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authorDan Carpenter <error27@gmail.com>2010-05-04 14:14:29 +0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-05-19 17:59:05 +0200
commit32ec4576c3fb37316b1d11a04b220527822f3f0d (patch)
treeb6e8d8e6574cca08c6f19e29bcaca6b8af1aa830 /drivers/media
parentV4L/DVB: media/IR/imon: potential double unlock on error (diff)
downloadlinux-32ec4576c3fb37316b1d11a04b220527822f3f0d.tar.xz
linux-32ec4576c3fb37316b1d11a04b220527822f3f0d.zip
V4L/DVB: media/az6027: doing dma on the stack
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>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/dvb/dvb-usb/az6027.c50
1 files changed, 41 insertions, 9 deletions
diff --git a/drivers/media/dvb/dvb-usb/az6027.c b/drivers/media/dvb/dvb-usb/az6027.c
index 8934788bd83b..baaa301c5768 100644
--- a/drivers/media/dvb/dvb-usb/az6027.c
+++ b/drivers/media/dvb/dvb-usb/az6027.c
@@ -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;
+
+ data = kmalloc(256, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
- if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
+ 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;
}