sysdeps/unix/sysdep.h

   1 /* Copyright (C) 1991-2022 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdeps/generic/sysdep.h>
  19 #include <single-thread.h>
  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 __SYSCALL_CONCAT_X(a,b)     a##b
  28 #define __SYSCALL_CONCAT(a,b)       __SYSCALL_CONCAT_X (a, b)
  29
  30
  31 #define __INTERNAL_SYSCALL0(name) \
  32   INTERNAL_SYSCALL (name, 0)
  33 #define __INTERNAL_SYSCALL1(name, a1) \
  34   INTERNAL_SYSCALL (name, 1, a1)
  35 #define __INTERNAL_SYSCALL2(name, a1, a2) \
  36   INTERNAL_SYSCALL (name, 2, a1, a2)
  37 #define __INTERNAL_SYSCALL3(name, a1, a2, a3) \
  38   INTERNAL_SYSCALL (name, 3, a1, a2, a3)
  39 #define __INTERNAL_SYSCALL4(name, a1, a2, a3, a4) \
  40   INTERNAL_SYSCALL (name, 4, a1, a2, a3, a4)
  41 #define __INTERNAL_SYSCALL5(name, a1, a2, a3, a4, a5) \
  42   INTERNAL_SYSCALL (name, 5, a1, a2, a3, a4, a5)
  43 #define __INTERNAL_SYSCALL6(name, a1, a2, a3, a4, a5, a6) \
  44   INTERNAL_SYSCALL (name, 6, a1, a2, a3, a4, a5, a6)
  45 #define __INTERNAL_SYSCALL7(name, a1, a2, a3, a4, a5, a6, a7) \
  46   INTERNAL_SYSCALL (name, 7, a1, a2, a3, a4, a5, a6, a7)
  47
  48 #define __INTERNAL_SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
  49 #define __INTERNAL_SYSCALL_NARGS(...) \
  50   __INTERNAL_SYSCALL_NARGS_X (__VA_ARGS__,7,6,5,4,3,2,1,0,)
  51 #define __INTERNAL_SYSCALL_DISP(b,...) \
  52   __SYSCALL_CONCAT (b,__INTERNAL_SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
  53
  54 /* Issue a syscall defined by syscall number plus any other argument required.
  55    It is similar to INTERNAL_SYSCALL macro, but without the need to pass the
  56    expected argument number as second parameter.  */
  57 #define INTERNAL_SYSCALL_CALL(...) \
  58   __INTERNAL_SYSCALL_DISP (__INTERNAL_SYSCALL, __VA_ARGS__)
  59
  60 #define __INTERNAL_SYSCALL_NCS0(name) \
  61   INTERNAL_SYSCALL_NCS (name, 0)
  62 #define __INTERNAL_SYSCALL_NCS1(name, a1) \
  63   INTERNAL_SYSCALL_NCS (name, 1, a1)
  64 #define __INTERNAL_SYSCALL_NCS2(name, a1, a2) \
  65   INTERNAL_SYSCALL_NCS (name, 2, a1, a2)
  66 #define __INTERNAL_SYSCALL_NCS3(name, a1, a2, a3) \
  67   INTERNAL_SYSCALL_NCS (name, 3, a1, a2, a3)
  68 #define __INTERNAL_SYSCALL_NCS4(name, a1, a2, a3, a4) \
  69   INTERNAL_SYSCALL_NCS (name, 4, a1, a2, a3, a4)
  70 #define __INTERNAL_SYSCALL_NCS5(name, a1, a2, a3, a4, a5) \
  71   INTERNAL_SYSCALL_NCS (name, 5, a1, a2, a3, a4, a5)
  72 #define __INTERNAL_SYSCALL_NCS6(name, a1, a2, a3, a4, a5, a6) \
  73   INTERNAL_SYSCALL_NCS (name, 6, a1, a2, a3, a4, a5, a6)
  74 #define __INTERNAL_SYSCALL_NCS7(name, a1, a2, a3, a4, a5, a6, a7) \
  75   INTERNAL_SYSCALL_NCS (name, 7, a1, a2, a3, a4, a5, a6, a7)
  76
  77 #define INTERNAL_SYSCALL_NCS_CALL(...) \
  78   __INTERNAL_SYSCALL_DISP (__INTERNAL_SYSCALL_NCS, __VA_ARGS__)
  79
  80 #define __INLINE_SYSCALL0(name) \
  81   INLINE_SYSCALL (name, 0)
  82 #define __INLINE_SYSCALL1(name, a1) \
  83   INLINE_SYSCALL (name, 1, a1)
  84 #define __INLINE_SYSCALL2(name, a1, a2) \
  85   INLINE_SYSCALL (name, 2, a1, a2)
  86 #define __INLINE_SYSCALL3(name, a1, a2, a3) \
  87   INLINE_SYSCALL (name, 3, a1, a2, a3)
  88 #define __INLINE_SYSCALL4(name, a1, a2, a3, a4) \
  89   INLINE_SYSCALL (name, 4, a1, a2, a3, a4)
  90 #define __INLINE_SYSCALL5(name, a1, a2, a3, a4, a5) \
  91   INLINE_SYSCALL (name, 5, a1, a2, a3, a4, a5)
  92 #define __INLINE_SYSCALL6(name, a1, a2, a3, a4, a5, a6) \
  93   INLINE_SYSCALL (name, 6, a1, a2, a3, a4, a5, a6)
  94 #define __INLINE_SYSCALL7(name, a1, a2, a3, a4, a5, a6, a7) \
  95   INLINE_SYSCALL (name, 7, a1, a2, a3, a4, a5, a6, a7)
  96
  97 #define __INLINE_SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
  98 #define __INLINE_SYSCALL_NARGS(...) \
  99   __INLINE_SYSCALL_NARGS_X (__VA_ARGS__,7,6,5,4,3,2,1,0,)
 100 #define __INLINE_SYSCALL_DISP(b,...) \
 101   __SYSCALL_CONCAT (b,__INLINE_SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
 102
 103 /* Issue a syscall defined by syscall number plus any other argument
 104    required.  Any error will be handled using arch defined macros and errno
 105    will be set accordingly.
 106    It is similar to INLINE_SYSCALL macro, but without the need to pass the
 107    expected argument number as second parameter.  */
 108 #define INLINE_SYSCALL_CALL(...) \
 109   __INLINE_SYSCALL_DISP (__INLINE_SYSCALL, __VA_ARGS__)
 110
 111 #if IS_IN (rtld)
 112 /* All cancellation points are compiled out in the dynamic loader.  */
 113 # define NO_SYSCALL_CANCEL_CHECKING 1
 114 #else
 115 # define NO_SYSCALL_CANCEL_CHECKING SINGLE_THREAD_P
 116 #endif
 117
 118 #define SYSCALL_CANCEL(...) \
 119   ({                                                                         \
 120     long int sc_ret;                                                         \
 121     if (NO_SYSCALL_CANCEL_CHECKING)                                          \
 122       sc_ret = INLINE_SYSCALL_CALL (__VA_ARGS__);                            \
 123     else                                                                     \
 124       {                                                                      \
 125         int sc_cancel_oldtype = LIBC_CANCEL_ASYNC ();                        \
 126         sc_ret = INLINE_SYSCALL_CALL (__VA_ARGS__);                          \
 127         LIBC_CANCEL_RESET (sc_cancel_oldtype);                               \
 128       }                                                                      \
 129     sc_ret;                                                                  \
 130   })
 131
 132 /* Issue a syscall defined by syscall number plus any other argument
 133    required.  Any error will be returned unmodified (including errno).  */
 134 #define INTERNAL_SYSCALL_CANCEL(...) \
 135   ({                                                                         \
 136     long int sc_ret;                                                         \
 137     if (NO_SYSCALL_CANCEL_CHECKING)                                          \
 138       sc_ret = INTERNAL_SYSCALL_CALL (__VA_ARGS__);                          \
 139     else                                                                     \
 140       {                                                                      \
 141         int sc_cancel_oldtype = LIBC_CANCEL_ASYNC ();                        \
 142         sc_ret = INTERNAL_SYSCALL_CALL (__VA_ARGS__);                        \
 143         LIBC_CANCEL_RESET (sc_cancel_oldtype);                               \
 144       }                                                                      \
 145     sc_ret;                                                                  \
 146   })
 147
 148 /* Machine-dependent sysdep.h files are expected to define the macro
 149    PSEUDO (function_name, syscall_name) to emit assembly code to define the
 150    C-callable function FUNCTION_NAME to do system call SYSCALL_NAME.
 151    r0 and r1 are the system call outputs.  MOVE(x, y) should be defined as
 152    an instruction such that "MOVE(r1, r0)" works.  ret should be defined
 153    as the return instruction.  */
 154
 155 #ifndef SYS_ify
 156 #define SYS_ify(syscall_name) SYS_##syscall_name
 157 #endif
 158
 159 /* Terminate a system call named SYM.  This is used on some platforms
 160    to generate correct debugging information.  */
 161 #ifndef PSEUDO_END
 162 #define PSEUDO_END(sym)
 163 #endif
 164 #ifndef PSEUDO_END_NOERRNO
 165 #define PSEUDO_END_NOERRNO(sym) PSEUDO_END(sym)
 166 #endif
 167 #ifndef PSEUDO_END_ERRVAL
 168 #define PSEUDO_END_ERRVAL(sym)  PSEUDO_END(sym)
 169 #endif
 170
 171 /* Wrappers around system calls should normally inline the system call code.
 172    But sometimes it is not possible or implemented and we use this code.  */
 173 #ifndef INLINE_SYSCALL
 174 #define INLINE_SYSCALL(name, nr, args...) __syscall_##name (args)
 175 #endif