redonkable/alistair23-linux
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V4L/DVB: media/az6027: doing dma on the stack

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I changed the dma buffers to use allocated memory instead of stack
memory.

The reason for this is documented in Documentation/DMA-API-HOWTO.txt
under the section:  "What memory is DMA'able?"  That document was only
added a couple weeks ago and there are still lots of modules which
haven't been corrected yet.  Btw. Smatch includes a pretty good test to
find places which use stack memory as a dma buffer.  That's how I found
these.  (http://smatch.sf.net).

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Dan Carpenter 2010-05-04 09:14:29 -03:00 committed by Mauro Carvalho Chehab
parent 9723dbb034
commit 32ec4576c3
1 changed files with 41 additions and 9 deletions
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50
drivers/media/dvb/dvb-usb/az6027.c
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@ -417,11 +417,15 @@ static int az6027_ci_read_attribute_mem(struct dvb_ca_en50221 *ca,
u16 value;
u16 index;
int blen;
u8 b[12];
u8 *b;
if (slot != 0)
return -EINVAL;
b = kmalloc(12, GFP_KERNEL);
if (!b)
return -ENOMEM;
mutex_lock(&state->ca_mutex);
req = 0xC1;
@ -438,6 +442,7 @@ static int az6027_ci_read_attribute_mem(struct dvb_ca_en50221 *ca,
}
mutex_unlock(&state->ca_mutex);
kfree(b);
return ret;
}
@ -485,11 +490,15 @@ static int az6027_ci_read_cam_control(struct dvb_ca_en50221 *ca,
u16 value;
u16 index;
int blen;
u8 b[12];
u8 *b;
if (slot != 0)
return -EINVAL;
b = kmalloc(12, GFP_KERNEL);
if (!b)
return -ENOMEM;
mutex_lock(&state->ca_mutex);
req = 0xC3;
@ -510,6 +519,7 @@ static int az6027_ci_read_cam_control(struct dvb_ca_en50221 *ca,
}
mutex_unlock(&state->ca_mutex);
kfree(b);
return ret;
}
@ -556,7 +566,11 @@ static int CI_CamReady(struct dvb_ca_en50221 *ca, int slot)
u16 value;
u16 index;
int blen;
u8 b[12];
u8 *b;
b = kmalloc(12, GFP_KERNEL);
if (!b)
return -ENOMEM;
req = 0xC8;
value = 0;
@ -570,6 +584,7 @@ static int CI_CamReady(struct dvb_ca_en50221 *ca, int slot)
} else{
ret = b[0];
}
kfree(b);
return ret;
}
@ -667,8 +682,11 @@ static int az6027_ci_poll_slot_status(struct dvb_ca_en50221 *ca, int slot, int o
u16 value;
u16 index;
int blen;
u8 b[12];
u8 *b;
b = kmalloc(12, GFP_KERNEL);
if (!b)
return -ENOMEM;
mutex_lock(&state->ca_mutex);
req = 0xC5;
@ -692,6 +710,7 @@ static int az6027_ci_poll_slot_status(struct dvb_ca_en50221 *ca, int slot, int o
}
mutex_unlock(&state->ca_mutex);
kfree(b);
return ret;
}
@ -943,10 +962,16 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n
u16 value;
int length;
u8 req;
u8 data[256];
u8 *data;
if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
data = kmalloc(256, GFP_KERNEL);
if (!data)
return -ENOMEM;
if (mutex_lock_interruptible(&d->i2c_mutex) < 0) {
kfree(data);
return -EAGAIN;
}
if (num > 2)
warn("more than 2 i2c messages at a time is not handled yet. TODO.");
@ -1016,6 +1041,7 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n
}
}
mutex_unlock(&d->i2c_mutex);
kfree(data);
return i;
}
@ -1036,8 +1062,14 @@ int az6027_identify_state(struct usb_device *udev,
struct dvb_usb_device_description **desc,
int *cold)
{
u8 b[16];
s16 ret = usb_control_msg(udev,
u8 *b;
s16 ret;
b = kmalloc(16, GFP_KERNEL);
if (!b)
return -ENOMEM;
ret = usb_control_msg(udev,
usb_rcvctrlpipe(udev, 0),
0xb7,
USB_TYPE_VENDOR | USB_DIR_IN,
@ -1048,7 +1080,7 @@ int az6027_identify_state(struct usb_device *udev,
USB_CTRL_GET_TIMEOUT);
*cold = ret <= 0;
kfree(b);
deb_info("cold: %d\n", *cold);
return 0;
}