linux-kernel - RE: [PATCH v11 14/31] x86/resctrl: Discover hardware telemetry events

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: <DS7PR11MB6077067F8807424708439981FCE1A@DS7PR11MB6077.namprd11.prod.outlook.com>
Date: Wed, 8 Oct 2025 17:20:21 +0000
From: "Luck, Tony" <tony.luck@...el.com>
To: "Chatre, Reinette" <reinette.chatre@...el.com>
CC: Fenghua Yu <fenghuay@...dia.com>, "Wieczor-Retman, Maciej"
	<maciej.wieczor-retman@...el.com>, Peter Newman <peternewman@...gle.com>,
	James Morse <james.morse@....com>, Babu Moger <babu.moger@....com>, "Drew
 Fustini" <dfustini@...libre.com>, Dave Martin <Dave.Martin@....com>, "Chen,
 Yu C" <yu.c.chen@...el.com>, "x86@...nel.org" <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"patches@...ts.linux.dev" <patches@...ts.linux.dev>
Subject: RE: [PATCH v11 14/31] x86/resctrl: Discover hardware telemetry events

> > static bool get_pmt_feature(enum pmt_feature_id feature, struct event_group **evgs,
> >                         unsigned int num_evg)
> > {
> >     struct pmt_feature_group *p;
> >     struct event_group **peg;
> >     bool ret = false;
> >
> >     for (peg = evgs; peg < &evgs[num_evg]; peg++) {
> >             p = intel_pmt_get_regions_by_feature(feature);
> >             if (IS_ERR_OR_NULL(p))
> >                     return false;
> >
> >             if (enable_events(*peg, p)) {
> >                     (*peg)->pfg = p;
> >                     ret = true;
> >             } else {
> >                     intel_pmt_put_feature_group(p);
> >             }
> >     }
> >     intel_pmt_put_feature_group(p);
>
> I am not able to tell why this "put" is needed? I assume the "put" of a
> pmt_feature_group assigned to an event_group will still be done in
> intel_aet_exit()?

Reinette

That "put" was left over from the previous version. You are right it
isn't needed. The "put" will be done in intel_aet_exit()

-Tony