << (NACL_MAP_PAGESHIFT-NACL_PAGESHIFT))
  62
  63 #define NACL_MEMORY_ALLOC_RETRY_MAX   256 /* see win/sel_memory.c */
  64
  65 /*
  66  * NACL_KERN_STACK_SIZE: The size of the secure stack allocated for
  67  * use while a NaCl thread is in kernel mode, i.e., during
  68  * startup/exit and during system call processing.
  69  */
  70 #define NACL_KERN_STACK_SIZE          (32 << 10)
  71
  72 /*
  73  * NACL_CONFIG_PATH_MAX: What is the maximum file path allowed in the
  74  * NaClSysOpen syscall?  This is on the kernel stack for validation
  75  * during the processing of the syscall, so beware running into
  76  * NACL_KERN_STACK_SIZE above.
  77  */
  78 #define NACL_CONFIG_PATH_MAX          1024
  79
  80 /*
  81  * Macro for the start address of the trampolines.
  82  * The first 64KB (16 pages) are inaccessible to prevent addr16/data16 attacks.
  83  */
  84 #define NACL_SYSCALL_START_ADDR       (16 << NACL_PAGESHIFT)
  85 /* Macro for the start address of a specific trampoline.  */
  86 #define NACL_SYSCALL_ADDR(syscall_number) \
  87     (NACL_SYSCALL_START_ADDR + (syscall_number << NACL_INSTR_BLOCK_SHIFT))
  88
  89 /*
  90  * Syscall trampoline code have a block size that may differ from the
  91  * alignment restrictions of the executable.  The ELF executable's
  92  * alignment restriction (16 or 32) defines what are potential entry
  93  * points, so the trampoline region must still respect that.  We
  94  * prefill the trampoline region with HLT, so non-syscall entry points
  95  * will not cause problems as long as our trampoline instruction
  96  * sequence never grows beyond 16 bytes, so the "odd" potential entry
  97  * points for a 16-byte aligned ELF will not be able to jump into the
  98  * middle of the trampoline code.
  99  */
 100 #define NACL_SYSCALL_BLOCK_SHIFT      5
 101 #define NACL_SYSCALL_BLOCK_SIZE       (1 << NACL_SYSCALL_BLOCK_SHIFT)
 102
 103 /*
 104  * macros to provide uniform access to identifiers from assembly due
 105  * to different C -> asm name mangling convention
 106  */
 107 #if NACL_WINDOWS || NACL_OSX
 108 # define IDENTIFIER(n)  _##n
 109 #else /* Linux */
 110 # define IDENTIFIER(n)  n
 111 #endif
 112
 113 #endif  /* NATIVE_CLIENT_SERVICE_RUNTIME_NACL_CONFIG_H_ */