Re: [PATCH] sysctl: Deprecate sys_sysctl in a user space visible fashion.

[ebiederm@xmission.com (Eric W. Biederman)]

Andrew Morton <akpm@linux-foundation.org> writes:

> On Tue, 28 Aug 2007 16:40:15 -0600 ebiederm@xmission.com (Eric W. Biederman)
> wrote:
>
>> +static int deprecated_sysctl_warning(struct __sysctl_args *args)
>> +{
>> +	static int msg_count;
>> +	int name[CTL_MAXNAME];
>> +	int i;
>> +
>> +	/* Read in the sysctl name for better debug message logging */
>> +	for (i = 0; i < args->nlen; i++)
>> +		if (get_user(name[i], args->name + i))
>> +			return -EFAULT;
>> +
>> +	/* Ignore accesses to kernel.version */
>> + if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
>> +		return 0;
>
> Do we want to do all the above if msg_count>=5?

Well.  It won't really change order of the algorithm because we have
to read the data in any way.  So an earlier short circuit exit
would speed things up by a little bit, but it really shouldn't
matter either way.

Eric