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[media] dw2102: Don't use dynamic static allocation
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Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
	drivers/media/usb/dvb-usb/dw2102.c:368:1: warning: 'dw2102_earda_i2c_transfer' uses dynamic stack allocation [enabled by default]
	drivers/media/usb/dvb-usb/dw2102.c:449:1: warning: 'dw2104_i2c_transfer' uses dynamic stack allocation [enabled by default]
	drivers/media/usb/dvb-usb/dw2102.c:512:1: warning: 'dw3101_i2c_transfer' uses dynamic stack allocation [enabled by default]
	drivers/media/usb/dvb-usb/dw2102.c:621:1: warning: 's6x0_i2c_transfer' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer to be the max size of
a control URB payload data (64 bytes).

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
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Mauro Carvalho Chehab committed Nov 8, 2013
1 parent 1d7fa35 commit 0065a79
Showing 1 changed file with 80 additions and 10 deletions.
90 changes: 80 additions & 10 deletions drivers/media/usb/dvb-usb/dw2102.c
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,9 @@
#include "stb6100_proc.h"
#include "m88rs2000.h"

/* Max transfer size done by I2C transfer functions */
#define MAX_XFER_SIZE 64

#ifndef USB_PID_DW2102
#define USB_PID_DW2102 0x2102
#endif
Expand Down Expand Up @@ -308,7 +311,14 @@ static int dw2102_earda_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg ms
case 2: {
/* read */
/* first write first register number */
u8 ibuf[msg[1].len + 2], obuf[3];
u8 ibuf[MAX_XFER_SIZE], obuf[3];

if (2 + msg[1].len > sizeof(ibuf)) {
warn("i2c rd: len=%d is too big!\n",
msg[1].len);
return -EOPNOTSUPP;
}

obuf[0] = msg[0].addr << 1;
obuf[1] = msg[0].len;
obuf[2] = msg[0].buf[0];
Expand All @@ -325,7 +335,14 @@ static int dw2102_earda_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg ms
switch (msg[0].addr) {
case 0x68: {
/* write to register */
u8 obuf[msg[0].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[0].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[1].len);
return -EOPNOTSUPP;
}

obuf[0] = msg[0].addr << 1;
obuf[1] = msg[0].len;
memcpy(obuf + 2, msg[0].buf, msg[0].len);
Expand All @@ -335,7 +352,14 @@ static int dw2102_earda_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg ms
}
case 0x61: {
/* write to tuner */
u8 obuf[msg[0].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[0].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[1].len);
return -EOPNOTSUPP;
}

obuf[0] = msg[0].addr << 1;
obuf[1] = msg[0].len;
memcpy(obuf + 2, msg[0].buf, msg[0].len);
Expand Down Expand Up @@ -401,7 +425,14 @@ static int dw2104_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], i
default: {
if (msg[j].flags == I2C_M_RD) {
/* read registers */
u8 ibuf[msg[j].len + 2];
u8 ibuf[MAX_XFER_SIZE];

if (2 + msg[j].len > sizeof(ibuf)) {
warn("i2c rd: len=%d is too big!\n",
msg[j].len);
return -EOPNOTSUPP;
}

dw210x_op_rw(d->udev, 0xc3,
(msg[j].addr << 1) + 1, 0,
ibuf, msg[j].len + 2,
Expand Down Expand Up @@ -430,7 +461,14 @@ static int dw2104_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], i
} while (len > 0);
} else {
/* write registers */
u8 obuf[msg[j].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[j].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[j].len);
return -EOPNOTSUPP;
}

obuf[0] = msg[j].addr << 1;
obuf[1] = msg[j].len;
memcpy(obuf + 2, msg[j].buf, msg[j].len);
Expand Down Expand Up @@ -463,7 +501,13 @@ static int dw3101_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
case 2: {
/* read */
/* first write first register number */
u8 ibuf[msg[1].len + 2], obuf[3];
u8 ibuf[MAX_XFER_SIZE], obuf[3];

if (2 + msg[1].len > sizeof(ibuf)) {
warn("i2c rd: len=%d is too big!\n",
msg[1].len);
return -EOPNOTSUPP;
}
obuf[0] = msg[0].addr << 1;
obuf[1] = msg[0].len;
obuf[2] = msg[0].buf[0];
Expand All @@ -481,7 +525,13 @@ static int dw3101_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
case 0x60:
case 0x0c: {
/* write to register */
u8 obuf[msg[0].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[0].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[0].len);
return -EOPNOTSUPP;
}
obuf[0] = msg[0].addr << 1;
obuf[1] = msg[0].len;
memcpy(obuf + 2, msg[0].buf, msg[0].len);
Expand Down Expand Up @@ -563,7 +613,14 @@ static int s6x0_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
default: {
if (msg[j].flags == I2C_M_RD) {
/* read registers */
u8 ibuf[msg[j].len];
u8 ibuf[MAX_XFER_SIZE];

if (msg[j].len > sizeof(ibuf)) {
warn("i2c rd: len=%d is too big!\n",
msg[j].len);
return -EOPNOTSUPP;
}

dw210x_op_rw(d->udev, 0x91, 0, 0,
ibuf, msg[j].len,
DW210X_READ_MSG);
Expand All @@ -590,7 +647,14 @@ static int s6x0_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
} while (len > 0);
} else if (j < (num - 1)) {
/* write register addr before read */
u8 obuf[msg[j].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[j].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[j].len);
return -EOPNOTSUPP;
}

obuf[0] = msg[j + 1].len;
obuf[1] = (msg[j].addr << 1);
memcpy(obuf + 2, msg[j].buf, msg[j].len);
Expand All @@ -602,7 +666,13 @@ static int s6x0_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
break;
} else {
/* write registers */
u8 obuf[msg[j].len + 2];
u8 obuf[MAX_XFER_SIZE];

if (2 + msg[j].len > sizeof(obuf)) {
warn("i2c wr: len=%d is too big!\n",
msg[j].len);
return -EOPNOTSUPP;
}
obuf[0] = msg[j].len + 1;
obuf[1] = (msg[j].addr << 1);
memcpy(obuf + 2, msg[j].buf, msg[j].len);
Expand Down

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