Commit 94457b36 authored by Tony Luck's avatar Tony Luck Committed by Thomas Gleixner
Browse files

x86/intel_rdt: Add diagnostics when writing the cpus file 



Can't add a cpu to a monitor group unless it belongs to parent
group. Can't delete cpus from the default group.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/757a869a25e9fc1b7a2e9bc43e1159455c1964a0.1506382469.git.tony.luck@intel.com
parent 29e74f35

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

+12 −3
Original line number Diff line number Diff line
@@ -264,8 +264,10 @@ static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, 


	/* Check whether cpus belong to parent ctrl group */

	cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);

	if (cpumask_weight(tmpmask))

	if (cpumask_weight(tmpmask)) {

		rdt_last_cmd_puts("can only add CPUs to mongroup that belong to parent\n");

		return -EINVAL;

	}



	/* Check whether cpus are dropped from this group */

	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
@@ -317,8 +319,10 @@ static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, 
	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);

	if (cpumask_weight(tmpmask)) {

		/* Can't drop from default group */

		if (rdtgrp == &rdtgroup_default)

		if (rdtgrp == &rdtgroup_default) {

			rdt_last_cmd_puts("Can't drop CPUs from default group\n");

			return -EINVAL;

		}



		/* Give any dropped cpus to rdtgroup_default */

		cpumask_or(&rdtgroup_default.cpu_mask,
@@ -383,8 +387,10 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, 
	}



	rdtgrp = rdtgroup_kn_lock_live(of->kn);

	rdt_last_cmd_clear();

	if (!rdtgrp) {

		ret = -ENOENT;

		rdt_last_cmd_puts("directory was removed\n");

		goto unlock;

	}
@@ -393,13 +399,16 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, 
	else

		ret = cpumask_parse(buf, newmask);



	if (ret)

	if (ret) {

		rdt_last_cmd_puts("bad cpu list/mask\n");

		goto unlock;

	}



	/* check that user didn't specify any offline cpus */

	cpumask_andnot(tmpmask, newmask, cpu_online_mask);

	if (cpumask_weight(tmpmask)) {

		ret = -EINVAL;

		rdt_last_cmd_puts("can only assign online cpus\n");

		goto unlock;

	}

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