Dynamic static allocation is evil, as Kernel stack is too low, and compilation complains about it on some archs:
drivers/media/dvb-frontends/stv0367.c:791:1: warning: 'stv0367_writeregs.constprop.4' 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: Jiri Kosina <jkos...@suse.cz> Cc: Geert Uytterhoeven <ge...@linux-m68k.org> --- drivers/media/dvb-frontends/stv0367.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-frontends/stv0367.c index 7b6dba3ce55e..28294b3be319 100644 --- a/drivers/media/dvb-frontends/stv0367.c +++ b/drivers/media/dvb-frontends/stv0367.c @@ -767,7 +767,7 @@ static struct st_register def0367cab[STV0367CAB_NBREGS] = { static int stv0367_writeregs(struct stv0367_state *state, u16 reg, u8 *data, int len) { - u8 buf[len + 2]; + u8 buf[80]; struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, @@ -776,6 +776,14 @@ int stv0367_writeregs(struct stv0367_state *state, u16 reg, u8 *data, int len) }; int ret; + if (2 + len > sizeof(buf)) { + printk(KERN_WARNING + "%s: i2c wr reg=%04x: len=%d is too big!\n", + KBUILD_MODNAME, reg, len); + return -EREMOTEIO; + } + + buf[0] = MSB(reg); buf[1] = LSB(reg); memcpy(buf + 2, data, len); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html