sysdeps/nacl/nacl-interfaces.h

   1 /* Using NaCl interface tables.
   2    Copyright (C) 2015-2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _NACL_INTERFACES_H
  20 #define _NACL_INTERFACES_H      1
  21
  22 #include <errno.h>
  23 #include <stdbool.h>
  24 #include <stddef.h>
  25 #include <stdint.h>
  26 #include <sys/types.h>
  27
  28 /* <nacl-irt.h> is massaged from native_client/src/untrusted/irt/irt.h so
  29    that it uses nacl_abi_*_t type names.  We must define those types first.  */
  30
  31 /* These are the same in the IRT ABI as in the libc ABI.  */
  32 typedef blksize_t nacl_abi_blksize_t;
  33 typedef dev_t nacl_abi_dev_t;
  34 typedef gid_t nacl_abi_gid_t;
  35 typedef ino_t nacl_abi_ino_t;
  36 typedef mode_t nacl_abi_mode_t;
  37 typedef nlink_t nacl_abi_nlink_t;
  38 typedef size_t nacl_abi_size_t;
  39 typedef time_t nacl_abi_time_t;
  40 typedef uid_t nacl_abi_uid_t;
  41 typedef struct dirent nacl_abi_dirent_t;
  42 typedef struct timeval nacl_abi_timeval_t;
  43 typedef struct timespec nacl_abi_timespec_t;
  44
  45 /* This is unsigned in the IRT ABI, but it's traditionally 'long int',
  46    so we stick with that.  */
  47 typedef clock_t nacl_abi_clock_t;
  48
  49 typedef int32_t nacl_abi_blkcnt_t;
  50
  51 /* This is different by design.  */
  52 typedef struct nacl_abi_stat nacl_abi_stat_t;
  53
  54 #include <nacl-irt.h>
  55
  56 /* This is how we access the IRT interface-query function.
  57    This formulation makes it usable as if it were a function name.  */
  58 #define __nacl_irt_query        (*(TYPE_nacl_irt_query) GLRO(dl_sysinfo))
  59
  60
  61 /* This describes one IRT (or IRT-like) interface that libc uses.
  62    This structure contains no pointers, so it can go into rodata
  63    without relocs.  Instead, the actual tables we use for these
  64    interfaces live in a parallel section in writable data.  */
  65 struct nacl_interface {
  66   size_t table_size;
  67   size_t namelen;
  68   char name[];
  69 };
  70
  71 /* Increment for 'const struct nacl_interface *' pointers.  */
  72 static inline const struct nacl_interface *
  73 next_nacl_interface (const struct nacl_interface *i)
  74 {
  75   uintptr_t align = __alignof (*i);
  76   return (const void *) (((uintptr_t) &i->name[i->namelen] + align - 1)
  77                          & -align);
  78 }
  79
  80 #if IS_IN (libpthread)
  81 # define libpthread_hidden_proto(name)  hidden_proto (name)
  82 #else
  83 # define libpthread_hidden_proto(name)
  84 #endif
  85
  86 #define DECLARE_INTERFACE(module, type) \
  87   extern struct type __##type; module##_hidden_proto (__##type);
  88
  89 #define NACL_MANDATORY_INTERFACE(module, id, type)      \
  90   DECLARE_INTERFACE (module, type)
  91 #define NACL_OPTIONAL_INTERFACE(module, id, type)       \
  92   DECLARE_INTERFACE (module, type)
  93 #include "nacl-interface-list.h"
  94 #undef  NACL_MANDATORY_INTERFACE
  95 #undef  NACL_OPTIONAL_INTERFACE
  96
  97 extern void __nacl_initialize_interfaces (void) attribute_hidden;
  98 extern bool __nacl_supply_interface_libc (const char *ident, size_t ident_len,
  99                                           const void *table, size_t tablesize)
 100   internal_function attribute_hidden;
 101 extern bool __nacl_supply_interface_rtld (const char *ident, size_t ident_len,
 102                                           const void *table, size_t tablesize);
 103   internal_function;
 104
 105 /* Convenience function for handling IRT call return values.  */
 106 static inline int
 107 __nacl_fail (int err)
 108 {
 109   errno = err;
 110   return -1;
 111 }
 112
 113 #define NACL_CALL(err, val) \
 114   ({ int _err = (err); _err ? __nacl_fail (_err) : (val); })
 115
 116 #endif  /* nacl-interfaces.h */