2.6.2: "-" or "_", thats the question

2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Hi folks,

'cat /proc/modules' returns most (all?) of the module names with
"_", e.g.

	:
	ipt_conntrack
	ip_conntrack
	iptable_filter
	ip_tables
	uhci_hcd
	ohci_hcd
	ehci_hcd
	:

Very consistent. But the filenames of some kernel modules are
still written with "-", e.g.

	/lib/modules/2.6.2/kernel/drivers/usb/host/ehci-hcd.ko
	/lib/modules/2.6.2/kernel/drivers/usb/host/ohci-hcd.ko
	/lib/modules/2.6.2/kernel/drivers/usb/host/uhci-hcd.ko

What would be the correct way to get the filename of a
loaded module? The basename would be sufficient.


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Coywolf Qi Hunt]

Harald Dunkel wrote:

> Hi folks,
>
> 'cat /proc/modules' returns most (all?) of the module names with
> "_", e.g.
>
>     :
>     ipt_conntrack
>     ip_conntrack
>     iptable_filter
>     ip_tables
>     uhci_hcd
>     ohci_hcd
>     ehci_hcd
>     :
>
> Very consistent. But the filenames of some kernel modules are
> still written with "-", e.g.
>
>     /lib/modules/2.6.2/kernel/drivers/usb/host/ehci-hcd.ko
>     /lib/modules/2.6.2/kernel/drivers/usb/host/ohci-hcd.ko
>     /lib/modules/2.6.2/kernel/drivers/usb/host/uhci-hcd.ko
>
> What would be the correct way to get the filename of a
> loaded module? The basename would be sufficient.
>
>
> Regards
>
> Harri
> -
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>
The symbole names used in source code, like function names tend to use 
"_", while the file names use "-" IMHO.


Coywolf Qi Hunt

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Coywolf Qi Hunt wrote:
> Harald Dunkel wrote:
> 
>>
>> What would be the correct way to get the filename of a
>> loaded module? The basename would be sufficient.
>>
>>
> The symbole names used in source code, like function names tend to use 
> "_", while the file names use "-" IMHO.
> 

Naturally the symbols in the code use '_', cause for C '-'
is not allowed within symbol names.

I am interested in the module file names. 'cat /proc/modules'
should return the correct module names, but for some modules
(like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Rusty Russell]

On Sun, 15 Feb 2004 10:58:54 +0100
Harald Dunkel <harald.dunkel@t-online.de> wrote:

> Coywolf Qi Hunt wrote:
> > Harald Dunkel wrote:
> > 
> >>
> >> What would be the correct way to get the filename of a
> >> loaded module? The basename would be sufficient.
> >>
> >>
> > The symbole names used in source code, like function names tend to use 
> > "_", while the file names use "-" IMHO.
> > 
> 
> Naturally the symbols in the code use '_', cause for C '-'
> is not allowed within symbol names.
> 
> I am interested in the module file names. 'cat /proc/modules'
> should return the correct module names, but for some modules
> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.

We canonicalize them at every point: you can use both.

Most users don't want to remember that it's ip_conntrack but uhci-hcd.

Hope that clarifies,
Rusty.
-- 
   there are those who do and those who hang on and you don't see too
   many doers quoting their contemporaries.  -- Larry McVoy

Re: 2.6.2: "-" or "_", thats the question

[Wakko Warner]

Rusty Russell wrote:
> Most users don't want to remember that it's ip_conntrack but uhci-hcd.

I'd like to chime in about this.

I'd prefer it be - all the way around (I know I can use either).  Since I
can ask for module uhci_hcd or uhci-hcd and get uhci-hcd.ko loaded, I've
been using -.  It's a bit easier to type since I don't have to hit shift for
each _

-- 
 Lab tests show that use of micro$oft causes cancer in lab animals

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Wakko Warner wrote:
> Rusty Russell wrote:
> 
>>Most users don't want to remember that it's ip_conntrack but uhci-hcd.
> 
> 
> I'd like to chime in about this.
> 
> I'd prefer it be - all the way around (I know I can use either).  Since I
> can ask for module uhci_hcd or uhci-hcd and get uhci-hcd.ko loaded, I've
> been using -.  It's a bit easier to type since I don't have to hit shift for
> each _
> 

It is really not important here whether anybody prefers '_'
or '-'. IMHO everybody should be free to use both, even
within one symbol filename.

What I do not like is that /proc/modules lies about the
names of the loaded modules. I can understand that you
are not affected by this problem, because all you see is
module-init-tools, but others _are_ affected.


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Wakko Warner]

> >>Most users don't want to remember that it's ip_conntrack but uhci-hcd.
> > 
> > I'd like to chime in about this.
> > 
> > I'd prefer it be - all the way around (I know I can use either).  Since I
> > can ask for module uhci_hcd or uhci-hcd and get uhci-hcd.ko loaded, I've
> > been using -.  It's a bit easier to type since I don't have to hit shift for
> > each _
> > 
> 
> It is really not important here whether anybody prefers '_'
> or '-'. IMHO everybody should be free to use both, even
> within one symbol filename.

That's good.  This is pretty much all I want =)

> What I do not like is that /proc/modules lies about the
> names of the loaded modules. I can understand that you
> are not affected by this problem, because all you see is
> module-init-tools, but others _are_ affected.

I did not realize that /proc/modules lied.  From a user standpoint, it may
not be /proc/modules lying, it may be module-init-tools lying to the kernel
about the module it just loaded.  I don't know, I have not looked at the
code for module-init-tools.  I checked one of my 2.6 machines and indeed all
modules are with an _ instead of a -

When I first noticed that [eou]hci_hcd was loaded I figured all modules were
using _ now.  When I was playing with alsa it never clicked in about the -
and _.  I see now that it's _ in /proc/modules.

[OT] why is the usb drivers named with -hcd at the end anyway?

-- 
 Lab tests show that use of micro$oft causes cancer in lab animals

Re: 2.6.2: "-" or "_", thats the question

[Randy.Dunlap]

On Wed, 18 Feb 2004 12:25:23 -0500 Wakko Warner <wakko@animx.eu.org> wrote:

| When I first noticed that [eou]hci_hcd was loaded I figured all modules were
| using _ now.  When I was playing with alsa it never clicked in about the -
| and _.  I see now that it's _ in /proc/modules.
| 
| [OT] why is the usb drivers named with -hcd at the end anyway?

Because some USB drivers are for USB devices (no -hcd at end)
and some of them are USB host controller drivers (HCDs), not for
USB devices per se.  It's just a simple differeniation.

--
~Randy

Re: 2.6.2: "-" or "_", thats the question

[Ryan Reich]

Harald Dunkel wrote:
> Coywolf Qi Hunt wrote:
> 
>> Harald Dunkel wrote:
>>
>>>
>>> What would be the correct way to get the filename of a
>>> loaded module? The basename would be sufficient.
>>>
>>>
>> The symbole names used in source code, like function names tend to use 
>> "_", while the file names use "-" IMHO.
>>
> 
> Naturally the symbols in the code use '_', cause for C '-'
> is not allowed within symbol names.
> 
> I am interested in the module file names. 'cat /proc/modules'
> should return the correct module names, but for some modules
> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.

According to the modprobe man page, the two symbols are interchangeable.

-- 
Ryan Reich
ryanr@uchicago.edu

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Ryan Reich wrote:
> Harald Dunkel wrote:
> 
>>
>> I am interested in the module file names. 'cat /proc/modules'
>> should return the correct module names, but for some modules
>> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.
> 
> 
> According to the modprobe man page, the two symbols are interchangeable.
> 
I know. But this requires some very ugly workarounds outside
of module-init-tools. For example, if you want to check
whether a module $module_name has already been loaded, you
cannot use

     grep -q "^${module_name} " /proc/modules

Instead you have to use a workaround like

     x="`echo $module_name | sed -e 's/-/_/g'`"
     cat /proc/modules | sed -e 's/-/_/g' | grep -q "^${x} "

This is inefficient and error-prone.

Maybe somebody has another idea for the workaround,
but I like the first version.


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Måns Rullgård]

Harald Dunkel <harald.dunkel@t-online.de> writes:

> Ryan Reich wrote:
>> Harald Dunkel wrote:
>>
>>>
>>> I am interested in the module file names. 'cat /proc/modules'
>>> should return the correct module names, but for some modules
>>> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.
>> According to the modprobe man page, the two symbols are
>> interchangeable.
>>
> I know. But this requires some very ugly workarounds outside
> of module-init-tools. For example, if you want to check
> whether a module $module_name has already been loaded, you
> cannot use
>
>      grep -q "^${module_name} " /proc/modules
>
> Instead you have to use a workaround like
>
>      x="`echo $module_name | sed -e 's/-/_/g'`"
>      cat /proc/modules | sed -e 's/-/_/g' | grep -q "^${x} "
>
> This is inefficient and error-prone.
>
> Maybe somebody has another idea for the workaround,
> but I like the first version.

/proc/modules uses only _ so you could use ${module_name/-/_}.

-- 
Måns Rullgård
mru@kth.se

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Måns Rullgård wrote:
> Harald Dunkel <harald.dunkel@t-online.de> writes:
> 
> 
> /proc/modules uses only _ so you could use ${module_name/-/_}.
> 

Please check the archive: My original complaint was about the
inconsistency between /proc/modules listing all modules with '_',
and the module filenames using both '-' and '_'. For me it is
not important which version is better. As a developer I have to
assume that '_' and '-' are ambiguous in this context. This
ambiguity is pretty strange for Unix, isn't it?


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Ryan Reich]

On Mon, 16 Feb 2004, Harald Dunkel wrote:

> Ryan Reich wrote:
> > Harald Dunkel wrote:
> >
> >>
> >> I am interested in the module file names. 'cat /proc/modules'
> >> should return the correct module names, but for some modules
> >> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.
> >
> >
> > According to the modprobe man page, the two symbols are interchangeable.
> >
> I know. But this requires some very ugly workarounds outside
> of module-init-tools. For example, if you want to check
> whether a module $module_name has already been loaded, you
> cannot use
>
>      grep -q "^${module_name} " /proc/modules
>
> Instead you have to use a workaround like
>
>      x="`echo $module_name | sed -e 's/-/_/g'`"
>      cat /proc/modules | sed -e 's/-/_/g' | grep -q "^${x} "
>
> This is inefficient and error-prone.
>
> Maybe somebody has another idea for the workaround,
> but I like the first version.

Well, you can shorten it by using 'tr':

cat /proc/modules | tr _ - | grep -q "^${module_name} "

/proc/modules uses the '_' and I suppose your problem is that your module name
list uses the '-', so this solves both at once.

-- 
Ryan Reich
ryanr@uchicago.edu

Re: 2.6.2: "-" or "_", thats the question

[Ryan Reich]

On Mon, 16 Feb 2004, Ryan Reich wrote:

> On Mon, 16 Feb 2004, Harald Dunkel wrote:
>
> > Ryan Reich wrote:
> > > Harald Dunkel wrote:
> > >
> > >>
> > >> I am interested in the module file names. 'cat /proc/modules'
> > >> should return the correct module names, but for some modules
> > >> (like uhci_hcd vs uhci-hcd.ko) '_' and '-' are messed up.
> > >
> > >
> > > According to the modprobe man page, the two symbols are interchangeable.
> > >
> > I know. But this requires some very ugly workarounds outside
> > of module-init-tools. For example, if you want to check
> > whether a module $module_name has already been loaded, you
> > cannot use
> >
> >      grep -q "^${module_name} " /proc/modules
> >
> > Instead you have to use a workaround like
> >
> >      x="`echo $module_name | sed -e 's/-/_/g'`"
> >      cat /proc/modules | sed -e 's/-/_/g' | grep -q "^${x} "
> >
> > This is inefficient and error-prone.
> >
> > Maybe somebody has another idea for the workaround,
> > but I like the first version.
>
> Well, you can shorten it by using 'tr':
>
> cat /proc/modules | tr _ - | grep -q "^${module_name} "
>
> /proc/modules uses the '_' and I suppose your problem is that your module name
> list uses the '-', so this solves both at once.

Sorry, I didn't realize that your problem was also the inconsistency in module
names.  Someone else suggested using a shell expansion; you could try

cat /proc/modules | tr _ - | grep -q "^${module_name/_/-}"

which is both short and works.

-- 
Ryan Reich
ryanr@uchicago.edu

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Ryan Reich wrote:
> On Mon, 16 Feb 2004, Ryan Reich wrote:
> 
> 
> 
> Sorry, I didn't realize that your problem was also the inconsistency in module
> names.  Someone else suggested using a shell expansion; you could try
> 
> cat /proc/modules | tr _ - | grep -q "^${module_name/_/-}"
> 
> which is both short and works.
> 

tr is usually in /usr/bin, which might not be available
at boot time. And probably you mean 'grep -q "^${module_name//_/-}"'


Did I mention that the inconsistency requires ugly and error-
prone workarounds? QED


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Tony Breeds]

On Mon, Feb 16, 2004 at 08:21:09AM +0100, Harald Dunkel wrote:

> I know. But this requires some very ugly workarounds outside
> of module-init-tools. For example, if you want to check
> whether a module $module_name has already been loaded, you
> cannot use
> 
>     grep -q "^${module_name} " /proc/modules
>
> Instead you have to use a workaround like
> 
>     x="`echo $module_name | sed -e 's/-/_/g'`"
>     cat /proc/modules | sed -e 's/-/_/g' | grep -q "^${x} "
> 
> This is inefficient and error-prone.
> 
> Maybe somebody has another idea for the workaround,
> but I like the first version.

just run modprobe?  Then you don't have to care.

IN_KERNEL=$(/sbin/modprobe -vn "${module_name}")
if [ -z "${IN_KERNEL}" ; then
	/bin/echo "Module: ${module_name} is in the kernel"
else
	/bin/echo "Module: ${module_name} would need to be loaded"
	/bin/echo "${IN_KERNEL}"
fi

Or similar.  Yeah it's a little ugly but only as prone to failure as
module-init-tools

Yours Tony

        linux.conf.au       http://lca2005.linux.org.au/
	Apr 18-23 2005      The Australian Linux Technical Conference!

Re: 2.6.2: "-" or "_", thats the question

[Ryan Reich]

Harald Dunkel wrote:
> Ryan Reich wrote:
> 
>> On Mon, 16 Feb 2004, Ryan Reich wrote:
>> 
>> Sorry, I didn't realize that your problem was also the inconsistency
>> in module names.  Someone else suggested using a shell expansion; you
>> could try
>> 
>> cat /proc/modules | tr _ - | grep -q "^${module_name/_/-}"
>> 
>> which is both short and works.
>> 
> tr is usually in /usr/bin, which might not be available at boot time.
> And probably you mean 'grep -q "^${module_name//_/-}"'
> 
> Did I mention that the inconsistency requires ugly and error- prone
> workarounds? QED

It's not THAT ugly, and it's also error-prone to type at the keyboard. The
only fundamental error in my suggestion was the location of tr.

Anyway, if you really want to correct the inconsistencies you need only
edit the sources for the modules in question; the names which appear in
/proc/modules appear to be defined in, for example,
drivers/usb/host/uhci-hcd.c, where the .description section of the module
is set. Or change the filenames, though I don't know how that will fly with
the make process.

-- 
Ryan Reich
ryanr@uchicago.edu

Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Ryan Reich wrote:

 > Anyway, if you really want to correct the inconsistencies you need only
 > edit the sources for the modules in question; the names which appear in
 > /proc/modules appear to be defined in, for example,
 > drivers/usb/host/uhci-hcd.c, where the .description section of the module
 > is set. Or change the filenames, though I don't know how that will fly with
 > the make process.
 >

Of course I could patch the kernel sources to remove the
inconsistencies in the module names. But IMHO it is much
more important to convince the kernel developers that this
inconsistency is bad.


Regards

Harri

Re: 2.6.2: "-" or "_", thats the question

[Sam Ravnborg]

On Tue, Feb 17, 2004 at 07:09:31AM +0100, Harald Dunkel wrote:
> Ryan Reich wrote:
> 
> > Anyway, if you really want to correct the inconsistencies you need only
> > edit the sources for the modules in question; the names which appear in
> > /proc/modules appear to be defined in, for example,
> > drivers/usb/host/uhci-hcd.c, where the .description section of the module
> > is set. Or change the filenames, though I don't know how that will fly 
> with
> > the make process.
> >
> 
> Of course I could patch the kernel sources to remove the
> inconsistencies in the module names. But IMHO it is much
> more important to convince the kernel developers that this
> inconsistency is bad.

When 2.7 opens I will try to find out if we can rename all victims.
I can tweak kbuild to warn for modules using '-', so we in the
end can get rid of this inconsistency.

Rusty - do you see any problems with this?

	Sam

Re: 2.6.2: "-" or "_", thats the question

[Arjan van de Ven]

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> When 2.7 opens I will try to find out if we can rename all victims.
> I can tweak kbuild to warn for modules using '-', so we in the
> end can get rid of this inconsistency.
> 
> Rusty - do you see any problems with this?

well I'm not Rusty by a long shot, but I do see a problem with this, or
at least a subtlety that needs taking into account: the pcmcia subsystem
(I include cardmgr in that) has an internal declaration of the module
name inside the module, and the filename of the module *HAS* to match
that or things just won't work. ide-cs is the one at risk here; I've had
to debug what turned out to be a mismatch during 2.4.2-era on this one
and believe me, that's not funny. 



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Re: 2.6.2: "-" or "_", thats the question

[Harald Dunkel]

Sam Ravnborg wrote:
> 
> When 2.7 opens I will try to find out if we can rename all victims.
> I can tweak kbuild to warn for modules using '-', so we in the
> end can get rid of this inconsistency.
> 
> Rusty - do you see any problems with this?
> 
> 	Sam
> 
Any chance to get this warning for 2.6?

What would happen if a symbol filename is changed by replacing
the '-' with '_'?

The module-init-tools wouldn't care. I don't know the internals
of kudzu, but discover2 uses modprobe to load the modules. The
internal workarounds in discover2 for the inconsistency would
become obsolete.

Maybe the alsa stuff? There are many alsa modules with '-'.

Would it be easier to fix the output of /proc/modules than
renaming all modules with '-'?


Of course I would be glad to help.


Regards

Harri