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[media] ascot2e: don't use variable length arrays

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The Linux stack is short; we need to be able to count the number
of bytes used at stack on each function. So, we don't like to
use variable-length arrays, as complained by smatch:
        drivers/media/dvb-frontends/horus3a.c:57:19: warning: Variable length array is used.

The max usecase of the driver seems to be 10 bytes + 1 for the
register.

So, let's be safe and allocate 11 bytes for the write buffer.
This should be enough to cover all cases. If not, let's print
an error message.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Mauro Carvalho Chehab 2015-08-11 15:36:15 -03:00
parent 4aabd91625
commit 8853780ec1
1 changed files with 10 additions and 2 deletions
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12
drivers/media/dvb-frontends/ascot2e.c
View file

@ -26,6 +26,8 @@
#include "ascot2e.h"
#include "dvb_frontend.h"
#define MAX_WRITE_REGSIZE 10
enum ascot2e_state {
STATE_UNKNOWN,
STATE_SLEEP,
@ -120,16 +122,22 @@ static int ascot2e_write_regs(struct ascot2e_priv *priv,
u8 reg, const u8 *data, u32 len)
{
int ret;
u8 buf[len+1];
u8 buf[MAX_WRITE_REGSIZE + 1];
struct i2c_msg msg[1] = {
{
.addr = priv->i2c_address,
.flags = 0,
.len = sizeof(buf),
.len = len + 1,
.buf = buf,
}
};
if (len + 1 >= sizeof(buf)) {
dev_warn(&priv->i2c->dev,"wr reg=%04x: len=%d is too big!\n",
reg, len + 1);
return -E2BIG;
}
ascot2e_i2c_debug(priv, reg, 1, data, len);
buf[0] = reg;
memcpy(&buf[1], data, len);