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
  37 /* Just like INLINE_SYSCALL(), but take a non-constant syscall (NCS) argument */
  38 #ifndef INLINE_SYSCALL_NCS
  39 # define INLINE_SYSCALL_NCS(name, nr, args...)                          \
  40 ({                                                                      \
  41         INTERNAL_SYSCALL_DECL(err);                                     \
  42         long res = INTERNAL_SYSCALL_NCS(name, err, nr, args);           \
  43         if (unlikely(INTERNAL_SYSCALL_ERROR_P(res, err))) {             \
  44                 __set_errno(INTERNAL_SYSCALL_ERRNO(res, err));          \
  45                 res = -1L;                                              \
  46         }                                                               \
  47         res;                                                            \
  48 })
  49 #endif
  50
  51 /* No point in forcing people to implement both when they only need one */
  52 #ifndef INTERNAL_SYSCALL
  53 # define INTERNAL_SYSCALL(name, err, nr, args...) INTERNAL_SYSCALL_NCS(__NR_##name, err, nr, args)
  54 #endif
  55
  56 #ifndef INTERNAL_SYSCALL_NCS
  57 # error your port needs to define INTERNAL_SYSCALL_NCS in bits/syscalls.h
  58 #endif
  59
  60 #ifndef _syscall0
  61
  62 #define C_DECL_ARGS_0()                 void
  63 #define C_DECL_ARGS_1(t, v)             t v
  64 #define C_DECL_ARGS_2(t, v, args...)    t v, C_DECL_ARGS_1(args)
  65 #define C_DECL_ARGS_3(t, v, args...)    t v, C_DECL_ARGS_2(args)
  66 #define C_DECL_ARGS_4(t, v, args...)    t v, C_DECL_ARGS_3(args)
  67 #define C_DECL_ARGS_5(t, v, args...)    t v, C_DECL_ARGS_4(args)
  68 #define C_DECL_ARGS_6(t, v, args...)    t v, C_DECL_ARGS_5(args)
  69
  70 #define C_ARGS_0()
  71 #define C_ARGS_1(t, v)                  v
  72 #define C_ARGS_2(t, v, args...)         v, C_ARGS_1(args)
  73 #define C_ARGS_3(t, v, args...)         v, C_ARGS_2(args)
  74 #define C_ARGS_4(t, v, args...)         v, C_ARGS_3(args)
  75 #define C_ARGS_5(t, v, args...)         v, C_ARGS_4(args)
  76 #define C_ARGS_6(t, v, args...)         v, C_ARGS_5(args)
  77
  78 #define SYSCALL_FUNC(nargs, type, name, args...)                        \
  79 type name(C_DECL_ARGS_##nargs(args)) {                                  \
  80         return (type)INLINE_SYSCALL(name, nargs, C_ARGS_##nargs(args)); \
  81 }
  82
  83 #define _syscall0(args...)              SYSCALL_FUNC(0, args)
  84 #define _syscall1(args...)              SYSCALL_FUNC(1, args)
  85 #define _syscall2(args...)              SYSCALL_FUNC(2, args)
  86 #define _syscall3(args...)              SYSCALL_FUNC(3, args)
  87 #define _syscall4(args...)              SYSCALL_FUNC(4, args)
  88 #define _syscall5(args...)              SYSCALL_FUNC(5, args)
  89 #define _syscall6(args...)              SYSCALL_FUNC(6, args)
  90
  91 #endif /* _syscall0 */
  92
  93 #endif /* __ASSEMBLER__ */
  94
  95 #endif