Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/tuners/e4000.c:50:1: warning: 'e4000_wr_regs' uses
dynamic stack allocation [enabled by default]
drivers/media/tuners/e4000.c:83:1: warning: 'e4000_rd_regs' uses
dynamic stack allocation [enabled by default]
drivers/media/tuners/fc2580.c:66:1: warning:
'fc2580_wr_regs.constprop.1' uses dynamic stack allocation [enabled by default]
drivers/media/tuners/fc2580.c:98:1: warning:
'fc2580_rd_regs.constprop.0' uses dynamic stack allocation [enabled by default]
drivers/media/tuners/tda18212.c:57:1: warning: 'tda18212_wr_regs' uses
dynamic stack allocation [enabled by default]
drivers/media/tuners/tda18212.c:90:1: warning:
'tda18212_rd_regs.constprop.0' uses dynamic stack allocation [enabled by
default]
drivers/media/tuners/tda18218.c:60:1: warning: 'tda18218_wr_regs' uses
dynamic stack allocation [enabled by default]
drivers/media/tuners/tda18218.c:92:1: warning:
'tda18218_rd_regs.constprop.0' uses dynamic stack allocation [enabled by
default]
Instead, let's enforce a limit for the buffer. Considering that I2C
transfers are generally limited, and that devices used on USB has a
max data length of 80, it seem safe to use 80 as the hard limit for all
those devices. On most cases, the limit is a way lower than that, but
80 is small enough to not affect the Kernel stack, and it is a no brain
limit, as using smaller ones would require to either carefully each
driver or to take a look on each datasheet.
Signed-off-by: Mauro Carvalho Chehab <m.che...@samsung.com>
Cc: Antti Palosaari <cr...@iki.fi>
---
drivers/media/tuners/e4000.c | 18 ++++++++++++++++--
drivers/media/tuners/fc2580.c | 18 ++++++++++++++++--
drivers/media/tuners/tda18212.c | 18 ++++++++++++++++--
drivers/media/tuners/tda18218.c | 18 ++++++++++++++++--
4 files changed, 64 insertions(+), 8 deletions(-)
diff --git a/drivers/media/tuners/e4000.c b/drivers/media/tuners/e4000.c
index ad9309da4a91..235e90251609 100644
--- a/drivers/media/tuners/e4000.c
+++ b/drivers/media/tuners/e4000.c
@@ -24,7 +24,7 @@
static int e4000_wr_regs(struct e4000_priv *priv, u8 reg, u8 *val, int len)
{
int ret;
- u8 buf[1 + len];
+ u8 buf[80];
struct i2c_msg msg[1] = {
{
.addr = priv->cfg->i2c_addr,
@@ -34,6 +34,13 @@ static int e4000_wr_regs(struct e4000_priv *priv, u8 reg, u8
*val, int len)
}
};
+ if (1 + len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c wr reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
buf[0] = reg;
memcpy(&buf[1], val, len);
@@ -53,7 +60,7 @@ static int e4000_wr_regs(struct e4000_priv *priv, u8 reg, u8
*val, int len)
static int e4000_rd_regs(struct e4000_priv *priv, u8 reg, u8 *val, int len)
{
int ret;
- u8 buf[len];
+ u8 buf[80];
struct i2c_msg msg[2] = {
{
.addr = priv->cfg->i2c_addr,
@@ -68,6 +75,13 @@ static int e4000_rd_regs(struct e4000_priv *priv, u8 reg, u8
*val, int len)
}
};
+ if (len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c rd reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
ret = i2c_transfer(priv->i2c, msg, 2);
if (ret == 2) {
memcpy(val, buf, len);
diff --git a/drivers/media/tuners/fc2580.c b/drivers/media/tuners/fc2580.c
index 81f38aae9c66..e27bf5be311d 100644
--- a/drivers/media/tuners/fc2580.c
+++ b/drivers/media/tuners/fc2580.c
@@ -41,7 +41,7 @@
static int fc2580_wr_regs(struct fc2580_priv *priv, u8 reg, u8 *val, int len)
{
int ret;
- u8 buf[1 + len];
+ u8 buf[80];
struct i2c_msg msg[1] = {
{
.addr = priv->cfg->i2c_addr,
@@ -51,6 +51,13 @@ static int fc2580_wr_regs(struct fc2580_priv *priv, u8 reg,
u8 *val, int len)
}
};
+ if (1 + len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c wr reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
buf[0] = reg;
memcpy(&buf[1], val, len);
@@ -69,7 +76,7 @@ static int fc2580_wr_regs(struct fc2580_priv *priv, u8 reg,
u8 *val, int len)
static int fc2580_rd_regs(struct fc2580_priv *priv, u8 reg, u8 *val, int len)
{
int ret;
- u8 buf[len];
+ u8 buf[80];
struct i2c_msg msg[2] = {
{
.addr = priv->cfg->i2c_addr,
@@ -84,6 +91,13 @@ static int fc2580_rd_regs(struct fc2580_priv *priv, u8 reg,
u8 *val, int len)
}
};
+ if (len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c rd reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
ret = i2c_transfer(priv->i2c, msg, 2);
if (ret == 2) {
memcpy(val, buf, len);
diff --git a/drivers/media/tuners/tda18212.c b/drivers/media/tuners/tda18212.c
index e4a84ee231cf..765b9f9d4bc6 100644
--- a/drivers/media/tuners/tda18212.c
+++ b/drivers/media/tuners/tda18212.c
@@ -32,7 +32,7 @@ static int tda18212_wr_regs(struct tda18212_priv *priv, u8
reg, u8 *val,
int len)
{
int ret;
- u8 buf[len+1];
+ u8 buf[80];
struct i2c_msg msg[1] = {
{
.addr = priv->cfg->i2c_address,
@@ -42,6 +42,13 @@ static int tda18212_wr_regs(struct tda18212_priv *priv, u8
reg, u8 *val,
}
};
+ if (1 + len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c wr reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
buf[0] = reg;
memcpy(&buf[1], val, len);
@@ -61,7 +68,7 @@ static int tda18212_rd_regs(struct tda18212_priv *priv, u8
reg, u8 *val,
int len)
{
int ret;
- u8 buf[len];
+ u8 buf[80];
struct i2c_msg msg[2] = {
{
.addr = priv->cfg->i2c_address,
@@ -76,6 +83,13 @@ static int tda18212_rd_regs(struct tda18212_priv *priv, u8
reg, u8 *val,
}
};
+ if (len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c rd reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
ret = i2c_transfer(priv->i2c, msg, 2);
if (ret == 2) {
memcpy(val, buf, len);
diff --git a/drivers/media/tuners/tda18218.c b/drivers/media/tuners/tda18218.c
index 2d31aeb6b088..e4e662c2e6ef 100644
--- a/drivers/media/tuners/tda18218.c
+++ b/drivers/media/tuners/tda18218.c
@@ -24,7 +24,7 @@
static int tda18218_wr_regs(struct tda18218_priv *priv, u8 reg, u8 *val, u8
len)
{
int ret = 0, len2, remaining;
- u8 buf[1 + len];
+ u8 buf[80];
struct i2c_msg msg[1] = {
{
.addr = priv->cfg->i2c_address,
@@ -33,6 +33,13 @@ static int tda18218_wr_regs(struct tda18218_priv *priv, u8
reg, u8 *val, u8 len)
}
};
+ if (1 + len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c wr reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
for (remaining = len; remaining > 0;
remaining -= (priv->cfg->i2c_wr_max - 1)) {
len2 = remaining;
@@ -63,7 +70,7 @@ static int tda18218_wr_regs(struct tda18218_priv *priv, u8
reg, u8 *val, u8 len)
static int tda18218_rd_regs(struct tda18218_priv *priv, u8 reg, u8 *val, u8
len)
{
int ret;
- u8 buf[reg+len]; /* we must start read always from reg 0x00 */
+ u8 buf[80]; /* we must start read always from reg 0x00 */
struct i2c_msg msg[2] = {
{
.addr = priv->cfg->i2c_address,
@@ -78,6 +85,13 @@ static int tda18218_rd_regs(struct tda18218_priv *priv, u8
reg, u8 *val, u8 len)
}
};
+ if (reg + len > sizeof(buf)) {
+ dev_warn(&priv->i2c->dev,
+ "%s: i2c wr reg=%04x: len=%d is too big!\n",
+ KBUILD_MODNAME, reg, len);
+ return -EREMOTEIO;
+ }
+
ret = i2c_transfer(priv->i2c, msg, 2);
if (ret == 2) {
memcpy(val, &buf[reg], len);
