Re: [PATCH] kvm: external module: support building against Windriver 2.0 (kernel 2.6.21)

[Jan Kiszka <jan.kiszka@siemens.com>]

Bernhard Kohl wrote:
> This is needed to compile kvm in a Windriver 2.0 distribution
> (kernel 2.6.21). This kernel has an include file marker.h, but
> trace_mark is not defined there. So the compat code in
> kernel/include-compat/linux/marker.h is not included.

I bet this is because Wind River patched some variant of LTTng into
their kernel.

However, I'm unsure if supporting significantly modified distribution
kernels is in the scope of this compat layer. If it is ok for the
maintainers, you should try to make the test more Wind River specific
(did you check that there is no side-effect for normal <= 2.6.21
kernels?) and maybe add a comment.

Jan

> 
> Signed-off-by: Bernhard Kohl <bernhard.kohl@nsn.com>
> ---
>  kernel/external-module-compat-comm.h |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/external-module-compat-comm.h
> b/kernel/external-module-compat-comm.h
> index a14cea2..e40501e 100644
> --- a/kernel/external-module-compat-comm.h
> +++ b/kernel/external-module-compat-comm.h
> @@ -25,6 +25,10 @@
>  #  undef CONFIG_KVM_TRACE
>  #endif
>  
> +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,21)
> +#define trace_mark(args...) ((void)0)
> +#endif
> +
>  /*
>   * 2.6.16 does not have GFP_NOWAIT
>   */

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