Thomas Weißschuh 53fcfafa8c tools/nolibc/unistd: add syscall()
syscall() is used by "normal" libcs to allow users to directly call
syscalls.
By having the same syntax inside nolibc users can more easily write code
that works with different libcs.

The macro logic is adapted from systemtaps STAP_PROBEV() macro that is
released in the public domain / CC0.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00

78 lines
2.1 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* unistd function definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_UNISTD_H
#define _NOLIBC_UNISTD_H
#include "std.h"
#include "arch.h"
#include "types.h"
#include "sys.h"
#define STDIN_FILENO 0
#define STDOUT_FILENO 1
#define STDERR_FILENO 2
static __attribute__((unused))
int msleep(unsigned int msecs)
{
struct timeval my_timeval = { msecs / 1000, (msecs % 1000) * 1000 };
if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
return (my_timeval.tv_sec * 1000) +
(my_timeval.tv_usec / 1000) +
!!(my_timeval.tv_usec % 1000);
else
return 0;
}
static __attribute__((unused))
unsigned int sleep(unsigned int seconds)
{
struct timeval my_timeval = { seconds, 0 };
if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
return my_timeval.tv_sec + !!my_timeval.tv_usec;
else
return 0;
}
static __attribute__((unused))
int usleep(unsigned int usecs)
{
struct timeval my_timeval = { usecs / 1000000, usecs % 1000000 };
return sys_select(0, 0, 0, 0, &my_timeval);
}
static __attribute__((unused))
int tcsetpgrp(int fd, pid_t pid)
{
return ioctl(fd, TIOCSPGRP, &pid);
}
#define _syscall(N, ...) \
({ \
long _ret = my_syscall##N(__VA_ARGS__); \
if (_ret < 0) { \
SET_ERRNO(-_ret); \
_ret = -1; \
} \
_ret; \
})
#define _syscall_narg(...) __syscall_narg(__VA_ARGS__, 6, 5, 4, 3, 2, 1, 0)
#define __syscall_narg(_0, _1, _2, _3, _4, _5, _6, N, ...) N
#define _syscall_n(N, ...) _syscall(N, __VA_ARGS__)
#define syscall(...) _syscall_n(_syscall_narg(__VA_ARGS__), ##__VA_ARGS__)
/* make sure to include all global symbols */
#include "nolibc.h"
#endif /* _NOLIBC_UNISTD_H */