Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Chetan Nanda]

Hi,

I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
3.10 kernel via writing  CONFIG_DEBUG_SET_MODULE_RONX=y at the end of
board specific config file.

But .config generated after kernel build do not have this option enabled.

Do I need to enable any other option also before enabling this one?


Thanks,
Chetan Nanda

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Chetan Nanda]

Hi,

I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
3.10 kernel (for ARM arch) via writing  CONFIG_DEBUG_SET_MODULE_RONX=y
at the end of
board specific config file.

But .config generated after kernel build do not have this option enabled.

Do I need to enable any other option also before enabling this one?


Thanks,
Chetan Nanda

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Valdis.Kletnieks at vt.edu]

On Thu, 14 Aug 2014 16:46:22 +0530, Chetan Nanda said:
> Hi,
>
> I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
> 3.10 kernel (for ARM arch) via writing  CONFIG_DEBUG_SET_MODULE_RONX=y
> at the end of
> board specific config file.
>
> But .config generated after kernel build do not have this option enabled.
>
> Do I need to enable any other option also before enabling this one?

Go into 'make menuconfig', Enter a '/'.  In the textbox, enter a substring
of the symbol (I entered 'MODULE_RONX').

At least on x86_64, this shows me:

  x Symbol: DEBUG_SET_MODULE_RONX [=y]                                                                                                  x
  x Type  : boolean                                                                                                                     x
  x Prompt: Set loadable kernel module data as NX and text as RO                                                                        x
  x   Location:                                                                                                                         x
  x (1) -> Kernel hacking                                                                                                               x
  x   Defined at arch/x86/Kconfig.debug:112                                                                                             x
  x   Depends on: MODULES [=y]

Perhaps it's different on ARM - seems pretty silly to enable MODULE_RONX
if your kernel doesn't have CONFIG_MODULES=y in the build.

But in general, you should *NOT* simply edit the config file, because
that does *not* do any checking of select/depend as you make the change.

Then when you actually make the kernel, it *will* re-drive the select/depend
logic, and convert the provided .config to a self-consistent form.  Of course,
there is zero guarantee that the self-consistent form corresponds to your
intentions....



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Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Nathan Lynch]

On 08/14/2014 05:24 AM, Chetan Nanda wrote:
> Hi,
> 
> I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
> 3.10 kernel via writing  CONFIG_DEBUG_SET_MODULE_RONX=y at the end of
> board specific config file.
> 
> But .config generated after kernel build do not have this option enabled.

That feature appears to have been added well after 3.10, so unless
you've backported it, this is expected behavior.

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Paul Bolle]

On Thu, 2014-08-14 at 09:38 -0400, Valdis Kletnieks wrote:
> On Thu, 14 Aug 2014 16:46:22 +0530, Chetan Nanda said:
> > I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
> > 3.10 kernel (for ARM arch) via writing  CONFIG_DEBUG_SET_MODULE_RONX=y
> > at the end of
> > board specific config file.
> >
> > But .config generated after kernel build do not have this option enabled.
> >
> > Do I need to enable any other option also before enabling this one?
> 
> Go into 'make menuconfig', Enter a '/'.  In the textbox, enter a substring
> of the symbol (I entered 'MODULE_RONX').
> 
> At least on x86_64, this shows me:
> 
>   x Symbol: DEBUG_SET_MODULE_RONX [=y]                                                                                                  x
>   x Type  : boolean                                                                                                                     x
>   x Prompt: Set loadable kernel module data as NX and text as RO                                                                        x
>   x   Location:                                                                                                                         x
>   x (1) -> Kernel hacking                                                                                                               x
>   x   Defined at arch/x86/Kconfig.debug:112                                                                                             x
>   x   Depends on: MODULES [=y]
> 
> Perhaps it's different on ARM - seems pretty silly to enable MODULE_RONX
> if your kernel doesn't have CONFIG_MODULES=y in the build.

DEBUG_SET_MODULE_RONX was added for ARM in v3.14:
$ git grep -nw DEBUG_SET_MODULE_RONX v3.13
v3.13:arch/s390/Kconfig.debug:32:config DEBUG_SET_MODULE_RONX
v3.13:arch/x86/Kconfig.debug:103:config DEBUG_SET_MODULE_RONX
$ git grep -nw DEBUG_SET_MODULE_RONX v3.14
v3.14:arch/arm/Kconfig.debug:1198:config DEBUG_SET_MODULE_RONX
v3.14:arch/s390/Kconfig.debug:32:config DEBUG_SET_MODULE_RONX
v3.14:arch/x86/Kconfig.debug:103:config DEBUG_SET_MODULE_RONX

See commit dca9aa92fc7c ("ARM: add DEBUG_SET_MODULE_RONX option to
Kconfig"). So using that Kconfig symbol in v3.10 is pointless (for ARM).

> But in general, you should *NOT* simply edit the config file, because
> that does *not* do any checking of select/depend as you make the change.
> 
> Then when you actually make the kernel, it *will* re-drive the select/depend
> logic, and convert the provided .config to a self-consistent form.

And, as Chetan noticed, it will also drop Kconfig symbols that are
unknown for that build (as, in this case, DEBUG_SET_MODULE_RONX).

> Of course,
> there is zero guarantee that the self-consistent form corresponds to your
> intentions....


Paul Bolle

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Chetan Nanda]

On Thu, Aug 14, 2014 at 10:49 PM, Nathan Lynch <Nathan_Lynch@mentor.com> wrote:
> On 08/14/2014 05:24 AM, Chetan Nanda wrote:
>> Hi,
>>
>> I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
>> 3.10 kernel via writing  CONFIG_DEBUG_SET_MODULE_RONX=y at the end of
>> board specific config file.
>>
>> But .config generated after kernel build do not have this option enabled.
>
> That feature appears to have been added well after 3.10, so unless
> you've backported it, this is expected behavior.
>
 Hi Nathan,
Thanks for you mail, It seems that support is there in 3.10 kernel
(atleast module.c file contains this flag) could be that CONFIG
support for ARM is missing,
As there is no entry for this flag in arm/Kconfig.debug.

Thanks,
Chetan Nanda

Option CONFIG_DEBUG_SET_MODULE_RONX not working for kernel 3.10

[Chetan Nanda]

On Fri, Aug 15, 2014 at 4:19 PM, Paul Bolle <pebolle@tiscali.nl> wrote:
> On Thu, 2014-08-14 at 09:38 -0400, Valdis Kletnieks wrote:
>> On Thu, 14 Aug 2014 16:46:22 +0530, Chetan Nanda said:
>> > I am trying to enable 'CONFIG_DEBUG_SET_MODULE_RONX' config option on
>> > 3.10 kernel (for ARM arch) via writing  CONFIG_DEBUG_SET_MODULE_RONX=y
>> > at the end of
>> > board specific config file.
>> >
>> > But .config generated after kernel build do not have this option enabled.
>> >
>> > Do I need to enable any other option also before enabling this one?
>>
>> Go into 'make menuconfig', Enter a '/'.  In the textbox, enter a substring
>> of the symbol (I entered 'MODULE_RONX').
>>
>> At least on x86_64, this shows me:
>>
>>   x Symbol: DEBUG_SET_MODULE_RONX [=y]                                                                                                  x
>>   x Type  : boolean                                                                                                                     x
>>   x Prompt: Set loadable kernel module data as NX and text as RO                                                                        x
>>   x   Location:                                                                                                                         x
>>   x (1) -> Kernel hacking                                                                                                               x
>>   x   Defined at arch/x86/Kconfig.debug:112                                                                                             x
>>   x   Depends on: MODULES [=y]
>>
>> Perhaps it's different on ARM - seems pretty silly to enable MODULE_RONX
>> if your kernel doesn't have CONFIG_MODULES=y in the build.
>
> DEBUG_SET_MODULE_RONX was added for ARM in v3.14:
> $ git grep -nw DEBUG_SET_MODULE_RONX v3.13
> v3.13:arch/s390/Kconfig.debug:32:config DEBUG_SET_MODULE_RONX
> v3.13:arch/x86/Kconfig.debug:103:config DEBUG_SET_MODULE_RONX
> $ git grep -nw DEBUG_SET_MODULE_RONX v3.14
> v3.14:arch/arm/Kconfig.debug:1198:config DEBUG_SET_MODULE_RONX
> v3.14:arch/s390/Kconfig.debug:32:config DEBUG_SET_MODULE_RONX
> v3.14:arch/x86/Kconfig.debug:103:config DEBUG_SET_MODULE_RONX
>
> See commit dca9aa92fc7c ("ARM: add DEBUG_SET_MODULE_RONX option to
> Kconfig"). So using that Kconfig symbol in v3.10 is pointless (for ARM).
>
>> But in general, you should *NOT* simply edit the config file, because
>> that does *not* do any checking of select/depend as you make the change.
>>
>> Then when you actually make the kernel, it *will* re-drive the select/depend
>> logic, and convert the provided .config to a self-consistent form.
>
> And, as Chetan noticed, it will also drop Kconfig symbols that are
> unknown for that build (as, in this case, DEBUG_SET_MODULE_RONX).
>
>> Of course,
>> there is zero guarantee that the self-consistent form corresponds to your
>> intentions....
>
Hi Valdis, Paul,

Thanks for your mails.
I would try to backport 'DEBUG_SET_MODULE_RONX' support from v3.14

Thanks,
Chetan Nanda
>
> Paul Bolle
>