modinfo <modulename> question

modinfo <modulename> question

[Justin Piszcz]

Is there anyway to get/see what parameters were passed to a kernel module? 
Running modinfo -p <module> will show the defaults, but for example, st, 
the scsi tape driver, is there a way to see what it is currently using? I 
know in dmesg it shows this when you load it initially (but if say dmesg 
has been cleared or the buffer was filled up)?

Re: modinfo <modulename> question

[Randy Dunlap]

On Wed, 5 Sep 2007 12:34:13 -0400 (EDT) Justin Piszcz wrote:

> Is there anyway to get/see what parameters were passed to a kernel module? 
> Running modinfo -p <module> will show the defaults, but for example, st, 
> the scsi tape driver, is there a way to see what it is currently using? I 
> know in dmesg it shows this when you load it initially (but if say dmesg 
> has been cleared or the buffer was filled up)?

If a "module" (whether built as a loadable module or builtin to the
kernel image) uses module_param() with a permission (or mode) field
that allows reading that parameter, then the parameter will show up
in /sys/module/<module>/parameters/<parameter>.

E.g., drivers/scsi/sg has these parameters listed and are readable
by anyone:

-rw-r--r-- 1 root root 4096 Sep  5 10:07 allow_dio
-rw-r--r-- 1 root root 4096 Sep  5 10:07 def_reserved_size
-rw-r--r-- 1 root root 4096 Sep  5 10:07 scatter_elem_sz

However, the st driver uses 0 for permission (mode), so none of its
parameters is visible.

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: modinfo <modulename> question

[Andreas Schwab]

Justin Piszcz <jpiszcz@lucidpixels.com> writes:

> Is there anyway to get/see what parameters were passed to a kernel module?

/sys/module/<module>/parameters

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: modinfo <modulename> question

[Justin Piszcz]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 515 bytes --]



On Wed, 5 Sep 2007, Andreas Schwab wrote:

> Justin Piszcz <jpiszcz@lucidpixels.com> writes:
>
>> Is there anyway to get/see what parameters were passed to a kernel module?
>
> /sys/module/<module>/parameters
>
> Andreas.
>
> -- 
> Andreas Schwab, SuSE Labs, schwab@suse.de
> SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
> PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
> "And now for something completely different."
>

And under 2.4?

Justin.

Re: modinfo <modulename> question

[Jan Engelhardt]

On Sep 5 2007 13:31, Justin Piszcz wrote:
>>
>> > Is there anyway to get/see what parameters were passed to a kernel 
>> > module?

Not really. Even if a module has parameters exported, they may carry 
default values (and hence, don't fulfill the word "passed", as would be 
the case with `modprobe foo` without {{any extra params} union {params 
in /etc/modprobe*}})

>> /sys/module/<module>/parameters
>
> And under 2.4?

/proc/<module-specific-place>. Generally, even less.



	Jan
-- 

Re: modinfo <modulename> question

[Chris Snook]

Justin Piszcz wrote:
> Is there anyway to get/see what parameters were passed to a kernel 
> module? Running modinfo -p <module> will show the defaults, but for 
> example, st, the scsi tape driver, is there a way to see what it is 
> currently using? I know in dmesg it shows this when you load it 
> initially (but if say dmesg has been cleared or the buffer was filled up)?

/sys/module/$MODULENAME/parameters/

Re: modinfo <modulename> question

[Bodo Eggert]

Justin Piszcz <jpiszcz@lucidpixels.com> wrote:

> Is there anyway to get/see what parameters were passed to a kernel module?
> Running modinfo -p <module> will show the defaults, but for example, st,
> the scsi tape driver, is there a way to see what it is currently using?

/sys/modules/$NAME/parameters (if it's using the new API)
-- 
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