Re: Race condition in module load causing undefined symbols

[Andrew Morton <akpm@osdl.org>]

Stephen Lord <lord@xfs.org> wrote:
>
> I am having troubles getting any recent kernel to boot successfully
>  on one of my machines, a generic 2.6GHz P4 box with HT enabled
>  running an updated Fedora Core 3 distro. This is present in
>  2.6.12-rc6. It does not manifest itself with the Fedora Core
>  kernels which have identical initrd contents as far as the
>  init script and the set of modules included goes.
> 
>  The problem manifests itself as various undefined symbols from
>  module loads.

Peculiar.  Module loading is all synchronous, isn't it?

> ...
>  The failures are different on different boots, sometimes the ata_piix
>  module cannot find symbols from libata, sometimes ext3 cannot find jbd
>  symbols, sometimes dm modules cannot find things from dm-mod, usually
>  it is a combination of these. End result is a panic when it cannot
>  find the root device.
> 
>   From the behavior, it appears that a module load is returning
>  control to user space before the previous one has got its symbols
>  loaded.

I wonder if rather than the intermittency being time-based, it is
load-address-based?  For example, suppose there's a bug in the symbol
lookup code?

Have you tried using a different gcc version?