From: Antti Palosaari <crope@iki.fi>
To: Mauro Carvalho Chehab <m.chehab@samsung.com>, unlisted-recipients:;
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
Mauro Carvalho Chehab <mchehab@infradead.org>
Subject: Re: [PATCH v3 13/29] [media] dvb-frontends: Don't use dynamic static allocation
Date: Tue, 05 Nov 2013 19:00:54 +0200 [thread overview]
Message-ID: <52792446.1020109@iki.fi> (raw)
In-Reply-To: <1383645702-30636-14-git-send-email-m.chehab@samsung.com>
Acked-by: Antti Palosaari <crope@iki.fi>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Antti
On 05.11.2013 12:01, Mauro Carvalho Chehab wrote:
> Dynamic static allocation is evil, as Kernel stack is too low, and
> compilation complains about it on some archs:
> drivers/media/dvb-frontends/af9013.c:77:1: warning: 'af9013_wr_regs_i2c' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/af9033.c:188:1: warning: 'af9033_wr_reg_val_tab' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/af9033.c:68:1: warning: 'af9033_wr_regs' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/bcm3510.c:230:1: warning: 'bcm3510_do_hab_cmd' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/cxd2820r_core.c:84:1: warning: 'cxd2820r_rd_regs_i2c.isra.1' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/rtl2830.c:56:1: warning: 'rtl2830_wr' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/rtl2832.c:187:1: warning: 'rtl2832_wr' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/tda10071.c:52:1: warning: 'tda10071_wr_regs' uses dynamic stack allocation [enabled by default]
> drivers/media/dvb-frontends/tda10071.c:84:1: warning: 'tda10071_rd_regs' 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 64 bytes for the control URBs.
>
> So, it seem safe to use 64 bytes as the hard limit for all those devices.
>
> On most cases, the limit is a way lower than that, but this limit
> 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.chehab@samsung.com>
> ---
> drivers/media/dvb-frontends/af9013.c | 12 +++++++++++-
> drivers/media/dvb-frontends/af9033.c | 21 +++++++++++++++++++--
> drivers/media/dvb-frontends/cxd2820r_core.c | 21 +++++++++++++++++++--
> drivers/media/dvb-frontends/rtl2830.c | 12 +++++++++++-
> drivers/media/dvb-frontends/rtl2832.c | 12 +++++++++++-
> drivers/media/dvb-frontends/tda10071.c | 21 +++++++++++++++++++--
> 6 files changed, 90 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/af9013.c b/drivers/media/dvb-frontends/af9013.c
> index a204f2828820..19ba66ad23fa 100644
> --- a/drivers/media/dvb-frontends/af9013.c
> +++ b/drivers/media/dvb-frontends/af9013.c
> @@ -24,6 +24,9 @@
>
> #include "af9013_priv.h"
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> struct af9013_state {
> struct i2c_adapter *i2c;
> struct dvb_frontend fe;
> @@ -50,7 +53,7 @@ static int af9013_wr_regs_i2c(struct af9013_state *priv, u8 mbox, u16 reg,
> const u8 *val, int len)
> {
> int ret;
> - u8 buf[3+len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->config.i2c_addr,
> @@ -60,6 +63,13 @@ static int af9013_wr_regs_i2c(struct af9013_state *priv, u8 mbox, u16 reg,
> }
> };
>
> + if (3 + len > sizeof(buf)) {
> + dev_warn(&priv->i2c->dev,
> + "%s: i2c wr reg=%04x: len=%d is too big!\n",
> + KBUILD_MODNAME, reg, len);
> + return -EINVAL;
> + }
> +
> buf[0] = (reg >> 8) & 0xff;
> buf[1] = (reg >> 0) & 0xff;
> buf[2] = mbox;
> diff --git a/drivers/media/dvb-frontends/af9033.c b/drivers/media/dvb-frontends/af9033.c
> index a777b4b944eb..11f1555e66dc 100644
> --- a/drivers/media/dvb-frontends/af9033.c
> +++ b/drivers/media/dvb-frontends/af9033.c
> @@ -21,6 +21,9 @@
>
> #include "af9033_priv.h"
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> struct af9033_state {
> struct i2c_adapter *i2c;
> struct dvb_frontend fe;
> @@ -40,7 +43,7 @@ static int af9033_wr_regs(struct af9033_state *state, u32 reg, const u8 *val,
> int len)
> {
> int ret;
> - u8 buf[3 + len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = state->cfg.i2c_addr,
> @@ -50,6 +53,13 @@ static int af9033_wr_regs(struct af9033_state *state, u32 reg, const u8 *val,
> }
> };
>
> + if (3 + len > sizeof(buf)) {
> + dev_warn(&state->i2c->dev,
> + "%s: i2c wr reg=%04x: len=%d is too big!\n",
> + KBUILD_MODNAME, reg, len);
> + return -EINVAL;
> + }
> +
> buf[0] = (reg >> 16) & 0xff;
> buf[1] = (reg >> 8) & 0xff;
> buf[2] = (reg >> 0) & 0xff;
> @@ -161,7 +171,14 @@ static int af9033_wr_reg_val_tab(struct af9033_state *state,
> const struct reg_val *tab, int tab_len)
> {
> int ret, i, j;
> - u8 buf[tab_len];
> + u8 buf[MAX_XFER_SIZE];
> +
> + if (tab_len > sizeof(buf)) {
> + dev_warn(&state->i2c->dev,
> + "%s: i2c wr len=%d is too big!\n",
> + KBUILD_MODNAME, tab_len);
> + return -EINVAL;
> + }
>
> dev_dbg(&state->i2c->dev, "%s: tab_len=%d\n", __func__, tab_len);
>
> diff --git a/drivers/media/dvb-frontends/cxd2820r_core.c b/drivers/media/dvb-frontends/cxd2820r_core.c
> index d9eeeb1dfa96..03930d5e9fea 100644
> --- a/drivers/media/dvb-frontends/cxd2820r_core.c
> +++ b/drivers/media/dvb-frontends/cxd2820r_core.c
> @@ -21,12 +21,15 @@
>
> #include "cxd2820r_priv.h"
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> /* write multiple registers */
> static int cxd2820r_wr_regs_i2c(struct cxd2820r_priv *priv, u8 i2c, u8 reg,
> u8 *val, int len)
> {
> int ret;
> - u8 buf[len+1];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = i2c,
> @@ -36,6 +39,13 @@ static int cxd2820r_wr_regs_i2c(struct cxd2820r_priv *priv, u8 i2c, u8 reg,
> }
> };
>
> + 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 -EINVAL;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> @@ -55,7 +65,7 @@ static int cxd2820r_rd_regs_i2c(struct cxd2820r_priv *priv, u8 i2c, u8 reg,
> u8 *val, int len)
> {
> int ret;
> - u8 buf[len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[2] = {
> {
> .addr = i2c,
> @@ -70,6 +80,13 @@ static int cxd2820r_rd_regs_i2c(struct cxd2820r_priv *priv, u8 i2c, u8 reg,
> }
> };
>
> + if (len > sizeof(buf)) {
> + dev_warn(&priv->i2c->dev,
> + "%s: i2c wr reg=%04x: len=%d is too big!\n",
> + KBUILD_MODNAME, reg, len);
> + return -EINVAL;
> + }
> +
> ret = i2c_transfer(priv->i2c, msg, 2);
> if (ret == 2) {
> memcpy(val, buf, len);
> diff --git a/drivers/media/dvb-frontends/rtl2830.c b/drivers/media/dvb-frontends/rtl2830.c
> index 362d26d11e82..b908800b390d 100644
> --- a/drivers/media/dvb-frontends/rtl2830.c
> +++ b/drivers/media/dvb-frontends/rtl2830.c
> @@ -27,11 +27,14 @@
>
> #include "rtl2830_priv.h"
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> /* write multiple hardware registers */
> static int rtl2830_wr(struct rtl2830_priv *priv, u8 reg, const u8 *val, int len)
> {
> int ret;
> - u8 buf[1+len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->cfg.i2c_addr,
> @@ -41,6 +44,13 @@ static int rtl2830_wr(struct rtl2830_priv *priv, u8 reg, const 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 -EINVAL;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
> index a95dfe0a5ce3..cd1e6965ac11 100644
> --- a/drivers/media/dvb-frontends/rtl2832.c
> +++ b/drivers/media/dvb-frontends/rtl2832.c
> @@ -22,6 +22,9 @@
> #include "dvb_math.h"
> #include <linux/bitops.h>
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> int rtl2832_debug;
> module_param_named(debug, rtl2832_debug, int, 0644);
> MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
> @@ -162,7 +165,7 @@ static const struct rtl2832_reg_entry registers[] = {
> static int rtl2832_wr(struct rtl2832_priv *priv, u8 reg, u8 *val, int len)
> {
> int ret;
> - u8 buf[1+len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->cfg.i2c_addr,
> @@ -172,6 +175,13 @@ static int rtl2832_wr(struct rtl2832_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 -EINVAL;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> diff --git a/drivers/media/dvb-frontends/tda10071.c b/drivers/media/dvb-frontends/tda10071.c
> index e79749cfec81..1d8bc2ea4b10 100644
> --- a/drivers/media/dvb-frontends/tda10071.c
> +++ b/drivers/media/dvb-frontends/tda10071.c
> @@ -20,6 +20,9 @@
>
> #include "tda10071_priv.h"
>
> +/* Max transfer size done by I2C transfer functions */
> +#define MAX_XFER_SIZE 64
> +
> static struct dvb_frontend_ops tda10071_ops;
>
> /* write multiple registers */
> @@ -27,7 +30,7 @@ static int tda10071_wr_regs(struct tda10071_priv *priv, u8 reg, u8 *val,
> int len)
> {
> int ret;
> - u8 buf[len+1];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->cfg.demod_i2c_addr,
> @@ -37,6 +40,13 @@ static int tda10071_wr_regs(struct tda10071_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 -EINVAL;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> @@ -56,7 +66,7 @@ static int tda10071_rd_regs(struct tda10071_priv *priv, u8 reg, u8 *val,
> int len)
> {
> int ret;
> - u8 buf[len];
> + u8 buf[MAX_XFER_SIZE];
> struct i2c_msg msg[2] = {
> {
> .addr = priv->cfg.demod_i2c_addr,
> @@ -71,6 +81,13 @@ static int tda10071_rd_regs(struct tda10071_priv *priv, u8 reg, u8 *val,
> }
> };
>
> + if (len > sizeof(buf)) {
> + dev_warn(&priv->i2c->dev,
> + "%s: i2c wr reg=%04x: len=%d is too big!\n",
> + KBUILD_MODNAME, reg, len);
> + return -EINVAL;
> + }
> +
> ret = i2c_transfer(priv->i2c, msg, 2);
> if (ret == 2) {
> memcpy(val, buf, len);
>
--
http://palosaari.fi/
next prev parent reply other threads:[~2013-11-05 17:00 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-05 10:01 [PATCH v3 00/29] Fix errors/warnings with allmodconfig/allyesconfig on non-x86 archs Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 01/29] [media] tda9887: remove an warning when compiling for alpha Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 02/29] [media] radio-shark: remove a warning when CONFIG_PM is not defined Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 03/29] [media] zoran: don't build it on alpha Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 04/29] [media] cx18: struct i2c_client is too big for stack Mauro Carvalho Chehab
2013-11-06 0:19 ` Andy Walls
2013-11-05 10:01 ` [PATCH v3 05/29] [media] tef6862: fix warning on avr32 arch Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 06/29] [media] iguanair: simplify calculation of carrier delay cycles Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 07/29] [media] platform drivers: Fix build on frv arch Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 08/29] [media] radio-si470x-i2c: fix a warning on ia64 Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 09/29] [media] rc: Fir warnings on m68k arch Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 10/29] [media] uvc/lirc_serial: Fix some warnings on parisc arch Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 11/29] [media] s5h1420: Don't use dynamic static allocation Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 12/29] [media] dvb-frontends: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 13/29] " Mauro Carvalho Chehab
2013-11-05 17:00 ` Antti Palosaari [this message]
2013-11-05 10:01 ` [PATCH v3 14/29] [media] stb0899_drv: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 15/29] [media] stv0367: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 16/29] [media] stv090x: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 17/29] [media] av7110_hw: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 18/29] [media] tuners: " Mauro Carvalho Chehab
2013-11-05 17:11 ` Antti Palosaari
2013-11-07 18:55 ` Antti Palosaari
2013-11-07 21:13 ` Mauro Carvalho Chehab
2013-11-07 23:27 ` Antti Palosaari
2013-11-05 10:01 ` [PATCH v3 19/29] [media] tuner-xc2028: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 20/29] [media] cimax2: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 21/29] [media] v4l2-async: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 22/29] [media] cxusb: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 23/29] [media] dibusb-common: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 24/29] [media] dw2102: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 25/29] [media] af9015: " Mauro Carvalho Chehab
2013-11-05 17:14 ` Antti Palosaari
2013-11-05 10:01 ` [PATCH v3 26/29] [media] af9035: " Mauro Carvalho Chehab
2013-11-05 17:17 ` Antti Palosaari
2013-11-05 10:01 ` [PATCH v3 27/29] [media] mxl111sf: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 28/29] [media] lirc_zilog: " Mauro Carvalho Chehab
2013-11-05 10:01 ` [PATCH v3 29/29] [media] cx18: disable compilation on frv arch Mauro Carvalho Chehab
2013-11-05 15:17 ` [PATCH v3 00/29] Fix errors/warnings with allmodconfig/allyesconfig on non-x86 archs Hans Verkuil
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