linux-kernel - Re: [RFC][PATCH 3/3] sched: User Mode Concurency Groups

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]

Date:   Mon, 17 Jan 2022 13:22:30 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Peter Oskolkov <posk@...k.io>
Cc:     mingo@...hat.com, tglx@...utronix.de, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, linux-api@...r.kernel.org, x86@...nel.org,
        pjt@...gle.com, posk@...gle.com, avagin@...gle.com,
        jannh@...gle.com, tdelisle@...terloo.ca
Subject: Re: [RFC][PATCH 3/3] sched: User Mode Concurency Groups

On Mon, Jan 17, 2022 at 12:35:29PM +0100, Peter Zijlstra wrote:
> @@ -794,16 +798,31 @@ SYSCALL_DEFINE3(umcg_ctl, u32, flags, st
>  		      UMCG_CTL_WORKER))
>  		return -EINVAL;
>  
> -	if (flags == UMCG_CTL_UNREGISTER) {
> -		if (self || !current->umcg_task)
> +	if (flags & UMCG_CTL_UNREGISTER) {
> +		int ret;
> +
> +		if (!self || self != current->umcg_task)
>  			return -EINVAL;
>  
> -		if (current->flags & PF_UMCG_WORKER) {
> -			umcg_worker_exit();
> -			// XXX wake server
> -		} else
> -			umcg_clear_task(current);
> +		current->flags &= ~PF_UMCG_WORKER;
>  
> +		ret = umcg_pin_pages();
> +		if (ret) {
> +			current->flags |= PF_UMCG_WORKER;
> +			return ret;
> +		}
> +
> +		ret = umcg_update_state(current, self, UMCG_TASK_RUNNING, UMCG_TASK_NONE);
> +		if (ret) {
> +			current->flags |= PF_UMCG_WORKER;
> +			return ret;
> +		}

Sorry, should obv only restore PF_UMCG_WORKER for workers.. /me fixes

> +
> +		if (current->flags & PF_UMCG_WORKER)
> +			umcg_wake(current);
> +
> +		umcg_unpin_pages();
> +		umcg_clear_task(current);
>  		return 0;
>  	}
>