lspci: Unable to load libkmod resources: error -12

lspci: Unable to load libkmod resources: error -12

[Joe Buehler]

When running lspci -v on Ubuntu 20.40, I get the error message:

lspci: Unable to load libkmod resources: error -12

I tracked this down to a possible libkmod issue.  The kernel I am using
has an empty modules.builtin.aliases.bin file (modules.builtin.aliases
does not exist).

kmod_load_resources() doesn't like this.  It calls index_mm_open() which
checks the file size, sees that it is less than sizeof(hdr), error
terminates, causing kmod_load_resources() to return -ENOMEM.

kmod version 27 as shipped with ubuntu 20.04

Please copy me on any responses, I am not on this list.

Joe Buehler

Re: lspci: Unable to load libkmod resources: error -12

[Lucas De Marchi]

On Fri, Dec 11, 2020 at 2:19 AM Joe Buehler <aspam@cox.net> wrote:
>
> When running lspci -v on Ubuntu 20.40, I get the error message:
>
> lspci: Unable to load libkmod resources: error -12
>
> I tracked this down to a possible libkmod issue.  The kernel I am using
> has an empty modules.builtin.aliases.bin file (modules.builtin.aliases
> does not exist).

It is indeed a little bit confusing, but modules.builtin.alias.bin is
created from
modules.builtin.modinfo that should come with the kernel.  Is this a
custom kernel or
one from the distro? modules.builtin.alias.bin should either not exist
(in case the kernel
doesn't have modules.builtin.modinfo) or should be a valid index.

Indeed depmod doesn't create the file unless it has something to
write. I wonder if the error wasn't
because the call to depmod failed for some reason (out of space?).

Looking at a ubuntu 20.04 system I do have both
modules.builtin.modinfo and modules.builtin.alias.bin. If I remove
modules.builtin.modinfo and call
depmod -a, then the latter is not created.

Lucas De Marchi

>
> kmod_load_resources() doesn't like this.  It calls index_mm_open() which
> checks the file size, sees that it is less than sizeof(hdr), error
> terminates, causing kmod_load_resources() to return -ENOMEM.
>
> kmod version 27 as shipped with ubuntu 20.04
>
> Please copy me on any responses, I am not on this list.
>
> Joe Buehler
>

Re: lspci: Unable to load libkmod resources: error -12

[Lucas De Marchi]

On Fri, Dec 18, 2020 at 6:56 AM Lucas De Marchi
<lucas.de.marchi@gmail.com> wrote:
>
> On Fri, Dec 11, 2020 at 2:19 AM Joe Buehler <aspam@cox.net> wrote:
> >
> > When running lspci -v on Ubuntu 20.40, I get the error message:
> >
> > lspci: Unable to load libkmod resources: error -12
> >
> > I tracked this down to a possible libkmod issue.  The kernel I am using
> > has an empty modules.builtin.aliases.bin file (modules.builtin.aliases
> > does not exist).
>
> It is indeed a little bit confusing, but modules.builtin.alias.bin is
> created from
> modules.builtin.modinfo that should come with the kernel.  Is this a
> custom kernel or
> one from the distro? modules.builtin.alias.bin should either not exist
> (in case the kernel
> doesn't have modules.builtin.modinfo) or should be a valid index.
>
> Indeed depmod doesn't create the file unless it has something to
> write. I wonder if the error wasn't
> because the call to depmod failed for some reason (out of space?).
>
> Looking at a ubuntu 20.04 system I do have both
> modules.builtin.modinfo and modules.builtin.alias.bin. If I remove
> modules.builtin.modinfo and call
> depmod -a, then the latter is not created.

oops, it turned out I was looking in the wrong directory. That should
be the behavior, but
it's not and and empty modules.builtin.alias.bin is being created.

Let me take a closer look what's going on.

thanks
Lucas De Marchi

>
> Lucas De Marchi
>
> >
> > kmod_load_resources() doesn't like this.  It calls index_mm_open() which
> > checks the file size, sees that it is less than sizeof(hdr), error
> > terminates, causing kmod_load_resources() to return -ENOMEM.
> >
> > kmod version 27 as shipped with ubuntu 20.04
> >
> > Please copy me on any responses, I am not on this list.
> >
> > Joe Buehler
> >