Re: [PATCH v2 4/4] ax.25: Remove the now superfluous sentinel elements from ctl_table array

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On Thu, Mar 28, 2024 at 12:49:34PM -0700, Kuniyuki Iwashima wrote:
> From: Joel Granados via B4 Relay <>
> Date: Thu, 28 Mar 2024 16:40:05 +0100
> > This commit comes at the tail end of a greater effort to remove the
> > empty elements at the end of the ctl_table arrays (sentinels) which will
> > reduce the overall build time size of the kernel and run time memory
> > bloat by ~64 bytes per sentinel (further information Link :
> >
> > 
> > When we remove the sentinel from ax25_param_table a buffer overflow
> > shows its ugly head. The sentinel's data element used to be changed when
> > CONFIG_AX25_DAMA_SLAVE was not defined.
> I think it's better to define the relation explicitly between the
> enum and sysctl table by BUILD_BUG_ON() in ax25_register_dev_sysctl()
>   BUILD_BUG_ON(AX25_MAX_VALUES != ARRAY_SIZE(ax25_param_table));
> and guard AX25_VALUES_DS_TIMEOUT with #ifdef CONFIG_AX25_DAMA_SLAVE
> as done for other enum.

When I remove AX25_VALUES_DS_TIMEOUT from the un-guarded build it
complains in net/ax25/ax25_ds_timer.c (ax25_ds_set_timer). Here is the

How best to address this? Should we just guard the whole function and do
nothing when not set? like this:

void ax25_ds_set_timer(ax25_dev *ax25_dev)
        if (ax25_dev == NULL)        ···/* paranoia */

        ax25_dev->dama.slave_timeout =
                msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
        mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);


I'm not too familiar with this, so pointing me to the "correct" way to
handle this would be helpfull.

Thx in advance.



Joel Granados

Attachment: signature.asc
Description: PGP signature

[Index of Archives]     [Netfitler Users]     [Berkeley Packet Filter]     [LARTC]     [Bugtraq]     [Yosemite Forum]

  Powered by Linux