linux-kernel - Re: [PATCH v2 2/2] selftests: sched: skip cs_prctl_test for systems with core scheduling disabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID:
 <SA2PR10MB47149CA0B28DBAC122A960E29BC02@SA2PR10MB4714.namprd10.prod.outlook.com>
Date: Mon, 24 Feb 2025 23:02:20 +0000
From: Chris Hyser <chris.hyser@...cle.com>
To: Sinadin Shan <sinadin.shan@...cle.com>,
        Shrikanth Hegde
	<sshegde@...ux.ibm.com>,
        "shuah@...nel.org" <shuah@...nel.org>
CC: "linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] selftests: sched: skip cs_prctl_test for systems
 with core scheduling disabled

>From: Sinadin Shan <sinadin.shan@...cle.com>
>Sent: Monday, February 24, 2025 7:10 AM
>To: Shrikanth Hegde; shuah@...nel.org
>Cc: linux-kselftest@...r.kernel.org; linux-kernel@...r.kernel.org; Chris Hyser
>Subject: Re: [PATCH v2 2/2] selftests: sched: skip cs_prctl_test for systems with core scheduling disabled
>
>On 24-02-2025 01:49 pm, Shrikanth Hegde wrote:
...
>> If the self-tests are to be used in development flow, these checks may
>> not be sufficient.
>
>Right, this particular case was overlooked. To handle this, the test
>could take a path to the custom config as an argument. I shall work on
>getting this fixed.

I was thinking something along the lines of just calling the prctl. 

If you call it and SCHED_CORE is not configured, you will get an EINVAL. Unfortunately,
passing other bad values in the other prctl args will also give an EINVAL, but if you call it with a
non-existent PID (say max_pid + 1) it will generate an ESRCH if the code is present.

So something like (and I'd look up the maxpid on the actual system):

int check_core_sched()
{
        ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, 32769, PIDTYPE_PID,                                                                                                                                                         
                         (unsigned long)&cookie);                                                                                                                                                                            

        printf("ret = %d\n", ret);                                                                                                                                                                             
        perror("Error:\n");     
}

-chrish