Re: [PATCH for-4.22 v2 8/8] x86/mwait-idle: Add C-states validation

[Jan Beulich <jbeulich@suse.com>]

On 14.05.2026 17:30, Roger Pau Monné wrote:
> On Tue, May 12, 2026 at 05:38:32PM +0200, Jan Beulich wrote:
>> From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
>>
>> Add validation for C-states specified via the "table=" module parameter.
>> Treat this module parameter as untrusted input and validate it thoroughly.
>>
>> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
>> Link: https://patch.msgid.link/20251216080402.156988-4-dedekind1@gmail.com
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git be6a150829b3
>>
>> Add __init to validate_cmdline_cstate(). Other adjustments to fit our env.
>>
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.

>> @@ -1697,6 +1737,21 @@ static void __init cmdline_table_adjust(
>>  		       state->name, state->exit_latency, state->target_residency);
>>  	}
>>  
>> +	/* Validate the adjusted C-states */
>> +	for (i = 0; i < state_count; i++) {
>> +		struct cpuidle_state *prev_state;
> 
> const?

Oh, yes, I should have done that with the other v2 change.

>  FWIW, you could also init the field at definition, but I
> understand this might diverge too much from the Linux code.

Right, hence why I left it. Generally I agree that using initializers is
preferable over separate assignments.

Jan