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Subject: Re: [PATCH -tip 23/32] sched: Add a per-thread core scheduling
 interface
From:   chris hyser <chris.hyser@oracle.com>
To:     "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc:     Nishanth Aravamudan <naravamudan@digitalocean.com>,
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References: <20201117232003.3580179-1-joel@joelfernandes.org>
 <20201117232003.3580179-24-joel@joelfernandes.org>
 <20201202214717.GA27531@chyser-vm-1.appad1iad.osdevelopmeniad.oraclevcn.com>
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Date:   Wed, 2 Dec 2020 18:13:07 -0500
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On 12/2/20 4:47 PM, Chris Hyser wrote:

> +	get_task_struct(task);
> +
> +	/*
> +	 * Check if this process has the right to modify the specified
> +	 * process. Use the regular "ptrace_may_access()" checks.
> +	 */
> +	if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
> +		rcu_read_unlock();
> +		err = -EPERM;
> +		goto out;
> +	}
> +	rcu_read_unlock();
> +
> +	if (flags == PR_SCHED_CORE_CLEAR) {
> +		dest = task;
> +		src = NULL;
> +	} else if (flags == PR_SCHED_CORE_SHARE_TO) {
> +		dest = task;
> +		src = current;
> +	} else if (flags == PR_SCHED_CORE_SHARE_FROM) {
> +		dest = current;
> +		src = task;
> +	}

I should have put in an else clause to catch bad input.

> +
> +	err = sched_core_share_tasks(dest, src);
>   out:
>   	if (task)
>   		put_task_struct(task);