[KJ] What does (P) in /proc/modules mean?

[KJ] What does (P) in /proc/modules mean?

[Badai Aqrandista]

Hi,

I have a plain kernel module like this:

#include <linux/module.h>
#include <linux/init.h>

MODULE_AUTHOR("Badai Aqrandista");
MODULE_LICENSE("Dual BSD/GPL");

static int cheepy_init(void)
{
        printk(KERN_ALERT "cheepy: Module loaded\n");
        return 0;
}

static void cheepy_cleanup(void)
{
        printk(KERN_ALERT "cheepy: Module unloaded\n");
}

module_init(cheepy_init);
module_exit(cheepy_cleanup);

When I load and unload it with insmod or rmmod, it does not print
anything on the console or log. On /proc/modules, there is (P) next to
its entry, like this:

cheepy 2560 0 - Live 0xd0a37000 (P)

What does (P) mean there?

-- 
Thanks,
Badai Aqrandista (cheepy)
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Randy Dunlap]

On Sun, 4 Mar 2007 14:05:24 +1000 Badai Aqrandista wrote:

> Hi,
> 
> I have a plain kernel module like this:
> 
> #include <linux/module.h>
> #include <linux/init.h>
> 
> MODULE_AUTHOR("Badai Aqrandista");
> MODULE_LICENSE("Dual BSD/GPL");
> 
> static int cheepy_init(void)
> {
>         printk(KERN_ALERT "cheepy: Module loaded\n");
>         return 0;
> }
> 
> static void cheepy_cleanup(void)
> {
>         printk(KERN_ALERT "cheepy: Module unloaded\n");
> }
> 
> module_init(cheepy_init);
> module_exit(cheepy_cleanup);
> 
> When I load and unload it with insmod or rmmod, it does not print
> anything on the console or log. On /proc/modules, there is (P) next to
> its entry, like this:
> 
> cheepy 2560 0 - Live 0xd0a37000 (P)
> 
> What does (P) mean there?

It means Proprietary.  What kernel version are you using?

It could be a kernel bug.  What other modules do you have loaded?

I'll do some checking with your sample module.


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Randy Dunlap]

On Sat, 3 Mar 2007 21:31:38 -0800 Randy Dunlap wrote:

> On Sun, 4 Mar 2007 14:05:24 +1000 Badai Aqrandista wrote:
> 
> > Hi,
> > 
> > I have a plain kernel module like this:
> > 
> > #include <linux/module.h>
> > #include <linux/init.h>
> > 
> > MODULE_AUTHOR("Badai Aqrandista");
> > MODULE_LICENSE("Dual BSD/GPL");
> > 
> > static int cheepy_init(void)
> > {
> >         printk(KERN_ALERT "cheepy: Module loaded\n");
> >         return 0;
> > }
> > 
> > static void cheepy_cleanup(void)
> > {
> >         printk(KERN_ALERT "cheepy: Module unloaded\n");
> > }
> > 
> > module_init(cheepy_init);
> > module_exit(cheepy_cleanup);
> > 
> > When I load and unload it with insmod or rmmod, it does not print
> > anything on the console or log. On /proc/modules, there is (P) next to
> > its entry, like this:
> > 
> > cheepy 2560 0 - Live 0xd0a37000 (P)
> > 
> > What does (P) mean there?
> 
> It means Proprietary.  What kernel version are you using?
> 
> It could be a kernel bug.  What other modules do you have loaded?
> 
> I'll do some checking with your sample module.

I just tested this module on 2.6.20, no license issues/problems
at all.  So what kernel version were you using and what other
modules were loaded or had been loaded?

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Badai Aqrandista]

Hi,

On 3/4/07, Randy Dunlap <rdunlap@xenotime.net> wrote:
> I just tested this module on 2.6.20, no license issues/problems
> at all.  So what kernel version were you using and what other
> modules were loaded or had been loaded?

I think I found the cause. It's the Makefile. I copied the Makefile
from ldd3 and it includes this line:

CFLAGS += $(DEBFLAGS) -I$(LDDINCDIR)

When I removed -I$(LDDINCDIR) from that line and recompiled the
module, the (P) mark is gone and all printk's are printed to the log.
And $(LDDINCDIR) variable is empty because I didn't pass it.

So I think I can reduce the problem to: passing an empty -I parameter
to CFLAGS makes the module proprietory.

Why is that?

Anyway, thanks for replying so quickly.

-- 
Thanks,
Badai Aqrandista (cheepy)
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Randy Dunlap]

On Sun, 4 Mar 2007 22:19:51 +1000 Badai Aqrandista wrote:

> Hi,
> 
> On 3/4/07, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > I just tested this module on 2.6.20, no license issues/problems
> > at all.  So what kernel version were you using and what other
> > modules were loaded or had been loaded?
> 
> I think I found the cause. It's the Makefile. I copied the Makefile
> from ldd3 and it includes this line:
> 
> CFLAGS += $(DEBFLAGS) -I$(LDDINCDIR)
> 
> When I removed -I$(LDDINCDIR) from that line and recompiled the
> module, the (P) mark is gone and all printk's are printed to the log.
> And $(LDDINCDIR) variable is empty because I didn't pass it.
> 
> So I think I can reduce the problem to: passing an empty -I parameter
> to CFLAGS makes the module proprietory.

I'll confirm that.

> Why is that?

Good question.  I have no idea.
Sam, do you have any idea why adding "-I " to a Makefile
causes a module license not to be found correctly?

From my testing:
cheepy: module license 'unspecified' taints kernel.
(2.6.20 kernel)

> Anyway, thanks for replying so quickly.


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Sam Ravnborg]

On Sun, Mar 04, 2007 at 10:23:59AM -0800, Randy Dunlap wrote:
> On Sun, 4 Mar 2007 22:19:51 +1000 Badai Aqrandista wrote:
> 
> > Hi,
> > 
> > On 3/4/07, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > > I just tested this module on 2.6.20, no license issues/problems
> > > at all.  So what kernel version were you using and what other
> > > modules were loaded or had been loaded?
> > 
> > I think I found the cause. It's the Makefile. I copied the Makefile
> > from ldd3 and it includes this line:
> > 
> > CFLAGS += $(DEBFLAGS) -I$(LDDINCDIR)

ldd3 is wrong. Never ever mess around with CFLAGS. Use EXTRA_CFLAGS
which is there for a purpose.
Copied Greg + Jon to notice them.

> > When I removed -I$(LDDINCDIR) from that line and recompiled the
> > module, the (P) mark is gone and all printk's are printed to the log.
> > And $(LDDINCDIR) variable is empty because I didn't pass it.
> > 
> > So I think I can reduce the problem to: passing an empty -I parameter
> > to CFLAGS makes the module proprietory.
> 
> I'll confirm that.
> 
> > Why is that?
> 
> Good question.  I have no idea.
> Sam, do you have any idea why adding "-I " to a Makefile
> causes a module license not to be found correctly?
Puzzeled???
I did not try it out myself but I do not see why it should
impact module licensing.
It is only in a very few places this flag is set which makes it
look even more strange.

	Sam
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

Re: [KJ] What does (P) in /proc/modules mean?

[Greg KH]

On Sun, Mar 04, 2007 at 10:30:21PM +0100, Sam Ravnborg wrote:
> On Sun, Mar 04, 2007 at 10:23:59AM -0800, Randy Dunlap wrote:
> > On Sun, 4 Mar 2007 22:19:51 +1000 Badai Aqrandista wrote:
> > 
> > > Hi,
> > > 
> > > On 3/4/07, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > > > I just tested this module on 2.6.20, no license issues/problems
> > > > at all.  So what kernel version were you using and what other
> > > > modules were loaded or had been loaded?
> > > 
> > > I think I found the cause. It's the Makefile. I copied the Makefile
> > > from ldd3 and it includes this line:
> > > 
> > > CFLAGS += $(DEBFLAGS) -I$(LDDINCDIR)
> 
> ldd3 is wrong. Never ever mess around with CFLAGS. Use EXTRA_CFLAGS
> which is there for a purpose.
> Copied Greg + Jon to notice them.

Thanks for letting us know, I think that for the few examples in LDD3
that use this, we didn't realize EXTRA_CFLAGS was possible (remember,
the book is quite old now...)

If we do a new release, this will be one of those things that we change.

thanks,

greg k-h
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors