Skip to contentSkip to conversation

module-init-tools 0.9.3, rmmod modules with '-'

BUG Vamsi Krishna S . 4 participants 9 messages Dec 16, 2002 – Dec 19, 2002

lore
Share & tools
lore

Vamsi Krishna S .

author
#0 lore raw

Hi Rusty,

It seems we cannot unload modules if they have a '-' in their name. filename2modname() in rmmod.c converts a '-' in the filename to '_'. Why? Are dashes not allowed as part of module names?

For eg: (kernel 2.5.52/module-init-tools 0.9.3)

[root@llm10 test-modules]# ./insmod probe-test.o [root@llm10 test-modules]# ./lsmod
Module Size Used by
probe-test 943 0
[root@llm10 test-modules]# cat /proc/modules probe-test 943 0
[root@llm10 test-modules]# ./rmmod -V module-init-tools version 0.9.3
[root@llm10 test-modules]# ./rmmod probe-test
ERROR: Module probe_test does not exist in /proc/modules
^note this

Editing filename2modname() to remove this special test for '-' seems to fix it. But, this is done explicitly, so I wonder if there is a deeper meaning to this. Can you please take a look and explain?

Thanks,
Vamsi.

Signature · 23 lines
Vamsi Krishna S.
Linux Technology Center,
IBM Software Lab, Bangalore.
Ph: +91 80 5044959
Internet: [email protected]
--
--- rmmod-old.c	2002-12-13 21:11:57.000000000 +0530
+++ rmmod.c	2002-12-13 21:10:44.000000000 +0530
@@ -157,9 +157,12 @@
 	else
 		afterslash++;
 
-	/* stop at first . */
+	/* Convert to underscores, stop at first . */
 	for (i = 0; afterslash[i] && afterslash[i] != '.'; i++) {
-		modname[i] = afterslash[i];
+		if (afterslash[i] == '-')
+			modname[i] = '_';
+		else
+			modname[i] = afterslash[i];
 	}
 	modname[i] = '\0';
 }
#1 lore raw

In message <[email protected]> you write:

Quoted 5 lines

Hi Rusty,

It seems we cannot unload modules if they have a '-' in their name. filename2modname() in rmmod.c converts a '-' in the filename to '_'. Why? Are dashes not allowed as part of module names?

How did you get a module which has - in its name? The build system *should* turn them into _'s.

Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

#2 lore raw
Quoted 2 lines · Rusty Russell

How did you get a module which has - in its name? The build system *should* turn them into _'s.

ALSA modules?

-rw-r--r--    1 root     root       170125 Dec 15 00:10 snd-mixer-oss.ko
-rw-r--r--    1 root     root       143685 Dec 15 00:10 snd-mpu401-uart.ko
-rw-r--r--    1 root     root       312564 Dec 15 00:10 snd-opl3-lib.ko
-rw-r--r--    1 root     root       194307 Dec 15 00:10 snd-opl3sa2.ko
-rw-r--r--    1 root     root       612512 Dec 15 00:10 snd-opl3-synth.ko
-rw-r--r--    1 root     root      1160272 Dec 15 00:10 snd-pcm.ko

But they do get converted when we load ie snd-pcm turns into snd_pcm

Signature · 1 line
function.linuxpower.ca
#3 lore raw

In message <[email protected]> y ou write:

Quoted 14 lines · Rusty Russell
Quoted 3 lines

How did you get a module which has - in its name? The build system *should* turn them into _'s.

ALSA modules?

(quoted diff) +0 -6
-rw-r--r--    1 root     root       170125 Dec 15 00:10 snd-mixer-oss.ko
-rw-r--r--    1 root     root       143685 Dec 15 00:10 snd-mpu401-uart.ko
-rw-r--r--    1 root     root       312564 Dec 15 00:10 snd-opl3-lib.ko
-rw-r--r--    1 root     root       194307 Dec 15 00:10 snd-opl3sa2.ko
-rw-r--r--    1 root     root       612512 Dec 15 00:10 snd-opl3-synth.ko
-rw-r--r--    1 root     root      1160272 Dec 15 00:10 snd-pcm.ko
Quoted 1 line

But they do get converted when we load ie snd-pcm turns into snd_pcm

Yes, the filenames are unchanged. But if you modprobe snd-mixer-oss, you'll see snd_mixer_oss in /proc/modules. But rmmod "snd-mixer-oss" works as expected. Basically, the kernel and tools see them as
equivalent: anything else is a bug, please report.

BTW, this was done for (1) simplicity, (2) so KBUILD_MODNAME can be used to construct identifiers, and (3) so parameters when the module is built-in have a consistent name.

Hope that clarifies!
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

author
#4 lore raw
Quoted 5 lines · Rusty Russell

BTW, this was done for (1) simplicity, (2) so KBUILD_MODNAME can be used to construct identifiers, and (3) so parameters when the module is built-in have a consistent name.

Ok, I see it now, this magic happens in scripts/Makefile.lib. My module has been built outside the kernel build system, that's why I saw this problem.

I guess avoiding '-' should do it, but is there a simple way to correctly build (simple, test) modules outside the kernel tree now?

Thanks,
Vamsi.

Signature · 5 lines
Vamsi Krishna S.
Linux Technology Center,
IBM Software Lab, Bangalore.
Ph: +91 80 5044959
Internet: [email protected]
#5 lore raw

In message <[email protected]> you write:

Quoted 6 lines · Rusty Russell
Quoted 5 lines

BTW, this was done for (1) simplicity, (2) so KBUILD_MODNAME can be used to construct identifiers, and (3) so parameters when the module is built-in have a consistent name.

Quoted 6 lines

Ok, I see it now, this magic happens in scripts/Makefile.lib. My module has been built outside the kernel build system, that's why I saw this problem.

I guess avoiding '-' should do it, but is there a simple way to correctly build (simple, test) modules outside the kernel tree now?

Has there ever been a simple way? You can either use _ in the name, or use tr on the -DKBUILD_MODNAME line, I guess.

Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

#6 lore raw
Quoted 7 lines · Rusty Russell

In message <[email protected]> you write:

Quoted 6 lines · Rusty Russell
Quoted 5 lines

BTW, this was done for (1) simplicity, (2) so KBUILD_MODNAME can be used to construct identifiers, and (3) so parameters when the module is built-in have a consistent name.

Quoted 8 lines
Quoted 6 lines

Ok, I see it now, this magic happens in scripts/Makefile.lib. My module has been built outside the kernel build system, that's why I saw this problem.

I guess avoiding '-' should do it, but is there a simple way to correctly build (simple, test) modules outside the kernel tree now?

Has there ever been a simple way?

Well, you can do

cd my_module
echo "obj-m := my_module.o" > Makefile
vi my_module.c
make -C <path/to/kernel/src> SUBDIRS=$PWD modules

That's not too bad (and basically works for 2.4 as well)

--Kai

#7 lore raw

In message <[email protected]> y ou write:

Quoted 11 lines · Rusty Russell
Quoted 1 line

Has there ever been a simple way?

Well, you can do

cd my_module
echo "obj-m := my_module.o" > Makefile
vi my_module.c
make -C <path/to/kernel/src> SUBDIRS=$PWD modules

That's not too bad (and basically works for 2.4 as well)

And then you're independent of changes in the build system, too. I like it.

Thanks for the tip!
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

author
#8 lore raw
In reply to Kai Germaschewski
Quoted 18 lines · Kai Germaschewski
Quoted 7 lines · Rusty Russell

In message <[email protected]> you write:

Quoted 6 lines · Rusty Russell
Quoted 5 lines

BTW, this was done for (1) simplicity, (2) so KBUILD_MODNAME can be used to construct identifiers, and (3) so parameters when the module is built-in have a consistent name.

Quoted 8 lines
Quoted 6 lines

Ok, I see it now, this magic happens in scripts/Makefile.lib. My module has been built outside the kernel build system, that's why I saw this problem.

I guess avoiding '-' should do it, but is there a simple way to correctly build (simple, test) modules outside the kernel tree now?

Has there ever been a simple way?

Quoted 9 lines

Well, you can do

cd my_module
echo "obj-m := my_module.o" > Makefile
vi my_module.c
make -C <path/to/kernel/src> SUBDIRS=$PWD modules

That's not too bad (and basically works for 2.4 as well)

That's way cool! Thank you.

Signature · 5 lines
Vamsi Krishna S.
Linux Technology Center,
IBM Software Lab, Bangalore.
Ph: +91 80 5044959
Internet: [email protected]