[PATCH 4.10 20/48] [media] dw2102: dont do DMA on stack

Greg Kroah-Hartman
2017-03-16T14:39:32Z

From: Jonathan McDowell <noodles@earth.li>

commit 606142af57dad981b78707234cfbd15f9f7b7125 upstream.

On Kernel 4.9, WARNINGs about doing DMA on stack are hit at
the dw2102 driver: one in su3000_power_ctrl() and the other in tt_s2_4600_frontend_attach().

Both were due to the use of buffers on the stack as parameters to
dvb_usb_generic_rw() and the resulting attempt to do DMA with them.

The device was non-functional as a result.

So, switch this driver over to use a buffer within the device state
structure, as has been done with other DVB-USB drivers.

Tested with TechnoTrend TT-connect S2-4600.

[mchehab@osg.samsung.com: fixed a warning at su3000_i2c_transfer() that
state var were dereferenced before check 'd']
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/dvb-usb/dw2102.c | 242 ++++++++++++++++++++++---------------
1 file changed, 144 insertions(+), 98 deletions(-)

--- a/drivers/media/usb/dvb-usb/dw2102.c
+++ b/drivers/media/usb/dvb-usb/dw2102.c
@@ -68,6 +68,7 @@
struct dw2102_state {
u8 initialized;
u8 last_lock;
+ u8 data[MAX_XFER_SIZE + 4];
struct i2c_client *i2c_client_demod;
struct i2c_client *i2c_client_tuner;

@@ -661,62 +662,72 @@ static int su3000_i2c_transfer(struct i2
int num)
{
struct dvb_usb_device *d = i2c_get_adapdata(adap);
- u8 obuf[0x40], ibuf[0x40];
+ struct dw2102_state *state;

if (!d)
return -ENODEV;
+
+ state = d->priv;
+
if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
return -EAGAIN;
+ if (mutex_lock_interruptible(&d->data_mutex) < 0) {
+ mutex_unlock(&d->i2c_mutex);
+ return -EAGAIN;
+ }

switch (num) {
case 1:
switch (msg[0].addr) {
case SU3000_STREAM_CTRL:
- obuf[0] = msg[0].buf[0] + 0x36;
- obuf[1] = 3;
- obuf[2] = 0;
- if (dvb_usb_generic_rw(d, obuf, 3, ibuf, 0, 0) < 0)
+ state->data[0] = msg[0].buf[0] + 0x36;
+ state->data[1] = 3;
+ state->data[2] = 0;
+ if (dvb_usb_generic_rw(d, state->data, 3,
+ state->data, 0, 0) < 0)
err("i2c transfer failed.");
break;
case DW2102_RC_QUERY:
- obuf[0] = 0x10;
- if (dvb_usb_generic_rw(d, obuf, 1, ibuf, 2, 0) < 0)
+ state->data[0] = 0x10;
+ if (dvb_usb_generic_rw(d, state->data, 1,
+ state->data, 2, 0) < 0)
err("i2c transfer failed.");
- msg[0].buf[1] = ibuf[0];
- msg[0].buf[0] = ibuf[1];
+ msg[0].buf[1] = state->data[0];
+ msg[0].buf[0] = state->data[1];
break;
default:
/* always i2c write*/
- obuf[0] = 0x08;
- obuf[1] = msg[0].addr;
- obuf[2] = msg[0].len;
+ state->data[0] = 0x08;
+ state->data[1] = msg[0].addr;
+ state->data[2] = msg[0].len;

- memcpy(&obuf[3], msg[0].buf, msg[0].len);
+ memcpy(&state->data[3], msg[0].buf, msg[0].len);

- if (dvb_usb_generic_rw(d, obuf, msg[0].len + 3,
- ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, msg[0].len + 3,
+ state->data, 1, 0) < 0)
err("i2c transfer failed.");

}
break;
case 2:
/* always i2c read */
- obuf[0] = 0x09;
- obuf[1] = msg[0].len;
- obuf[2] = msg[1].len;
- obuf[3] = msg[0].addr;
- memcpy(&obuf[4], msg[0].buf, msg[0].len);
+ state->data[0] = 0x09;
+ state->data[1] = msg[0].len;
+ state->data[2] = msg[1].len;
+ state->data[3] = msg[0].addr;
+ memcpy(&state->data[4], msg[0].buf, msg[0].len);

- if (dvb_usb_generic_rw(d, obuf, msg[0].len + 4,
- ibuf, msg[1].len + 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, msg[0].len + 4,
+ state->data, msg[1].len + 1, 0) < 0)
err("i2c transfer failed.");

- memcpy(msg[1].buf, &ibuf[1], msg[1].len);
+ memcpy(msg[1].buf, &state->data[1], msg[1].len);
break;
default:
warn("more than 2 i2c messages at a time is not handled yet.");
break;
}
+ mutex_unlock(&d->data_mutex);
mutex_unlock(&d->i2c_mutex);
return num;
}
@@ -844,17 +855,23 @@ static int su3000_streaming_ctrl(struct
static int su3000_power_ctrl(struct dvb_usb_device *d, int i)
{
struct dw2102_state *state = (struct dw2102_state *)d->priv;
- u8 obuf[] = {0xde, 0};
+ int ret = 0;

info("%s: %d, initialized %d", __func__, i, state->initialized);

if (i && !state->initialized) {
+ mutex_lock(&d->data_mutex);
+
+ state->data[0] = 0xde;
+ state->data[1] = 0;
+
state->initialized = 1;
/* reset board */
- return dvb_usb_generic_rw(d, obuf, 2, NULL, 0, 0);
+ ret = dvb_usb_generic_rw(d, state->data, 2, NULL, 0, 0);
+ mutex_unlock(&d->data_mutex);
}

- return 0;
+ return ret;
}

static int su3000_read_mac_address(struct dvb_usb_device *d, u8 mac[6])
@@ -1309,49 +1326,57 @@ static int prof_7500_frontend_attach(str
return 0;
}

-static int su3000_frontend_attach(struct dvb_usb_adapter *d)
+static int su3000_frontend_attach(struct dvb_usb_adapter *adap)
{
- u8 obuf[3] = { 0xe, 0x80, 0 };
- u8 ibuf[] = { 0 };
+ struct dvb_usb_device *d = adap->dev;
+ struct dw2102_state *state = d->priv;
+
+ mutex_lock(&d->data_mutex);

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ state->data[0] = 0xe;
+ state->data[1] = 0x80;
+ state->data[2] = 0;
+
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x02;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x02;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");
msleep(300);

- obuf[0] = 0xe;
- obuf[1] = 0x83;
- obuf[2] = 0;
+ state->data[0] = 0xe;
+ state->data[1] = 0x83;
+ state->data[2] = 0;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x83;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x83;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0x51;
+ state->data[0] = 0x51;

- if (dvb_usb_generic_rw(d->dev, obuf, 1, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 1, state->data, 1, 0) < 0)
err("command 0x51 transfer failed.");

- d->fe_adap[0].fe = dvb_attach(ds3000_attach, &su3000_ds3000_config,
- &d->dev->i2c_adap);
- if (d->fe_adap[0].fe == NULL)
+ mutex_unlock(&d->data_mutex);
+
+ adap->fe_adap[0].fe = dvb_attach(ds3000_attach, &su3000_ds3000_config,
+ &d->i2c_adap);
+ if (adap->fe_adap[0].fe == NULL)
return -EIO;

- if (dvb_attach(ts2020_attach, d->fe_adap[0].fe,
+ if (dvb_attach(ts2020_attach, adap->fe_adap[0].fe,
&dw2104_ts2020_config,
- &d->dev->i2c_adap)) {
+ &d->i2c_adap)) {
info("Attached DS3000/TS2020!");
return 0;
}
@@ -1360,47 +1385,55 @@ static int su3000_frontend_attach(struct
return -EIO;
}

-static int t220_frontend_attach(struct dvb_usb_adapter *d)
+static int t220_frontend_attach(struct dvb_usb_adapter *adap)
{
- u8 obuf[3] = { 0xe, 0x87, 0 };
- u8 ibuf[] = { 0 };
+ struct dvb_usb_device *d = adap->dev;
+ struct dw2102_state *state = d->priv;
+
+ mutex_lock(&d->data_mutex);

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ state->data[0] = 0xe;
+ state->data[1] = 0x87;
+ state->data[2] = 0x0;
+
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x86;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x86;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x80;
- obuf[2] = 0;
+ state->data[0] = 0xe;
+ state->data[1] = 0x80;
+ state->data[2] = 0;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

msleep(50);

- obuf[0] = 0xe;
- obuf[1] = 0x80;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x80;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d->dev, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0x51;
+ state->data[0] = 0x51;

- if (dvb_usb_generic_rw(d->dev, obuf, 1, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 1, state->data, 1, 0) < 0)
err("command 0x51 transfer failed.");

- d->fe_adap[0].fe = dvb_attach(cxd2820r_attach, &cxd2820r_config,
- &d->dev->i2c_adap, NULL);
- if (d->fe_adap[0].fe != NULL) {
- if (dvb_attach(tda18271_attach, d->fe_adap[0].fe, 0x60,
- &d->dev->i2c_adap, &tda18271_config)) {
+ mutex_unlock(&d->data_mutex);
+
+ adap->fe_adap[0].fe = dvb_attach(cxd2820r_attach, &cxd2820r_config,
+ &d->i2c_adap, NULL);
+ if (adap->fe_adap[0].fe != NULL) {
+ if (dvb_attach(tda18271_attach, adap->fe_adap[0].fe, 0x60,
+ &d->i2c_adap, &tda18271_config)) {
info("Attached TDA18271HD/CXD2820R!");
return 0;
}
@@ -1410,23 +1443,30 @@ static int t220_frontend_attach(struct d
return -EIO;
}

-static int m88rs2000_frontend_attach(struct dvb_usb_adapter *d)
+static int m88rs2000_frontend_attach(struct dvb_usb_adapter *adap)
{
- u8 obuf[] = { 0x51 };
- u8 ibuf[] = { 0 };
+ struct dvb_usb_device *d = adap->dev;
+ struct dw2102_state *state = d->priv;
+
+ mutex_lock(&d->data_mutex);

- if (dvb_usb_generic_rw(d->dev, obuf, 1, ibuf, 1, 0) < 0)
+ state->data[0] = 0x51;
+
+ if (dvb_usb_generic_rw(d, state->data, 1, state->data, 1, 0) < 0)
err("command 0x51 transfer failed.");

- d->fe_adap[0].fe = dvb_attach(m88rs2000_attach, &s421_m88rs2000_config,
- &d->dev->i2c_adap);
+ mutex_unlock(&d->data_mutex);

- if (d->fe_adap[0].fe == NULL)
+ adap->fe_adap[0].fe = dvb_attach(m88rs2000_attach,
+ &s421_m88rs2000_config,
+ &d->i2c_adap);
+
+ if (adap->fe_adap[0].fe == NULL)
return -EIO;

- if (dvb_attach(ts2020_attach, d->fe_adap[0].fe,
+ if (dvb_attach(ts2020_attach, adap->fe_adap[0].fe,
&dw2104_ts2020_config,
- &d->dev->i2c_adap)) {
+ &d->i2c_adap)) {
info("Attached RS2000/TS2020!");
return 0;
}
@@ -1439,44 +1479,50 @@ static int tt_s2_4600_frontend_attach(st
{
struct dvb_usb_device *d = adap->dev;
struct dw2102_state *state = d->priv;
- u8 obuf[3] = { 0xe, 0x80, 0 };
- u8 ibuf[] = { 0 };
struct i2c_adapter *i2c_adapter;
struct i2c_client *client;
struct i2c_board_info board_info;
struct m88ds3103_platform_data m88ds3103_pdata = {};
struct ts2020_config ts2020_config = {};

- if (dvb_usb_generic_rw(d, obuf, 3, ibuf, 1, 0) < 0)
+ mutex_lock(&d->data_mutex);
+
+ state->data[0] = 0xe;
+ state->data[1] = 0x80;
+ state->data[2] = 0x0;
+
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x02;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x02;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");
msleep(300);

- obuf[0] = 0xe;
- obuf[1] = 0x83;
- obuf[2] = 0;
+ state->data[0] = 0xe;
+ state->data[1] = 0x83;
+ state->data[2] = 0;

- if (dvb_usb_generic_rw(d, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0xe;
- obuf[1] = 0x83;
- obuf[2] = 1;
+ state->data[0] = 0xe;
+ state->data[1] = 0x83;
+ state->data[2] = 1;

- if (dvb_usb_generic_rw(d, obuf, 3, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 3, state->data, 1, 0) < 0)
err("command 0x0e transfer failed.");

- obuf[0] = 0x51;
+ state->data[0] = 0x51;

- if (dvb_usb_generic_rw(d, obuf, 1, ibuf, 1, 0) < 0)
+ if (dvb_usb_generic_rw(d, state->data, 1, state->data, 1, 0) < 0)
err("command 0x51 transfer failed.");

+ mutex_unlock(&d->data_mutex);
+
/* attach demod */
m88ds3103_pdata.clk = 27000000;
m88ds3103_pdata.i2c_wr_max = 33;