[linux-audio-user] Can't load realtime-lsm module

[Jack O'Quin]

Alex Marandon <al at alpage.org> writes:

> Trying to get Jack running with a 2.6.5 kernel.
> 
> # modprobe -v realtime gid=102 allcaps=1
> insmod /lib/modules/2.6.5/extra/realtime.ko gid=102 allcaps=1
> FATAL: Error inserting realtime (/lib/modules/2.6.5/extra/realtime.ko):
> Invalid argument
> 
> Kernel was built with:
> 
> CONFIG_PREEMPT=y
> CONFIG_SECURITY_CAPABILITIES=m
> CONFIG_SECURITY=y
> CONFIG_SECURITY_CAPABILITIES=m
> CONFIG_SECURITY_SELINUX=y

That looks fine.  But, the error you're getting normally indicates
that CONFIG_SECURITY_CAPABILITIES was not set to "m".

Did you set these?

  CONFIG_MODULES=y
  CONFIG_MODULE_UNLOAD=y

What does `grep Realtime /var/log/messages' say after modprobe fails?

> When building LSM, I wasn't able de run make as a user :
> 
> $ make
> CONFIG_SECURITY_CAPABILITIES=m
> make modules -C /usr/src/linux SUBDIRS=/home2/al/realtime-lsm-0.1.0
> make[1]: Entering directory `/usr/src/linux-2.6.5'
> *** Warning: Overriding SUBDIRS on the command line can cause
> ***          inconsistencies
> make[2]: `arch/i386/kernel/asm-offsets.s' is up to date.
> CC [M]  /home2/al/realtime-lsm-0.1.0/realcap.o
> CC [M]  /home2/al/realtime-lsm-0.1.0/commoncap.o
> LD [M]  /home2/al/realtime-lsm-0.1.0/realtime.o
> /bin/sh: line 1: .tmp_versions/realtime.mod: Permission denied
> Building modules, stage 2.
> MODPOST
> /bin/sh: line 1: ./.__modpost.cmd: Permission denied
> make[2]: *** [__modpost] Error 1
> make[1]: *** [modules] Error 2
> make[1]: Leaving directory `/usr/src/linux-2.6.5'
> make: *** [all] Error 2
> 
> But it works when make is run as root. The README file says that only make
> install has to be run as superuser.

The way the Makefile currently works, it needs write access to the
kernel build tree.  I'll update the README to make that clear.  

I hope some day we will figure out a way to avoid modifying the kernel
build tree.
-- 
  joq