[PATCH] clocksource: Fix permissions for available_clocksource

[PATCH] clocksource: Fix permissions for available_clocksource

[Heiko Carstens]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

File permissions for
/sys/devices/system/clocksource/clocksource0/available_clocksource
are 600 which allows write access. But this is in fact a read only
file. So change permissions to 400.

Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
 kernel/time/clocksource.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/kernel/time/clocksource.c
===================================================================
--- linux-2.6.orig/kernel/time/clocksource.c
+++ linux-2.6/kernel/time/clocksource.c
@@ -474,7 +474,7 @@ sysfs_show_available_clocksources(struct
 static SYSDEV_ATTR(current_clocksource, 0600, sysfs_show_current_clocksources,
 		   sysfs_override_clocksource);
 
-static SYSDEV_ATTR(available_clocksource, 0600,
+static SYSDEV_ATTR(available_clocksource, 0400,
 		   sysfs_show_available_clocksources, NULL);
 
 static struct sysdev_class clocksource_sysclass = {

Re: [PATCH] clocksource: Fix permissions for available_clocksource

[Thomas Gleixner]

On Fri, 2 May 2008, Heiko Carstens wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
> 
> File permissions for
> /sys/devices/system/clocksource/clocksource0/available_clocksource
> are 600 which allows write access. But this is in fact a read only
> file. So change permissions to 400.

Indeed. The question is whether we should make this 444. There is no
harm, when users can read the info. Same applies for the
current_clocksource entry, making it 644 should be fine.
 
Thanks,
	tglx

> Cc: John Stultz <johnstul@us.ibm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> ---
>  kernel/time/clocksource.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/kernel/time/clocksource.c
> ===================================================================
> --- linux-2.6.orig/kernel/time/clocksource.c
> +++ linux-2.6/kernel/time/clocksource.c
> @@ -474,7 +474,7 @@ sysfs_show_available_clocksources(struct
>  static SYSDEV_ATTR(current_clocksource, 0600, sysfs_show_current_clocksources,
>  		   sysfs_override_clocksource);
>  
> -static SYSDEV_ATTR(available_clocksource, 0600,
> +static SYSDEV_ATTR(available_clocksource, 0400,
>  		   sysfs_show_available_clocksources, NULL);
>  
>  static struct sysdev_class clocksource_sysclass = {
> 

Re: [PATCH] clocksource: Fix permissions for available_clocksource

[Heiko Carstens]

On Fri, May 02, 2008 at 04:36:37PM +0200, Thomas Gleixner wrote:
> On Fri, 2 May 2008, Heiko Carstens wrote:
> > From: Heiko Carstens <heiko.carstens@de.ibm.com>
> > 
> > File permissions for
> > /sys/devices/system/clocksource/clocksource0/available_clocksource
> > are 600 which allows write access. But this is in fact a read only
> > file. So change permissions to 400.
> 
> Indeed. The question is whether we should make this 444. There is no
> harm, when users can read the info. Same applies for the
> current_clocksource entry, making it 644 should be fine.

Sure, I can send an on-top patch for this.

Btw. did you recently try writing "jiffies" to current_clocksource?
That seems to be a trick to stop the clock...

Re: [PATCH] clocksource: Fix permissions for available_clocksource

[Thomas Gleixner]

On Fri, 2 May 2008, Heiko Carstens wrote:
> On Fri, May 02, 2008 at 04:36:37PM +0200, Thomas Gleixner wrote:
> > On Fri, 2 May 2008, Heiko Carstens wrote:
> > > From: Heiko Carstens <heiko.carstens@de.ibm.com>
> > > 
> > > File permissions for
> > > /sys/devices/system/clocksource/clocksource0/available_clocksource
> > > are 600 which allows write access. But this is in fact a read only
> > > file. So change permissions to 400.
> > 
> > Indeed. The question is whether we should make this 444. There is no
> > harm, when users can read the info. Same applies for the
> > current_clocksource entry, making it 644 should be fine.
> 
> Sure, I can send an on-top patch for this.

Yes, please.
 
> Btw. did you recently try writing "jiffies" to current_clocksource?
> That seems to be a trick to stop the clock...

Hmm, that's after the kernel switched to highres and/or nohz, right ?
This came up earlier, but it got dropped from my to todo list. :(
Will have a look.

Thanks,

	tglx

Re: [PATCH] clocksource: Fix permissions for available_clocksource

[john stultz]

On Fri, 2008-05-02 at 12:49 +0200, Heiko Carstens wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
> 
> File permissions for
> /sys/devices/system/clocksource/clocksource0/available_clocksource
> are 600 which allows write access. But this is in fact a read only
> file. So change permissions to 400.
> 
> Cc: John Stultz <johnstul@us.ibm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

Ah, good catch. 

Acked-by: John Stultz <johnstul@us.ibm.com>


> ---
>  kernel/time/clocksource.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/kernel/time/clocksource.c
> ===================================================================
> --- linux-2.6.orig/kernel/time/clocksource.c
> +++ linux-2.6/kernel/time/clocksource.c
> @@ -474,7 +474,7 @@ sysfs_show_available_clocksources(struct
>  static SYSDEV_ATTR(current_clocksource, 0600, sysfs_show_current_clocksources,
>  		   sysfs_override_clocksource);
> 
> -static SYSDEV_ATTR(available_clocksource, 0600,
> +static SYSDEV_ATTR(available_clocksource, 0400,
>  		   sysfs_show_available_clocksources, NULL);
> 
>  static struct sysdev_class clocksource_sysclass = {

Re: [PATCH] clocksource: Fix permissions for available_clocksource

[Heiko Carstens]

On Fri, May 02, 2008 at 05:34:06PM +0200, Thomas Gleixner wrote:
> On Fri, 2 May 2008, Heiko Carstens wrote:
> > On Fri, May 02, 2008 at 04:36:37PM +0200, Thomas Gleixner wrote:
> > > On Fri, 2 May 2008, Heiko Carstens wrote:
> > > > From: Heiko Carstens <heiko.carstens@de.ibm.com>
> > > > 
> > > > File permissions for
> > > > /sys/devices/system/clocksource/clocksource0/available_clocksource
> > > > are 600 which allows write access. But this is in fact a read only
> > > > file. So change permissions to 400.
> > > 
> > > Indeed. The question is whether we should make this 444. There is no
> > > harm, when users can read the info. Same applies for the
> > > current_clocksource entry, making it 644 should be fine.
> > 
> > Sure, I can send an on-top patch for this.
> 
> Yes, please.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
 kernel/time/clocksource.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6/kernel/time/clocksource.c
===================================================================
--- linux-2.6.orig/kernel/time/clocksource.c
+++ linux-2.6/kernel/time/clocksource.c
@@ -471,10 +471,10 @@ sysfs_show_available_clocksources(struct
 /*
  * Sysfs setup bits:
  */
-static SYSDEV_ATTR(current_clocksource, 0600, sysfs_show_current_clocksources,
+static SYSDEV_ATTR(current_clocksource, 0644, sysfs_show_current_clocksources,
 		   sysfs_override_clocksource);
 
-static SYSDEV_ATTR(available_clocksource, 0400,
+static SYSDEV_ATTR(available_clocksource, 0444,
 		   sysfs_show_available_clocksources, NULL);
 
 static struct sysdev_class clocksource_sysclass = {