syscall.c

qemu性能直逼VMware的仿真器QEMU 的模擬速度約為實機的 25％；約為 Bochs 的 60 倍。Plex86、User-Mode-Linux、VMware 和 Virtual PC 則比

/*
 *  Linux syscalls
 * 
 *  Copyright (c) 2003 Fabrice Bellard
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <elf.h>
#include <endian.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/mman.h>
#include <sys/swap.h>
#include <signal.h>
#include <sched.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/poll.h>
#include <sys/times.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/statfs.h>
#include <utime.h>
#include <sys/sysinfo.h>
//#include <sys/user.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#define termios host_termios
#define winsize host_winsize
#define termio host_termio
#define sgttyb host_sgttyb /* same as target */
#define tchars host_tchars /* same as target */
#define ltchars host_ltchars /* same as target */

#include <linux/termios.h>
#include <linux/unistd.h>
#include <linux/utsname.h>
#include <linux/cdrom.h>
#include <linux/hdreg.h>
#include <linux/soundcard.h>
#include <linux/dirent.h>
#include <linux/kd.h>

#include "qemu.h"

//#define DEBUG

#if defined(TARGET_I386) || defined(TARGET_ARM) || defined(TARGET_SPARC) \
    || defined(TARGET_M68K)
/* 16 bit uid wrappers emulation */
#define USE_UID16
#endif

//#include <linux/msdos_fs.h>
#define	VFAT_IOCTL_READDIR_BOTH		_IOR('r', 1, struct dirent [2])
#define	VFAT_IOCTL_READDIR_SHORT	_IOR('r', 2, struct dirent [2])


#undef _syscall0
#undef _syscall1
#undef _syscall2
#undef _syscall3
#undef _syscall4
#undef _syscall5
#undef _syscall6

#define _syscall0(type,name)		\
type name (void)			\
{					\
	return syscall(__NR_##name);	\
}

#define _syscall1(type,name,type1,arg1)		\
type name (type1 arg1)				\
{						\
	return syscall(__NR_##name, arg1);	\
}

#define _syscall2(type,name,type1,arg1,type2,arg2)	\
type name (type1 arg1,type2 arg2)			\
{							\
	return syscall(__NR_##name, arg1, arg2);	\
}

#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3)	\
type name (type1 arg1,type2 arg2,type3 arg3)			\
{								\
	return syscall(__NR_##name, arg1, arg2, arg3);		\
}

#define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)	\
type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4)				\
{										\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4);			\
}

#define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,	\
		  type5,arg5)							\
type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5)		\
{										\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5);		\
}


#define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,	\
		  type5,arg5,type6,arg6)					\
type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5,type6 arg6)	\
{										\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5, arg6);	\
}


#define __NR_sys_uname __NR_uname
#define __NR_sys_getcwd1 __NR_getcwd
#define __NR_sys_getdents __NR_getdents
#define __NR_sys_getdents64 __NR_getdents64
#define __NR_sys_rt_sigqueueinfo __NR_rt_sigqueueinfo

#if defined(__alpha__) || defined (__ia64__) || defined(__x86_64__)
#define __NR__llseek __NR_lseek
#endif

#ifdef __NR_gettid
_syscall0(int, gettid)
#else
static int gettid(void) {
    return -ENOSYS;
}
#endif
_syscall1(int,sys_uname,struct new_utsname *,buf)
_syscall2(int,sys_getcwd1,char *,buf,size_t,size)
_syscall3(int, sys_getdents, uint, fd, struct dirent *, dirp, uint, count);
_syscall3(int, sys_getdents64, uint, fd, struct dirent64 *, dirp, uint, count);
_syscall5(int, _llseek,  uint,  fd, ulong, hi, ulong, lo,
          loff_t *, res, uint, wh);
_syscall3(int,sys_rt_sigqueueinfo,int,pid,int,sig,siginfo_t *,uinfo)
#ifdef __NR_exit_group
_syscall1(int,exit_group,int,error_code)
#endif

extern int personality(int);
extern int flock(int, int);
extern int setfsuid(int);
extern int setfsgid(int);
extern int setresuid(uid_t, uid_t, uid_t);
extern int getresuid(uid_t *, uid_t *, uid_t *);
extern int setresgid(gid_t, gid_t, gid_t);
extern int getresgid(gid_t *, gid_t *, gid_t *);
extern int setgroups(int, gid_t *);

static inline long get_errno(long ret)
{
    if (ret == -1)
        return -errno;
    else
        return ret;
}

static inline int is_error(long ret)
{
    return (unsigned long)ret >= (unsigned long)(-4096);
}

static target_ulong target_brk;
static target_ulong target_original_brk;

void target_set_brk(target_ulong new_brk)
{
    target_original_brk = target_brk = new_brk;
}

long do_brk(target_ulong new_brk)
{
    target_ulong brk_page;
    long mapped_addr;
    int	new_alloc_size;

    if (!new_brk)
        return target_brk;
    if (new_brk < target_original_brk)
        return -ENOMEM;
    
    brk_page = HOST_PAGE_ALIGN(target_brk);

    /* If the new brk is less than this, set it and we're done... */
    if (new_brk < brk_page) {
	target_brk = new_brk;
    	return target_brk;
    }

    /* We need to allocate more memory after the brk... */
    new_alloc_size = HOST_PAGE_ALIGN(new_brk - brk_page + 1);
    mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size, 
                                        PROT_READ|PROT_WRITE,
                                        MAP_ANON|MAP_FIXED|MAP_PRIVATE, 0, 0));
    if (is_error(mapped_addr)) {
	return mapped_addr;
    } else {
	target_brk = new_brk;
    	return target_brk;
    }
}

static inline fd_set *target_to_host_fds(fd_set *fds, 
                                         target_long *target_fds, int n)
{
#if !defined(BSWAP_NEEDED) && !defined(WORDS_BIGENDIAN)
    return (fd_set *)target_fds;
#else
    int i, b;
    if (target_fds) {
        FD_ZERO(fds);
        for(i = 0;i < n; i++) {
            b = (tswapl(target_fds[i / TARGET_LONG_BITS]) >>
                 (i & (TARGET_LONG_BITS - 1))) & 1;
            if (b)
                FD_SET(i, fds);
        }
        return fds;
    } else {
        return NULL;
    }
#endif
}

static inline void host_to_target_fds(target_long *target_fds, 
                                      fd_set *fds, int n)
{
#if !defined(BSWAP_NEEDED) && !defined(WORDS_BIGENDIAN)
    /* nothing to do */
#else
    int i, nw, j, k;
    target_long v;

    if (target_fds) {
        nw = (n + TARGET_LONG_BITS - 1) / TARGET_LONG_BITS;
        k = 0;
        for(i = 0;i < nw; i++) {
            v = 0;
            for(j = 0; j < TARGET_LONG_BITS; j++) {
                v |= ((FD_ISSET(k, fds) != 0) << j);
                k++;
            }
            target_fds[i] = tswapl(v);
        }
    }
#endif
}

#if defined(__alpha__)
#define HOST_HZ 1024
#else
#define HOST_HZ 100
#endif

static inline long host_to_target_clock_t(long ticks)
{
#if HOST_HZ == TARGET_HZ
    return ticks;
#else
    return ((int64_t)ticks * TARGET_HZ) / HOST_HZ;
#endif
}

static inline void host_to_target_rusage(target_ulong target_addr,
                                         const struct rusage *rusage)
{
    struct target_rusage *target_rusage;

    lock_user_struct(target_rusage, target_addr, 0);
    target_rusage->ru_utime.tv_sec = tswapl(rusage->ru_utime.tv_sec);
    target_rusage->ru_utime.tv_usec = tswapl(rusage->ru_utime.tv_usec);
    target_rusage->ru_stime.tv_sec = tswapl(rusage->ru_stime.tv_sec);
    target_rusage->ru_stime.tv_usec = tswapl(rusage->ru_stime.tv_usec);
    target_rusage->ru_maxrss = tswapl(rusage->ru_maxrss);
    target_rusage->ru_ixrss = tswapl(rusage->ru_ixrss);
    target_rusage->ru_idrss = tswapl(rusage->ru_idrss);
    target_rusage->ru_isrss = tswapl(rusage->ru_isrss);
    target_rusage->ru_minflt = tswapl(rusage->ru_minflt);
    target_rusage->ru_majflt = tswapl(rusage->ru_majflt);
    target_rusage->ru_nswap = tswapl(rusage->ru_nswap);
    target_rusage->ru_inblock = tswapl(rusage->ru_inblock);
    target_rusage->ru_oublock = tswapl(rusage->ru_oublock);
    target_rusage->ru_msgsnd = tswapl(rusage->ru_msgsnd);
    target_rusage->ru_msgrcv = tswapl(rusage->ru_msgrcv);
    target_rusage->ru_nsignals = tswapl(rusage->ru_nsignals);
    target_rusage->ru_nvcsw = tswapl(rusage->ru_nvcsw);
    target_rusage->ru_nivcsw = tswapl(rusage->ru_nivcsw);
    unlock_user_struct(target_rusage, target_addr, 1);
}

static inline void target_to_host_timeval(struct timeval *tv,
                                          target_ulong target_addr)
{
    struct target_timeval *target_tv;

    lock_user_struct(target_tv, target_addr, 1);
    tv->tv_sec = tswapl(target_tv->tv_sec);
    tv->tv_usec = tswapl(target_tv->tv_usec);
    unlock_user_struct(target_tv, target_addr, 0);
}

static inline void host_to_target_timeval(target_ulong target_addr,
                                          const struct timeval *tv)
{
    struct target_timeval *target_tv;

    lock_user_struct(target_tv, target_addr, 0);
    target_tv->tv_sec = tswapl(tv->tv_sec);
    target_tv->tv_usec = tswapl(tv->tv_usec);
    unlock_user_struct(target_tv, target_addr, 1);
}


static long do_select(long n, 
                      target_ulong rfd_p, target_ulong wfd_p, 
                      target_ulong efd_p, target_ulong target_tv)
{
    fd_set rfds, wfds, efds;
    fd_set *rfds_ptr, *wfds_ptr, *efds_ptr;
    target_long *target_rfds, *target_wfds, *target_efds;
    struct timeval tv, *tv_ptr;
    long ret;
    int ok;

    if (rfd_p) {
        target_rfds = lock_user(rfd_p, sizeof(target_long) * n, 1);
        rfds_ptr = target_to_host_fds(&rfds, target_rfds, n);
    } else {
        target_rfds = NULL;
        rfds_ptr = NULL;
    }
    if (wfd_p) {
        target_wfds = lock_user(wfd_p, sizeof(target_long) * n, 1);
        wfds_ptr = target_to_host_fds(&wfds, target_wfds, n);
    } else {
        target_wfds = NULL;
        wfds_ptr = NULL;
    }
    if (efd_p) {
        target_efds = lock_user(efd_p, sizeof(target_long) * n, 1);
        efds_ptr = target_to_host_fds(&efds, target_efds, n);
    } else {
        target_efds = NULL;
        efds_ptr = NULL;
    }
            
    if (target_tv) {
        target_to_host_timeval(&tv, target_tv);
        tv_ptr = &tv;
    } else {
        tv_ptr = NULL;
    }
    ret = get_errno(select(n, rfds_ptr, wfds_ptr, efds_ptr, tv_ptr));
    ok = !is_error(ret);

    if (ok) {
        host_to_target_fds(target_rfds, rfds_ptr, n);
        host_to_target_fds(target_wfds, wfds_ptr, n);
        host_to_target_fds(target_efds, efds_ptr, n);

        if (target_tv) {
            host_to_target_timeval(target_tv, &tv);
        }
    }
    if (target_rfds)
        unlock_user(target_rfds, rfd_p, ok ? sizeof(target_long) * n : 0);
    if (target_wfds)
        unlock_user(target_wfds, wfd_p, ok ? sizeof(target_long) * n : 0);
    if (target_efds)
        unlock_user(target_efds, efd_p, ok ? sizeof(target_long) * n : 0);

    return ret;
}

static inline void target_to_host_sockaddr(struct sockaddr *addr,
                                           target_ulong target_addr,
                                           socklen_t len)
{
    struct target_sockaddr *target_saddr;

    target_saddr = lock_user(target_addr, len, 1);
    memcpy(addr, target_saddr, len);
    addr->sa_family = tswap16(target_saddr->sa_family);
    unlock_user(target_saddr, target_addr, 0);
}

static inline void host_to_target_sockaddr(target_ulong target_addr,
                                           struct sockaddr *addr,
                                           socklen_t len)
{
    struct target_sockaddr *target_saddr;

    target_saddr = lock_user(target_addr, len, 0);
    memcpy(target_saddr, addr, len);
    target_saddr->sa_family = tswap16(addr->sa_family);
    unlock_user(target_saddr, target_addr, len);
}

/* ??? Should this also swap msgh->name?  */
static inline void target_to_host_cmsg(struct msghdr *msgh,
                                       struct target_msghdr *target_msgh)
{
    struct cmsghdr *cmsg = CMSG_FIRSTHDR(msgh);
    struct target_cmsghdr *target_cmsg = TARGET_CMSG_FIRSTHDR(target_msgh);
    socklen_t space = 0;

    while (cmsg && target_cmsg) {
        void *data = CMSG_DATA(cmsg);
        void *target_data = TARGET_CMSG_DATA(target_cmsg);