From 04da2daee383391954b34e7d0fe0281d75447d61 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 3 Sep 2014 20:44:04 -0300 Subject: [PATCH] [media] ngene: properly handle __user ptr 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] *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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-core/dvb_ringbuffer.c | 26 +++++++++++++++++++++++++ drivers/media/dvb-core/dvb_ringbuffer.h | 2 ++ drivers/media/pci/ngene/ngene-dvb.c | 2 +- 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/media/dvb-core/dvb_ringbuffer.c b/drivers/media/dvb-core/dvb_ringbuffer.c index a5712cd7c65f..1100e98a7b1d 100644 --- a/drivers/media/dvb-core/dvb_ringbuffer.c +++ b/drivers/media/dvb-core/dvb_ringbuffer.c @@ -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); diff --git a/drivers/media/dvb-core/dvb_ringbuffer.h b/drivers/media/dvb-core/dvb_ringbuffer.h index 41f04dae69b6..9e1e11b7c39c 100644 --- a/drivers/media/dvb-core/dvb_ringbuffer.h +++ b/drivers/media/dvb-core/dvb_ringbuffer.h @@ -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); /** diff --git a/drivers/media/pci/ngene/ngene-dvb.c b/drivers/media/pci/ngene/ngene-dvb.c index a8a4045f66d7..59bb2858c8d0 100644 --- a/drivers/media/pci/ngene/ngene-dvb.c +++ b/drivers/media/pci/ngene/ngene-dvb.c @@ -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; }