serial2002: switch serial2002_tty_write to kernel_{read/write}

Instead of playing games with the address limit.  This also gains
us proper usage of the write counter, time stamp updates and kvec
validation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2017-09-01 17:39:16 +02:00 committed by Al Viro
parent 73e18f7c0b
commit 9a779bc149

View File

@ -106,16 +106,8 @@ static long serial2002_tty_ioctl(struct file *f, unsigned int op,
static int serial2002_tty_write(struct file *f, unsigned char *buf, int count)
{
const char __user *p = (__force const char __user *)buf;
int result;
loff_t offset = 0;
mm_segment_t oldfs;
oldfs = get_fs();
set_fs(KERNEL_DS);
result = __vfs_write(f, p, count, &offset);
set_fs(oldfs);
return result;
loff_t pos = 0;
return kernel_write(f, buf, count, &pos);
}
static void serial2002_tty_read_poll_wait(struct file *f, int timeout)
@ -148,19 +140,14 @@ static int serial2002_tty_read(struct file *f, int timeout)
{
unsigned char ch;
int result;
loff_t pos = 0;
result = -1;
if (!IS_ERR(f)) {
mm_segment_t oldfs;
char __user *p = (__force char __user *)&ch;
loff_t offset = 0;
oldfs = get_fs();
set_fs(KERNEL_DS);
if (f->f_op->poll) {
serial2002_tty_read_poll_wait(f, timeout);
if (__vfs_read(f, p, 1, &offset) == 1)
if (kernel_read(f, &ch, 1, &pos) == 1)
result = ch;
} else {
/* Device does not support poll, busy wait */
@ -171,14 +158,13 @@ static int serial2002_tty_read(struct file *f, int timeout)
if (retries >= timeout)
break;
if (__vfs_read(f, p, 1, &offset) == 1) {
if (kernel_read(f, &ch, 1, &pos) == 1) {
result = ch;
break;
}
usleep_range(100, 1000);
}
}
set_fs(oldfs);
}
return result;
}