linux-kernel - Re: [PATCH 2/5] x86/mbm: Intel Memory B/W Monitoring enumeration and init

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: <alpine.DEB.2.10.1602241010090.28838@vshiva-Udesk>
Date:	Wed, 24 Feb 2016 10:12:06 -0800 (PST)
From:	Vikas Shivappa <vikas.shivappa@...el.com>
To:	Thomas Gleixner <tglx@...utronix.de>
cc:	Vikas Shivappa <vikas.shivappa@...ux.intel.com>,
	vikas.shivappa@...el.com, x86@...nel.org,
	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	peterz@...radead.org, ravi.v.shankar@...el.com,
	tony.luck@...el.com, fenghua.yu@...el.com,
	kanaka.d.juvva@...el.com, h.peter.anvin@...el.com
Subject: Re: [PATCH 2/5] x86/mbm: Intel Memory B/W Monitoring enumeration
 and init



On Wed, 24 Feb 2016, Thomas Gleixner wrote:

> On Wed, 10 Feb 2016, Vikas Shivappa wrote:ar
>> +static int intel_mbm_init(void)
>> +{
>> +	int ret = 0, array_size, maxid = cqm_max_rmid + 1;
>> +
>> +	mbm_socket_max = cpumask_weight(&cqm_cpumask);
>
> This should use the new topology_max_packages() function, so you can alloc
> your array correctly even if not all sockets are online/plugged yet.

Will fix. Thanks for pointing out.

>
>> +	array_size = sizeof(struct sample) * maxid * mbm_socket_max;
>> +	mbm_local = kmalloc(array_size, GFP_KERNEL);
>> +	if (!mbm_local) {
>> +		ret = -ENOMEM;
>
> return -ENOMEM is sufficient here.

Will fix

>
>> +		goto out;
>> +	}
>> +
>> +	mbm_total = kmalloc(array_size, GFP_KERNEL);
>> +	if (!mbm_total) {
>> +		kfree(mbm_local);
>> +		ret = -ENOMEM;
>> +	}
>> +out:
>> +
>> +	return ret;
>> +}
>> +
>>  	cqm_l3_scale = boot_cpu_data.x86_cache_occ_scale;
>> @@ -1384,14 +1520,34 @@ static int __init intel_cqm_init(void)
>>
>>  	__perf_cpu_notifier(intel_cqm_cpu_notifier);
>
> You really should register the notifier _AFTER_ registering the pmu. That
> needs to be fixed anyway, because the existing code leaks the notifier AND
> memory in case perf_pmu_register fails.

Correct, Will fix the notifier leak

Thanks,
Vikas

>
> Thanks,
>
> 	tglx
>