Re: [PATCH v2 4/6] sched: Extend task command name to 64 bytes

["André Almeida" <andrealmeid@igalia.com>]

Em 27/05/2026 05:42, David Laight escreveu:
> On Tue, 26 May 2026 12:31:03 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
>> On Mon, 25 May 2026 11:42:41 +0100
>> David Laight <david.laight.linux@gmail.com> wrote:
>>
>>>>>   	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
>>>>> @@ -2601,16 +2601,16 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
>>>>>   			error = -EINVAL;
>>>>>   		break;
>>>>>   	case PR_SET_NAME:
>>>>> -		comm[sizeof(me->comm) - 1] = 0;
>>>>> +		comm[TASK_COMM_LEN - 1] = 0;
>>>>>   		if (strncpy_from_user(comm, (char __user *)arg2,
>>>>> -				      sizeof(me->comm) - 1) < 0)
>>>>> +				      TASK_COMM_LEN - 1) < 0)
>>>>
>>>> Nak - you can't do that.
>>>> You are reading data that the application doesn't expect you to read.
>>>
>>> Or have I got confused over the names...
>>
>> You may have gotten confused by names, as sizeof(me->comm) is the same as
>> TASK_COMM_LEN. Basically, the above doesn't change anything.
> 
> The name of the patch doesn't help:
> 	sched: Extend task command name to 64 bytes
> 

well, I will try to make it clear next time :)


> If you want to catch/check all the uses I suspect that all the
> occurrences of TASK_COMM_LEN need changing.
> For clarity this one should probably be TASK_COMM_LEN_OLD.
> (that might be problematic for the uapi headers)
> 

That works for me as well, and I don't see TASK_COMM_LEN being used at 
include/uapi/.

> -- David
> 
>>
>> -- Steve
>