syscalls.c

它通过提供glibc兼容使得应用程序移植到较小的c 库时相当得容易. 它能够应用到带虚拟存储的Linux和uClinux上.在大多数带MMU部件的平台上为使它更加紧凑,它也能够编译成共享库.uClib

/* vi: set sw=4 ts=4: */
/*
 * Syscalls for uClibc
 *
 * Copyright (C) 2000 by Lineo, inc
 * Copyright (C) 2001, 2002 by Erik Andersen
 * Written by Erik Andersen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#define _GNU_SOURCE
#define _LARGEFILE64_SOURCE
#include <features.h>
#undef __OPTIMIZE__
/* We absolutely do _NOT_ want interfaces silently
 *  *  * renamed under us or very bad things will happen... */
#ifdef __USE_FILE_OFFSET64
# undef __USE_FILE_OFFSET64
#endif

#include <errno.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <endian.h>


//#define __NR_exit             1
//See _exit.c

//#define __NR_fork             2
#ifdef L___libc_fork
#include <unistd.h>
#	ifdef __UCLIBC_HAS_MMU__
#define __NR___libc_fork __NR_fork
		_syscall0(pid_t, __libc_fork);
		weak_alias (__libc_fork, fork)
#	else
		pid_t fork(void)
		{
			__set_errno(ENOSYS);
			return -1;
		}
#	endif
#endif

//#define __NR_read             3
#ifdef L___libc_read
#include <unistd.h>
#define __NR___libc_read __NR_read
_syscall3(ssize_t, __libc_read, int, fd, __ptr_t, buf, size_t, count);
weak_alias(__libc_read, read)
#endif

//#define __NR_write            4
#ifdef L___libc_write
#include <unistd.h>
#define __NR___libc_write __NR_write
_syscall3(ssize_t, __libc_write, int, fd, const __ptr_t, buf, size_t, count);
weak_alias(__libc_write, write)
/* Stupid libgcc.a from gcc 2.95.x uses __write in pure.o
 * which is a blatent GNU libc-ism... */
weak_alias (__libc_write, __write)
#endif

//#define __NR_open             5
#ifdef L___syscall_open
#define __NR___syscall_open __NR_open
#include <stdarg.h>
/* Do not include fcntl.h, so gcc doesn't whine the prototype */
static inline
_syscall3(int, __syscall_open, const char *, fn, int, flags, __kernel_mode_t, mode);
int __libc_open (const char * fn, int flags, mode_t mode)
{
	  return __syscall_open(fn, flags, mode);
}

weak_alias(__libc_open, open)
#endif

//#define __NR_close            6
#ifdef L___libc_close
#include <unistd.h>
#define __NR___libc_close __NR_close
_syscall1(int, __libc_close, int, fd);
weak_alias(__libc_close, close)
#endif

//#define __NR_waitpid          7
// Implemented using wait4 

//#define __NR_creat            8
#ifdef L___syscall_creat
#include <fcntl.h>
#ifdef __NR_creat
#define __NR___syscall_creat __NR_creat
_syscall2(int, __syscall_creat, const char *, file, __kernel_mode_t, mode);
int creat (const char *file, mode_t mode)
{
	  return __syscall_creat (file, mode);
}
#else
extern int __libc_open (const char *file, int flags, mode_t mode);
int creat (const char *file, mode_t mode)
{
	  return __libc_open (file, O_WRONLY|O_CREAT|O_TRUNC, mode);
}
#endif
#endif

//#define __NR_link             9
#ifdef L_link
#include <unistd.h>
_syscall2(int, link, const char *, oldpath, const char *, newpath);
#endif

//#define __NR_unlink           10
#ifdef L_unlink
#include <unistd.h>
_syscall1(int, unlink, const char *, pathname);
#endif

//#define __NR_execve           11
#ifdef L_execve
#include <unistd.h>
_syscall3(int, execve, const char *, filename, char *const *, argv,
		  char *const *, envp);
#endif

//#define __NR_chdir            12
#ifdef L_chdir
#include <unistd.h>
_syscall1(int, chdir, const char *, path);
#endif

//#define __NR_time             13
#ifdef L_time
#include <time.h>
#include <sys/time.h>
#ifdef __NR_time
_syscall1(time_t, time, time_t *, t);
#else
time_t time (time_t *t)
{ 
	time_t result;
	struct timeval tv;
	if (gettimeofday (&tv, (struct timezone *) NULL)) {
		result = (time_t) -1;
	} else { result = (time_t) tv.tv_sec; }
	if (t != NULL) { *t = result; }
	return result;
}
#endif
#endif

//#define __NR_mknod            14
#ifdef L___syscall_mknod
#define __NR___syscall_mknod __NR_mknod
#include <sys/stat.h>
_syscall3(int, __syscall_mknod, const char *, path, __kernel_mode_t, mode, __kernel_dev_t, dev);
int mknod(const char *path, mode_t mode, dev_t dev)
{ 
	__kernel_dev_t k_dev;
	/* We must convert the dev_t value to a __kernel_dev_t */
	k_dev = ((major(dev) & 0xff) << 8) | (minor(dev) & 0xff);
	return __syscall_mknod(path, mode, k_dev);
}
#endif

//#define __NR_chmod            15
#ifdef L___syscall_chmod
#include <sys/stat.h>
#define __NR___syscall_chmod __NR_chmod
static inline 
_syscall2(int, __syscall_chmod, const char *, path, __kernel_mode_t, mode);
int chmod(const char *path, mode_t mode)
{
	return __syscall_chmod(path, mode);
}
#endif

/* Old kernels don't have lchown -- do chown instead.  This
 * is sick and wrong, but at least things will compile.  
 * They may not follow links when they should though... */
#ifndef __NR_lchown 
#define __NR_lchown __NR_chown
#endif

//#define __NR_lchown           16
#ifdef L___syscall_lchown
#include <unistd.h>
#define __NR___syscall_lchown __NR_lchown
static inline 
_syscall3(int, __syscall_lchown, const char *, path, __kernel_uid_t, owner, __kernel_gid_t, group);
int lchown(const char *path, uid_t owner, gid_t group)
{
	return __syscall_lchown(path, owner, group);
}
#endif


//#define __NR_break            17

//#define __NR_oldstat          18

//#define __NR_lseek            19
#ifdef L___libc_lseek
#include <unistd.h>
#define __NR___libc_lseek __NR_lseek
_syscall3(__off_t, __libc_lseek, int, fildes, __off_t, offset, int, whence);
weak_alias(__libc_lseek, lseek)
#endif

//#define __NR_getpid           20
#ifdef L___libc_getpid
#include <unistd.h>
#if defined (__alpha__)
#define __NR_getpid     __NR_getxpid
#endif
#define __NR___libc_getpid __NR_getpid
_syscall0(pid_t, __libc_getpid);
weak_alias(__libc_getpid, getpid)
weak_alias(__libc_getpid, __getpid)
#endif

//#define __NR_mount            21
#ifdef L_mount
#include <sys/mount.h>
_syscall5(int, mount, const char *, specialfile, const char *, dir,
		  const char *, filesystemtype, unsigned long, rwflag,
		  const void *, data);
#endif

//#define __NR_umount           22
#ifdef L_umount
#include <sys/mount.h>
_syscall1(int, umount, const char *, specialfile);
#endif

//#define __NR_setuid           23
#ifdef L___syscall_setuid
#define __NR___syscall_setuid __NR_setuid
#include <unistd.h>
static inline 
_syscall1(int, __syscall_setuid, __kernel_uid_t, uid);
int setuid(uid_t uid)
{
	if (uid == (uid_t) ~0 || uid != (uid_t) ((int) uid)) {
		__set_errno (EINVAL);
		return -1;
	}
	return(__syscall_setuid(uid));
}
#endif

//#define __NR_getuid           24
#ifdef L_getuid
#include <unistd.h>
#if defined (__alpha__)
#define __NR_getuid     __NR_getxuid
#endif
_syscall0(uid_t, getuid);
#endif

//#define __NR_stime            25
#ifdef L_stime
#include <time.h>
#include <sys/time.h>
#ifdef _NR_stime
_syscall1(int, stime, const time_t *, t);
#else
int stime(const time_t *when)
{ 
	struct timeval tv;
	if (when == NULL) { __set_errno (EINVAL); return -1; }
	tv.tv_sec = *when;
	tv.tv_usec = 0;
	return settimeofday (&tv, (struct timezone *) 0);
}
#endif
#endif

//#define __NR_ptrace           26
#ifdef L___ptrace
#include <sys/ptrace.h>
#define __NR___ptrace __NR_ptrace
_syscall4(long, __ptrace, enum __ptrace_request, request, __kernel_pid_t, pid,
		void*, addr, void*, data);
#endif


//#define __NR_alarm            27
#ifdef L_alarm
#include <unistd.h>
#ifdef __NR_alarm
_syscall1(unsigned int, alarm, unsigned int, seconds);
#else
#include <sys/time.h>
unsigned int alarm (unsigned int seconds)
{
	struct itimerval old, new;
	unsigned int retval;
	new.it_value.tv_usec = 0;
	new.it_interval.tv_sec = 0;
	new.it_interval.tv_usec = 0;
	new.it_value.tv_sec = (long int) seconds;
	if (setitimer (ITIMER_REAL, &new, &old) < 0) { return 0; }
	retval = old.it_value.tv_sec;
	if (old.it_value.tv_usec) { ++retval; }
	return retval;
}
#endif
#endif

//#define __NR_oldfstat         28

//#define __NR_pause            29
#ifdef L___libc_pause
#include <unistd.h>
#ifdef __NR_pause
#define __NR___libc_pause __NR_pause
_syscall0(int, __libc_pause);
weak_alias(__libc_pause, pause)
#else
#include <signal.h>
int __libc_pause (void)
{
	return(__sigpause(sigblock(0), 0));
}
weak_alias(__libc_pause, pause)
#endif
#endif

//#define __NR_utime            30
#ifdef L_utime
#include <utime.h>
#ifdef __NR_utime
_syscall2(int, utime, const char *, file, const struct utimbuf *, times);
#else
#include <stdlib.h>
#include <sys/time.h>
int utime(const char *file, const struct utimbuf *times)
{
	struct timeval timevals[2];
	if (times != NULL) {
		timevals[0].tv_usec = 0L;
		timevals[1].tv_usec = 0L;
		timevals[0].tv_sec = (long int) times->actime;
		timevals[1].tv_sec = (long int) times->modtime;
	} else {
		if (gettimeofday (&timevals[0], NULL) < 0) { return -1; }
		timevals[1] = timevals[0];
	}
	return utimes(file, timevals);
}
#endif
#endif

//#define __NR_utimed
#ifdef L_utimes
#include <utime.h>
#ifdef __NR_utimes
_syscall2(int, utimes, const char *, file, const struct timeval *, tvp);
#else
#include <stdlib.h>
#include <sys/time.h>
int utimes (const char *file, const struct timeval tvp[2])
{
	struct utimbuf buf, *times;
	if (tvp) {
		times = &buf;
		times->actime = tvp[0].tv_sec;
		times->modtime = tvp[1].tv_sec;
	} else { times = NULL; }
	return utime(file, times);
}
#endif
#endif

//#define __NR_stty             31
#ifdef L_stty
#include <sgtty.h>
int stty (int __fd, __const struct sgttyb *__params);
{
	__set_errno(ENOSYS);
	return -1;
}
#endif

//#define __NR_gtty             32
#ifdef L_gtty
#include <sgtty.h>
int gtty (int __fd, struct sgttyb *__params)
{
	__set_errno(ENOSYS);
	return -1;
}
#endif

//#define __NR_access           33
#ifdef L_access
#include <unistd.h>
_syscall2(int, access, const char *, pathname, int, mode);
#endif

//#define __NR_nice             34
#ifdef L_nice
#include <unistd.h>
#ifdef __NR_nice
_syscall1(int, nice, int, inc);
#else
#include <sys/resource.h>
int nice (int incr)
{
	int save, prio, result;
	save = errno;
	__set_errno (0);
	prio = getpriority (PRIO_PROCESS, 0);
	if (prio == -1) {
		if (errno != 0) { return -1; } 
		else { __set_errno (save); }
	}
	result = setpriority (PRIO_PROCESS, 0, prio + incr);
	if (result != -1) { return prio + incr; } else { return -1; }
}
#endif
#endif

//#define __NR_ftime            35

//#define __NR_sync             36
//See sync.c

//#define __NR_kill             37
#ifdef L___syscall_kill
#include <signal.h>
#undef kill
#define __NR___syscall_kill __NR_kill
static inline
_syscall2(int, __syscall_kill, __kernel_pid_t, pid, int, sig);
int kill(pid_t pid, int sig)
{
	return(__syscall_kill(pid, sig));
}
#endif

//#define __NR_rename           38
#ifdef L_rename
#include <stdio.h>
_syscall2(int, rename, const char *, oldpath, const char *, newpath);
#endif

//#define __NR_mkdir            39
#ifdef L___syscall_mkdir
#include <sys/stat.h>
#define __NR___syscall_mkdir __NR_mkdir
static inline 
_syscall2(int, __syscall_mkdir, const char *, pathname, __kernel_mode_t, mode);
int mkdir(const char * pathname, mode_t mode)
{
	return(__syscall_mkdir(pathname, mode));
}
#endif

//#define __NR_rmdir            40
#ifdef L_rmdir
#include <unistd.h>
_syscall1(int, rmdir, const char *, pathname);
#endif

//#define __NR_dup              41
#ifdef L_dup
#include <unistd.h>
_syscall1(int, dup, int, oldfd);
#endif

//#define __NR_pipe             42
#ifdef L_pipe
#include <unistd.h>
_syscall1(int, pipe, int *, filedes);
#endif

//#define __NR_times            43
#ifdef L_times
#include <sys/times.h>
_syscall1(clock_t, times, struct tms *, buf);
#endif

//#define __NR_prof             44

//#define __NR_brk              45

//#define __NR_setgid           46
#ifdef L___syscall_setgid
#include <unistd.h>
#define __NR___syscall_setgid __NR_setgid
static inline 
_syscall1(int, __syscall_setgid, __kernel_gid_t, gid);