linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] powerpc: compile kernel for linkstations optimized for size
@ 2008-10-13  4:07 Rogério Brito
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
                   ` (3 more replies)
  0 siblings, 4 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-13  4:07 UTC (permalink / raw)
  To: linux-kernel; +Cc: linuxppc-dev, akpm, rbrito

From: Rogério Brito <rbrito@ime.usp.br>

Since Linkstations and Kuroboxes often have *very* little memory (as
they are embedded systems), it is desirable to get their kernels
compiled optimized for size.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>

---

I have been using kernels optimized for size on my Kurobox (standard)
for many different releases and I have experienced no problem with this
option enabled. Thus, this patch.

--- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
+++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 00:38:58.000000000 -0300
@@ -90,7 +90,7 @@ CONFIG_NAMESPACES=y
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_INITRAMFS_SOURCE=""
-# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_SYSCTL=y
 # CONFIG_EMBEDDED is not set
 CONFIG_SYSCTL_SYSCALL=y


-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13  4:07 [PATCH] powerpc: compile kernel for linkstations optimized for size Rogério Brito
@ 2008-10-13  4:51 ` Rogério Brito
  2008-10-13 18:05   ` Guennadi Liakhovetski
                     ` (2 more replies)
  2008-10-13 18:03 ` [PATCH] powerpc: compile kernel for linkstations optimized for size Guennadi Liakhovetski
                   ` (2 subsequent siblings)
  3 siblings, 3 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-13  4:51 UTC (permalink / raw)
  To: linux-kernel; +Cc: linuxppc-dev, akpm, rbrito

The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
Randomization" option enabled.

Since some of these machines are facing the internet, it helps to have
heap randomization enabled. This patch enables it.


Signed-off-by: Rogério Brito <rbrito@ime.usp.br>

---

--- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
+++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 01:11:28.000000000 -0300
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
-# Linux kernel version: 2.6.27-rc4
-# Thu Aug 21 00:52:05 2008
+# Linux kernel version: 2.6.27
+# Mon Oct 13 01:11:21 2008
 #
 # CONFIG_PPC64 is not set
 
@@ -101,7 +101,7 @@ CONFIG_HOTPLUG=y
 CONFIG_PRINTK=y
 CONFIG_BUG=y
 CONFIG_ELF_CORE=y
-CONFIG_COMPAT_BRK=y
+# CONFIG_COMPAT_BRK is not set
 CONFIG_BASE_FULL=y
 CONFIG_FUTEX=y
 CONFIG_ANON_INODES=y
@@ -1211,7 +1211,6 @@ CONFIG_USB_STORAGE=m
 # CONFIG_USB_STORAGE_ALAUDA is not set
 # CONFIG_USB_STORAGE_ONETOUCH is not set
 # CONFIG_USB_STORAGE_KARMA is not set
-# CONFIG_USB_STORAGE_SIERRA is not set
 # CONFIG_USB_STORAGE_CYPRESS_ATACB is not set
 # CONFIG_USB_LIBUSUAL is not set
 

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: compile kernel for linkstations optimized for size
  2008-10-13  4:07 [PATCH] powerpc: compile kernel for linkstations optimized for size Rogério Brito
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
@ 2008-10-13 18:03 ` Guennadi Liakhovetski
  2008-10-13 21:28   ` Rogério Brito
  2008-10-17  9:37 ` Rogério Brito
  2008-10-28 13:58 ` Kumar Gala
  3 siblings, 1 reply; 14+ messages in thread
From: Guennadi Liakhovetski @ 2008-10-13 18:03 UTC (permalink / raw)
  To: Rogério Brito; +Cc: linux-kernel, linuxppc-dev, akpm

On Mon, 13 Oct 2008, Rogério Brito wrote:

> From: Rogério Brito <rbrito@ime.usp.br>
> 
> Since Linkstations and Kuroboxes often have *very* little memory (as
> they are embedded systems), it is desirable to get their kernels
> compiled optimized for size.
> 
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
> 
> ---
> 
> I have been using kernels optimized for size on my Kurobox (standard)
> for many different releases and I have experienced no problem with this
> option enabled. Thus, this patch.

The comment for this option says: "watch out for broken compilers," if 
this doesn't hold any more, it should be remove, if it still holds, I 
wouldn't turn this on by default, as I don't think we can test all 
possible (cross- or native-) compilers users might want to use. In any 
case this is one of options that users can select themselves, if it suits 
them. Also I don't think your CC list is correct, you wanted to send this 
to the powerpc list and one of powerpc / subarch maintainer.

Thanks
Guennadi

> 
> --- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
> +++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 00:38:58.000000000 -0300
> @@ -90,7 +90,7 @@ CONFIG_NAMESPACES=y
>  # CONFIG_PID_NS is not set
>  CONFIG_BLK_DEV_INITRD=y
>  CONFIG_INITRAMFS_SOURCE=""
> -# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
> +CONFIG_CC_OPTIMIZE_FOR_SIZE=y
>  CONFIG_SYSCTL=y
>  # CONFIG_EMBEDDED is not set
>  CONFIG_SYSCTL_SYSCALL=y
> 
> 
> -- 
> Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
> http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
> Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
@ 2008-10-13 18:05   ` Guennadi Liakhovetski
  2008-10-13 18:44     ` Scott Wood
  2008-10-17  9:38   ` Rogério Brito
  2008-10-28 13:58   ` Kumar Gala
  2 siblings, 1 reply; 14+ messages in thread
From: Guennadi Liakhovetski @ 2008-10-13 18:05 UTC (permalink / raw)
  To: Rogério Brito; +Cc: linux-kernel, linuxppc-dev, akpm

On Mon, 13 Oct 2008, Rogério Brito wrote:

> The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> Randomization" option enabled.
> 
> Since some of these machines are facing the internet, it helps to have
> heap randomization enabled. This patch enables it.

Same as the previous patch - this is one of options, that users select 
according to their needs. If any specific distribution enables this option 
by default in their kernels, they can do this too, don't think this is 
critical enough to patch the defconfig.

Thanks
Guennadi

> 
> 
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
> 
> ---
> 
> --- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
> +++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 01:11:28.000000000 -0300
> @@ -1,7 +1,7 @@
>  #
>  # Automatically generated make config: don't edit
> -# Linux kernel version: 2.6.27-rc4
> -# Thu Aug 21 00:52:05 2008
> +# Linux kernel version: 2.6.27
> +# Mon Oct 13 01:11:21 2008
>  #
>  # CONFIG_PPC64 is not set
>  
> @@ -101,7 +101,7 @@ CONFIG_HOTPLUG=y
>  CONFIG_PRINTK=y
>  CONFIG_BUG=y
>  CONFIG_ELF_CORE=y
> -CONFIG_COMPAT_BRK=y
> +# CONFIG_COMPAT_BRK is not set
>  CONFIG_BASE_FULL=y
>  CONFIG_FUTEX=y
>  CONFIG_ANON_INODES=y
> @@ -1211,7 +1211,6 @@ CONFIG_USB_STORAGE=m
>  # CONFIG_USB_STORAGE_ALAUDA is not set
>  # CONFIG_USB_STORAGE_ONETOUCH is not set
>  # CONFIG_USB_STORAGE_KARMA is not set
> -# CONFIG_USB_STORAGE_SIERRA is not set
>  # CONFIG_USB_STORAGE_CYPRESS_ATACB is not set
>  # CONFIG_USB_LIBUSUAL is not set
>  
> 
> -- 
> Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
> http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
> Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13 18:05   ` Guennadi Liakhovetski
@ 2008-10-13 18:44     ` Scott Wood
  2008-10-13 19:27       ` Guennadi Liakhovetski
                         ` (2 more replies)
  0 siblings, 3 replies; 14+ messages in thread
From: Scott Wood @ 2008-10-13 18:44 UTC (permalink / raw)
  To: Guennadi Liakhovetski
  Cc: Rogério Brito, linuxppc-dev, akpm, linux-kernel

On Mon, Oct 13, 2008 at 08:05:09PM +0200, Guennadi Liakhovetski wrote:
> On Mon, 13 Oct 2008, Rogério Brito wrote:
> 
> > The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> > Randomization" option enabled.
> > 
> > Since some of these machines are facing the internet, it helps to have
> > heap randomization enabled. This patch enables it.
> 
> Same as the previous patch - this is one of options, that users select 
> according to their needs. If any specific distribution enables this option 
> by default in their kernels, they can do this too, don't think this is 
> critical enough to patch the defconfig.

Just because users/distros can change it doesn't mean it's pointless to
discuss what default is sane, and make changes if the current default
isn't.

For security-related options it's usually best to default to the more
secure state, especially since the option description talks about it
being needed mainly for libc5 compatibility -- did libc5 ever even exist
for powerpc?  

The only reason it was turned on in the first place was likely the
"default y", which in turn is there to avoid breaking old x86 distros.

-Scott

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13 18:44     ` Scott Wood
@ 2008-10-13 19:27       ` Guennadi Liakhovetski
  2008-10-13 20:56       ` Rogério Brito
  2008-10-19  2:53       ` Rogério Brito
  2 siblings, 0 replies; 14+ messages in thread
From: Guennadi Liakhovetski @ 2008-10-13 19:27 UTC (permalink / raw)
  To: Scott Wood; +Cc: Rogério Brito, linuxppc-dev, akpm, linux-kernel

On Mon, 13 Oct 2008, Scott Wood wrote:

> On Mon, Oct 13, 2008 at 08:05:09PM +0200, Guennadi Liakhovetski wrote:
> > On Mon, 13 Oct 2008, Rogério Brito wrote:
> > 
> > > The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> > > Randomization" option enabled.
> > > 
> > > Since some of these machines are facing the internet, it helps to have
> > > heap randomization enabled. This patch enables it.
> > 
> > Same as the previous patch - this is one of options, that users select 
> > according to their needs. If any specific distribution enables this option 
> > by default in their kernels, they can do this too, don't think this is 
> > critical enough to patch the defconfig.
> 
> Just because users/distros can change it doesn't mean it's pointless to
> discuss what default is sane, and make changes if the current default
> isn't.
> 
> For security-related options it's usually best to default to the more
> secure state, especially since the option description talks about it
> being needed mainly for libc5 compatibility -- did libc5 ever even exist
> for powerpc?  

In a 2.6.27-rc5-ish snapshot I counted 68 enabled and 11 disabled 
CONFIG_COMPAT_BRK under arch/powerpc/configs/. Ok, enabling it for all 
would be a bit rude, and one has to start somewhere...

> The only reason it was turned on in the first place was likely the
> "default y", which in turn is there to avoid breaking old x86 distros.

Then maybe it would be better to make default y only for some platforms?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13 18:44     ` Scott Wood
  2008-10-13 19:27       ` Guennadi Liakhovetski
@ 2008-10-13 20:56       ` Rogério Brito
  2008-10-19  2:53       ` Rogério Brito
  2 siblings, 0 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-13 20:56 UTC (permalink / raw)
  To: Scott Wood; +Cc: Guennadi Liakhovetski, linuxppc-dev, akpm, linux-kernel

Hi, Scott, Guennadi.

On 13/10/2008, at 16:44, Scott Wood wrote:

> On Mon, Oct 13, 2008 at 08:05:09PM +0200, Guennadi Liakhovetski wrote:
>> On Mon, 13 Oct 2008, Rogério Brito wrote:
>>
>>> The current defconfig for Linkstation/Kuroboxes has the "Disable  
>>> Heap
>>> Randomization" option enabled.
>>>
>>> Since some of these machines are facing the internet, it helps to  
>>> have
>>> heap randomization enabled. This patch enables it.
>>
>> Same as the previous patch - this is one of options, that users  
>> select
>> according to their needs. If any specific distribution enables  
>> this option
>> by default in their kernels, they can do this too, don't think  
>> this is
>> critical enough to patch the defconfig.

I think that the matter is not being critical or not, but of  
including a sane default as the kernel should be a place for best- 
current-practices.

> Just because users/distros can change it doesn't mean it's  
> pointless to
> discuss what default is sane, and make changes if the current default
> isn't.

Exactly my point.

> For security-related options it's usually best to default to the more
> secure state, especially since the option description talks about it
> being needed mainly for libc5 compatibility -- did libc5 ever even  
> exist
> for powerpc?

I don't know, but even Debian's very ancient distributions all came  
with libc6 on powerpc.

> The only reason it was turned on in the first place was likely the
> "default y", which in turn is there to avoid breaking old x86 distros.

Exactly. Agreed 100%.


Regards, Rogério Brito.

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org




^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: compile kernel for linkstations optimized for size
  2008-10-13 18:03 ` [PATCH] powerpc: compile kernel for linkstations optimized for size Guennadi Liakhovetski
@ 2008-10-13 21:28   ` Rogério Brito
  0 siblings, 0 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-13 21:28 UTC (permalink / raw)
  To: Guennadi Liakhovetski; +Cc: linux-kernel, linuxppc-dev, akpm

Hi, Guennadi.

On 13/10/2008, at 16:03, Guennadi Liakhovetski wrote:

> On Mon, 13 Oct 2008, Rogério Brito wrote:
>
>> From: Rogério Brito <rbrito@ime.usp.br>
>>
>> Since Linkstations and Kuroboxes often have *very* little memory (as
>> they are embedded systems), it is desirable to get their kernels
>> compiled optimized for size.
>>
>> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
>>
>> ---
>>
>> I have been using kernels optimized for size on my Kurobox (standard)
>> for many different releases and I have experienced no problem with  
>> this
>> option enabled. Thus, this patch.
>
> The comment for this option says: "watch out for broken compilers," if
> this doesn't hold any more, it should be remove, if it still holds, I
> wouldn't turn this on by default, as I don't think we can test all

Pragmatically speaking, -O2 can be broken too (and see the amount of  
ICEs that you can get with newer kernels even compiling with -O2).  
Unless you prove that the compiler is correct and keeps all its  
invariants, then you can rely on this. But, pragmatically speaking  
again, gcc has bugs.

But leaving the mathematical situation aside (Dijkstra would have  
spanked all of us here :)), as I mentioned below the signed off line,  
I have been using -Os and it is working fine. It's serving me quite  
well and with a decent uptime:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  
- - -
lutz:~# uptime
  19:22:53 up 17 days,  5:56,  1 user,  load average: 0.00, 0.00, 0.00
lutz:~# uname -a
Linux lutz 2.6.27-rc6.try02 #8 Fri Sep 26 11:29:55 BRT 2008 ppc GNU/ 
Linux
lutz:~#
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  
- - -

And, despite the 0.00 load, I'm streaming music with it via mt-daapd  
and serving cifs mounts.

> possible (cross- or native-) compilers users might want to use. In any
> case this is one of options that users can select themselves, if it  
> suits
> them.

And that is, not to mention, with a very home-brew and quick'n'dirty  
cross-compiled kernel (with a vanilla gcc 4.2.0 taken straight from  
gcc.gnu.org; the same with the kernel: no patches applied).

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org




^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: compile kernel for linkstations optimized for size
  2008-10-13  4:07 [PATCH] powerpc: compile kernel for linkstations optimized for size Rogério Brito
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
  2008-10-13 18:03 ` [PATCH] powerpc: compile kernel for linkstations optimized for size Guennadi Liakhovetski
@ 2008-10-17  9:37 ` Rogério Brito
  2008-10-28 13:58 ` Kumar Gala
  3 siblings, 0 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-17  9:37 UTC (permalink / raw)
  To: linux-kernel; +Cc: linuxppc-dev, akpm, paulus

Hi,

It's been some days since I sent the patch below. I would appreciate if any
feedback was given.


Thanks, Rogério Brito.

On Oct 13 2008, Rogério Brito wrote:
> From: Rogério Brito <rbrito@ime.usp.br>
> 
> Since Linkstations and Kuroboxes often have *very* little memory (as
> they are embedded systems), it is desirable to get their kernels
> compiled optimized for size.
> 
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
> 
> ---
> 
> I have been using kernels optimized for size on my Kurobox (standard)
> for many different releases and I have experienced no problem with this
> option enabled. Thus, this patch.
> 
> --- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
> +++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 00:38:58.000000000 -0300
> @@ -90,7 +90,7 @@ CONFIG_NAMESPACES=y
>  # CONFIG_PID_NS is not set
>  CONFIG_BLK_DEV_INITRD=y
>  CONFIG_INITRAMFS_SOURCE=""
> -# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
> +CONFIG_CC_OPTIMIZE_FOR_SIZE=y
>  CONFIG_SYSCTL=y
>  # CONFIG_EMBEDDED is not set
>  CONFIG_SYSCTL_SYSCALL=y
> 
> 
> -- 
> Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
> http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
> Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
  2008-10-13 18:05   ` Guennadi Liakhovetski
@ 2008-10-17  9:38   ` Rogério Brito
  2008-10-28 13:58   ` Kumar Gala
  2 siblings, 0 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-17  9:38 UTC (permalink / raw)
  To: linux-kernel; +Cc: linuxppc-dev, akpm, paulus

Hi,

This other patch was also sent some days ago and I would appreciate some
feedback on it.


Regards, Rogério Brito.

On Oct 13 2008, Rogério Brito wrote:
> The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> Randomization" option enabled.
> 
> Since some of these machines are facing the internet, it helps to have
> heap randomization enabled. This patch enables it.
> 
> 
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
> 
> ---
> 
> --- linux/arch/powerpc/configs/linkstation_defconfig.old	2008-10-13 00:33:00.000000000 -0300
> +++ linux/arch/powerpc/configs/linkstation_defconfig	2008-10-13 01:11:28.000000000 -0300
> @@ -1,7 +1,7 @@
>  #
>  # Automatically generated make config: don't edit
> -# Linux kernel version: 2.6.27-rc4
> -# Thu Aug 21 00:52:05 2008
> +# Linux kernel version: 2.6.27
> +# Mon Oct 13 01:11:21 2008
>  #
>  # CONFIG_PPC64 is not set
>  
> @@ -101,7 +101,7 @@ CONFIG_HOTPLUG=y
>  CONFIG_PRINTK=y
>  CONFIG_BUG=y
>  CONFIG_ELF_CORE=y
> -CONFIG_COMPAT_BRK=y
> +# CONFIG_COMPAT_BRK is not set
>  CONFIG_BASE_FULL=y
>  CONFIG_FUTEX=y
>  CONFIG_ANON_INODES=y
> @@ -1211,7 +1211,6 @@ CONFIG_USB_STORAGE=m
>  # CONFIG_USB_STORAGE_ALAUDA is not set
>  # CONFIG_USB_STORAGE_ONETOUCH is not set
>  # CONFIG_USB_STORAGE_KARMA is not set
> -# CONFIG_USB_STORAGE_SIERRA is not set
>  # CONFIG_USB_STORAGE_CYPRESS_ATACB is not set
>  # CONFIG_USB_LIBUSUAL is not set
>  
> 
> -- 
> Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
> http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
> Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13 18:44     ` Scott Wood
  2008-10-13 19:27       ` Guennadi Liakhovetski
  2008-10-13 20:56       ` Rogério Brito
@ 2008-10-19  2:53       ` Rogério Brito
  2008-10-19  3:16         ` Rogério Brito
  2 siblings, 1 reply; 14+ messages in thread
From: Rogério Brito @ 2008-10-19  2:53 UTC (permalink / raw)
  To: Scott Wood
  Cc: Guennadi Liakhovetski, linuxppc-dev, akpm, linux-kernel, paulus, benh

Hi.

On Oct 13 2008, Scott Wood wrote:
> On Mon, Oct 13, 2008 at 08:05:09PM +0200, Guennadi Liakhovetski wrote:
> > On Mon, 13 Oct 2008, Rogério Brito wrote:
> > > The current defconfig for Linkstation/Kuroboxes has the "Disable
> > > Heap Randomization" option enabled.
> > > 
> > > Since some of these machines are facing the internet, it helps to
> > > have heap randomization enabled. This patch enables it.
> > 
> > Same as the previous patch - this is one of options, that users
> > select according to their needs. If any specific distribution
> > enables this option by default in their kernels, they can do this
> > too, don't think this is critical enough to patch the defconfig.

I guess, Guennadi, that this is questionable. Many people would base
their configs on the defconfig.

Also, the defconfig has many questionable settings for an embedded
platform like the Kurobox.

And it seems that there is something not quite right for these embedded
systems. Here is something that I get with a vanilla linkstation_defconfig:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

This gets me (with bootlogd enabled):

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Wed Dec 31 21:00:15 1969: Cannot access the Hardware Clock via any known method.
Wed Dec 31 21:00:15 1969: Use the --debug option to see the details of our search for an access method.
Wed Dec 31 21:00:15 1969: Unable to set System Clock to: Thu Jan 1 00:00:15 UTC 1970 ^[[33m(warning).^[[39;49m
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

I just saw that in the default config:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# CONFIG_PPC_CLOCK is not set
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Maybe this should be enabled? I can iterate once more to see if this
option would make any difference here.

> Just because users/distros can change it doesn't mean it's pointless
> to discuss what default is sane, and make changes if the current
> default isn't.

100% agreed again, Scott. To repeat myself here, I think that the
defconfig should show the users the best current practices.

> For security-related options it's usually best to default to the more
> secure state, especially since the option description talks about it
> being needed mainly for libc5 compatibility -- did libc5 ever even
> exist for powerpc?
> 
> The only reason it was turned on in the first place was likely the
> "default y", which in turn is there to avoid breaking old x86 distros.

I'm including both Paul and BenH here.


Regards, Rogério Brito.

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-19  2:53       ` Rogério Brito
@ 2008-10-19  3:16         ` Rogério Brito
  0 siblings, 0 replies; 14+ messages in thread
From: Rogério Brito @ 2008-10-19  3:16 UTC (permalink / raw)
  To: Scott Wood
  Cc: Guennadi Liakhovetski, linuxppc-dev, akpm, linux-kernel, paulus,
	benh, rbrito

Hi again.

On Oct 18 2008, Rogério Brito wrote:
> And it seems that there is something not quite right for these embedded
> systems. Here is something that I get with a vanilla linkstation_defconfig:
> 
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(...)
> I just saw that in the default config:
> 
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> # CONFIG_PPC_CLOCK is not set
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> 
> Maybe this should be enabled? I can iterate once more to see if this
> option would make any difference here.

Even if I enable this option, I still get the same problem as above. :-(


Regards, Rogério Brito.

-- 
Rogério Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: compile kernel for linkstations optimized for size
  2008-10-13  4:07 [PATCH] powerpc: compile kernel for linkstations optimized for size Rogério Brito
                   ` (2 preceding siblings ...)
  2008-10-17  9:37 ` Rogério Brito
@ 2008-10-28 13:58 ` Kumar Gala
  3 siblings, 0 replies; 14+ messages in thread
From: Kumar Gala @ 2008-10-28 13:58 UTC (permalink / raw)
  To: Rogério Brito; +Cc: linux-kernel, linuxppc-dev, akpm


On Oct 12, 2008, at 11:07 PM, Rogério Brito wrote:

> From: Rogério Brito <rbrito@ime.usp.br>
>
> Since Linkstations and Kuroboxes often have *very* little memory (as
> they are embedded systems), it is desirable to get their kernels
> compiled optimized for size.
>
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
>
> ---

applied to merge.

- k

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH] powerpc: enable heap randomization for linkstations
  2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
  2008-10-13 18:05   ` Guennadi Liakhovetski
  2008-10-17  9:38   ` Rogério Brito
@ 2008-10-28 13:58   ` Kumar Gala
  2 siblings, 0 replies; 14+ messages in thread
From: Kumar Gala @ 2008-10-28 13:58 UTC (permalink / raw)
  To: Rogério Brito; +Cc: linux-kernel, linuxppc-dev, akpm


On Oct 12, 2008, at 11:51 PM, Rogério Brito wrote:

> The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> Randomization" option enabled.
>
> Since some of these machines are facing the internet, it helps to have
> heap randomization enabled. This patch enables it.
>
>
> Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
>
> ---


applied to merge.

- k

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2008-10-28 13:59 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-10-13  4:07 [PATCH] powerpc: compile kernel for linkstations optimized for size Rogério Brito
2008-10-13  4:51 ` [PATCH] powerpc: enable heap randomization for linkstations Rogério Brito
2008-10-13 18:05   ` Guennadi Liakhovetski
2008-10-13 18:44     ` Scott Wood
2008-10-13 19:27       ` Guennadi Liakhovetski
2008-10-13 20:56       ` Rogério Brito
2008-10-19  2:53       ` Rogério Brito
2008-10-19  3:16         ` Rogério Brito
2008-10-17  9:38   ` Rogério Brito
2008-10-28 13:58   ` Kumar Gala
2008-10-13 18:03 ` [PATCH] powerpc: compile kernel for linkstations optimized for size Guennadi Liakhovetski
2008-10-13 21:28   ` Rogério Brito
2008-10-17  9:37 ` Rogério Brito
2008-10-28 13:58 ` Kumar Gala

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).