sysdeps/unix/sysdep.h

   1 /* Copyright (C) 1991-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdeps/generic/sysdep.h>
  19
  20 #include <sys/syscall.h>
  21 #define HAVE_SYSCALLS
  22
  23 /* Note that using a `PASTE' macro loses.  */
  24 #define SYSCALL__(name, args)   PSEUDO (__##name, name, args)
  25 #define SYSCALL(name, args)     PSEUDO (name, name, args)
  26
  27 #define __SYSCALL0(name) \
  28   INLINE_SYSCALL (name, 0)
  29 #define __SYSCALL1(name, a1) \
  30   INLINE_SYSCALL (name, 1, a1)
  31 #define __SYSCALL2(name, a1, a2) \
  32   INLINE_SYSCALL (name, 2, a1, a2)
  33 #define __SYSCALL3(name, a1, a2, a3) \
  34   INLINE_SYSCALL (name, 3, a1, a2, a3)
  35 #define __SYSCALL4(name, a1, a2, a3, a4) \
  36   INLINE_SYSCALL (name, 4, a1, a2, a3, a4)
  37 #define __SYSCALL5(name, a1, a2, a3, a4, a5) \
  38   INLINE_SYSCALL (name, 5, a1, a2, a3, a4, a5)
  39 #define __SYSCALL6(name, a1, a2, a3, a4, a5, a6) \
  40   INLINE_SYSCALL (name, 6, a1, a2, a3, a4, a5, a6)
  41 #define __SYSCALL7(name, a1, a2, a3, a4, a5, a6, a7) \
  42   INLINE_SYSCALL (name, 7, a1, a2, a3, a4, a5, a6, a7)
  43
  44 #define __SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
  45 #define __SYSCALL_NARGS(...) \
  46   __SYSCALL_NARGS_X (__VA_ARGS__,7,6,5,4,3,2,1,0,)
  47 #define __SYSCALL_CONCAT_X(a,b)     a##b
  48 #define __SYSCALL_CONCAT(a,b)       __SYSCALL_CONCAT_X (a, b)
  49 #define __SYSCALL_DISP(b,...) \
  50   __SYSCALL_CONCAT (b,__SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
  51
  52 #define __SYSCALL_CALL(...) __SYSCALL_DISP (__SYSCALL, __VA_ARGS__)
  53
  54 #define SYSCALL_CANCEL(...) \
  55   ({                                                                         \
  56     long int sc_ret;                                                         \
  57     if (SINGLE_THREAD_P)                                                     \
  58       sc_ret = __SYSCALL_CALL (__VA_ARGS__);                                 \
  59     else                                                                     \
  60       {                                                                      \
  61         int sc_cancel_oldtype = LIBC_CANCEL_ASYNC ();                        \
  62         sc_ret = __SYSCALL_CALL (__VA_ARGS__);                               \
  63         LIBC_CANCEL_RESET (sc_cancel_oldtype);                               \
  64       }                                                                      \
  65     sc_ret;                                                                  \
  66   })
  67
  68 /* Machine-dependent sysdep.h files are expected to define the macro
  69    PSEUDO (function_name, syscall_name) to emit assembly code to define the
  70    C-callable function FUNCTION_NAME to do system call SYSCALL_NAME.
  71    r0 and r1 are the system call outputs.  MOVE(x, y) should be defined as
  72    an instruction such that "MOVE(r1, r0)" works.  ret should be defined
  73    as the return instruction.  */
  74
  75 #ifndef SYS_ify
  76 #define SYS_ify(syscall_name) SYS_##syscall_name
  77 #endif
  78
  79 /* Terminate a system call named SYM.  This is used on some platforms
  80    to generate correct debugging information.  */
  81 #ifndef PSEUDO_END
  82 #define PSEUDO_END(sym)
  83 #endif
  84 #ifndef PSEUDO_END_NOERRNO
  85 #define PSEUDO_END_NOERRNO(sym) PSEUDO_END(sym)
  86 #endif
  87 #ifndef PSEUDO_END_ERRVAL
  88 #define PSEUDO_END_ERRVAL(sym)  PSEUDO_END(sym)
  89 #endif
  90
  91 /* Wrappers around system calls should normally inline the system call code.
  92    But sometimes it is not possible or implemented and we use this code.  */
  93 #ifndef INLINE_SYSCALL
  94 #define INLINE_SYSCALL(name, nr, args...) __syscall_##name (args)
  95 #endif