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[media] ngene: properly handle __user ptr

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Sparse is complaining about ngene's bad usage of a __user ptr:

>> drivers/media/pci/ngene/ngene-dvb.c:62:48: sparse: incorrect type in argument 2 (different address spaces)
   drivers/media/pci/ngene/ngene-dvb.c:62:48:    expected unsigned char const [usertype] *buf
   drivers/media/pci/ngene/ngene-dvb.c:62:48:    got char const [noderef] <asn:1>*buf

As this is intercepting a .write() file ops, we can't just memcpy. We need to use
copy_from_user.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Mauro Carvalho Chehab 2014-09-03 20:44:04 -03:00
parent ce9e1ac1b9
commit 04da2daee3
3 changed files with 29 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
drivers/media/dvb-core/dvb_ringbuffer.c
View file

@ -166,6 +166,31 @@ ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t
return len;
}
ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
const u8 __user *buf, size_t len)
{
int status;
size_t todo = len;
size_t split;
split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0;
if (split > 0) {
status = copy_from_user(rbuf->data+rbuf->pwrite, buf, split);
if (status)
return len - todo;
buf += split;
todo -= split;
rbuf->pwrite = 0;
}
status = copy_from_user(rbuf->data+rbuf->pwrite, buf, todo);
if (status)
return len - todo;
rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
return len;
}
ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t len)
{
int status;
@ -297,3 +322,4 @@ EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup);
EXPORT_SYMBOL(dvb_ringbuffer_read_user);
EXPORT_SYMBOL(dvb_ringbuffer_read);
EXPORT_SYMBOL(dvb_ringbuffer_write);
EXPORT_SYMBOL(dvb_ringbuffer_write_user);

2
drivers/media/dvb-core/dvb_ringbuffer.h
View file

@ -133,6 +133,8 @@ extern void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf,
*/
extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf,
size_t len);
extern ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
const u8 __user *buf, size_t len);
/**

2
drivers/media/pci/ngene/ngene-dvb.c
View file

@ -59,7 +59,7 @@ static ssize_t ts_write(struct file *file, const char __user *buf,
(&dev->tsout_rbuf) >= count) < 0)
return 0;
dvb_ringbuffer_write(&dev->tsout_rbuf, buf, count);
dvb_ringbuffer_write_user(&dev->tsout_rbuf, buf, count);
return count;
}