sys_ia32.c

linux 内核源代码

 */
static long
mprotect_subpage (unsigned long address, int new_prot)
{
	int old_prot;
	struct vm_area_struct *vma;

	if (new_prot == PROT_NONE)
		return 0;		/* optimize case where nothing changes... */
	vma = find_vma(current->mm, address);
	old_prot = get_page_prot(vma, address);
	return sys_mprotect(address, PAGE_SIZE, new_prot | old_prot);
}

#endif /* PAGE_SHIFT > IA32_PAGE_SHIFT */

asmlinkage long
sys32_mprotect (unsigned int start, unsigned int len, int prot)
{
	unsigned int end = start + len;
#if PAGE_SHIFT > IA32_PAGE_SHIFT
	long retval = 0;
#endif

	prot = get_prot32(prot);

#if PAGE_SHIFT <= IA32_PAGE_SHIFT
	return sys_mprotect(start, end - start, prot);
#else
	if (OFFSET4K(start))
		return -EINVAL;

	end = IA32_PAGE_ALIGN(end);
	if (end < start)
		return -EINVAL;

	retval = ia32_compare_pp(&start, &end);

	if (retval < 0)
		return retval;

	mutex_lock(&ia32_mmap_mutex);
	{
		if (offset_in_page(start)) {
			/* start address is 4KB aligned but not page aligned. */
			retval = mprotect_subpage(PAGE_START(start), prot);
			if (retval < 0)
				goto out;

			start = PAGE_ALIGN(start);
			if (start >= end)
				goto out;	/* retval is already zero... */
		}

		if (offset_in_page(end)) {
			/* end address is 4KB aligned but not page aligned. */
			retval = mprotect_subpage(PAGE_START(end), prot);
			if (retval < 0)
				goto out;

			end = PAGE_START(end);
		}
		retval = sys_mprotect(start, end - start, prot);
	}
  out:
	mutex_unlock(&ia32_mmap_mutex);
	return retval;
#endif
}

asmlinkage long
sys32_mremap (unsigned int addr, unsigned int old_len, unsigned int new_len,
		unsigned int flags, unsigned int new_addr)
{
	long ret;

#if PAGE_SHIFT <= IA32_PAGE_SHIFT
	ret = sys_mremap(addr, old_len, new_len, flags, new_addr);
#else
	unsigned int old_end, new_end;

	if (OFFSET4K(addr))
		return -EINVAL;

	old_len = IA32_PAGE_ALIGN(old_len);
	new_len = IA32_PAGE_ALIGN(new_len);
	old_end = addr + old_len;
	new_end = addr + new_len;

	if (!new_len)
		return -EINVAL;

	if ((flags & MREMAP_FIXED) && (OFFSET4K(new_addr)))
		return -EINVAL;

	if (old_len >= new_len) {
		ret = sys32_munmap(addr + new_len, old_len - new_len);
		if (ret && old_len != new_len)
			return ret;
		ret = addr;
		if (!(flags & MREMAP_FIXED) || (new_addr == addr))
			return ret;
		old_len = new_len;
	}

	addr = PAGE_START(addr);
	old_len = PAGE_ALIGN(old_end) - addr;
	new_len = PAGE_ALIGN(new_end) - addr;

	mutex_lock(&ia32_mmap_mutex);
	ret = sys_mremap(addr, old_len, new_len, flags, new_addr);
	mutex_unlock(&ia32_mmap_mutex);

	if ((ret >= 0) && (old_len < new_len)) {
		/* mremap expanded successfully */
		ia32_set_pp(old_end, new_end, flags);
	}
#endif
	return ret;
}

asmlinkage long
sys32_pipe (int __user *fd)
{
	int retval;
	int fds[2];

	retval = do_pipe(fds);
	if (retval)
		goto out;
	if (copy_to_user(fd, fds, sizeof(fds)))
		retval = -EFAULT;
  out:
	return retval;
}

static inline long
get_tv32 (struct timeval *o, struct compat_timeval __user *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 __user *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)));
}

asmlinkage unsigned long
sys32_alarm (unsigned int seconds)
{
	return alarm_setitimer(seconds);
}

/* Translations due to time_t size differences.  Which affects all
   sorts of things, like timeval and itimerval.  */

extern struct timezone sys_tz;

asmlinkage long
sys32_gettimeofday (struct compat_timeval __user *tv, struct timezone __user *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;
}

asmlinkage long
sys32_settimeofday (struct compat_timeval __user *tv, struct timezone __user *tz)
{
	struct timeval ktv;
	struct timespec kts;
	struct timezone ktz;

	if (tv) {
		if (get_tv32(&ktv, tv))
			return -EFAULT;
		kts.tv_sec = ktv.tv_sec;
		kts.tv_nsec = ktv.tv_usec * 1000;
	}
	if (tz) {
		if (copy_from_user(&ktz, tz, sizeof(ktz)))
			return -EFAULT;
	}

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

struct getdents32_callback {
	struct compat_dirent __user *current_dir;
	struct compat_dirent __user *previous;
	int count;
	int error;
};

struct readdir32_callback {
	struct old_linux32_dirent __user * dirent;
	int count;
};

static int
filldir32 (void *__buf, const char *name, int namlen, loff_t offset, u64 ino,
	   unsigned int d_type)
{
	struct compat_dirent __user * dirent;
	struct getdents32_callback * buf = (struct getdents32_callback *) __buf;
	int reclen = ROUND_UP(offsetof(struct compat_dirent, d_name) + namlen + 1, 4);
	u32 d_ino;

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
		return -EOVERFLOW;
	buf->error = -EFAULT;	/* only used if we fail.. */
	dirent = buf->previous;
	if (dirent)
		if (put_user(offset, &dirent->d_off))
			return -EFAULT;
	dirent = buf->current_dir;
	buf->previous = dirent;
	if (put_user(d_ino, &dirent->d_ino)
	    || put_user(reclen, &dirent->d_reclen)
	    || copy_to_user(dirent->d_name, name, namlen)
	    || put_user(0, dirent->d_name + namlen))
		return -EFAULT;
	dirent = (struct compat_dirent __user *) ((char __user *) dirent + reclen);
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
}

asmlinkage long
sys32_getdents (unsigned int fd, struct compat_dirent __user *dirent, unsigned int count)
{
	struct file * file;
	struct compat_dirent __user * lastdirent;
	struct getdents32_callback buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, filldir32, &buf);
	if (error < 0)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}

static int
fillonedir32 (void * __buf, const char * name, int namlen, loff_t offset, u64 ino,
	      unsigned int d_type)
{
	struct readdir32_callback * buf = (struct readdir32_callback *) __buf;
	struct old_linux32_dirent __user * dirent;
	u32 d_ino;

	if (buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
		return -EOVERFLOW;
	buf->count++;
	dirent = buf->dirent;
	if (put_user(d_ino, &dirent->d_ino)
	    || put_user(offset, &dirent->d_offset)
	    || put_user(namlen, &dirent->d_namlen)
	    || copy_to_user(dirent->d_name, name, namlen)
	    || put_user(0, dirent->d_name + namlen))
		return -EFAULT;
	return 0;
}

asmlinkage long
sys32_readdir (unsigned int fd, void __user *dirent, unsigned int count)
{
	int error;
	struct file * file;
	struct readdir32_callback buf;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.count = 0;
	buf.dirent = dirent;

	error = vfs_readdir(file, fillonedir32, &buf);
	if (error >= 0)
		error = buf.count;
	fput(file);
out:
	return error;
}

struct sel_arg_struct {
	unsigned int n;
	unsigned int inp;
	unsigned int outp;
	unsigned int exp;
	unsigned int tvp;
};

asmlinkage long
sys32_old_select (struct sel_arg_struct __user *arg)
{
	struct sel_arg_struct a;

	if (copy_from_user(&a, arg, sizeof(a)))
		return -EFAULT;
	return compat_sys_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),
				 compat_ptr(a.exp), compat_ptr(a.tvp));
}

#define SEMOP		 1
#define SEMGET		 2
#define SEMCTL		 3
#define SEMTIMEDOP	 4
#define MSGSND		11
#define MSGRCV		12
#define MSGGET		13
#define MSGCTL		14
#define SHMAT		21
#define SHMDT		22
#define SHMGET		23
#define SHMCTL		24

asmlinkage long
sys32_ipc(u32 call, int first, int second, int third, u32 ptr, u32 fifth)
{
	int version;

	version = call >> 16; /* hack for backward compatibility */
	call &= 0xffff;

	switch (call) {
	      case SEMTIMEDOP:
		if (fifth)
			return compat_sys_semtimedop(first, compat_ptr(ptr),
				second, compat_ptr(fifth));
		/* else fall through for normal semop() */
	      case SEMOP:
		/* struct sembuf is the same on 32 and 64bit :)) */
		return sys_semtimedop(first, compat_ptr(ptr), second,
				      NULL);
	      case SEMGET:
		return sys_semget(first, second, third);
	      case SEMCTL:
		return compat_sys_semctl(first, second, third, compat_ptr(ptr));

	      case MSGSND:
		return compat_sys_msgsnd(first, second, third, compat_ptr(ptr));
	      case MSGRCV:
		return compat_sys_msgrcv(first, second, fifth, third, version, compat_ptr(ptr));
	      case MSGGET:
		return sys_msgget((key_t) first, second);
	      case MSGCTL:
		return compat_sys_msgctl(first, second, compat_ptr(ptr));

	      case SHMAT:
		return compat_sys_shmat(first, second, third, version, compat_ptr(ptr));
		break;
	      case SHMDT:
		return sys_shmdt(compat_ptr(ptr));
	      case SHMGET:
		return sys_shmget(first, (unsigned)second, third);
	      case SHMCTL:
		return compat_sys_shmctl(first, second, compat_ptr(ptr));

	      default:
		return -ENOSYS;
	}
	return -EINVAL;
}

asmlinkage long
compat_sys_wait4 (compat_pid_t pid, compat_uint_t * stat_addr, int options,
		 struct compat_rusage *ru);

asmlinkage long
sys32_waitpid (int pid, unsigned int *stat_addr, int options)
{
	return compat_sys_wait4(pid, stat_addr, options, NULL);
}

static unsigned int
ia32_peek (struct task_struct *child, unsigned long addr, unsigned int *val)
{
	size_t copied;
	unsigned int ret;

	copied = access_process_vm(child, addr, val, sizeof(*val), 0);
	return (copied != sizeof(ret)) ? -EIO : 0;
}

static unsigned int
ia32_poke (struct task_struct *child, unsigned long addr, unsigned int val)
{

	if (access_process_vm(child, addr, &val, sizeof(val), 1) != sizeof(val))
		return -EIO;
	return 0;
}

/*
 *  The order in which registers are stored in the ptrace regs structure
 */
#define PT_EBX	0
#define PT_ECX	1
#define PT_EDX	2
#define PT_ESI	3
#define PT_EDI	4
#define PT_EBP	5
#define PT_EAX	6
#define PT_DS	7
#define PT_ES	8
#define PT_FS	9
#define PT_GS	10
#define PT_ORIG_EAX 11
#define PT_EIP	12
#define PT_CS	13
#define PT_EFL	14
#define PT_UESP	15
#define PT_SS	16

static unsigned int
getreg (struct task_struct *child, int regno)
{
	struct pt_regs *child_regs;

	child_regs = task_pt_regs(child);
	switch (regno / sizeof(int)) {
	      case PT_EBX: return child_regs->r11;
	      case PT_ECX: return child_regs->r9;
	      case PT_EDX: return child_regs->r10;
	      case PT_ESI: return child_regs->r14;
	      case PT_EDI: return child_regs->r15;
	      case PT_EBP: return child_regs->r13;
	      case PT_EAX: return child_regs->r8;
	      case PT_ORIG_EAX: return child_regs->r1; /* see dispatch_to_ia32_handler() */
	      case PT_EIP: return child_regs->cr_iip;
	      case PT_UESP: return child_regs->r12;
	      case PT_EFL: return child->thread.eflag;
	      case PT_DS: case PT_ES: case PT_FS: case PT_GS: case PT_SS:
		return __USER_DS;
	      case PT_CS: return __USER_CS;
	      default:
		printk(KERN_ERR "ia32.getreg(): unknown register %d\n", regno);
		break;
	}
	return 0;
}

static void
putreg (struct task_struct *child, int regno, unsigned int value)
{
	struct pt_regs *child_regs;

	child_regs = task_pt_regs(child);
	switch (regno / sizeof(int)) {
	      case PT_EBX: child_regs->r11 = value; break;
	      case PT_ECX: child_regs->r9 = value; break;
	      case PT_EDX: child_regs->r10 = value; break;
	      case PT_ESI: child_regs->r14 = value; break;
	      case PT_EDI: child_regs->r15 = value; break;
	      case PT_EBP: child_regs->r13 = value; break;
	      case PT_EAX: child_regs->r8 = value; break;
	      case PT_ORIG_EAX: child_regs->r1 = value; break;
	      case PT_EIP: child_regs->cr_iip = value; break;
	      case PT_UESP: child_regs->r12 = value; break;
	      case PT_EFL: child->thread.eflag = value; break;
	      case PT_DS: case PT_ES: case PT_FS: case PT_GS: case PT_SS:
		if (value != __USER_DS)
			printk(KERN_ERR