Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

[Émeric MASCHINO]

Hi,

Say that I have a proprietary closed-source ia64 kernel module that I
can't rebuild because I'm missing some additional bits (IP library and
Intel compiler runtime library). Guess who I'm talking about ;-)

I however know the exact kernel source and gcc versions that were used
to build this module. I'm however missing the original kernel
configuration, so had to guess it (among other things). Using
zx1_defconfig as first attempt, I've built a kernel that cannot load
the module at the moment.

But diff'ing System.map of the kernel that I've just recompiled with
the one of the kernel that was used to build the proprietary module
shows that the entry points of matching symbols are identical.
Similarly, diff'ing the Module.symvers of my kernel against the one of
the kernel that was used to build the proprietary module shows the
same exported functions, but different hex signatures.

I'm thus wondering if there's a way to rebuild a kernel, passing it in
some ways the information in a given System.map and/or Module.symvers
file in order to impose the entry points of the kernel symbols and the
hex signatures of the exported functions.

Thanks,

     Emeric

Re: Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

[Alex]

> Hi,

Hi, Émeric

> I'm however missing the original kernel
> configuration

Isn't it a /src/linux-rtgfx-2.6.5-7.244-obj/ia64/rtgfx/.config
from the kernel-rtgfx-source-2.6.5-7.244.ia64.rpm?

Please note that it's for sgi machines, not hp ones:
# CONFIG_IA64_HP_ZX1 is not set
CONFIG_IA64_SGI_SN2=y
So it's not usable as is

Re: Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

[Alex]

> Isn't it a /src/linux-rtgfx-2.6.5-7.244-obj/ia64/rtgfx/.config
> from the kernel-rtgfx-source-2.6.5-7.244.ia64.rpm?
> 
> Please note that it's for sgi machines, not hp ones:
> # CONFIG_IA64_HP_ZX1 is not set
> CONFIG_IA64_SGI_SN2=y
> So it's not usable as is

And CONFIG_MODVERSIONS=n is your solution to running proprietary
modules without their recompilation on a different kernel.

Re: Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

[Émeric MASCHINO]

Hi,

Sorry for the late reply, was out of town the passed days.

> And CONFIG_MODVERSIONS=n is your solution to running proprietary
> modules without their recompilation on a different kernel.

No go if the kABI has evolved. You can even rebuild a "fake" kernel
with a totally different version but nevertheless naming it with what
the module was targeted for or forcing CONFIG_MODVERSIONS=y, but
sooner or later (quite sooner!), you'll get kernel panics, hard locks
and/or other unwanted reboots ;-)

     Émeric

Re: Rebuilding a kernel for a proprietary closed-source ia64 module: possible or not?

[Émeric MASCHINO]

Hi again,

> Isn't it a /src/linux-rtgfx-2.6.5-7.244-obj/ia64/rtgfx/.config
> from the kernel-rtgfx-source-2.6.5-7.244.ia64.rpm?

I'm indeed talking about fglrx, but not the one in SLES.
So don't know how was the kernel that created it configured.

BTW, I've also tried to rebuild the SLES rtgfx kernel, but changing
from SN2 to ZX1. Same problem as previously posted: function hex
signatures differ while I'm however using the same kernel tree, but
with a different configuration.

     Émeric