Re: insmod question.

["Manish Regmi" <regmi.manish@xxxxxxxxx>]

On 7/1/06, pankaj chauhan <chauhan_ait@xxxxxxxxxxx> wrote:
> hi all,
>
> i have a module say my_mod.ko, which is composed to
> two two binaries say my_mod1.o and my_mod2.o. I am
> trying to insmod this module on 2.6.11, which is
> compiled by gcc 3.4.3, If i compile my_mod1 and
> my_mod2 with gcc3.4.3 and my_mod.ko gets insmoded with
> no problems. But if my_mod2.o is compiled with gcc
> 2.95 then my_mod.ko does not get insmoded and it says
> "Invalid module format: unknown error 8".
>
> I understand that the kernel and the module should be
> compiled with same gcc version to work properly (for
> which i do'nt know the reason, if somebody please tell
> me the reason that will be great). But what i do'nt
> understand is that what is the difference when i
> compile my_mod2 with gcc 3.4 or 2.95, and how it is
> detected that my_mod2.o is compiled with a different
> gcc version, as far as i understand there is no
> information about the compiler in ELF file which tells
> you that which compiler version was used to for
> compilation (please correct me if i am wrong).

There is a string called version magic which stores info on kernel
version, compiler version etc. The kernel compares the module's
vermagic with that of kernls.

regards
Manish Regmi

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