static ssize_t compat_do_readv_writev(int type, struct file *file,
const struct compat_iovec __user *uvector,
unsigned long nr_segs, loff_t *pos)
{
compat_ssize_t tot_len;
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
struct iov_iter iter;
ssize_t ret;
io_fn_t fn;
iov_fn_t fnv;
iter_fn_t iter_fn;
ret = compat_import_iovec(type, uvector, nr_segs,
UIO_FASTIOV, &iov, &iter);
if (ret < 0)
return ret;
tot_len = iov_iter_count(&iter);
if (!tot_len)
goto out;
ret = rw_verify_area(type, file, pos, tot_len);
if (ret < 0)
goto out;
fnv = NULL;
if (type == READ) {
fn = file->f_op->read;
fnv = file->f_op->aio_read;
iter_fn = file->f_op->read_iter;
} else {
fn = (io_fn_t)file->f_op->write;
fnv = file->f_op->aio_write;
iter_fn = file->f_op->write_iter;
file_start_write(file);
}
if (iter_fn)
ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
else if (fnv)
ret = do_sync_readv_writev(file, &iter, pos, fnv);
else
ret = do_loop_readv_writev(file, &iter, pos, fn);
if (type != READ)
file_end_write(file);
out:
kfree(iov);
if ((ret + (type == READ)) > 0) {
if (type == READ)
fsnotify_access(file);
else
fsnotify_modify(file);
}
return ret;
}
int get_compat_msghdr(struct msghdr *kmsg,
struct compat_msghdr __user *umsg,
struct sockaddr __user **save_addr,
struct iovec **iov)
{
compat_uptr_t uaddr, uiov, tmp3;
compat_size_t nr_segs;
ssize_t err;
if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
__get_user(uaddr, &umsg->msg_name) ||
__get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
__get_user(uiov, &umsg->msg_iov) ||
__get_user(nr_segs, &umsg->msg_iovlen) ||
__get_user(tmp3, &umsg->msg_control) ||
__get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
__get_user(kmsg->msg_flags, &umsg->msg_flags))
return -EFAULT;
if (!uaddr)
kmsg->msg_namelen = 0;
if (kmsg->msg_namelen < 0)
return -EINVAL;
if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
kmsg->msg_namelen = sizeof(struct sockaddr_storage);
kmsg->msg_control = compat_ptr(tmp3);
if (save_addr)
*save_addr = compat_ptr(uaddr);
if (uaddr && kmsg->msg_namelen) {
if (!save_addr) {
err = move_addr_to_kernel(compat_ptr(uaddr),
kmsg->msg_namelen,
kmsg->msg_name);
if (err < 0)
return err;
}
} else {
kmsg->msg_name = NULL;
kmsg->msg_namelen = 0;
}
if (nr_segs > UIO_MAXIOV)
return -EMSGSIZE;
kmsg->msg_iocb = NULL;
return compat_import_iovec(save_addr ? READ : WRITE,
compat_ptr(uiov), nr_segs,
UIO_FASTIOV, iov, &kmsg->msg_iter);
}
static size_t compat_readv(struct file *file,
const struct compat_iovec __user *vec,
unsigned long vlen, loff_t *pos, rwf_t flags)
{
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
struct iov_iter iter;
ssize_t ret;
ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
if (ret >= 0) {
ret = do_iter_read(file, &iter, pos, flags);
kfree(iov);
}
if (ret > 0)
add_rchar(current, ret);
inc_syscr(current);
return ret;
}
static ssize_t
compat_process_vm_rw(compat_pid_t pid,
const struct compat_iovec __user *lvec,
unsigned long liovcnt,
const struct compat_iovec __user *rvec,
unsigned long riovcnt,
unsigned long flags, int vm_write)
{
struct iovec iovstack_l[UIO_FASTIOV];
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
struct iov_iter iter;
ssize_t rc = -EFAULT;
int dir = vm_write ? WRITE : READ;
if (flags != 0)
return -EINVAL;
rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
if (rc < 0)
return rc;
if (!iov_iter_count(&iter))
goto free_iovecs;
rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
UIO_FASTIOV, iovstack_r,
&iov_r);
if (rc <= 0)
goto free_iovecs;
rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
kfree(iov_r);
kfree(iov_l);
return rc;
}
