linux32.c

h内核

/*
 * Conversion between 32-bit and 64-bit native system calls.
 *
 * Copyright (C) 2000 Silicon Graphics, Inc.
 * Written by Ulf Carlsson ([e-mail])
 * sys32_execve from ia64/ia32 code, Feb 2000, Kanoj Sarcar ([e-mail])
 */
#include <linux/config.h>
#include <linux/compiler.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/highuid.h>
#include <linux/dirent.h>
#include <linux/resource.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/times.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/shm.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/icmpv6.h>
#include <linux/syscalls.h>
#include <linux/sysctl.h>
#include <linux/utime.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/timex.h>
#include <linux/dnotify.h>
#include <linux/module.h>
#include <linux/binfmts.h>
#include <linux/security.h>
#include <linux/compat.h>
#include <linux/vfs.h>

#include <net/sock.h>
#include <net/scm.h>

#include <asm/ipc.h>
#include <asm/sim.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/mman.h>

/* Use this to get at 32-bit user passed pointers. */
/* A() macro should be used for places where you e.g.
   have some internal variable u32 and just want to get
   rid of a compiler warning. AA() has to be used in
   places where you want to convert a function argument
   to 32bit pointer or when you e.g. access pt_regs
   structure and want to consider 32bit registers only.
 */
#define A(__x) ((unsigned long)(__x))
#define AA(__x) ((unsigned long)((int)__x))

#ifdef __MIPSEB__
#define merge_64(r1,r2)	((((r1) & 0xffffffffUL) << 32) + ((r2) & 0xffffffffUL))
#endif
#ifdef __MIPSEL__
#define merge_64(r1,r2)	((((r2) & 0xffffffffUL) << 32) + ((r1) & 0xffffffffUL))
#endif

/*
 * Revalidate the inode. This is required for proper NFS attribute caching.
 */

int cp_compat_stat(struct kstat *stat, struct compat_stat *statbuf)
{
	struct compat_stat tmp;

	if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
		return -EOVERFLOW;

	memset(&tmp, 0, sizeof(tmp));
	tmp.st_dev = new_encode_dev(stat->dev);
	tmp.st_ino = stat->ino;
	tmp.st_mode = stat->mode;
	tmp.st_nlink = stat->nlink;
	SET_UID(tmp.st_uid, stat->uid);
	SET_GID(tmp.st_gid, stat->gid);
	tmp.st_rdev = new_encode_dev(stat->rdev);
	tmp.st_size = stat->size;
	tmp.st_atime = stat->atime.tv_sec;
	tmp.st_mtime = stat->mtime.tv_sec;
	tmp.st_ctime = stat->ctime.tv_sec;
#ifdef STAT_HAVE_NSEC
	tmp.st_atime_nsec = stat->atime.tv_nsec;
	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
#endif
	tmp.st_blocks = stat->blocks;
	tmp.st_blksize = stat->blksize;
	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

asmlinkage unsigned long
sys32_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
         unsigned long flags, unsigned long fd, unsigned long pgoff)
{
	struct file * file = NULL;
	unsigned long error;

	error = -EINVAL;
	if (!(flags & MAP_ANONYMOUS)) {
		error = -EBADF;
		file = fget(fd);
		if (!file)
			goto out;
	}
	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

	down_write(&current->mm->mmap_sem);
	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
	up_write(&current->mm->mmap_sem);
	if (file)
		fput(file);

out:
	return error;
}


asmlinkage int sys_truncate64(const char *path, unsigned int high,
			      unsigned int low)
{
	if ((int)high < 0)
		return -EINVAL;
	return sys_truncate(path, ((long) high << 32) | low);
}

asmlinkage int sys_ftruncate64(unsigned int fd, unsigned int high,
			       unsigned int low)
{
	if ((int)high < 0)
		return -EINVAL;
	return sys_ftruncate(fd, ((long) high << 32) | low);
}

/*
 * sys_execve() executes a new program.
 */
asmlinkage int sys32_execve(nabi_no_regargs struct pt_regs regs)
{
	int error;
	char * filename;

	filename = getname(compat_ptr(regs.regs[4]));
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = compat_do_execve(filename, compat_ptr(regs.regs[5]),
				 compat_ptr(regs.regs[6]), &regs);
	putname(filename);

out:
	return error;
}

struct dirent32 {
	unsigned int	d_ino;
	unsigned int	d_off;
	unsigned short	d_reclen;
	char		d_name[NAME_MAX + 1];
};

static void
xlate_dirent(void *dirent64, void *dirent32, long n)
{
	long off;
	struct dirent *dirp;
	struct dirent32 *dirp32;

	off = 0;
	while (off < n) {
		dirp = (struct dirent *)(dirent64 + off);
		dirp32 = (struct dirent32 *)(dirent32 + off);
		off += dirp->d_reclen;
		dirp32->d_ino = dirp->d_ino;
		dirp32->d_off = (unsigned int)dirp->d_off;
		dirp32->d_reclen = dirp->d_reclen;
		strncpy(dirp32->d_name, dirp->d_name, dirp->d_reclen - ((3 * 4) + 2));
	}
	return;
}

asmlinkage long
sys32_getdents(unsigned int fd, void * dirent32, unsigned int count)
{
	long n;
	void *dirent64;

	dirent64 = (void *)((unsigned long)(dirent32 + (sizeof(long) - 1)) & ~(sizeof(long) - 1));
	if ((n = sys_getdents(fd, dirent64, count - (dirent64 - dirent32))) < 0)
		return(n);
	xlate_dirent(dirent64, dirent32, n);
	return(n);
}

asmlinkage int old_readdir(unsigned int fd, void * dirent, unsigned int count);

asmlinkage int
sys32_readdir(unsigned int fd, void * dirent32, unsigned int count)
{
	int n;
	struct dirent dirent64;

	if ((n = old_readdir(fd, &dirent64, count)) < 0)
		return(n);
	xlate_dirent(&dirent64, dirent32, dirent64.d_reclen);
	return(n);
}

struct rusage32 {
        struct compat_timeval ru_utime;
        struct compat_timeval ru_stime;
        int    ru_maxrss;
        int    ru_ixrss;
        int    ru_idrss;
        int    ru_isrss;
        int    ru_minflt;
        int    ru_majflt;
        int    ru_nswap;
        int    ru_inblock;
        int    ru_oublock;
        int    ru_msgsnd;
        int    ru_msgrcv;
        int    ru_nsignals;
        int    ru_nvcsw;
        int    ru_nivcsw;
};

static int
put_rusage (struct rusage32 *ru, struct rusage *r)
{
	int err;

	if (verify_area(VERIFY_WRITE, ru, sizeof *ru))
		return -EFAULT;

	err = __put_user (r->ru_utime.tv_sec, &ru->ru_utime.tv_sec);
	err |= __put_user (r->ru_utime.tv_usec, &ru->ru_utime.tv_usec);
	err |= __put_user (r->ru_stime.tv_sec, &ru->ru_stime.tv_sec);
	err |= __put_user (r->ru_stime.tv_usec, &ru->ru_stime.tv_usec);
	err |= __put_user (r->ru_maxrss, &ru->ru_maxrss);
	err |= __put_user (r->ru_ixrss, &ru->ru_ixrss);
	err |= __put_user (r->ru_idrss, &ru->ru_idrss);
	err |= __put_user (r->ru_isrss, &ru->ru_isrss);
	err |= __put_user (r->ru_minflt, &ru->ru_minflt);
	err |= __put_user (r->ru_majflt, &ru->ru_majflt);
	err |= __put_user (r->ru_nswap, &ru->ru_nswap);
	err |= __put_user (r->ru_inblock, &ru->ru_inblock);
	err |= __put_user (r->ru_oublock, &ru->ru_oublock);
	err |= __put_user (r->ru_msgsnd, &ru->ru_msgsnd);
	err |= __put_user (r->ru_msgrcv, &ru->ru_msgrcv);
	err |= __put_user (r->ru_nsignals, &ru->ru_nsignals);
	err |= __put_user (r->ru_nvcsw, &ru->ru_nvcsw);
	err |= __put_user (r->ru_nivcsw, &ru->ru_nivcsw);

	return err;
}

asmlinkage int
sys32_wait4(compat_pid_t pid, unsigned int * stat_addr, int options,
	    struct rusage32 * ru)
{
	if (!ru)
		return sys_wait4(pid, stat_addr, options, NULL);
	else {
		struct rusage r;
		int ret;
		unsigned int status;
		mm_segment_t old_fs = get_fs();

		set_fs(KERNEL_DS);
		ret = sys_wait4(pid, stat_addr ? &status : NULL, options, &r);
		set_fs(old_fs);
		if (put_rusage (ru, &r)) return -EFAULT;
		if (stat_addr && put_user (status, stat_addr))
			return -EFAULT;
		return ret;
	}
}

asmlinkage int
sys32_waitpid(compat_pid_t pid, unsigned int *stat_addr, int options)
{
	return sys32_wait4(pid, stat_addr, options, NULL);
}

struct sysinfo32 {
        s32 uptime;
        u32 loads[3];
        u32 totalram;
        u32 freeram;
        u32 sharedram;
        u32 bufferram;
        u32 totalswap;
        u32 freeswap;
        u16 procs;
	u32 totalhigh;
	u32 freehigh;
	u32 mem_unit;
	char _f[8];
};

asmlinkage int sys32_sysinfo(struct sysinfo32 *info)
{
	struct sysinfo s;
	int ret, err;
	mm_segment_t old_fs = get_fs ();
	
	set_fs (KERNEL_DS);
	ret = sys_sysinfo(&s);
	set_fs (old_fs);
	err = put_user (s.uptime, &info->uptime);
	err |= __put_user (s.loads[0], &info->loads[0]);
	err |= __put_user (s.loads[1], &info->loads[1]);
	err |= __put_user (s.loads[2], &info->loads[2]);
	err |= __put_user (s.totalram, &info->totalram);
	err |= __put_user (s.freeram, &info->freeram);
	err |= __put_user (s.sharedram, &info->sharedram);
	err |= __put_user (s.bufferram, &info->bufferram);
	err |= __put_user (s.totalswap, &info->totalswap);
	err |= __put_user (s.freeswap, &info->freeswap);
	err |= __put_user (s.procs, &info->procs);
	err |= __put_user (s.totalhigh, &info->totalhigh);
	err |= __put_user (s.freehigh, &info->freehigh);
	err |= __put_user (s.mem_unit, &info->mem_unit);
	if (err)
		return -EFAULT;
	return ret;
}

#define RLIM_INFINITY32	0x7fffffff
#define RESOURCE32(x) ((x > RLIM_INFINITY32) ? RLIM_INFINITY32 : x)

struct rlimit32 {
	int	rlim_cur;
	int	rlim_max;
};

#ifdef __MIPSEB__
asmlinkage long sys32_truncate64(const char * path, unsigned long __dummy,
	int length_hi, int length_lo)
#endif
#ifdef __MIPSEL__
asmlinkage long sys32_truncate64(const char * path, unsigned long __dummy,
	int length_lo, int length_hi)
#endif
{
	loff_t length;

	length = ((unsigned long) length_hi << 32) | (unsigned int) length_lo;

	return sys_truncate(path, length);
}

#ifdef __MIPSEB__
asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long __dummy,
	int length_hi, int length_lo)
#endif
#ifdef __MIPSEL__
asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long __dummy,
	int length_lo, int length_hi)
#endif
{
	loff_t length;

	length = ((unsigned long) length_hi << 32) | (unsigned int) length_lo;

	return sys_ftruncate(fd, length);
}

static inline long
get_tv32(struct timeval *o, struct compat_timeval *i)
{
	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
		(__get_user(o->tv_sec, &i->tv_sec) |
		 __get_user(o->tv_usec, &i->tv_usec)));
}

static inline long
put_tv32(struct compat_timeval *o, struct timeval *i)
{
	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
		(__put_user(i->tv_sec, &o->tv_sec) |
		 __put_user(i->tv_usec, &o->tv_usec)));
}

extern struct timezone sys_tz;

asmlinkage int
sys32_gettimeofday(struct compat_timeval *tv, struct timezone *tz)
{
	if (tv) {
		struct timeval ktv;
		do_gettimeofday(&ktv);
		if (put_tv32(tv, &ktv))
			return -EFAULT;
	}
	if (tz) {
		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
			return -EFAULT;
	}
	return 0;
}

static inline long get_ts32(struct timespec *o, struct compat_timeval *i)
{
	long usec;

	if (!access_ok(VERIFY_READ, i, sizeof(*i)))
		return -EFAULT;
	if (__get_user(o->tv_sec, &i->tv_sec))
		return -EFAULT;
	if (__get_user(usec, &i->tv_usec))
		return -EFAULT;
	o->tv_nsec = usec * 1000;
		return 0;
}

asmlinkage int
sys32_settimeofday(struct compat_timeval *tv, struct timezone *tz)
{
	struct timespec kts;
	struct timezone ktz;

 	if (tv) {
		if (get_ts32(&kts, tv))
			return -EFAULT;
	}
	if (tz) {
		if (copy_from_user(&ktz, tz, sizeof(ktz)))
			return -EFAULT;
	}

	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
}

asmlinkage int sys32_llseek(unsigned int fd, unsigned int offset_high,
			    unsigned int offset_low, loff_t * result,
			    unsigned int origin)
{
	return sys_llseek(fd, offset_high, offset_low, result, origin);
}

/* From the Single Unix Spec: pread & pwrite act like lseek to pos + op +
   lseek back to original location.  They fail just like lseek does on
   non-seekable files.  */

asmlinkage ssize_t sys32_pread(unsigned int fd, char * buf,
			       size_t count, u32 unused, u64 a4, u64 a5)
{
	ssize_t ret;
	struct file * file;
	ssize_t (*read)(struct file *, char *, size_t, loff_t *);
	loff_t pos;

	ret = -EBADF;
	file = fget(fd);
	if (!file)
		goto bad_file;
	if (!(file->f_mode & FMODE_READ))
		goto out;
	pos = merge_64(a4, a5);
	ret = rw_verify_area(READ, file, &pos, count);
	if (ret)
		goto out;
	ret = -EINVAL;
	if (!file->f_op || !(read = file->f_op->read))
		goto out;
	if (pos < 0)
		goto out;
	ret = -ESPIPE;
	if (!(file->f_mode & FMODE_PREAD))
		goto out;
	ret = read(file, buf, count, &pos);
	if (ret > 0)
		dnotify_parent(file->f_dentry, DN_ACCESS);
out:
	fput(file);
bad_file:
	return ret;
}