libc/sysdeps/linux/common/bits/syscalls-common.h

   1 /*
   2  * Common syscall type defines
   3  *
   4  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   5  */
   6
   7 #ifndef _SYSCALLS_COMMON_H
   8 #define _SYSCALLS_COMMON_H      1
   9
  10 #ifndef _SYSCALL_H
  11 # error "Never use <bits/syscalls-common.h> directly; include <sys/syscall.h> instead."
  12 #endif
  13
  14 #ifndef SYS_ify
  15 # define SYS_ify(syscall_name) (__NR_##syscall_name)
  16 #endif
  17
  18 #ifndef __ASSEMBLER__
  19
  20 #include <errno.h>
  21
  22 #ifndef INTERNAL_SYSCALL_DECL
  23 # define INTERNAL_SYSCALL_DECL(err)         do { } while (0)
  24 #endif
  25 #ifndef INTERNAL_SYSCALL_ERROR_P
  26 # define INTERNAL_SYSCALL_ERROR_P(val, err) ((unsigned long)val >= (unsigned long)(-4095))
  27 #endif
  28 #ifndef INTERNAL_SYSCALL_ERRNO
  29 # define INTERNAL_SYSCALL_ERRNO(val, err)   (-(val))
  30 #endif
  31
  32 /* Define a macro which expands into the inline wrapper code for a system call */
  33 #ifndef INLINE_SYSCALL
  34 # define INLINE_SYSCALL(name, nr, args...) INLINE_SYSCALL_NCS(__NR_##name, nr, args)
  35 #endif
  36 #ifndef INLINE_SYSCALL_NOERR
  37 # define INLINE_SYSCALL_NOERR(name, nr, args...) INLINE_SYSCALL_NOERR_NCS(__NR_##name, nr, args)
  38 #endif
  39
  40 /* Just like INLINE_SYSCALL(), but take a non-constant syscall (NCS) argument */
  41 #ifndef INLINE_SYSCALL_NCS
  42 # define INLINE_SYSCALL_NCS(num, nr, args...)                           \
  43 (__extension__                                                          \
  44  ({                                                                     \
  45         long __res;                                                     \
  46         INTERNAL_SYSCALL_DECL(__err);                                   \
  47         (__extension__                                                  \
  48          ({                                                             \
  49            __res = INTERNAL_SYSCALL_NCS(num, __err, nr, args);          \
  50            if (unlikely(INTERNAL_SYSCALL_ERROR_P(__res, __err))) {      \
  51                 __set_errno(INTERNAL_SYSCALL_ERRNO(__res, __err));      \
  52                 __res = -1L;                                            \
  53            }                                                            \
  54            __res;                                                       \
  55           })                                                            \
  56         );                                                              \
  57   })                                                                    \
  58 )
  59 #endif
  60 #ifndef INLINE_SYSCALL_NOERR_NCS
  61 # define INLINE_SYSCALL_NOERR_NCS(num, nr, args...)                     \
  62 ({                                                                      \
  63         long __res;                                                     \
  64         INTERNAL_SYSCALL_DECL(__err);                                   \
  65         __res = INTERNAL_SYSCALL_NCS(num, __err, nr, args);             \
  66         __res;                                                          \
  67 })
  68 #endif
  69
  70 /* No point in forcing people to implement both when they only need one */
  71 #ifndef INTERNAL_SYSCALL
  72 # define INTERNAL_SYSCALL(name, err, nr, args...) INTERNAL_SYSCALL_NCS(__NR_##name, err, nr, args)
  73 #endif
  74
  75 #ifndef INTERNAL_SYSCALL_NCS
  76 # error your port needs to define INTERNAL_SYSCALL_NCS in bits/syscalls.h
  77 #endif
  78
  79 #ifndef _syscall0
  80
  81 #define C_DECL_ARGS_0()                 void
  82 #define C_DECL_ARGS_1(t, v)             t v
  83 #define C_DECL_ARGS_2(t, v, args...)    t v, C_DECL_ARGS_1(args)
  84 #define C_DECL_ARGS_3(t, v, args...)    t v, C_DECL_ARGS_2(args)
  85 #define C_DECL_ARGS_4(t, v, args...)    t v, C_DECL_ARGS_3(args)
  86 #define C_DECL_ARGS_5(t, v, args...)    t v, C_DECL_ARGS_4(args)
  87 #define C_DECL_ARGS_6(t, v, args...)    t v, C_DECL_ARGS_5(args)
  88
  89 #define C_ARGS_0()
  90 #define C_ARGS_1(t, v)                  v
  91 #define C_ARGS_2(t, v, args...)         v, C_ARGS_1(args)
  92 #define C_ARGS_3(t, v, args...)         v, C_ARGS_2(args)
  93 #define C_ARGS_4(t, v, args...)         v, C_ARGS_3(args)
  94 #define C_ARGS_5(t, v, args...)         v, C_ARGS_4(args)
  95 #define C_ARGS_6(t, v, args...)         v, C_ARGS_5(args)
  96
  97 #define SYSCALL_FUNC(nargs, type, name, args...)                        \
  98 type name(C_DECL_ARGS_##nargs(args)) {                                  \
  99         return (type)INLINE_SYSCALL(name, nargs, C_ARGS_##nargs(args)); \
 100 }
 101
 102 #define SYSCALL_NOERR_FUNC(nargs, type, name, args...)                  \
 103 type name(C_DECL_ARGS_##nargs(args)) {                                  \
 104         return (type)INLINE_SYSCALL_NOERR(name, nargs, C_ARGS_##nargs(args));   \
 105 }
 106
 107 #define _syscall0(args...)              SYSCALL_FUNC(0, args)
 108 #define _syscall_noerr0(args...)        SYSCALL_NOERR_FUNC(0, args)
 109 #define _syscall1(args...)              SYSCALL_FUNC(1, args)
 110 #define _syscall_noerr1(args...)        SYSCALL_NOERR_FUNC(1, args)
 111 #define _syscall2(args...)              SYSCALL_FUNC(2, args)
 112 #define _syscall3(args...)              SYSCALL_FUNC(3, args)
 113 #define _syscall4(args...)              SYSCALL_FUNC(4, args)
 114 #define _syscall5(args...)              SYSCALL_FUNC(5, args)
 115 #define _syscall6(args...)              SYSCALL_FUNC(6, args)
 116
 117 #endif /* _syscall0 */
 118
 119 #endif /* __ASSEMBLER__ */
 120
 121 #endif