linux-kernel - RE: [EXT] Re: [PATCH v4 5/6] perf: imx_perf: limit counter ID from user space and optimize counter usage

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: Thu, 29 Feb 2024 10:29:45 +0000
From: Xu Yang <xu.yang_2@....com>
To: Will Deacon <will@...nel.org>
CC: Frank Li <frank.li@....com>, "mark.rutland@....com"
	<mark.rutland@....com>, "robh+dt@...nel.org" <robh+dt@...nel.org>,
	"krzysztof.kozlowski+dt@...aro.org" <krzysztof.kozlowski+dt@...aro.org>,
	"conor+dt@...nel.org" <conor+dt@...nel.org>, "shawnguo@...nel.org"
	<shawnguo@...nel.org>, "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
	"kernel@...gutronix.de" <kernel@...gutronix.de>, "festevam@...il.com"
	<festevam@...il.com>, "john.g.garry@...cle.com" <john.g.garry@...cle.com>,
	"jolsa@...nel.org" <jolsa@...nel.org>, "namhyung@...nel.org"
	<namhyung@...nel.org>, "irogers@...gle.com" <irogers@...gle.com>,
	dl-linux-imx <linux-imx@....com>, "mike.leach@...aro.org"
	<mike.leach@...aro.org>, "leo.yan@...aro.org" <leo.yan@...aro.org>,
	"peterz@...radead.org" <peterz@...radead.org>, "mingo@...hat.com"
	<mingo@...hat.com>, "acme@...nel.org" <acme@...nel.org>,
	"alexander.shishkin@...ux.intel.com" <alexander.shishkin@...ux.intel.com>,
	"adrian.hunter@...el.com" <adrian.hunter@...el.com>,
	"linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>, "devicetree@...r.kernel.org"
	<devicetree@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "linux-perf-users@...r.kernel.org"
	<linux-perf-users@...r.kernel.org>, "imx@...ts.linux.dev"
	<imx@...ts.linux.dev>
Subject: RE: [EXT] Re: [PATCH v4 5/6] perf: imx_perf: limit counter ID from
 user space and optimize counter usage


> 
> On Wed, Jan 31, 2024 at 01:58:10PM +0800, Xu Yang wrote:
> > The user can pass any counter ID to perf app. However, current pmu driver
> > doesn't judge the validity of the counter ID. This will add necessary
> > check for counter ID from user space. Besides, this pmu has 10 counters
> > except cycle counter which can be used to count reference events and
> > counter specific evnets. This will also add supports to auto allocate
> > counter if the user doesn't pass it the perf. Then, the usage of counter
> > will be optimized.
> >
> > Signed-off-by: Xu Yang <xu.yang_2@....com>
> >
> > ---
> > Changes in v2:
> >  - limit counter ID from user to 0-10
> >  - combine dynamic and static allocation of counter
> > Changes in v3:
> >  - no changes
> > Changes in v4:
> >  - rename ddr_perf_is_specific_event()
> >  - use macro definitions to parse config attr
> > ---
> >  drivers/perf/fsl_imx9_ddr_perf.c | 72 +++++++++++++++++++++++++++++++-
> >  1 file changed, 71 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/perf/fsl_imx9_ddr_perf.c b/drivers/perf/fsl_imx9_ddr_perf.c
> > index 94041f06c152..e71496809c52 100644
> > --- a/drivers/perf/fsl_imx9_ddr_perf.c
> > +++ b/drivers/perf/fsl_imx9_ddr_perf.c
> > @@ -51,6 +51,7 @@
> >
> >  #define NUM_COUNTERS         11
> >  #define CYCLES_COUNTER               0
> > +#define CYCLES_EVENT_ID              0
> >
> >  #define CONFIG_EVENT_MASK    0x00FF
> >  #define CONFIG_EVENT_OFFSET  0
> > @@ -240,6 +241,19 @@ static struct attribute *ddr_perf_events_attrs[] = {
> >       NULL,
> >  };
> >
> > +/*
> > + * An event is either reference evnet or counter specific event.
> > + * For counter specific event, the event count will only be incremented
> > + * on the corresponding counter.
> > + */
> > +static bool ddr_perf_is_counter_specific_event(int event)
> > +{
> > +     if (event >= 64 && event <= 73)
> > +             return true;
> > +     else
> > +             return false;
> 
> Just collapse this to 'return event >= 64 && event <= 73;'

Okay.

Thanks,
Xu Yang

> 
> Will