[lug] Kernel Module Compile Config Q

[Vishal Verma]

On Fri, Jun 27, 2014 at 5:33 PM,  <stimits at comcast.net> wrote:
> I'm wondering about a module compile for network bridging (3.10 kernel)
> which results in a kernel panic. I'm thinking the panic is because of a
> config change dependency which might demand rebuilding the whole kernel. I
> want to know if this dependency and sticking to only module compiles without
> a new kernel compile would be the cause. Can I get away without rebuilding
> and installing a new kernel?

It would help to post the stack trace from the panic, and the kernel
source tree (is it a standard distro kernel, or a vanilla 3.10...

> .
> This is the running kernel source tree and entirely configured based on
> current running system (I have the config in /boot option), with proper
> preparation before compile (compile itself is on the native system). Then I
> add bridge support as a module (via make menuconfig). Intentionally building
> CONFIG_BRIDGE=m results in a couple of other dependencies which builds
> modules that insmod without error, but one non-optional dependency is
> CONFIG_BRIDGE_NETFILTER=Y, so I cannot insmod this. With module dependencies
> loaded via insmod, I then insmod bridge.ko...kernel panic.

Sounds like it could be a bug in the init path of the module, again,
the stack trace would help.

> .
> The dependency which is forced as a non-module is CONFIG_BRIDGE_NETFILTER=Y,
> and I'm guessing this is why I won't be able to stick to a pure module
> build. In general, if I build something as a module, and if that module
> forces some other CONFIG_WHATEVER=Y, is this always asking for trouble? I'd

As far as I know, this itself shouldn't be a problem.

> really like to stick to not flashing the kernel image itself on this
> embedded system.

-Vishal