[Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

/proc/timer_list and /proc/slabinfo are not supposed to be written,
so there should be no write permissions on it.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: David Rientjes <rientjes@google.com>

---
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index a999b92..fddd69d 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -286,7 +286,7 @@ static int __init init_timer_list_procfs(void)
 {
 	struct proc_dir_entry *pe;
 
-	pe = proc_create("timer_list", 0644, NULL, &timer_list_fops);
+	pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
 	if (!pe)
 		return -ENOMEM;
 	return 0;
diff --git a/mm/slab.c b/mm/slab.c
index 7b5d4de..a19e4be 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4473,7 +4473,7 @@ static const struct file_operations proc_slabstats_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
 #ifdef CONFIG_DEBUG_SLAB_LEAK
 	proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
 #endif
diff --git a/mm/slub.c b/mm/slub.c
index b9f1491..aba2c1b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4726,7 +4726,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
 	return 0;
 }
 module_init(slab_proc_init);

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Ingo Molnar]

* Amerigo Wang <amwang@redhat.com> wrote:

> /proc/timer_list and /proc/slabinfo are not supposed to be 
> written, so there should be no write permissions on it.

good catch!

> --- a/kernel/time/timer_list.c
> +++ b/kernel/time/timer_list.c

I have applied the timer_list bits to the timer tree. The SLUB/SLAB 
bits should go into the SLAB tree i guess.

Thanks,

	Ingo

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Pekka Enberg]

On Mon, 2009-08-17 at 11:48 +0200, Ingo Molnar wrote:
> * Amerigo Wang <amwang@redhat.com> wrote:
> 
> > /proc/timer_list and /proc/slabinfo are not supposed to be 
> > written, so there should be no write permissions on it.
> 
> good catch!
> 
> > --- a/kernel/time/timer_list.c
> > +++ b/kernel/time/timer_list.c
> 
> I have applied the timer_list bits to the timer tree. The SLUB/SLAB 
> bits should go into the SLAB tree i guess.

Yeah, I'll grab the slab parts to slab.git if I don't see a separate
patch in my inbox when I get home. Thanks!

			Pekka

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Christoph Lameter]

On Mon, 17 Aug 2009, Pekka Enberg wrote:

> > I have applied the timer_list bits to the timer tree. The SLUB/SLAB
> > bits should go into the SLAB tree i guess.
>
> Yeah, I'll grab the slab parts to slab.git if I don't see a separate
> patch in my inbox when I get home. Thanks!

slab needs the write permissions for tuning!

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Pekka Enberg]

Hi Christoph,

Christoph Lameter wrote:
> On Mon, 17 Aug 2009, Pekka Enberg wrote:
> 
>>> I have applied the timer_list bits to the timer tree. The SLUB/SLAB
>>> bits should go into the SLAB tree i guess.
>> Yeah, I'll grab the slab parts to slab.git if I don't see a separate
>> patch in my inbox when I get home. Thanks!
> 
> slab needs the write permissions for tuning!

Oh, crap, you're right, I had forgotten about that. It's probably best 
to keep slub permissions as-is, no?

			Pekka

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Christoph Lameter]

On Mon, 17 Aug 2009, Pekka Enberg wrote:

> > slab needs the write permissions for tuning!
>
> Oh, crap, you're right, I had forgotten about that. It's probably best to keep
> slub permissions as-is, no?

slub perms can be changed. The patch is okay for that. But there is no
write method in slub. Effectively it makes no difference. Just the
display is nicer in /proc.


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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

[-- Attachment #1: Type: text/plain, Size: 580 bytes --]

Christoph Lameter wrote:
> On Mon, 17 Aug 2009, Pekka Enberg wrote:
>
>   
>>> slab needs the write permissions for tuning!
>>>       
>> Oh, crap, you're right, I had forgotten about that. It's probably best to keep
>> slub permissions as-is, no?
>>     

Oops! I misread the code... sorry.

>
> slub perms can be changed. The patch is okay for that. But there is no
> write method in slub. Effectively it makes no difference. Just the
> display is nicer in /proc.
>
>
>   
Ah, ok, I update this part of patch, attached.

Thanks!

Signed-off-by: WANG Cong <amwang@redhat.com>




[-- Attachment #2: proc-file-write-permission-fix2.diff --]
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diff --git a/mm/slub.c b/mm/slub.c
index b9f1491..aba2c1b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4726,7 +4726,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
 	return 0;
 }
 module_init(slab_proc_init);

Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Li Zefan]

>  static int __init slab_proc_init(void)
>  {
> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
> +	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);

S_IRUSR|S_IRUGO == S_IRUGO

>  	return 0;
>  }
>  module_init(slab_proc_init);

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

[-- Attachment #1: Type: text/plain, Size: 344 bytes --]

Li Zefan wrote:
>>  static int __init slab_proc_init(void)
>>  {
>> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
>> +	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
>>     
>
> S_IRUSR|S_IRUGO == S_IRUGO
>
>   

Ah, yeah. Thanks!

Update it.

Signed-off-by: WANG Cong <amwang@redhat.com>



[-- Attachment #2: proc-file-write-permission-fix2.diff --]
[-- Type: text/plain, Size: 414 bytes --]

diff --git a/mm/slub.c b/mm/slub.c
index b9f1491..61398c0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4726,7 +4726,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
 	return 0;
 }
 module_init(slab_proc_init);

Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Wu Fengguang]

On Tue, Aug 18, 2009 at 11:08:30AM +0800, Amerigo Wang wrote:

> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
> +	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);

Style nitpick. The spaces were packed to fit into 80-col I guess.


ERROR: space required after that ',' (ctx:VxV)
#10: FILE: mm/slub.c:4729:
+       proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
                              ^

ERROR: space required after that ',' (ctx:VxV)
#10: FILE: mm/slub.c:4729:
+       proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
                                      ^

ERROR: space required after that ',' (ctx:VxO)
#10: FILE: mm/slub.c:4729:
+       proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
                                           ^

ERROR: space required before that '&' (ctx:OxV)
#10: FILE: mm/slub.c:4729:
+       proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
                                            ^

Thanks,
Fengguang

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

Wu Fengguang wrote:
> On Tue, Aug 18, 2009 at 11:08:30AM +0800, Amerigo Wang wrote:
>
>   
>> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
>> +	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
>>     
>
> Style nitpick. The spaces were packed to fit into 80-col I guess.
>
>   

Yeah, I noticed this too, the reason I didn't fix this is that I don't 
want to mix coding style fix with this one. We can fix it in another 
patch, if you want. :)

Thanks.

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Wu Fengguang]

On Wed, Aug 19, 2009 at 10:36:30AM +0800, Amerigo Wang wrote:
> Wu Fengguang wrote:
> > On Tue, Aug 18, 2009 at 11:08:30AM +0800, Amerigo Wang wrote:
> >
> >   
> >> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
> >> +	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
> >>     
> >
> > Style nitpick. The spaces were packed to fit into 80-col I guess.
> >
> >   
> 
> Yeah, I noticed this too, the reason I didn't fix this is that I don't 
> want to mix coding style fix with this one. We can fix it in another 
> patch, if you want. :)

Why not? This don't hurt readability of the patch, hehe.

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

[-- Attachment #1: Type: text/plain, Size: 937 bytes --]

Wu Fengguang wrote:
> On Wed, Aug 19, 2009 at 10:36:30AM +0800, Amerigo Wang wrote:
>   
>> Wu Fengguang wrote:
>>     
>>> On Tue, Aug 18, 2009 at 11:08:30AM +0800, Amerigo Wang wrote:
>>>
>>>   
>>>       
>>>> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
>>>> +	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
>>>>     
>>>>         
>>> Style nitpick. The spaces were packed to fit into 80-col I guess.
>>>
>>>   
>>>       
>> Yeah, I noticed this too, the reason I didn't fix this is that I don't 
>> want to mix coding style fix with this one. We can fix it in another 
>> patch, if you want. :)
>>     
>
> Why not? This don't hurt readability of the patch, hehe.
>   

Here we go.

Pekka, could you please also take the patch attached below? It is just a 
trivial coding style fix. And it is based on the my previous patch.

Thanks!


Signed-off-by: WANG Cong <amwang@redhat.com>




[-- Attachment #2: mm-slub_c-style-fix.diff --]
[-- Type: text/plain, Size: 915 bytes --]

diff --git a/mm/slub.c b/mm/slub.c
index 61398c0..1cd60ff 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1109,8 +1109,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	}
 
 	if (kmemcheck_enabled
-		&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS)))
-	{
+		&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
 		int pages = 1 << oo_order(oo);
 
 		kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
@@ -2001,7 +2000,7 @@ static inline int calculate_order(int size)
 				return order;
 			fraction /= 2;
 		}
-		min_objects --;
+		min_objects--;
 	}
 
 	/*
@@ -4726,7 +4725,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-	proc_create("slabinfo",S_IRUGO,NULL,&proc_slabinfo_operations);
+	proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
 	return 0;
 }
 module_init(slab_proc_init);

Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Pekka Enberg]

Amerigo Wang wrote:
> Pekka, could you please also take the patch attached below? It is just a 
> trivial coding style fix. And it is based on the my previous patch.

The last hunk was already in slab.git because I fixed your patch up by 
hand. I applied the rest but can you please send proper patches in the 
future? That is, no attachments and a "git am" friendly subject line. 
Thanks!

			Pekka

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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Amerigo Wang]

Pekka Enberg wrote:
> Amerigo Wang wrote:
>> Pekka, could you please also take the patch attached below? It is 
>> just a trivial coding style fix. And it is based on the my previous 
>> patch.
>
> The last hunk was already in slab.git because I fixed your patch up by 
> hand. I applied the rest but can you please send proper patches in the 
> future? That is, no attachments and a "git am" friendly subject line. 
> Thanks!

Nice. Thanks!


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Re: [Patch] proc: drop write permission on 'timer_list' and 'slabinfo'

[Pekka Enberg]

Li Zefan wrote:
>>  static int __init slab_proc_init(void)
>>  {
>> -	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
>> +	proc_create("slabinfo",S_IRUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
> 
> S_IRUSR|S_IRUGO == S_IRUGO
> 
>>  	return 0;
>>  }
>>  module_init(slab_proc_init);
> 

I went ahead and fixed that. Applied, thanks everyone!

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