* [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
@ 2013-11-25 2:53 Lan Tianyu
2013-11-25 4:30 ` Viresh Kumar
0 siblings, 1 reply; 6+ messages in thread
From: Lan Tianyu @ 2013-11-25 2:53 UTC (permalink / raw)
To: rjw, viresh.kumar, hg197; +Cc: Lan Tianyu, cpufreq, linux-pm, linux-kernel
Currently, cpuinfo_cur_freq is only accessible for root user while
other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
to ordinary user. This seems make no sense. This patch is to change
it.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
drivers/cpufreq/cpufreq.c | 2 +-
include/linux/cpufreq.h | 4 ----
2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 02d534d..1926465 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -605,7 +605,7 @@ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
}
-cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
+cpufreq_freq_attr_ro(cpuinfo_cur_freq);
cpufreq_freq_attr_ro(cpuinfo_min_freq);
cpufreq_freq_attr_ro(cpuinfo_max_freq);
cpufreq_freq_attr_ro(cpuinfo_transition_latency);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 5bd6ab9..b4bb677 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -166,10 +166,6 @@ struct freq_attr {
static struct freq_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)
-#define cpufreq_freq_attr_ro_perm(_name, _perm) \
-static struct freq_attr _name = \
-__ATTR(_name, _perm, show_##_name, NULL)
-
#define cpufreq_freq_attr_rw(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)
--
1.8.4.rc0.1.g8f6a3e5.dirty
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
2013-11-25 2:53 [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege Lan Tianyu
@ 2013-11-25 4:30 ` Viresh Kumar
2013-11-25 5:33 ` Lan Tianyu
0 siblings, 1 reply; 6+ messages in thread
From: Viresh Kumar @ 2013-11-25 4:30 UTC (permalink / raw)
To: Lan Tianyu
Cc: Rafael J. Wysocki, hg197, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On 25 November 2013 08:23, Lan Tianyu <tianyu.lan@intel.com> wrote:
> Currently, cpuinfo_cur_freq is only accessible for root user while
> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
> to ordinary user. This seems make no sense. This patch is to change
> it.
There is nothing wrong with the code and so this is more of a design
change..
Probably Rafael can help us here as cpufreq_cur_freq will read stuff
directly from hardware instead of using cached value in software.
--
viresh
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
2013-11-25 4:30 ` Viresh Kumar
@ 2013-11-25 5:33 ` Lan Tianyu
2013-11-25 11:26 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Lan Tianyu @ 2013-11-25 5:33 UTC (permalink / raw)
To: Viresh Kumar
Cc: Rafael J. Wysocki, hg197, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On 2013年11月25日 12:30, Viresh Kumar wrote:
> On 25 November 2013 08:23, Lan Tianyu <tianyu.lan@intel.com> wrote:
>> Currently, cpuinfo_cur_freq is only accessible for root user while
>> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
>> to ordinary user. This seems make no sense. This patch is to change
>> it.
>
> There is nothing wrong with the code and so this is more of a design
> change..
>
> Probably Rafael can help us here as cpufreq_cur_freq will read stuff
> directly from hardware instead of using cached value in software.
I think so, too. I also tried to checking the reason of the privilege by
git log but the code was there before linux kernel being migrated to git
repository.
>
> --
> viresh
>
--
Best regards
Tianyu Lan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
2013-11-25 5:33 ` Lan Tianyu
@ 2013-11-25 11:26 ` Rafael J. Wysocki
2013-11-25 11:55 ` Lan Tianyu
0 siblings, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2013-11-25 11:26 UTC (permalink / raw)
To: Lan Tianyu
Cc: Viresh Kumar, hg197, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On Monday, November 25, 2013 01:33:39 PM Lan Tianyu wrote:
> On 2013年11月25日 12:30, Viresh Kumar wrote:
> > On 25 November 2013 08:23, Lan Tianyu <tianyu.lan@intel.com> wrote:
> >> Currently, cpuinfo_cur_freq is only accessible for root user while
> >> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
> >> to ordinary user. This seems make no sense. This patch is to change
> >> it.
> >
> > There is nothing wrong with the code and so this is more of a design
> > change..
> >
> > Probably Rafael can help us here as cpufreq_cur_freq will read stuff
> > directly from hardware instead of using cached value in software.
>
> I think so, too. I also tried to checking the reason of the privilege by
> git log but the code was there before linux kernel being migrated to git
> repository.
And it has always behaved in the same way? Then I wouldn't change it.
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
2013-11-25 11:26 ` Rafael J. Wysocki
@ 2013-11-25 11:55 ` Lan Tianyu
2013-11-25 12:14 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Lan Tianyu @ 2013-11-25 11:55 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Viresh Kumar, hg197, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On 11/25/2013 07:26 PM, Rafael J. Wysocki wrote:
> On Monday, November 25, 2013 01:33:39 PM Lan Tianyu wrote:
>> On 2013年11月25日 12:30, Viresh Kumar wrote:
>>> On 25 November 2013 08:23, Lan Tianyu <tianyu.lan@intel.com> wrote:
>>>> Currently, cpuinfo_cur_freq is only accessible for root user while
>>>> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
>>>> to ordinary user. This seems make no sense. This patch is to change
>>>> it.
>>>
>>> There is nothing wrong with the code and so this is more of a design
>>> change..
>>>
>>> Probably Rafael can help us here as cpufreq_cur_freq will read stuff
>>> directly from hardware instead of using cached value in software.
>>
>> I think so, too. I also tried to checking the reason of the privilege by
>> git log but the code was there before linux kernel being migrated to git
>> repository.
>
> And it has always behaved in the same way? Then I wouldn't change it.
>
It has been there since 2.6.12-rc2 or more early. But the
cpuinfo_cur_freq is read-only and seems no harmful.
Request from bug 65611.
https://bugzilla.kernel.org/show_bug.cgi?id=65611.
> Thanks!
>
--
Best Regards
Tianyu Lan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege
2013-11-25 11:55 ` Lan Tianyu
@ 2013-11-25 12:14 ` Rafael J. Wysocki
0 siblings, 0 replies; 6+ messages in thread
From: Rafael J. Wysocki @ 2013-11-25 12:14 UTC (permalink / raw)
To: Lan Tianyu
Cc: Viresh Kumar, hg197, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On Monday, November 25, 2013 07:55:33 PM Lan Tianyu wrote:
> On 11/25/2013 07:26 PM, Rafael J. Wysocki wrote:
> > On Monday, November 25, 2013 01:33:39 PM Lan Tianyu wrote:
> >> On 2013年11月25日 12:30, Viresh Kumar wrote:
> >>> On 25 November 2013 08:23, Lan Tianyu <tianyu.lan@intel.com> wrote:
> >>>> Currently, cpuinfo_cur_freq is only accessible for root user while
> >>>> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available
> >>>> to ordinary user. This seems make no sense. This patch is to change
> >>>> it.
> >>>
> >>> There is nothing wrong with the code and so this is more of a design
> >>> change..
> >>>
> >>> Probably Rafael can help us here as cpufreq_cur_freq will read stuff
> >>> directly from hardware instead of using cached value in software.
> >>
> >> I think so, too. I also tried to checking the reason of the privilege by
> >> git log but the code was there before linux kernel being migrated to git
> >> repository.
> >
> > And it has always behaved in the same way? Then I wouldn't change it.
> >
>
> It has been there since 2.6.12-rc2 or more early. But the
> cpuinfo_cur_freq is read-only and seems no harmful.
If it reads things directly from hardware, it may not be totally neutral.
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-11-25 2:53 [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege Lan Tianyu
2013-11-25 4:30 ` Viresh Kumar
2013-11-25 5:33 ` Lan Tianyu
2013-11-25 11:26 ` Rafael J. Wysocki
2013-11-25 11:55 ` Lan Tianyu
2013-11-25 12:14 ` Rafael J. Wysocki
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