diff options
| author | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2013-11-02 05:05:18 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2013-11-08 09:45:38 -0200 |
| commit | 8393796dfa4cf5dffcceec464c7789bec3a2f471 (patch) | |
| tree | f8410ce34146d3f4ef8bbcfb109328ea245c5574 /drivers/media/dvb-frontends/bcm3510.c | |
| parent | 9736a89dafe07359d9c86bf9c3b815a250b354bc (diff) | |
[media] dvb-frontends: Don't use dynamic static allocation
Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/dvb-frontends/bcm3510.c:230:1: warning: 'bcm3510_do_hab_cmd' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/itd1000.c:69:1: warning: 'itd1000_write_regs.constprop.0' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/mt312.c:126:1: warning: 'mt312_write' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/nxt200x.c:111:1: warning: 'nxt200x_writebytes' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stb6100.c:216:1: warning: 'stb6100_write_reg_range.constprop.3' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stv6110.c:98:1: warning: 'stv6110_write_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stv6110x.c:85:1: warning: 'stv6110x_write_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/tda18271c2dd.c:147:1: warning: 'WriteRegs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/zl10039.c:119:1: warning: 'zl10039_write' 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>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Diffstat (limited to 'drivers/media/dvb-frontends/bcm3510.c')
| -rw-r--r-- | drivers/media/dvb-frontends/bcm3510.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/media/dvb-frontends/bcm3510.c b/drivers/media/dvb-frontends/bcm3510.c index 1b77909c0c71..39a29dd29519 100644 --- a/drivers/media/dvb-frontends/bcm3510.c +++ b/drivers/media/dvb-frontends/bcm3510.c @@ -44,6 +44,9 @@ #include "bcm3510.h" #include "bcm3510_priv.h" +/* Max transfer size done by bcm3510_do_hab_cmd() function */ +#define MAX_XFER_SIZE 128 + struct bcm3510_state { struct i2c_adapter* i2c; @@ -201,9 +204,19 @@ static int bcm3510_hab_send_request(struct bcm3510_state *st, u8 *buf, int len) static int bcm3510_do_hab_cmd(struct bcm3510_state *st, u8 cmd, u8 msgid, u8 *obuf, u8 olen, u8 *ibuf, u8 ilen) { - u8 ob[olen+2],ib[ilen+2]; + u8 ob[MAX_XFER_SIZE], ib[MAX_XFER_SIZE]; int ret = 0; + if (ilen + 2 > sizeof(ib)) { + deb_hab("do_hab_cmd: ilen=%d is too big!\n", ilen); + return -EINVAL; + } + + if (olen + 2 > sizeof(ob)) { + deb_hab("do_hab_cmd: olen=%d is too big!\n", olen); + return -EINVAL; + } + ob[0] = cmd; ob[1] = msgid; memcpy(&ob[2],obuf,olen); |