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* How many params can be accept by kernel module at most?
@ 2010-11-01  6:17 tingwei liu
  2010-11-01  9:29 ` Américo Wang
  0 siblings, 1 reply; 8+ messages in thread
From: tingwei liu @ 2010-11-01  6:17 UTC (permalink / raw)
  To: linux-kernel

How many params can be accept by kernel module at most?

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  6:17 How many params can be accept by kernel module at most? tingwei liu
@ 2010-11-01  9:29 ` Américo Wang
  2010-11-01  9:32   ` tingwei liu
  0 siblings, 1 reply; 8+ messages in thread
From: Américo Wang @ 2010-11-01  9:29 UTC (permalink / raw)
  To: tingwei liu; +Cc: linux-kernel

On Mon, Nov 01, 2010 at 02:17:23PM +0800, tingwei liu wrote:
>How many params can be accept by kernel module at most?

If you mean dynamically, these parameters are passed as a whole to kernel,
from the source code, you can see the max length is ~0UL>>1.

If you mean statically, IOW, the max paramenters you can provide in your module,
this is limited by ELF section size.

Hope this helps.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  9:29 ` Américo Wang
@ 2010-11-01  9:32   ` tingwei liu
  2010-11-01  9:49     ` tingwei liu
  0 siblings, 1 reply; 8+ messages in thread
From: tingwei liu @ 2010-11-01  9:32 UTC (permalink / raw)
  To: Américo Wang; +Cc: linux-kernel

What's the meaning of dynamically and statically?
You response help me much. Thank you

2010/11/1 Américo Wang <xiyou.wangcong@gmail.com>:
> On Mon, Nov 01, 2010 at 02:17:23PM +0800, tingwei liu wrote:
>>How many params can be accept by kernel module at most?
>
> If you mean dynamically, these parameters are passed as a whole to kernel,
> from the source code, you can see the max length is ~0UL>>1.
>
> If you mean statically, IOW, the max paramenters you can provide in your module,
> this is limited by ELF section size.
>
> Hope this helps.
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  9:32   ` tingwei liu
@ 2010-11-01  9:49     ` tingwei liu
  2010-11-01  9:54       ` tingwei liu
  2010-11-01  9:59       ` Américo Wang
  0 siblings, 2 replies; 8+ messages in thread
From: tingwei liu @ 2010-11-01  9:49 UTC (permalink / raw)
  To: Américo Wang; +Cc: linux-kernel

The params are transferred by command line. And the params are all in
program statically. So the stack size determine the params number. For
example: stack size is 4K,and params are unsigned int type with 4
bytes,so the max number of params is 1 thousand。

2010/11/1 tingwei liu <tingw.liu@gmail.com>:
> What's the meaning of dynamically and statically?
> You response help me much. Thank you
>
> 2010/11/1 Américo Wang <xiyou.wangcong@gmail.com>:
>> On Mon, Nov 01, 2010 at 02:17:23PM +0800, tingwei liu wrote:
>>>How many params can be accept by kernel module at most?
>>
>> If you mean dynamically, these parameters are passed as a whole to kernel,
>> from the source code, you can see the max length is ~0UL>>1.
>>
>> If you mean statically, IOW, the max paramenters you can provide in your module,
>> this is limited by ELF section size.
>>
>> Hope this helps.
>>
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  9:49     ` tingwei liu
@ 2010-11-01  9:54       ` tingwei liu
  2010-11-01  9:59       ` Américo Wang
  1 sibling, 0 replies; 8+ messages in thread
From: tingwei liu @ 2010-11-01  9:54 UTC (permalink / raw)
  To: Américo Wang; +Cc: linux-kernel

My description is correct or not ?

2010/11/1 tingwei liu <tingw.liu@gmail.com>:
> The params are transferred by command line. And the params are all in
> program statically. So the stack size determine the params number. For
> example: stack size is 4K,and params are unsigned int type with 4
> bytes,so the max number of params is 1 thousand。
>
> 2010/11/1 tingwei liu <tingw.liu@gmail.com>:
>> What's the meaning of dynamically and statically?
>> You response help me much. Thank you
>>
>> 2010/11/1 Américo Wang <xiyou.wangcong@gmail.com>:
>>> On Mon, Nov 01, 2010 at 02:17:23PM +0800, tingwei liu wrote:
>>>>How many params can be accept by kernel module at most?
>>>
>>> If you mean dynamically, these parameters are passed as a whole to kernel,
>>> from the source code, you can see the max length is ~0UL>>1.
>>>
>>> If you mean statically, IOW, the max paramenters you can provide in your module,
>>> this is limited by ELF section size.
>>>
>>> Hope this helps.
>>>
>>
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  9:49     ` tingwei liu
  2010-11-01  9:54       ` tingwei liu
@ 2010-11-01  9:59       ` Américo Wang
  2010-11-01 13:42         ` tingwei liu
  1 sibling, 1 reply; 8+ messages in thread
From: Américo Wang @ 2010-11-01  9:59 UTC (permalink / raw)
  To: tingwei liu; +Cc: Américo Wang, linux-kernel

On Mon, Nov 01, 2010 at 05:49:53PM +0800, tingwei liu wrote:
>The params are transferred by command line. And the params are all in
>program statically. So the stack size determine the params number. For
>example: stack size is 4K,and params are unsigned int type with 4
>bytes,so the max number of params is 1 thousand。
>

Please don't top-reply.

That is not true, the parameters are passed via 'uargs' of init_module()
dynamically, this is when you invoke modprobe/insmod.

For your own kernel module, you may use module_param() to provide
parameters, the max of this is limited to the size of ELF section size,
since they are stored in "__param" section.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01  9:59       ` Américo Wang
@ 2010-11-01 13:42         ` tingwei liu
  2010-11-02  1:40           ` Thiago Farina
  0 siblings, 1 reply; 8+ messages in thread
From: tingwei liu @ 2010-11-01 13:42 UTC (permalink / raw)
  To: Américo Wang; +Cc: linux-kernel

2010/11/1 Américo Wang <xiyou.wangcong@gmail.com>:
> On Mon, Nov 01, 2010 at 05:49:53PM +0800, tingwei liu wrote:
>>The params are transferred by command line. And the params are all in
>>program statically. So the stack size determine the params number. For
>>example: stack size is 4K,and params are unsigned int type with 4
>>bytes,so the max number of params is 1 thousand。
>>
>
> Please don't top-reply.
>
> That is not true, the parameters are passed via 'uargs' of init_module()
> dynamically, this is when you invoke modprobe/insmod.
>
> For your own kernel module, you may use module_param() to provide
> parameters, the max of this is limited to the size of ELF section size,
> since they are stored in "__param" section.
>

I really use module_param() to provide parameters. How much of the ELF
section size? How can I find the document of the ELF.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: How many params can be accept by kernel module at most?
  2010-11-01 13:42         ` tingwei liu
@ 2010-11-02  1:40           ` Thiago Farina
  0 siblings, 0 replies; 8+ messages in thread
From: Thiago Farina @ 2010-11-02  1:40 UTC (permalink / raw)
  To: tingwei liu; +Cc: Américo Wang, linux-kernel

On Mon, Nov 1, 2010 at 11:42 AM, tingwei liu <tingw.liu@gmail.com> wrote:
> I really use module_param() to provide parameters. How much of the ELF
> section size? How can I find the document of the ELF.

Searching on Google might help?

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2010-11-02  1:40 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-11-01  6:17 How many params can be accept by kernel module at most? tingwei liu
2010-11-01  9:29 ` Américo Wang
2010-11-01  9:32   ` tingwei liu
2010-11-01  9:49     ` tingwei liu
2010-11-01  9:54       ` tingwei liu
2010-11-01  9:59       ` Américo Wang
2010-11-01 13:42         ` tingwei liu
2010-11-02  1:40           ` Thiago Farina

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