From: Antti Palosaari <crope@iki.fi>
To: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
Mauro Carvalho Chehab <mchehab@infradead.org>
Subject: Re: [PATCHv2 14/29] dvb-frontends: Don't use dynamic static allocation
Date: Sat, 02 Nov 2013 19:10:57 +0200 [thread overview]
Message-ID: <52753221.3060101@iki.fi> (raw)
In-Reply-To: <1383399097-11615-15-git-send-email-m.chehab@samsung.com>
Acked-by: Antti Palosaari <crope@iki.fi>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Antti
On 02.11.2013 15:31, 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 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.chehab@samsung.com>
> Cc: Antti Palosaari <crope@iki.fi>
> ---
> drivers/media/dvb-frontends/af9013.c | 9 ++++++++-
> drivers/media/dvb-frontends/af9033.c | 18 ++++++++++++++++--
> drivers/media/dvb-frontends/cxd2820r_core.c | 18 ++++++++++++++++--
> drivers/media/dvb-frontends/rtl2830.c | 9 ++++++++-
> drivers/media/dvb-frontends/rtl2832.c | 9 ++++++++-
> drivers/media/dvb-frontends/tda10071.c | 18 ++++++++++++++++--
> 6 files changed, 72 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/af9013.c b/drivers/media/dvb-frontends/af9013.c
> index a204f2828820..f968dc0e5de9 100644
> --- a/drivers/media/dvb-frontends/af9013.c
> +++ b/drivers/media/dvb-frontends/af9013.c
> @@ -50,7 +50,7 @@ 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[80];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->config.i2c_addr,
> @@ -60,6 +60,13 @@ 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 -EREMOTEIO;
> + }
> +
> 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..efa2efafa97f 100644
> --- a/drivers/media/dvb-frontends/af9033.c
> +++ b/drivers/media/dvb-frontends/af9033.c
> @@ -40,7 +40,7 @@ static int af9033_wr_regs(struct af9033_state *state, u32 reg, const u8 *val,
> int len)
> {
> int ret;
> - u8 buf[3 + len];
> + u8 buf[80];
> struct i2c_msg msg[1] = {
> {
> .addr = state->cfg.i2c_addr,
> @@ -50,6 +50,13 @@ 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 -EREMOTEIO;
> + }
> +
> buf[0] = (reg >> 16) & 0xff;
> buf[1] = (reg >> 8) & 0xff;
> buf[2] = (reg >> 0) & 0xff;
> @@ -161,7 +168,14 @@ 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[80];
> +
> + if (tab_len > sizeof(buf)) {
> + dev_warn(&state->i2c->dev,
> + "%s: i2c wr len=%d is too big!\n",
> + KBUILD_MODNAME, tab_len);
> + return -EREMOTEIO;
> + }
>
> 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..8ef96a96b141 100644
> --- a/drivers/media/dvb-frontends/cxd2820r_core.c
> +++ b/drivers/media/dvb-frontends/cxd2820r_core.c
> @@ -26,7 +26,7 @@ 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[80];
> struct i2c_msg msg[1] = {
> {
> .addr = i2c,
> @@ -36,6 +36,13 @@ 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 -EREMOTEIO;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> @@ -55,7 +62,7 @@ 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[80];
> struct i2c_msg msg[2] = {
> {
> .addr = i2c,
> @@ -70,6 +77,13 @@ 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 -EREMOTEIO;
> + }
> +
> 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..bd54fd8b3e2d 100644
> --- a/drivers/media/dvb-frontends/rtl2830.c
> +++ b/drivers/media/dvb-frontends/rtl2830.c
> @@ -31,7 +31,7 @@
> static int rtl2830_wr(struct rtl2830_priv *priv, u8 reg, const u8 *val, int len)
> {
> int ret;
> - u8 buf[1+len];
> + u8 buf[80];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->cfg.i2c_addr,
> @@ -41,6 +41,13 @@ 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 -EREMOTEIO;
> + }
> +
> 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..067547fd6ac5 100644
> --- a/drivers/media/dvb-frontends/rtl2832.c
> +++ b/drivers/media/dvb-frontends/rtl2832.c
> @@ -162,7 +162,7 @@ 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[80];
> struct i2c_msg msg[1] = {
> {
> .addr = priv->cfg.i2c_addr,
> @@ -172,6 +172,13 @@ 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 -EREMOTEIO;
> + }
> +
> 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..6f007f55d35d 100644
> --- a/drivers/media/dvb-frontends/tda10071.c
> +++ b/drivers/media/dvb-frontends/tda10071.c
> @@ -27,7 +27,7 @@ static int tda10071_wr_regs(struct tda10071_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.demod_i2c_addr,
> @@ -37,6 +37,13 @@ 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 -EREMOTEIO;
> + }
> +
> buf[0] = reg;
> memcpy(&buf[1], val, len);
>
> @@ -56,7 +63,7 @@ static int tda10071_rd_regs(struct tda10071_priv *priv, u8 reg, u8 *val,
> int len)
> {
> int ret;
> - u8 buf[len];
> + u8 buf[80];
> struct i2c_msg msg[2] = {
> {
> .addr = priv->cfg.demod_i2c_addr,
> @@ -71,6 +78,13 @@ 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 -EREMOTEIO;
> + }
> +
> ret = i2c_transfer(priv->i2c, msg, 2);
> if (ret == 2) {
> memcpy(val, buf, len);
>
--
http://palosaari.fi/
next prev parent reply other threads:[~2013-11-02 17:11 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-02 13:31 [PATCHv2 00/29] Fix errors/warnings with allmodconfig/allyesconfig on non-x86 archs Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 01/29] tda9887: remove an warning when compiling for alpha Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 02/29] radio-shark: remove a warning when CONFIG_PM is not defined Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 03/29] zoran: don't build it on alpha Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 04/29] cx18: struct i2c_client is too big for stack Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 05/29] tef6862: fix warning on avr32 arch Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 06/29] iguanair: shut up a gcc " Mauro Carvalho Chehab
2013-11-03 22:10 ` Sean Young
2013-11-03 22:13 ` [PATCH] [media] iguanair: simplify calculation of carrier delay cycles Sean Young
2013-11-02 13:31 ` [PATCHv2 07/29] platform drivers: Fix build on cris and frv archs Mauro Carvalho Chehab
2013-11-04 4:03 ` Ben Hutchings
2013-11-04 11:28 ` Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 08/29] cx18: disable compilation on frv arch Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 09/29] radio-si470x-i2c: fix a warning on ia64 Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 10/29] rc: Fir warnings on m68k arch Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 11/29] uvc/lirc_serial: Fix some warnings on parisc arch Mauro Carvalho Chehab
2013-11-04 14:22 ` Laurent Pinchart
2013-11-04 14:43 ` Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 12/29] s5h1420: Don't use dynamic static allocation Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 13/29] dvb-frontends: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 14/29] " Mauro Carvalho Chehab
2013-11-02 17:10 ` Antti Palosaari [this message]
2013-11-02 13:31 ` [PATCHv2 15/29] stb0899_drv: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 16/29] stv0367: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 17/29] stv090x: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 18/29] av7110_hw: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 19/29] tuners: " Mauro Carvalho Chehab
2013-11-02 17:12 ` Antti Palosaari
2013-11-02 17:25 ` Hans Verkuil
2013-11-02 21:15 ` Mauro Carvalho Chehab
2013-11-02 21:53 ` Hans Verkuil
2013-11-02 21:59 ` Hans Verkuil
2013-11-03 0:21 ` Mauro Carvalho Chehab
2013-11-03 9:12 ` Mauro Carvalho Chehab
2013-11-03 11:54 ` Antti Palosaari
2013-11-04 13:26 ` Hans Verkuil
2013-11-04 14:24 ` Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 20/29] tuner-xc2028: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 21/29] cimax2: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 22/29] v4l2-async: " Mauro Carvalho Chehab
2013-11-04 13:15 ` Hans Verkuil
2013-11-05 11:36 ` Mauro Carvalho Chehab
2013-11-05 11:42 ` Sylwester Nawrocki
2013-11-05 12:03 ` Mauro Carvalho Chehab
2013-11-05 12:35 ` Hans Verkuil
2013-11-05 13:16 ` Mauro Carvalho Chehab
2013-11-05 14:18 ` Hans Verkuil
2013-11-02 13:31 ` [PATCHv2 23/29] cxusb: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 24/29] dibusb-common: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 25/29] dw2102: " Mauro Carvalho Chehab
2013-11-02 13:31 ` [PATCHv2 26/29] af9015: " Mauro Carvalho Chehab
2013-11-02 17:05 ` Antti Palosaari
2013-11-02 13:31 ` [PATCHv2 27/29] af9035: " Mauro Carvalho Chehab
2013-11-02 17:19 ` Antti Palosaari
2013-11-02 13:31 ` [PATCHv2 28/29] mxl111sf: " Mauro Carvalho Chehab
2013-11-04 0:50 ` Michael Krufky
2013-11-04 10:58 ` Mauro Carvalho Chehab
2013-11-04 11:04 ` Michael Krufky
2013-11-02 13:31 ` [PATCHv2 29/29] lirc_zilog: " Mauro Carvalho Chehab
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